Tuesday, December 31, 2013

The "Rheology" of Fire Ants

The New York Times had a fun video a couple of weeks ago showing that groups of fire ants can show viscoelastic behavior. By clinging to each other, they show solid-like behavior, but by releasing that grip, they can flow like a liquid. While viscoelastic behavior is much more common than most people realize, this is the first time it has been observed in groups of living things. (Note that the article states that it is a first for "living things" which is clearly incorrect. As far as I know, all living things show viscoelastic behavior within at least some parts of themselves, whether it is the viscoelastic behavior of cells, mucosal fluids, blood, etc.) Being that ants are macroscopic beings, their flow would show characteristics of a granular flow rather than fluid flow, a subtle but sometimes important difference.

What is left undiscussed in the video is how the ants are able to communicate what behavior is desired at any given moment. Each ant can't be deciding on its own whether to grip or release; there has to be a rapid, universal signaling mechanism or else it would be chaos. I find this, along with the similar phenomena of flocking behavior and quorum sensing to be some of the most fascinating aspects of biology.

Monday, December 30, 2013

A Chemical Mystery - Can You Solve It?

My wife and I were able to use our chemical knowledge this past week to solve a perplexing problem. I'll post first what we observed and then let you try and figure it out.

We have a gas cooktop in our house here in Minnesota. A couple of weeks ago, the flames on it started burning more orange-like so we called in a repair guy. Non-blue flames are indicative of a rich fuel/oxygen mixture, one that can potentially put out CO, although it is less of a danger for cooktops than furnaces as the former are used for shorter periods of time often with the vent fan running too. But in any case, the regulator was failing and instead of feeding 3-4 inches water column of gas, it was feeding 6-8. A new regulator was installed and the pressure of the gas was reduced to the normal levels, but the orange flames persisted.

We tried adjusting the Venturi openings that let the air into the burners, but that didn't do anything. Besides, it would be freaky odd for all four burners to suddenly have their Venturi openings block at the same time. And then my wife (a Ph. D. in chemistry) found the solution, one which we have been able to positively confirm: by making an adjustment elsewhere in the house, we can on demand change the flames from blue to orange and back again. Neat, huh? And we also know now not to worry about the color of the flame.

Here's some other information that may or may not be helpful to finding the solution. The house is in Minnesota and is sealed up tight for the winter (it was -16 oF this morning!). Since the air is so dry, we run ultrasonic humidifiers in a couple of rooms in the house. About the same time as the problem occurred, we brought a real Christmas tree into the house. We have a dog (a Welsh Terrier), and had house guests staying on and off over the past few weeks. To make meals easier on the cook, we have been using a crockpot (electric slow cooker) a lot the last few weeks. We have hard water and soften it. Speaking of water, we have a gas water heater. Speaking of gas, we have a gas furnace and we also have a gas fireplace on both levels of the house.

With your knowledge of undergraduate chemistry, you now have enough information to solve the "Mystery of the Orange Flame". I will also tell you that the answer has nothing to do with polymers science so to make up for that, I've included a picture of a cute kitten playing with a random polymer coil. (If we had cats at our house (we never will), they would play with random polymer coils and not balls of yarn.)
Why are the flames on the cooktop burner orange and not blue? Start with the water softener. It replaces the calcium and magnesium in the hard water with sodium. That water then goes into the ultrasonic humidifiers. (Distilled water would be a better option, but since these things go through gallons of water a day, it isn't too practical of an option to be trucking in that much distilled.) The humidifier then tosses the sodium into the air where it spreads through the house. Some of it ends up in the feed air to the burner where it burns it's characteristic yellow. Combine that small amount of yellow with a rich blue flame and you get an orange flame.

To further convince ourselves of this, we shut of the humidifiers and after 4 hours, the flames went blue. Turned on the humidifiers and the flames went back to orange. Mystery solved. We were running a good old-fashioned flame test.

My wife then found a video that shows these changes in a most dramatic fashion:
Ignore the audio in the video, as it gives a wrong rationale for the color change. Just look at the pictures. Just that tiny bit of sodium is enough to significantly color the flames.

Friday, December 20, 2013

The Rheology of Santa Claus

Many scientific investigations have been performed regarding Santa Claus [1], but never before has a rheological analysis of St. Nick been undertaken. Let me change that.

The need for Santa to exhibit non-Newtonian rheology is obvious on several fronts. All chimneys by design have a narrower opening at the top than at the bottom and in cases of interest, the opening at the top of the chimney is smaller than Father Frost himself. In order to transverse such geometric disparities, it is necessary that Santa's body be of a soft, gel-like material (more on this below), that can be greatly deformed without mechanical failure. While it may be further desired that full elastic recovery is achieved, it appears that this is in fact beyond the capabilities of Kris Kringle. For support of this conclusion, examine the three representative illustrations below of Pere Noel. They are similar, indicating a goodly amount of elastic recovery has been obtained, but the differences clearly indicate that full recovery was not recovered and furthermore that viscous flow has occurred.
In short, the appearance of Father Christmas will very greatly depending on whose chimney he has recently passed through (subject to an appropriate memory function integral with more recent chimneys having stronger influence over his current appearance than chimneys from the past). Further evidence comes from the "mouths of babes" who for decades have noticed that the Santas appearing in stores, parades and elsewhere all look slightly different. Parents at a loss of words for explaining these differences now have a scientifically supported explanation to quiet the constant questions coming without end.

Rheological understanding is also needed to clarify the events occurring while Babbo Natale is flowing through the chimney. Going up and down the chimney leads to conditions of both shear and, depending on the flow direction, either extensional or expansive flow. It is desired that the Jolly Old Elf be able to flow freely in order to rapidly accomplish his worldwide sojourn. As a rheopectic St. Nick would be highly undesirable in achieving this (his rate of flow would decrease the faster that he tried to move), we can conclude that Sinter Klaas's viscosity decreases both in shear and extension, strongly indicative of pseudoplasticity. (The discussion here has focused on steady-state dynamics; flow under transient conditions (start-up and cessation of flow) are left as an exercise for the interested student.)

In summary, I have unequivocally demonstrated that Santa Claus 1) is made of a non-Newtonian gel that shows both viscous and elastic behavior, and 2) exhibits pseudoplastic flow characteristics.

Before concluding, the author is compelled to state his shock that the rheology of Santa Claus has never been discussed to any serious extent, let alone this thoroughly. The link between Santa and rheology was first noticed 190 years ago, back in 1823(!) when the eminent American rheologist Clement Moore [2] published his famous poem, "A Visit from Saint Nicholas", perhaps better know as "Twas The Night Before Christmas". In that, he described Saint Nicholas as having "...a little round belly, That shook when he laugh'd, like a bowl full of jelly". Jelly! Probably the oldest known gel of all and a classic material with intriguing rheological characteristics. How many times has that line been read and heard and spoken, and yet never once has the connection been made to the larger aspects of Santa's rheological nature!? For shame. There are many professional rheologists this year that are going to be receiving a lump of coal in their stockings and it won't be high grade anthracite, but a well-deserved stinky, sulfur-laden lump of lignite instead.

[1] These certainly could be called pseudo-scientific or tongue-in-cheek-scientific as well, such as this perspective from North Carolina State. Or what you are reading here today.

[2] Ok, so he was just some guy that noticed a little rheological behavior and now he's going to cash in big on it. It's no different than what happened with Deborah Deborah or Heraclitus.

Wednesday, December 18, 2013

Nitrile Gloves Are Not The Universal Glove!

Looks like it's time to review the choices for rubber gloves in the lab again. Just a few minutes ago on twitter, there was this conversation:
This is endlessly maddening to me:"...nitrile. So they are good except in contact with strong oxidizers (nitric acid!)..."

Not that is absolutely incorrect. As I've written in the past, "Any given rubber glove will be attacked by some solvents and not others. Is that so surprising?".

That same post has links to glove manufacturer's sites where they have recommendations for what you can and cannot expose their gloves to. The Ansell site for instance, recommends against using nitrile gloves for exposure to
  • acetaldehyde
  • acetone
  • analine
  • benzaldehyde
  • benzene
  • γ-butyrolactone
  • chlorobenzene
  • chloroform
  • chloronapthlanene
  • chlorotoluene
  • ethylene dichloride
  • dimethylacetamide
  • dimethylformamide
  • 1,4-dioxane
  • epichlorohydrin
  • ethyl acetate
  • furfural
  • methyl bromide
  • methyl chloride
  • methylene bis(4-phenylisocyanate)
  • methyl ethyl ketone
  • methyl iodide
  • methyl methacrylate
  • N-methyl-2-pyrrolidone
  • morpholoine
  • nitorbenzene
  • nitropropane (both isomers
  • phenol
  • propylene oxide
  • pyridine
  • silicon etch
  • Skydrol 500B-4
  • styrene
  • sulfuric acid
  • sulfur dichloride
  • trichloroethylene
  • Vetrel SMT
  • and as noted in the Tweet, nitric acid.
That list is quite a bit longer than just the nitric acid that was noted.

Please, please, please, don't just assume that nitrile gloves are the glove of choice. These charts have been put together for a reason - to protect you, but they are useless if not referred to. The links are freely available, so find whatever charts you need, print them out and refer to them often.

Nitrile gloves are not the universal glove. To pass on as reliable information that they are safe is to risk the health of anyone reading or hearing that. We can do better than that.

Monday, December 16, 2013

What does EPDM stand for?

While the abbreviations used to describe the make-up of polymers and rubbers is reasonably straightforward (PVA being probably the worst offender - is that polyvinyl acetate or polyvinyl alcohol?), the rubber EPDM is another nasty one. The first three letters are reasonable: "E" for ethylene, "P" for propylene and "D" for diene, which in theory could be any diene, but in practice is usually one of a few options. The "M" is the mystery however. People either have no idea or they think that it stands for "monomer". Huh?

The truth is well removed from that as it actually isn't part of an abbreviation at all. It is drawn from an ASTM standard, which is quite appropriate as the name ASTM isn't an abbreviation for anything either. (It used to stand for American Society for Testing and Materials, but it doesn't anymore). The standard D1418 is used to classify rubbers and the M-class is for rubbers that have saturated backbones. Why M? Heaven only knows. Other letters used to classify rubbers are N, for nitrogen-containing backbones and O for oxygen-containing backbones. So far so good. But then there is R for unsaturated backbones, Q for silicon- and oxygen-containing backbones (siloxane polymers have their own naming scheme, in which Q fits in quite nicely, but that is another story for another day), T for sulfur-containing backbones, U for carbon-, oxygen- and nitrogen-containing backbones and finally Z for phosphorus and nitrogen-containing backbones.

Given all of that, M isn't that bad of a choice, but since the letter S is available (since sulfur was bumped to T), why not go with S?

This all came about from a recent discussion with a friend over Superballs, the big black ones made by Wham-O. I had always thought that they were made from EPDM (with a pinch or two of carbon black), but it turns out that they are actually made from butadiene. You learn something new everyday.

Thursday, December 12, 2013

Some Goofy Thoughts on Plastic Bags Being Seized

While plastic bag bans have been proliferating of late, I only read yesterday of action being taken against a shop: "The team seized around 45 kgs of polythene bags below 40 micron thickness...". The story did get my mind wandering. For instance,
  • Do the police have calipers (calibrated ones, at that) to measure the film thickness? I've worked with films for most of my 20+ career and with my fingers can easily tell the difference between a 25 micron (1 mil) and a 50 micron (2 mil) film, and maybe on a good day, even a 37.5 micron film (1.5 mil), but my fingers are not capable of higher resolution. So do the police now have to carry around calipers on their gun belt?
  • The seized bags are now evidence, and we all have seen enough cop shows to know what happens to evidence: it is put inside a PLASTIC BAG. Hopefully the evidence bags are greater than 40 microns thick or there could be some high drama in the courtroom.
  • I wonder if all the evidence will make it back to the police station, or are cops going to start having a reputation for being the people with the best plastic bags?
  • After the bag is brought back to the crime lab, I wonder how the analysis goes. Is it like CSI? (For those of you unfamiliar with the US TV show, imagine any old analytical lab but with good-looking geeks and dramatic lighting). "Hey I got something. I ran a tensile test according to ASTM D638 and got some really strong peaks, so I dissolved the bag in hot xylene and ran a high-temp GPC and sure enough, there is a lot of metallocene-catalyzed polymer in this material. This is not some local product; this is an import and it is loaded. I mean this stuff is so strong, it could get an elephant high...err, that didn't come out right. I mean, these bags are so strong that they could lift an elephant up high...I wish I could've done more analysis, but I've only had the samples for 5 minutes. Anyway, we gotta do something before more of this stuff hits the streets."
  • I wonder how far the bag limits extend. Say for instance a drug dealer is caught and the weed is in thin-film bags. Do dealers get extra time in jail for that?
Just some thoughts. While this particular story happened in Indore, a city in central India, I would have the same thought regardless of where the seizures occurred.

Wednesday, December 11, 2013

Greenwashing Blue Jeans into Plastic

It's funny how much greenwashing can occur from good intentions and how it worsens with time. Take for instance, this attempt (a Kickstarter effort) to make plastic using recycled blue jean fibers as a reinforcing agent.
The resulting material is named Denimite (catchy enough) and has that classic indigo blue color. The composite is made by mixing an epoxy in with the fibers and then heating and compressing the material in a mold until the epoxy has reacted. The low viscosity resins undoubtedly soak into the cotton fibers before they react, thereby ensuring a good strong interface between the resin and the fibers, an essential feature to make the fibers/matrix a composite and not just a filled system.

The environmental angle is that the jeans are otherwise destined for the landfill and the epoxy is somewhat sustainably produced [1]. The Kickstarter is looking for $10,000 for a larger press (a 30" x 120" - that's 10 feet long!). In my mind, that is only a small part of what they need. Molds would be a bigger concern as they cost far more and each one needs to be custom made. Customers typically pay for them (so that they can take them and run off to a cheaper competitor when they find one!), but finding customers is a chicken-and-egg thing. Compression molding is not a fast process and that hurts the economics further. Also, the entrepreneurs are looking to get into countertops, an area that seems to have few demands but is deceptively challenging. [2] I wish them luck in their venture; they are going to need it.

Once the media got wind of this kickstarter, the greenwashing took off. The Kickstarter was originally entitled: "Denimite: Where good jeans go when they die". That's fine and dandy. But then Gizmag.com picked it up and it became "Denimite repurposes blue jeans into a "green" material". At least there are quotation marks around the word "green". But then cleantechnia.com called it "Recycled Jeans Become Green Plastics in New Process" and we're off to the races. The denim has never become plastic - it is merely encased in another plastic that is only somewhat green (and compression molding is hardly a new process). This greenwashing was then repeated verbatim in the echochamber by beforeitsnews.com.

And that's how things get hyped. A simple project with good intentions and a green-ish story of compression molding a denim/epoxy material becomes a transformation of blue jeans, via a new process, into a green plastic.

[1] It would be ironic if the epoxy was based on bisphenol A, and many of them are. But further, why use an epoxy? A totally bio-based (meth)acrylate would be greener option, would possibly cure faster and show many/all of the same mechanical properties.

[2] In my last job, I worked on a project for a client who made countertops that were loaded with minerals. They had a number of issues that were a failure of the resin that I would not have expected. It was an eye opening experience.

Tuesday, December 10, 2013

Describing Polymers with Everyday Items

I used to have 2 simple models (or maybe 3, you decide) that used everyday items to explain what polymers are like to people with formal education in the subject. I picked up a third one yesterday that I really liked. Let me list them all:
  1. /2. The most common image that people use to describe a polymer is a spaghetti noodle, which is fine for starters, but it falls short fairly quickly, even if you expand the length of the noodle to 20 feet or so. A bowl of spaghetti is somewhat better in that the noodles are coiled up somewhat with short segments going here and there randomly (until twirled by the diner's fork). But the analogy fails when it comes to describing entanglements and getting a chain to move past its neighbors since the noodles (when properly cooked and oiled) slip past each other pretty easily. Much like playing pick-up-sticks, you can pull slowly on the end of one noodle and remove it from the bowl without disturbing any other noodle and that is not realistic of polymer dynamics. Polymers are either all moving (molten state) or not (glassy state) [*].
  2. Moving polymers have a fading memory of what they shape there were previously in. The cooperation of their neighbors that I just noted often comes too slowly which leaves this lasting (but fading) impact on the molecule. Dragging a garden hose around is a (poor) example of polymer memory. If I'm watering the flower beds on the east side of the house and want to move the hose to the south side, it's not just a matter of dragging the spray nozzle around to where I want it - the entire hose has to go with it and it remembers where it was previously lying. I may have a free path to the new location for the nozzle but the remainder of the hose may have to cross trees, lawn chairs, toys... and so sometimes you have to do a lot of maneuvering to remove the memory that the hose has. Like polymers, garden hoses have a fading memory of where they previously were. Move them enough and they have no recall at all, although they keep picking up new memories along the way.
  3. The new idea is one of those so obvious ideas that makes you wonder why you didn't think of it earlier, particularly since it fits in so well with the current holiday season: A big hat tip to the redditor thewizardofosmium for this idea: "Does anyone else look at XMas lights and think of polymer chains with a high friction factor due to rigid side chains?" As I noted earlier, it is possible to pull a single spaghetti noodle free from a pile, but try pulling a strand of Christmas lights out of a jumbled pile. It would be easiest (relatively speaking of course) if the lights were little miniatures or LED bulbs. Doing it with C9 bulbs would give you dreams of something quite distinct from "visions of sugar-plums", and icicle lights would be a pleasure that only the Grinch could deliver.
    The larger/bulkier the side chain, the higher the glass transition temperature will be since mobility is already restricted and it is easy to freeze the molecules in their current position with no hope of any further movement relative to each other.
Our lights are already up for this year, but I'm sure to be thinking of this imagery when I take them down. And put them up next year. And take them down...

[*] Let's make life simple and ignore semi-crystalline polymers for now, shall we?

Monday, December 09, 2013

Real vs. Plastic Christmas Trees

It's that time of year to repeat the great debate over real and artificial Christmas trees. Each side has it advocates (real trees vs. plastic) and as it truly is with most environmental matters, it is difficult to get to the truth. A report from a few year back that did a life cycle analysis (LCA) concluded that real trees are better option, but I'm not so sure that the LCA was done well.

For starters, the LCA was generous about how little work is actually done on a Christmas tree farm. (One of my best friend's growing up would help his dad on their Christmas tree farm so I got the skinny from him.) Trees need to be sheared annually in order to achieve that Christmas tree shape and also to have proper branching to allow for hanging of the ornaments. This means multiple trips into the farm field each year. But the dirty little secret is that trees are often painted. Both of these steps reduce the "greeness" of real trees.

The most significant finding of the LCA however, is transportation plays the largest role in the comparison:
"...it is now clear from this LCA study that, regardless of the chosen type of tree, the impacts on the environment are negligible compared to other activities, such as car use."
But the kicker is that on page 7, the report assumes that people only travel 5 km to get their tree. This is a very short distance for anyone and a very dubious assumption.

I'm not trying to suggest that artificial trees are a greener option, but only that the issues involved in this (or any other) LCA can be quite complicated. Creating a proper LCA is very challenging. The best ones lay open the assumptions and calculation methods so that other scenarios can be examined and also so that the sensitivity of the various factors can be studied.

So is the Spevacek household a Palace of Plastic with Architectural Artifacts of Artificial trees paying homage to hydrocarbons holed from the Holocene [*] are as you might expect? In fact no, it is not. My wife and I have it both ways. The main tree is real and has always been real. (My parents had an artificial tree when I was growing up and I couldn't stand the thing. I will never get an artificial tree.) We bought a Siberian fir this year - What an incredible aroma! - What an incredible layer of sap on your hands! We also have a few small artificial trees scattered around the house that we have "inherited" over the years. (And by the way, the artificial trees are far older than 6 years, the assumed lifespan in the LCA. We have no plans to retire them anytime soon either.)

So make your own decision and go with what makes you feel happy. Christmas trees choices do not have a major impact on the environment either way, not compared to other choices that we live with for more than just 3 -5 weeks a year.

[*] I know that petroleum is removed from rocks older than the Holocene - I just needed something geologic for the alliteration.

Tuesday, December 03, 2013

Dow Chemical to Drop the Chemical, in both Word and Deed

The Urethane Blog is reporting that Dow Chemical is thinking about dropping the "chemical" from it's name. Much as very few people refer to E. I. du Pont de Nemours and Company by it's full name and instead go with "Dupont", very few people also refer to the company as "Dow Chemical". I don't remember the last time that the company's logo even had "chemical" in it. However, it is a handy name to have for Google searches, since if you search just "Dow", you get a mix of sites about the company and also the Dow Jones Industrial Average, which not surprisingly, is also seldom referred to by its full name but simply as "the Dow".

While we can all ask "what's in a name" [*], the bigger picture is that Dow is moving out of the commodity chemical business and has identified a$5 billion slice of their chlorine business that can be carved out of the company. It's not clear if a ready buyer for this exists, if one has to be found or it the business will be spun off on its own.

While it is not surprising that after a merger/acquisition, there are layoffs as a result of duplication of employees, it has also been my experience that spin-offs seem to also result in layoffs. In some cases it is because the CEO of the spin-off company looks at the books differently than the CEO of the spinning-off company, and in other cases it is because the spinning-off company stuck with spin off with excess employees that it want to cut anyway, but didn't want the blood on their hands. But with over 2000 employees being identified as part of this $5 billion carve-out, we can be sure that sadly some people will be cut sooner or later.

[*] To misquote the Bard, "What's in a name? That which we call a chemical plant By any other name would smell as malodorous".

Monday, November 25, 2013

Whistleblowing - Some Thoughts

Dr. Fredrik von Kieseritzky, aka Dr. Freddy, the author of the Synthetic Remarks blog has stated that he is willing to be the "whistle blower" for anyone that knows of corruption within the world of chemistry. While I admire his ambitions and his objective, ("sunshine is the best disinfectant"), this is effort may come with a heavy price for anyone involved in it.

1) While Dr. Freddy thinks he has the law on his side to protect your anonymity, I would seriously recommend that any potential whistle blower think again. All he can supply for support is a link to a Wikipedia page. Very seldom is the law ever clear. Even something as simple as a point of the US Constitution has volumes of case law that are necessary to interpret a simple sentence, and that case law is often not static but changes over time. The fact that Sergeant Bradley Manning is spending 35 years in a military prison while Julian Assange is free says that you need to think long and hard about what it means to be a whistleblower. Swedish law will protect you while you are in Sweden and will not protect you anywhere else. Hire a Swedish lawyer before you proceed so you can go in with your eyes wide open.

2) While Dr. Freddy has suggestions about how to avoid detection (all of which seems pretty good), I would still emphasize caution. As the recent episodes with Mr. Snowden showed, the reach of the NSA or other agencies is far greater than we can possibly imagine. The fact that the Russian President Mr. Putin is using typewriters strongly suggests that the NSA is not gathering information by hacking PGP keys or other security features, but may in fact have the ultimate backdoor via firmware. If they want access to your computer, they will get it and short of disconnecting it from any network, you probably can't stop it.

3) Institutions with damaging information intentionally limit access to it, not only so that it is less likely to be leaked, but also so that they can quickly identify possible leakers. If you know damaging information and leak it, don't think that you won't be under suspicion, especially if you have history of stating your dissatisfaction.

As for Dr. Freddy, I need to caution him as well. Consider the case of a Mr. Dan Rather, who used to be the lead reporter for the US's CBS News. Back in 2004 when President George W. Bush was up for reelection, Dan got a copy of letters that showed that Bush was disobeying orders while in the Air Guard back in the 70's. Dan and all the resources at CBS agreed that the letter was in fact authentic and so they ran the story. As soon as release it, it became clear that the documents could not have been prepared on a typewriter for that that time period. Dan had been duped by a liberal/Democratic operative that didn't want to see George Bush reelected. Firings and lawsuits soon followed. The person that gave Dan the letters was left unharmed.

I can't imagine that Dr. Freddy has better resources to authenticate documents. Further, I'm not sure what the Swedish laws are regarding libel and other defamatory remarks are, but I can't imagine that they take to kindly to publishing damaging words that are untrue.

A whistleblowing site is quite different than finding fraudulent published papers such as has been done by Paul Bracher, Stuart Cantrill and others. In these cases, the authentication of the papers is never an issue - they are accessible from the publishers website. Paul, Stuart and others are pointing out items within the papers that look suspicious.

Again, I understand what Dr. Freddy is trying to accomplish and I support his actions. But I would strongly advise caution for him and any potential whistleblowers. I think the issues that I've raised here are serious enough that it should give pause to both sides. People not involved in this may be cheering the whistleblowing on (who doesn't love to see a trainwreck), but since they have nothing to lose, it's easy support to give. That support won't be there when trouble arises. The people will, watching excitedly the next phase of the trainwreck, but their support won't.

Friday, November 22, 2013

Talking Turkey (Netting, that is)

I expect readership to be down next week with the Thanksgiving Holiday, so today will be the day to talk turkey. More specifically, the netting that surrounds the turkey when you buy it at the store. Unless you have worked in the manufacturing of plastic netting [1], you WILL take that netting for granted. Don't. It is far more sophisticated than you realize. Take a look at the netting closely. It is a continuous tube, and there are two layers of strands in the netting. It stretches in both the x- and y-directions and is perfect for conforming to the odd shape of a cleaned, plastic-wrapped turkey and most importantly, it forms a nice handle so that you don't have to bearhug the thing with both arms.

The process for making diamond netting is known as the Netlon process. According to one source, it is only the ninth basic textile process since the dawn of civilization. The inventor, Frank Mercer, became not only a Fellow of the Royal Society, but was also OBE and won numerous other awards from Her Majesty for this revolutionary process.

The Netlon process is fun to watch in action, and really pretty simple, although much more difficult to describe. (Sadly, I can't find an online video showing the process.) Let me describe it this way. Much like pushing Play-Doh through the Play-Doh Fun Factory to make Play-Doh worms, molten plastic is extruded through 2 slotted dies which produce continuous strands of the plastic. The slots are located in a circular pattern around the dies, and most importantly, one die is located within the other one and along the same axis. This is what produces the 2-layers of the net. However, what I've described so far would only produce long strands of fiber and not netting. The netting is made by taking the dies and counter-rotating them. The plastic is molten enough that the two strands meld together where they cross. If both dies rotate at the same speed, a tube of netting with the lovely diamond pattern is produced. This diamond pattern is what gives the netting its biaxial deformability even when the plastic itself is not stretchy.

This is not the only process for making plastic netting. There are others, but the netting they produce are not as appropriate for wrapping a turkey. They generally don't deform as well (unless made of fundamentally elastic material) and are seldom made in a tubular form. They are another subject for another day. As for today, I hope you have a better appreciation for that little bit of netting that's around the turkey. It's also likely around the onions that were used in the stuffing [2], and caramelized for the haricot verts salad [3] and the gravy and the...

[1] I have.

[2] Of course we stuff our bird even as the TV news always tells us not to. Why don't the same TV news crews do live shots from outside a hospital on the day after telling us how many people were treated for food poisoning that came about because they stuffed their bird? Because there aren't any.

[3] The only way I will eat green beans is in my wife's haricot verts salad. Caramelized onions, beans, toasted pine nuts and a spoonful of creme fraiche. Simply incredible and it pairs so well with turkey and chicken.

Tuesday, November 19, 2013

Your Plastic Waste is Valuable

I've been saying for nearly two years now that 'your plastic waste is valuable and the plastics industry wants it'. The local newspaper supports this idea in an article published yesterday showing that the state of Minnesota alone (with just just 1.7 of the US's population) tossed more than $217 million dollars worth of recyclable materials away as trash. And 42% of that value - $93 million - is attributable to plastics:
"...at $500 per ton, what now goes into trash cans would be worth $93 million to manufacturers."
If Minnesota is representative of the whole US, then nationwide there is more than $5.4 billion dollars of recyclable plastic that is waste. Minnesota is actually a bad example of the potential, since across the state, recycling rates are already high:
"Minnesota’s average recycling rate is higher than that of most states — and it has stayed high, just under 50 percent of what gets thrown away..."
which means that nationwide figure would be even higher. Any company spending $5+ billion on raw materials is pretty good sized, so you can see the potential.

Repeat after me: Your plastic waste is valuable and the plastics industry wants it.

Monday, November 18, 2013

73 Quarters of Losses - And Still in Business

Amerityre Corporation makes polyurethane foam tires and not much else. Certainly not money. Last week, the company announced their latest quarterly results and were pleased that they had cut their loss to $174,566 from $277,889 a year ago. While companies can loose money a quarter or more and still be in business, to have this quarter be the company's 73rd consecutive quarterly loss and still remain in business is quite surprising, at least for an established company that is making something as mundane as tires. The last line of the press release is particularly jawdropping: "The fiscal 2014 first quarter loss brings the company's cumulative loss over 18 years to $63.3 million."

Startups will often report long strings of quarterly losses, but that is often expected, particularly for innovative companies that are developing new-to-the-world products or medical devices that have long approval times. Amerityre is none of these. They have been in business since 1995 and while it can be argued that their technology is innovative, their last claimed innovation, polyurethane elastomer tires, came back in 2003, all of 10 years ago.

The tire business is very cutthroat because of the many competitors fighting over the very small margins available. There was hope that run-flat tires would have changed that and allow for higher margins, but the tires never became as accepted as the businesses hoped [1], and so nothing has changed. And that is what Amerityre is competing against. There will be niches that they can do well in, but that's all. $63 millions dollars is not a niche business.

I'm amazed that someone keeps bankrolling the company, and that that someone is stockholders. "Amerityre is asking shareholders at its upcoming annual meeting on Dec. 4 to approve increasing the number of authorized common shares to 75 million from 55 million to help raise $2 million to $3 million to help 'meet…current obligations and grow revenues...' " The thinly traded stock is available for less than a dime if anyone out there is interested. [2] I wish them luck. They must have a very compelling story if they think they can raise another $2 - $3 million in the open market, but I just don't see it.

[1] Personally speaking, my wife had a set on one of her cars. Besides being noisier than other tires, the tires didn't last very long. When it was time to replace them, we either had to continue with run-flats or buy standard tires and new rims since the two tires were incompatible with each other. Never again.

[2] I probably should include one of those disclosures that states that I do not, never have and do not intend to own any stock in Amerityre. I'm the last guy in the world you want stock tips from.

Friday, November 15, 2013

The Stick-Slip Mystery Deepens

Every once in a while, I run across a journal article where the title completely underwhelms me. Such as this one: "Strong dynamical effects during stick-slip adhesive peeling".

If you know what stick-slip adhesive peeling is (and as you'll see in a moment, you already do know), then you know it is a highly dynamical phenomena. Stick-slip peeling is what happens when you pull a piece of pressure-sensitive adhesive off the roll and it makes a loud noise. Here in the US, regular old-fashioned Scotch Magic tape (the one used around the home and office, and also for wrapping Xmas gifts) is pretty quiet, but compare that to the clear tape used to tape up boxes for shipping. That noise is at most a minor inconvenience at home, but imagine that you have a factory full of automated box taping machines that are all running and making that stick-slip noise. Now you have have an environmental hazard where workers need hearing protection. All because the tape won't peel off smoothly, but instead behaves in a highly-dynamic fashion of peeling for a little bit, then stopping, then starting again, then stopping...

So to say that there are "strong dynamical effects during stick-slip adhesive peeling" is stating the obvious. The research results, however are not.

Using a high speed camera, the researchers [*] built on existing research, redocumenting a number of well established phenomenon, such as that amplitude of the stick-slip length increases with the pulling speed and that the stick-slip cycle time decreases with the same. But what they also unexpectedly found was that the time for the stick phase (Tstick) and the time for the slip phase (Tslip) varied independently of each other. (Tss is the total cycle time = Tstick + Tslip.) Depending on the peel speed, either phase could dominate the total cycle time, which makes it all the more challenging to attempt a reduction in this phenomena. This discovery is way beyond current theory.

Earlier in my career, I spent a lot of time on adhesive development which can be plenty challenging in its own right. I knew of "issues" in stick-slip, but never worried about it as long as my new rolls of tape could be unrolled. But clearly the whole arena of stick-slip is a fascinating area to research. Many people already know about the triboluminescence that can be seen from peeling Scotch tape from the roll quickly (do it in a dark room with your eyes well adjusted to the darkness), but you may also recall that half a dozen years ago, researchers found that the stick-slip phenomenon can lead to the generation of x-rays.

If I ever get back into adhesive research, I think I might spend a little time poking around in stick-slip behavior. There is undoubtedly much more to be discovered.

[*] Marie-Julie Dalbe, Stephane Santucci, Pierre-Philippe Cortetc and Loïc Vanel

Tuesday, November 12, 2013

Carbon Dioxide as a Strong Viscosity Modifier

It's well known that adding "stuff" to polymer solutions alters the viscosity. Whether that "stuff" is inert fillers (spherical, rodlike or othewise), (co)solvent(s), or anything else, the viscosity of the modified solution will change to some degree. But keep in mind that this "stuff" that I'm referring to are what physicists call condensed matter - solid, liquids and anything else in between. Anything but gases.

A new paper in Polymer Chemistry changes that. Canadian researchers have developed an aqueous polymer with a viscosity that is strongly modified after dissolution of CO2 in the water. [*] The top row on the right hand figure (along with the decoder ring at the bottom) shows the chemical makeup of the polymer and how the polymer-polymer interactions are affected by the CO2. Recall that dissolved CO2 in water acidifies it via the formation of carbonic acid (H2CO3). The acid then interacts with the basic, tertiary amine. Not surprisingly, salts (NaCl in this case) also cause havoc at the same sites, either amplifying or further reducing the effective interactions.

The impact of changing these polymer-polymer interactions on the Brookfield viscosity is quite large as this next figure shows. In the absence of salt, the dissolved CO2 knocks the viscosity down by a factor of 100, and the addition of salt takes it down by almost another factor of 100. (For reference, water has a viscosity of about 1 mPa s, while honey would be on the order of 10,000 mPa s.)

The paper has more details about concentration affects (for both the CO2 and salt), and also shows that these changes are repeatedly reversible as sparging the solution with nitrogen brings back the original viscosity. While this polymer was specifically designed to maximize the impact of the carbonic acid on the viscosity, it wouldn't surprise me to learn that other aqueous, ionic systems could also be similarly affected, although most likely to a much smaller degree.

[*] To be clear, this paper is not proclaiming the initial discovery of gases strongly modifying viscosity. Previous research exists, but this is the first time I've become aware of it.

Friday, November 08, 2013

Comments on "Are We Refereeing Ourselves to Death"?

Angewandte Chemie has an open access editorial regarding how the refereeing system is being increasingly overburdened as the number of submitted manuscripts increases without limit. While the author has a number of helpful suggestions such as increasing the number of referees from China and other countries that are increasing their submissions, and also asking authors to show some self-control by not just automatically submitting to Nature/Science and then working on down the line until a paper is accepted. There are other good suggestions as well, but sadly, the author misses out on a huge opportunity that could drastically increase the number of referees available.

**Use industrial scientists.**

I don't have exact figures, but industrial scientists outnumber professors by what, 20x? 40x? Maybe even more? Whatever the number, all that manpower is available and yet it is seldom tapped. I am a outlier in that I referee for the Royal Society of Chemistry (RSC) but I have never encountered any other industrial scientists who referee papers at all for any publisher. Why is that? Cynical thoughts would be that academia doesn't want to dirty itself by working with "prostitutes of science", people who weren't "good enough" to make it as professors, or people who wouldn't be interested in research that doesn't have immediate economic applications. Or is the thought that because industrial scientists don't publish much compared to their academic counterparts, they aren't interested in what's in the literature or making sure that it is kept to high standards? Most assuredly, they are very interested. Some industrial scientists will say no, but that also happens with professors that are asked.

If I were working for journal and needed to find referees, I would start trying to tap this potential workforce now. Start with the few people you do know that are in industry and ask them who else they can recommend. And ask those recommendations for additional recommendations. And then do something with them. Start sending them manuscripts, even if you already have your 3 reviewers lined up. Take these new reviewers out for a test spin and see how they stake up to the regular reviewers. Once you have confidence in them, then start using them and give your regular reviewers a bit of a break. And by lining these new reviewers up early and using them, you are more likely to have their loyalty down the road when other publishers approach them.

When the RSC first approached me to referee about 10 years ago, I was honored by the request and have been happily helping them out. I contacted the American Chemical Society (ACS) shortly thereafter to volunteer my help. They said they would be in touch but have never yet sent a manuscript to me. So if the RSC and the ACS were to both approach me for refereeing and I only have time for one, who do you think I'm going to help?

Monday, November 04, 2013

Who's Been Eating My Ocean Plastic?

Reports (1 and 2) came out last week of a newly discovered "sink" for much of the plastic floating in the Pacific Ocean gyre - fish, and lanternfish in particular are eating it.
NOT Ocean Plastic
Sadly, the research was only presented in a seminar and so no formal paper (let alone peer-reviewed) paper has been issued yet, and so much of what has been published on the interlinks all comes down to the same PR release being recycled over and over (even more sadly with yet another misleading picture about what plastic in the gyres looks like). But the initial reports indicate that researchers found far less plastic in the gyres than they expected [1], and after ruling out UV and microbial degradation [2], they were able to conclude that lanternfish were eating the plastic [3]. Lanternfish are small fish that live in the day in relatively deep waters to escape predators and then rise to the ocean top at night to feed, apparently mistaking plastic particles for more nourishing victuals. And since lanternfish make up 65% of all deep sea fish biomass, they can have quite an impact.

(Through my footnotes I am raising a lot of questions which I realize will eventually be answered when the results are properly published. I'll wait patiently until then and then have another say on the matter.)

So is this good news? I don't see it as such. Consumption of plastics by any stomach-containing animal removes the plastic from the larger environment, but always temporarily rather than permanently. Plastic are not digestible and so the plastic is only temporarily stored within the animal swallowing it. Whether the pieces quickly pass through the animal's digestive track or remain trapped within the animal until the animal dies and decomposes, the particles are not permanently removed from the environment. And since lanternfish make up such a large niche in the open water ocean, they are a food source for a number of other species, listed in the Wikipedia article as "whales and dolphins; large pelagic fish such as salmon, tuna and sharks; grenadiers and other deep-sea fish (including other lanternfish); pinnipeds; sea birds, notably penguins; and large squid such as the jumbo squid..." All of this further supports that the sink is temporary, not permanent.

Plastic waste has no business being in the ocean, and lanternfish eating up large quantities of it does nothing to change this perspective.

[1] How did the researchers arrive at their expected value of plastic waste? Since the waste has been extensively measured elsewhere, why did they feed a need to derive a new value?

[2] How was this ruled out? Recent research suggests that microbial degradation is more significant than initially thought.

[3] How? Did they actually see lanternfish eating plastic?

Thursday, October 31, 2013

Obtaining Innovation

Angewandte Chemie has a new editorial essay entitled "The Organization of Innovation - The History of an Obsession" which is worth a read. It has a short history of attempts by countries to have innovative companies. While it considers the years of 1920 - 1960 to be a Golden Era of innovation, it does caution against attempting to return to the past.
"If we want to get out of the spot we are in, we first need to figure out how we were maneuvered into it in the first place. This Essay is an invitation to make headway in this process. However, anyone who might be inclined to infer from this discussion that the solution to the problem would be a return to the 1950s would be on the wrong track. The epoch that spanned the years 1920–1960 yields insights into what has gone wrong today, but not into how to make things better for tomorrow. There is no going back to ivory towers and industrial monopolies; the solution can only lie in the future. But the crux of the problem with innovation is bound to remain the same: we will never know exactly what prompts it."
Bell Labs is discussed heavily, and I never knew the role that building architecture played in that environment:
"[Director of Bell Labs, Marvin] Kelly had come up with a concept of long corridors that the researchers would have to walk down to attend to some of their less cerebral activities (such as trips to the bathroom). This is where he pictured the all-important informal exchange of ideas taking place, outside of the established work groups...Statements by researchers who returned to universities after working at Bell Labs support the idea that this communications concept actually worked."
I find this rather intriguing as I've had managers who have quoted research that shows that the level of interaction between 2 people drops with the distance to some exponential power. I never believed it, as even at my current job, I spend far more time working with people from other buildings than with labmates. Now I have some ammunition to shoot back with!

As for the statement "we will never know exactly what prompts [innovation]", I think I have some insight. I've worked at 2 companies that were hotbeds of innovation. One was very large (3M) and one was very small (Aspen Research). The only common factor that I can see between the two was that they both hired good scientists and engineers with a wide range of backgrounds and let them interact with each other. 3M does this through their Tech Forum, an group of non-managerial technical people that provide a forum for researchers to present their research to the entire company through talks and semi-annual poster sessions.

Aspen had to take a different approach and that was by hiring intelligently. Aspen had about 20 chemists, engineers (chemical, aerospace, mechanical), physicists, metallurgists, etc., most with advanced degrees and ALL with over 20 years experience in multiple companies and industries. As a direct consequence, when it came time to brainstorm, I had to invite people with diverse backgrounds into the session. And the output showed the value of tapping this diversity. Crazy ideas came from all quarters [*], most of which died their well-deserved deaths, but the nuggets left behind made it all worthwhile. If it had been possible for me to pull together an equal-sized group of polymer chemists, the results would have been far, far less.

It's that simple. If you want innovation, get together a group of good scientists and engineers and let them interact. Whether it's the architectural approach of Bell Lab, the Tech Forum approach of 3M or the hiring technical diversity approach of Aspen Research, the result is the same.

[*] We use to say that it the brainstorming session wasn't over until someone had suggested an idea from Star Trek.

Wednesday, October 30, 2013

Making Plastic a Verb

I've never been a big Black Eyed Peas fan [*], but in a recent interview in The Guardian, Will.i.am said had some interesting thoughts about plastic waste that are close to what I've been saying for some time:
"The reason why a city doesn't recycle is because people don't see waste as a commodity. They see waste as waste. I was like wow, with the technology we have today it's only waste because we waste the opportunity to turn it into something else. So let's not recycle, let's upcycle."
As I stated in the not too distant past, the whole upcycle/downcycle concept is pretty meaningless, but the idea that waste is "...only waste because we waste the opportunity to turn it into something else" is very powerful.
"Let's make plastic a verb because right now plastic is a noun. Take a plastic bottle. Before it was plastic it was oil, before it was oil it was a living creature. Therefore it's not plastic at all. Plastic is a process, it's like a continuous reformation and transformation of an object. The brain is plastic; plasticity of the mind means your brain is always growing. If you go to the doctor and get plastic surgery they're not putting plastic on your nose, they're just altering it."
While you can argue that plastic is also an adjective, Will.i.am clearly understands the true meaning of the word plastic. Plastic deformation is an old concept from material science that dates back to the mid-17th century and refers to the ability of a material to have its shape altered. When synthetic polymers were being developed a hundred years ago, they had this properties in spades and so the name plastic was a natural fit for these novel materials. Will.i.am is taking it the next step and looking at the big picture that extends for eons.

There are a lot more interesting thoughts in the interview - I highly recommend reading it.

[*] Every time I see the name Will.I.Am, I keep wanting to follow it up with that old Chevy Chase line, "...and you're not".

Tuesday, October 29, 2013

A New Chemistry Lab Building, But Without New Chemistry Jobs

It's just piles of dirt being moved around, but soon it will be a brand spanking new lab building for 700 technical people that should be finished in 2015.

Sadly, that does not mean that 700 new technical people are going to be hired. They already are employed, but will just being shifted around to the new building. One or more existing buildings will be razed after all the moving around is done.

Monday, October 28, 2013

SoBe, What Were You Thinking?

I can see environmentalists being angry with SoBe's latest ad campaign, as it plays on the old idea of "message in a bottle".
The only problem: SoBe's bottles are plastic. While SoBe is obviously not suggesting that people toss their plastic bottles in the ocean, the association is something that just should be avoided. Especially when it's one of the ads showing up on the Facebook page of an leading advocate fighting against ocean plastic, Stiv Wilson.

Unfortunately, the Huffington Post article cited above makes its own mistake using the picture on the right as representative of plastic in an ocean gyre. Ironically, it's almost too bad that the pollution isn't that bad. A scene such as this could be economically cleaned up and the recovered material could be reused to make some new products. Sadly, that is not the case with ocean plastic.

The picture on the left was take by Scripps Institute researchers and shows what plastic in an ocean gyre really looks like. It exists in such dilute concentrations (and such small particles) that economical recovery operations are just not feasible. Such a picture, despite being factually correct, makes it much tougher to sell the idea of pollution to the public. Presenting it as an "island of plastic" that is (twice) "the size of Texas" is much easier and brings out more revulsion from the public.

As I have said numerous times over the years, plastic waste has no business being in the ocean. The romantic, old idea of a message in a bottle does nothing to help matters and shows an insensitivity to a very large environmental issue, one that is a serious problem in its own right, but also one that decreases the public's respect for the plastics industry. SoBe really needs to rethink the ad.

Thursday, October 24, 2013

"Dear, Do These Jean Make My Butt Look Ultrahigh Molecular Weighty?"

In the never ending efforts to improve the fabrics of our lives (recall the earlier effort to make clothing photocatalytic, Plastemart reports (o.k., it looks like nothing more than a cut-and-paste job of a PR release) that Levi's jeans will soon be made incorporating ultrahigh molecular weight polyethylene (UHMWPE) fibers into the fabric. Arguably the strongest fibers in the world (at least on a per weight basis), these fibers should make for some pretty tough jeans.

I was first exposed to UHMWPE during grad school when I used it as part of my research. The production of the fibers with this resin is different than most fiber manufacturing processes, which simply extrude the molten plastic through a small circular hole and pull on it to orient and thin the fiber. Due to the very high molecular weight, such processing is well nigh impossible since the viscosity of the molten resin is too high and it would also undergo too much shear degradation. So an alternative method is employed: gel spinning. The resin is dispersed in a low viscosity liquid so it has 'gel-like' properties [*] which can easily be extruded and pulled thin. As the thinning is going on, the crystalliization expels the liquid leaving behind just the polymer. The liquid also helps lubricate the polymer chains so that orientation can be increased.

These fibers are going to show up in the Trooper styles of the 501 jeans. So nice time you get pulled over by a trooper for doing 50 in a 40, you can strike up a conversation about how strong his jeans look. Maybe he'll let you off.

[*] although it certainly doesn't meet the standards (either Flory's or IUPAC's) for being a gel.

Wednesday, October 23, 2013

Dog and Pony Show

I'm not going to be writing much today as we have a poster session in our lab in a few hours and there is still lots to clean and prep.

You may recall earlier in the year that I blogged once or twice that I was working in a new lab. New as in vacant lab space. New as in totally void of all supplies, equipment and chemicals. New as in nothing had been spilled and no foul odors had yet to be created.

That has all changed and we are fully operational turning out good results. We had an open house back in March to show off the new space and we are having another one today to show off to both our US and international colleagues what we are accomplishing. It should be a good, upbeat day.

Tuesday, October 22, 2013

Shale Gas - Biobased Chemicals New Best Friend?

I have to admit to thinking that the shale gas revolution would be trouble for any and all options of making monomers and other chemicals from biobased materials. With a suddenly-cheaper, petroleum-based feedstock, int would be a foul financial environment in which no new investments in biobased chemicals would be made and existing investments would possibly struggle to continue.

But a new paper suggests that not only might shale gas not hurt biobased chemicals production, but it might even be a boon to it. While the authors discuss a number of reasons why, this one plot is most telling:
I certainly knew that shale gas would go a long ways towards increasing ethylene production, but I had no idea that it would come at the expense of propylene and butadiene. And that's where biobased chemicals can make a difference. The authors discuss routes for biobased production not only of these chemicals, but other outputs as well (such as BTX) that are expected to become scarcer as more retrofitting is done to access shale gas rather than the traditional naptha feedstock.

There are enough specific companies named exploring these options that it is difficult to call this article a pie-in-the-sky dream radiating from an Ivory Tower. It does tend to focus on drop-in replacements for existing chemicals, which is both good and bad. Good in that it is easy to find markets for the outputs since these chemicals are commodities; bad in that it keeps us focused on using monomers (and other chemicals too!) that were the natural fallout of crackers, rather than those that are the natural fallout of biochemistry, such as furanics. Petroleum-based furanic-based polymers are terribly expensive, while those that are biobased are (or more correctly, have the potential) to be inexpensive, and we certainly haven't explored all the materials that we can make with these unique monomers.

Nonetheless, the idea that shale gas could help establish a biobased-chemical economy is a counterintuitive, but compelling idea. As the report states:
"It is often said that the Stone Age did not end because we ran out of stones and that the age of oil will not end because we run out of fossil fuels. Ironically, one might indeed even think that the large-scale utilization of an unconventional fossil resource, such as shale gas, may usher in a new era of a more sustainable chemical industry that produces—at least in part—some of its main bulk chemicals from biomass."

Monday, October 21, 2013

Even More Pitch Experiments

While the Pitch Drop Experiment at the University is billed by both the Guinness Book of World Records and it's own webpage [1] as the longest running experiment, ScienceNews reported last week of other experiments that are similar in nature and one that is clearly the winner of the longest running experiment. I loved the article as I was not aware of any of these other experiments.

Two of the experiments are the design of Lord Kelvin. The first involves a layer of pitch in a shallow, broad dish. Corks were placed under the pitch and bullets were on top. Over time, the corks floated to the top and the bullets sank. What I find most fascinating was that this was used as a model for the now-deposed concept of aether which permeated the universe.
"Pitch was the only earthly material Kelvin knew of that could simultaneously behave as a solid and a fluid. He and other physicists of his era believed that a similar substance called the ether permeated the cosmos. Ether needed to be rigid enough to propagate rapidly oscillating light waves, yet fluid enough for planets and other objects to travel through it. Pitch was a great analog."
(The concept of aether was finally set aside for good when Einstein developed the concepts of relativity. While this experiment may have been the first time that rheology and cosmological physics crossed paths it wasn't the last. The same matrix calculations that Einstein developed for his Theory of Relativity are used today in many rheological equations.)

The second experiment, also attributed to Lord Kelvin, was an artificial glacier, in which pitch was placed at the top of a ramp and slowly crept down it over time, much how a glacier slowly flows down a moutainside or other slope.

But the last experiment described by ScienceNews tops all of this, even a couple of other experiments [2] that aren't mentioned.
"Despite its head start, the newly rediscovered 1914 pitch experiment in Wales has not produced a single drop. The funnel stem is about 80 millimeters long, Aberystwyth lab technician Stephen Fearn says, yet the pitch has descended a mere 6 millimeters in the century since physicist G.T.R. “Taffy” Evans set it up. At that rate, the pitch won’t emerge from the funnel — let alone form a drop — for another 1,300 years. It’s unclear what type of pitch Evans used and why it flows so slowly."
Obviously a much more viscous pitch, but still rheology trumps all as there is sufficient evidence from the last 99 years that it is flowing. As they say, "When the going gets tough, the tough get rheology".

[1] Be sure to check out the high res version!

[2] Including another one from Lord Kelvin - what was it with this guy and long-running experiments?

Friday, October 18, 2013

The Skin Off My Back

I've never posted a NSFW entry before, but after doing over a thousand posts, maybe I'm allowed a little slack. Don't worry; you'll have to scroll down a bit before you get to the fleshy parts. (Ooh, ooh! Tell me you can't wait! Just make sure you aren't reading this too close to your lunch hour. I don't want to be responsible for you losing either your appetite or your lunch. I told you it's not safe for work)

Last weekend, I was cleaning out the garage (or garage for those that speak British English) and I came across a box of 'work' stuff that I had forgot about. There were 2 things in particular in that box that caught my attention. One I will write about today (the fleshy one); the other will be written about in the future.

One more than one occasion (here and here), I've blogged about how at my previous employment gig, I literally gave the skin off my back to help with a client's project. The project was the development of a medical adhesive and the best way to test the performance of any medical adhesive is on human skin. The part of the human body most often used for testing is the back as it is large and fairly flat. And since asking for volunteers gets messy for a number of legal reasons [*], I had someone put strips of the new adhesive variations on my back and pull them off (using an Instron to measure the force). Some stuck more than others and some were rather painful; hence the skin off my back remark.

This is all well and good, yet I never submitted any proof to my readers that this actually occurred. But that box had a CD with pictures of the whole ordeal. And here they are.
My skin grew back of course, since it truly is a "SELF-HEALING" material (unlike what we saw yesterday).

The dynamics of this project were a little unusual. The client was buying an adhesive from a large corporation, one about a thousand times bigger in sales than us. The client loved the adhesive that I developed, but they never bought any from us. They just used it as leverage to get a price break from the big guy. So it goes.

[*]The Nuremburg Code, was developed after World War II and closely regulates human experimentation to ensure that all human subjects are voluntary and give informed consent.

Thursday, October 17, 2013

Is This Really Self-Healing?

Self-healing materials are growing rapidly in popularity, at least as far as research topics go. I mentioned one example a couple of weeks back that was pretty impressive , but a new paper doesn't even come close to reaching what was achieved previously. (More on that in a minute)

From the well-respected Matyjaszewski group (a perennial candidate on Chembark's Nobel Prize predictions) comes this offering: "Introduction of self-healing properties into covalent polymer networks via the photodissociation of alkoxyamine junctions". The chemistry is also very trendy using not only ATRP (this is the Matyjaszewski groups after all) but also "click" chemistry [1] to build up a network with alkoxyamine junctions. The paper goes into extensive detail (lots of Electron Spin Resonance spectra) about how UV light can be used to breakdown the network thereby increasing the mobility of the chains so that additional UV light can be used to reform the network.

So I'm reading all of this, getting pretty excited until it is time to for the research to deliver the knockout punch - show me that this stuff self-heals! And for that, you get to see the set of photos on the right. The top set shows a "scratched" film [2], the second set shows the film after 2 hours of radiation, and the third shows the film after 24 hours of radiation. But that's all you get. No evidence that the mechanical strength of the film is x% of the original or anything else along those lines.

I don't think this paper was refereed very well. The chemistry aspects are all spot on, but when you are talking "self-healing", emphasis needs to be placed just as much on the mechanical properties and how much they recover after the healing is over with. This paper really falls short in that manner, and as I noted in footnote 2, it can be questioned if there was any damage that needed healing in the first place.

So is this polymer really self healing? At this point, I'm not convinced in the least.

[1] For crying out loud, polymer people, can we decide on what "click" chemistry is? Half the world wants it only refer to the the copper-catalyzed alkyne/azide cycloaddition reaction, (as is the case in this paper that I'm discussing) and the other half wants to include thiol-ene, Diels-Alder and a whole host of other reactions such as was originally proposed by Nobel Prize winner Sharpless. [†] I prefer the latter option myself, but more importantly, I prefer that we make a decision and stick with it.

[2] Scratched? They put 600 nm indentations into the film using an ATM in tapping mode! Scratched? Wouldn't compressed be a better word? I'm struck by how the "scratch" fills in from the bottom up (as you would expect from elastic rebound), even though the top of the coating receives the most light and should therefore heal faster. Maybe it is a scratch, but you better prove it, or at least make one in a more conventional manner that isn't open to questions.

[†] You don't suppose that the difference in usage is what sets off the Nobel Prize winner from the wannabe, do you?

Wednesday, October 16, 2013

Hiding behind Lawyers

We all hate lawyers. This is not a new feeling, but one that has existed for centuries. Shakespeare was the one who first wrote the popular saying "...let's kill all the lawyers" [1]. And so lawyers get blamed for many, many problems in society, often deservedly so.

But since it is easy to blame them for so much, it is also easy to overextend that blame. To hide behind them. To hide your weakness and lack of resolution. Doing this, in my mind, is worse than whatever else we blame on lawyers.

The bottom line is that if you hire a lawyer, they work FOR YOU; you do not work FOR THEM. You hired them; they did not hire you. As such, they are there to advise and counsel you, to use their experience and knowledge to guide you. But they are NOT there to make decisions for you, to make you say and not say certain things, to run you business for you...[2] Gather their input and that of others, mull it over and make a decision, but that decision is ultimately yours. You can try and say "My lawyer won't let me..." but that is a lie. That is a pathetic lie. That is you hiding behind your lawyer because you don't have the guts to come out and say that you made the decision yourself.

So when an apologist goes online to blames lawyers for the mishandling of the Scientific American blogging fiasco, that is just plain wrong. I'd be shocked if lawyers weren't involved to some degree, but it is still is the SciAm people who made the final decisions and they are the ones that need to be held accountable, not their lawyers.

[1] People will argue that this line is taken out of context. As it occurs in the play, revolutionaries are plotting to overthrow the king and see lawyers as part of the status quo standing in their way. Hence, if you like society, then the lawyers are good people keeping that society going and so it can be interpreted as a pro-lawyer comment. I disagree. Lawyers defend both sides (both pro- and anti-revolutionaries), so they cannot be seen as all good.

[2 ]We have all seen people testifying before Congress taking the 5th amendment, (that part of the US Constitution that gives us the right to not incriminate ourselves). Repeat after me: "On advice of counsel, I decline to answer that question..." What's that first part? "On advice of counsel..." That's right, the lawyer gave advice and the client took it and recognizes it for what it is - advice.

Tuesday, October 15, 2013

Turning Plastic Bags into Carbon Nanotubes

Researchers at The University of Adelaide have announced that they have a new process for making carbon nanotubes from plastic bags. This is all well and good, but you can probably anticipate the environmental "spin" that they will put on it:
" 'Non-biodegradable plastic bags are a serious menace to natural ecosystems and present a problem in terms of disposal,' says Professor Dusan Losic, ARC Future Fellow and Research Professor of Nanotechnology in the University's School of Chemical Engineering. 'Transforming these waste materials through 'nanotechnological recycling' provides a potential solution for minimising environmental pollution at the same time as producing high-added value products.' "
That wasn't too hard to predict, was it? Because we can now take your trash plastic bags and make something really valuable with them, people will be much more careful with disposing of them properly.

I am very skeptical as people easily could have reacted in such a pro-environmental manner when it was announced that the 2-D cousin of nanotubes - graphene - could be made from pretty much anything including chocolate, plastic, grass, dog poop, cockroach legs and even Girl Scout Cookies. But they didn't. And they won't now either.

It's a nice piece of research, but nothing earth shattering, or maybe more to the point here, nothing earth saving. At least they didn't mention this as a motivation for cleaning up the plastic in the ocean gyres.

Thursday, October 10, 2013

Safety Glasses

While you know that I am a big supporter of wearing appropriate PPE when working with chemicals (remember this recent example where I had 8 different PPE's on me at one time), other people at the company where I work aren't. The company has decided to crack down.
I think this will work, unless you're feeling lucky...

Wednesday, October 09, 2013

Preventing Oxygen Inhibition during Polymerizations

As chemists, we often work with oxygen sensitive materials and there are a variety of techniques for handling such materials. Today's post however, is about a slight variation of oxygen sensitivity - one where the reaction itself is oxygen sensitive, rather than the chemicals themselves.

Free-radical acrylate polymerization is a very common example. As a new review paper states,
"[Oxygen] may react with primary initiating (R•) or propagating radicals (P-M•) to form peroxyl radicals (POO•), which are not energetically favorable toward initiating acrylate polymerization. These peroxyl radicals tend instead to terminate polymerization through radical−radical recombination (forming peroxide bridges, POOP) or by abstracting hydrogen from an adjacent molecule (POO• + RH → POOH + R•), where often the newly formed radical (R•) has insufficient reactivity toward the acrylate double bond to reinstate the initiation process."
These issues are not a concern in traditional bulk polymerizations since the surface area contacting oxygen is very small, or the oxygen can easily be flushed from the reactor. For coatings on the other hand, the surface area becomes enormous and the impact of the inhibition - an uncured surface - cannot be ignored.

While the focus of the review paper is unnecessarily just on photoinitiated reactions (most of the schemes can be applied to any free-radical polymerization), the review does an excellent job of highlighting ALL the available options, covering both physical and chemical methods, including some options that I was previously unaware of such as the use of boranes and phosphines. This article will serve well as a reference for years to come.

Tuesday, October 08, 2013

3 Small Bites

Some short thoughts about what I am reading elsewhere.
  • Retraction Watch noted that a recent paper in the Journal of Applied Polymer Science, "Drug release properties of poly(vinyl pyrrolidone)/acrylic acid copolymer hydrogels", was retracted as it was the third time that some of it had been published, a no-no if there ever one was. But I just wonder what the paper was REALLY about, since it had previously been published in places that I would never think to look for polymer research, the Arab Journal of Nuclear Sciences and Applications and also in Proceeding, 2nd International Conference on Radiation Sciences and Applications.
  • Gene Quinn of the IPWatchdog blog (a blog I highly recommend for anyone with an interest in patents [*]) last week discussed some surprisingly short claims that appear in recent applications, such as
    "Claim 1 from Application Serial No. 13/416,904:
    Asymmetrical 2,5-disubstituted-1,4-diaminobenzenes"
    According to the application, symmetrically substituted 1,4-diaminobenzenes are easy to come by; it's the asymmetric ones that are the challenge. I can't say otherwise, but I think I would have expanded the claims to include asymmetrically substituted diaminonathphalenes, anthracenes, and other polycyclic aromatic hydrocarbons.
  • Ninesights has a request for a "Reduced Cost and Complexity Heating Plate" which is a laugher. They want this new heatplate to
    • Be applicable to plates between 5-10 inches in width and 10-20 inches in length
    • Work with 15 Amp, 115 Volt power (20 Amp is acceptable but not preferred
    • Provide uniform heat to the entire surface
    • Reach 300 F in 3 seconds or less
    • Be resistant to water, punctures and cutting by sharp objects
    • Be integrated with a power controller/temperature regulator that maintains 300 F when significant heat drain loads are placed on the plates
    • Presents a stainless steel surface
    15 Amps, 115 VAC will give you at absolute most 1.725 kJ/s of energy, which means you have to heat the entire plate up from RT to 149 C (a ΔT of about 127 K) with just 5.175 kJ of energy. Stainless steel has a heat capacity of 460 J/kg/K, so that means you can have no more than 88.6 g of stainless. Since the specific gravity of stainless is about 7.85, you have only 11.7 cm3 to work with. As the minimal area is 300 cm2, the thickness of the steel can be no more than 0.35 mm - foil for all practical purposes. And that means it will not be resistant to "punctures and cutting by shart objects". This also assumes that nothing else in the heating plate has any thermal mass at all. Any such mass will further reduce the thickness of the stainless. As will a power efficiency of less than 1. And energy losses to the external environment via conduction, convection AND radiation.

    Walt Disney famously said "It's kind of fun to do the impossible", but this is not what he had in mind. The conservation of energy and these undergraduate level calculations are spoiling the fun of a "Major Equipment Supplier". Gee, maybe there really is a STEM shortage. There appears to be one at this company.
[*] The blog is so good that other IP attorneys, including copywrite attorneys who should know better have copied entire columns and published them elsewhere without proper permission or even attribution. Gene doesn't like that. Gene takes action. Don't cross Gene.