Friday, May 28, 2010

"Nothing's Changed"

It's funny the streaks that we run into with clients. This week we kept encountering ones told by their supplier(s) that nothing had changed: the input material was the same (still meeting the same incoming and outgoing specs), the supplier had processed it the same as always and yet the client was noticing big changes in the product.

Our only logical conclusion was the the laws of chemistry and physics had changed this week and nobody informed us (or our clients).

All kidding aside, I've heard the same comments - "nothing's changed" - everywhere I've worked and it is a serious issue as something has changed. It just means you need to look a little further into what's going on.

What really should be said instead of "nothing's changed" is this:

"Everything that we are keeping an eye on has not changed; something that we are not keeping an eye on has changed and it is ruining everything."

And that's totally different from "nothing's changed". Knowing that, the whole mindset quickly changes and people start thinking more freely.

Ode to Thiols

I do a lot of work with thiol-ene polymers, so this poem, courtesy of Carbon-Based Curiosities is wonderful. A nicely framed copy will soon be adorning the walls of my lab.

O Captain! Mercaptan! Your fearful prep is done;
The lab has weathered every rot, the prize you sought is won;
The paper’s near, the lauds I hear, reviewers all exulting,
While follow nose the steady smell, aroma grim and daring,
But O heart! heart! heart!
O the taste of vomit up,
Where on the bench your thiol lies,
Smelling like a butt.

O Captain! Mercaptan! Wise up and fear the smells;
Wise up – for you alarms are rung – for you my stomach trills;
For you Febreze and freshen’d air – for you the lab a-cursng;
For you they call, the offended mass, their eager noses turning;
Here ‘captan! Dear product!
The cheese you must have cut;
It is no dream that on the bench,
You smell just like a butt.

The Captain does not answer, his face is pale and still,
My labmate does not feel my arm, just nauseated will;
The prize now anchored safe and sound, in the hood it’s closed and done;
With fearful zip, the victor skipped, away from object won;
Exult, O smells, and sing, “O hells!”
The stench, revulsive glut,
Walk not near hoods Mercaptans lie,
They smell just like a butt.

Thursday, May 27, 2010

Polymer Science - An Old and Ancient Art

I'm just not sure what the fuss is about. In the last few days, there have numerous reports (here and here) of Mesoamericans processing polyisoprene into rubber 3500 years ago, using an morning glory "juice". But this has already been known since 1999. I wish one of the reports would clearly state what was newly discovered.

I also wonder how they thought to mix the two plant liquids together. Morning glory seeds are known for hallucinogenic properties, so they might have had a large orchard of the vines growing and wondered what to do with the waste.

Wednesday, May 26, 2010

How to Not Plot Your Data

I only saw two talks while at ANTEC last week, one of which I was appalled by. In this study, different variables were measured which I'll call 'X' and 'Y'. Without any theory or rationale behind his analysis, he prepared a number of plots that showed various correlations, using semi-log or log-log plots as needed to get strong correlations. Do this long enough with any data set and you will find eventually find something that looks good but is useless. You're not learning anything, you're not disproving anything, you're just doing busy work. However, one plot in particular left me aghast. The plot had the ratio X/Y on the y-axis, and X on the x-axis. ???? How can this be? Divide both sides by 'X' and you then have a plot of 1/Y vs. 1 - the equivalent of a bar chart of the various values of 'Y' that were measured. I walked out at that point.

It certainly would not be out of place to blame the reviewer of the paper, but I hold the author to an even higher standard: the bio of the speaker stated that he had earned a Ph.D. from one of the finer schools in the land, proof that the degree only shows what you once did, not what you are still doing.

Redundancy in a Journal Title

As I mentioned last week, there were a lot of publishers at ANTEC. I flipped through the various journal available, and for some reason, one of the titles just caught me the wrong way: "The Journal of Vinyl and Additive Technology". Between the "vinyl" and the "additive", we've got this double covered. The journal should just be renamed as the "Journal of Additive Technology", as that is pretty much all the more that vinyl really is - additives.

Tuesday, May 25, 2010

Exhibits that I liked at ANTEC

These four exhibits at ANTEC caughty my eye:

1) The combination IR/AFM instrument offered by NanoIR. I never got a chance to ask how they got around the diffraction limit (seeing objects smaller than the wavelength of the photos), a real concern since IR wavelengths are much larger than even visible light. I suspect that the IR is absorbed from the sample, rather than reflected off of it.

2) The scratch hardness tester sold by Surface Machine Systems (and prototyped by the Polymer Technology Center at Texas A & M). In a world that still uses pencil hardness testing and other antiquated methods, this is what a hardness tester should be - a fully instrumented stylus that continuously records normal and tangential forces as it is dragged across the surface with a controlled pressure. The challenging part is left to you however: interpreting the data. If a force of 'x' Newtons is needed to scratch a coating, what does that tell you? Certainly it is helpful for making relative comparisons (a coating that scratches at '2x' Newtons is better than a coating that scratches at 'x' Newtons), but is the actual value of 'x' meaningful on it's own? I don't see that it is, much as we (technical people) like to have quantiatitive numbers for reassurance.

3) Halloysite clay offered by Applied Minerals. This clay is naturally in a nanotubular form, easily dispersible and much cheaper than carbon nanotubes. The outer and inner walls also have permanent charges on them.

4) The water-based coating that adheres to PP without any additional processing steps (although a 40 minute cure time @ 85 oC is required). PP is always a challenge to adhere to with only fluoropolymers and silicones being more difficult. (PE and other olefins are no joy either.)

My time was short at ANTEC this year, so I didn't get to see as much as I would have liked. Consider these just my personal view of what I saw and what drew my attention.

Saturday, May 22, 2010

On the Lack of Posting

Dear Readers,

This has been a unexpectedly tough week for posting. Since arriving back home, one of our dogs have become quite sick and will be operated on on Monday. Time and thoughts have thus been devoted elsewhere. Things will improve next week. Thanks for your patience.

Wednesday, May 19, 2010

Back in the Office

Back from ANTEC and trying to get caught up, so this will be a quick post with more to follow tomorrow and Friday.

Based on previous conferences, attendance seemed down at the exhibit hall and the talks. My talk went well (I thought) but I was hoping for quite a larger group of attendees. Regardless, I am most grateful to those who sat through my talk.

Because of a flight delay (the plane kept flying south to avoid thunderstorms in the area - any further south and the Cuban Air Force would have been on us), I got pulled into setting up my company's booth and didn't get to sit in as many talks as I was hoping for.

I did find a few exciting items in the exhibit hall and I will talk at greater length about them later this week. I was struck by how many publishers were there: Elsevier, Wiley, RARA, CRC... Somewhat strange if you ask me.

Friday, May 14, 2010

Off to ANTEC

I will probably not be posting on Monday and Tuesday as I will be at the Society of Plastics Engineers' ANTEC meeting in Orlando presenting a paper, and hopefully attending a few good talks that I can talk about on my return. If anyone reading this is attending the conference, my talk is at 4PM on Monday, "Significant Acceleration of a UV-Cured Coating". I gave a teaser of it a few weeks back. If you are there and get a chance, please stop by and say hi.

Polymers Are Not Chemicals!

Too funny. Does this include plastics?

Take the Aspen Challenge

You could win $500 plus tickets to the Food & Wine show in Aspen - the cute village in Colorado, not my employers building in Minnesota, although if anyone wants to stop by, feel free. We do quite a bit of work in the food industry and may even have some samples lying around to chow on if you do show up. (We'll scrape the mold off first, promise!)

Just realize that it has absolutely nothing to do with my employer, Aspen Research, even though it could. After all, we do plenty of work with plastics.

Thursday, May 13, 2010

Airborne Polymers

Polymers are never thought of as being airborne, except maybe for the angel hair that forms when cleaning molten polymer off of a hot die or such. (Oh, and I can't forget about the stuff that conspiracy theorists believe is added to contrails.) Given that polymers have molecular weights of thousand, tens or hundreds of thousands and in some cases, millions of Daltons, they have no volatility at all and cannot evaporate.

But there is another way to get a polymer airborne, and that is to polymerize it in the air. "Science" had a report back in 2004 (open access copy) that showed polymers being built from various volatile organic components after exposure to UV light [*]. The degree of polymerization is not very high (the 9-mer seems to be as far as can be detected), so I would personally call them oligomers, but nonetheless, these chains still have molecular weights close to 1000 in some cases, too heavy to be launched by evaporation. (And given all the oxygen atoms in these hydrocarbons, there are a lot of dipoles along the chain, further increasing the molecular interactions and limiting volatility.)

[*] What spectral output did the light have? This is important, as some bulbs do a much better job matching the solar output that other bulbs do. But all reports in Science greatly lack in experimental details because of the space constraints.

Followup on "The World's Smallest Rheologist?"

Twice this week, I should have held off posting for an hour. In both cases, I immediately find another site or alert with some additional relevant info. "Biotechniques" has a report on how the shape of stem cells can alter there performance. The shape was control by microprint different chemicals on the surface, chemicals which selectively altered the adhesion of the cells, thereby forcing a shape onto them. Look at this picture:

Researchers have cultured human stem cells in a variety of shapes and patterns, to control differentiation into osteogenic or adipogenic cell lineages. This immunofluorescence image depicts two different stem cells shapes, a flower and a star. The green color is the actin stress filaments in the cell, the red is the focal adhesions of the cell where the cell attaches to the surface, and the blue is the nucleus.

Specifically, the cells on the left predominantly became bone cells, while the ones on the right became fat cells.

All because of shape, all because the cells are pulling on the surface. How cool is that?

Wednesday, May 12, 2010

The World's Smallest Rheologist?

Tautologically, research articles with eye-catching titles tend to catch my eye. “How Deeply Cells Feel…” is one such report that I’m glad did grab my attention. The report is the latest in a serious of studies concerned with cell adhesion to surfaces. Being chemists, we certainly aren’t surprised that cells respond to chemicals in their local environment, but I was unaware that the physical environment matters too. Cells actively sense the stiffness of the substrate that they are attached to by pulling on it. If the substrate is soft enough, the cells can even form wrinkles in the surface. This particular report was concerned with layered substrates and how well cells can detect the stiffness of the underlying substrate when it is covered with a thin, softer layer.

Having a rheological bent to my thoughts, I was struck by this question which does not seem to have been raised:

When the cell pulls on the substrate, is the pulling continuous or, as occurs in dynamic mechanical analysis, is it modulated in some manner?

Certainly the latter approach would be able to help the cell better understand the substrate, and given that large molecules such as proteins naturally oscillate, it is not inconceivable that the adherents of the cell would too. This can be important as in all the cases that I’ve seen, the modulus of the substrate is taken as a constant, an assumption that clearly needs to be questioned when the substrate is a softer viscoelastic gel.

So are cells the worlds smallest rheologists?

Tuesday, May 11, 2010

Follow Up on "9 Shocking Things Made From Oil"

I wish I had seen this blog post before I made mine. Not that it changes anything; it just re-emphasizes the futility.

10 Things I Like about Polymer Chemistry

  1. Acrylates: You can polymerize them in bulk, suspension, emulsion and solvent, anionically and cationically, and UV or E-Beam or visible curing. What more can you ask for?
  2. Thiol-ene polymers: A/B copolymerization without a condensation reaction
  3. Intrinsic viscosity - that infinite dilution can tell you anything at all about 100% concentration is simply amazing
  4. Styrenic block copolymers - stretchy rubber that you can melt and dissolve over and over again
  5. Dendrimers
  6. The nylon rope trick
  7. Foaming polyurethane, all because of water
  8. Being the career advice of a newly minted "Graduate"
  9. A time-temperature superposition that just covers the shear rates that you needed.
  10. Blown polypropylene film lines. Big ones. Really big ones. One big, shiny, bright bubble slowly moving downhill.


From Chemjobber.

"9 Shocking Things Made from Oil" - Not!

When you see something like this ("9 Shocking Things made from Oil", none of which are shocking) I get so frustrated. What do you do? You could try and post something in the comments to try and educate some of the readers or the author, but would it even do any good at all? The frustration goes beyond the title too, to all the vitriolic captions of each picture. And this is one of the most popular websites in the world.

Flow-Induced Phase Separation

Last week I posted about flow-induced crystallization, an eminently useful concept. PET is a useful material because of it. Without it, the polymer would crystallize too slowly to be useful. Another closely related field which is far more fascinating from an intellectual stand is flow-induced phase separation.

This is actually a much broader field, as the term "phase" can include both polymer-polymer phase separation and polymer-solvent phase separation. Regardless of the specifics, think of it as de-mixing caused by the flow field. This is the opposite of normal experience. If you are trying to dissolve sugar in your lemonade, you use a flow field to help the dissolution, don't you?

As was mentioned earlier, the flow field changes the shape of the polymer and so the thermodynamics of the system are changed. In many cases, the change is too small to have an impact, but in some cases it can lead to tremendous changes.

In my studies, I was working with a dilute solution (0.1 wt%) of ultrahigh molecular weight polyethylene dissolved in hot xylene. When working with polymers in solvents, "dilute" is not just a qualitative description, but is actually a semi-quantitative term. For those working in the field, "dilute" means that the polymer concentration was so low that each polymer chain was physically isolated from the other chains. There was no overlap of the coils.

When this solution was put in an extensional flow field however, the coils begin to overlap and came crashing out of solution. That may seem obvious, but look at it from a different perspective: the flow field caused the polymer chains to move UP a concentration gradient from 0.1% to 100%. Powerful stuff.

Of course, the industrial application were very limited. Does anybody really want to work with a 0.1 wt% solution? Even with a top-notch solvent recovery system, you still will have very low output.

Monday, May 10, 2010

Time-temperature Superposition and going nuts

Just got a bollus of new samples that need their viscoelasticity measured. The measuring is hardly the problem - it's when I have to do the time-temperature superpositon that I start getting blurry-eyed. I always do them by hand. Given the software package I am working with, the automatic superposition is passable at best, most often useless and sometimes you have to wonder how any self-respecting machine could crank some of the results out just that way. I suspect [1] that the software has improved some, so that if this old machine ever gives up the ghost [2] then my life will be simpler.

Let me show you an example. Here's what the raw data: Then here's what the automatic software shiften things too:
Look at that. There all sorts of slack that can be taken up. It's disgusting.

While the final plot that I made by hand isn't clean, (the sample was getting too soft at the highest temperatures and things got noisy) it is so much better at the higher shears. As you can tell, these plots were made in Excel which certainly is less than desirable but much better than the instrument's software, but that also then requires that I cut-and-paste the data between the different programs. So that's my day. After a running a dozen of these, I'm pretty much brain-dead.


[1] Hope and pray?
[2] Not likely at all. Rheometrics built the RDA II to survive a direct ICBM hit. It will be something for the cockroaches to play with in the post nuclear era.

Friday, May 07, 2010

Seeing the Spin

Cool but probably meaningless. Scientists now have images of electron spin, that property that everyone learns in their freshman chemistry to build up the periodic table. Spin up, spin down, singlets, triplets... That the electrons aren't actually spinning is not important. Quarks have the properties of flavor and color and they don't exist as actual "flavors" or "colors" either.

As I led in with, I'm not sure that pictures are useful for much. I feel the same way about scanning tunneling microscopy which is able to show us individual atoms, but for some people, seeing is believing. Regardless, the technology is certainly impressive.

99 Plastic Bands on the Wall...

Of course there is the “Plastic Ono Band”, but I also found the following bands, all with "Plastic" somewhere in their names. And I couldn't resist adding some snarky comments too.
  1. Arthur Loves Plastic (Don't we all?)
  2. Bigger Than Plastic
  3. British Plastic (You say polythene and I say polyethylene...)
  4. Deep on Plastic
  5. Discount Plastic Surgery (Never, never a good idea)
  6. Faith in Plastics (In God we Trust, all other pay with plastic)
  7. Facing the Plastic (Is this a torture devised by Dick Cheney?)
  8. Fantastic Plastic Machine (A six-stringed extruder? A resin dryer/bass drum combo?)
  9. Frozen Plastic (Was "Glass Transition" already taken?)
  10. Future in Plastics (What Mr. McGuire promised)
  11. Heavy Plastic (Metal filled, I'm assuming)
  12. Holly and Plastic
  13. Kitchen and the Plastic Spoons
  14. Liquid for Plastics (Nice to see reactive polymers aren't forgotten)
  15. Little Plastic Pilots
  16. Mars Plastic (If NASA is going to look for life on Mars, look for some plastic too!)
  17. More Plastic
  18. My Plastic Jon Benet Doll (Sick, really sick.)
  19. P. Skunk Willy and the Plastic Crumb Toppings
  20. Paper or Plastic (There should be a question mark,right?)
  21. Perfect in Plastic
  22. Pete Plastic
  23. Plastic (Gee, how long did it take you to come up with that name?)
  24. Plastic Angel
  25. Plastic Art Foundation
  26. Plastic Assault
  27. Plastic Avengers
  28. Plastic Babies
  29. Plastic Bag (If a city bans plastic bags, does that apply to this band too?)
  30. Plastic Bastard
  31. Plastic Bertrand

  32. Plastic Birds (Such as Pink Flamingos?)

  33. Plastic Bob (Any relation to Pete? (#22 on this list))

  34. Plastic Boy

  35. Plastic Chord (Is it the lost one the Moody Blues were looking for)

  36. Plastic City Play

  37. Plastic Clock Radio

  38. Plastic Cloud (What you get when there is an explosion by the hoppers)

  39. Plastic Constellations (such as the Big Hopper and the Little Hopper)

  40. Plastic Crimewave Sound (There's a lot of bands on this list that fit that description)

  41. Plastic D'Amour

  42. Plastic Dog

  43. Plastic Eaters (Happily munching on all those new biodegradable plastics)

  44. Plastic Fantastic

  45. Plastic Fruit

  46. Plastic Happiness

  47. Plastic Heroes

  48. Plastic Jesus (As with "Plastic", not much thought here)

  49. Plastic Joe

  50. Plastic Lite

  51. Plastic Little

  52. Plastic Love (The English version of "Plastic D'Amour")

  53. Plastic Mastery (Something we should all be seeking)

  54. Plastic Mode

  55. Plastic Nebraska

  56. Plastic Noise Experience

  57. Plastic Operator

  58. Plastic Orgasm People (Not Safe for the Work Place)

  59. Plastic Palace Alice

  60. Plastic Pals

  61. Plastic Parachute

  62. Plastic Park

  63. Plastic Parts Band

  64. Plastic Penny

  65. Plastic People of the Universe (Seriously, these guys were/are still very good. And Powerful.)

  66. Plastic Pioneers ("We've got Flory up front, Natta on lead, Carothers on bass, and you gotta see Staudinger on drums!")

  67. Plastic Princess

  68. Plastic Rose

  69. Plastic Saints

  70. Plastic Septet

  71. Plastic Shapes

  72. Plastic Soul Band

  73. Plastic Sound

  74. Plastic Soy Sauce ("Waiter, there's plastic in my soy sauce")

  75. Plastic Submarine (Yellow, perhaps?)

  76. Plastic Surgery Again, so original)

  77. Plastic Surprise

  78. Plastic Theatre Art

  79. Plastic Toys

  80. Plastic Tree

  81. Plastic Venus

  82. Plastic Voice

  83. Plastic Wooden Fruit ("Wood-Polymer Composite" is the correct term)

  84. Plastic Zoo

  85. Plastics (Please, put some thought into your band name!)
  86. Plastics Hi-Fi

  87. Pull's Plastic Playground

  88. Red Plastic Bag

  89. Red Plastic Buddha

  90. Social Plastic

  91. Static and Plastic Dust

  92. Suddenly Plastic

  93. Super Elastic Bubble Plastic

  94. Tracy and the Plastics

  95. Susan Gilbert and Plastic Duck

  96. Vibralux Mercury Mad and the Plastic Bitches

  97. Wicked Plastic

  98. Yazz and the Plastic Population

  99. Yolanda and the Plastic Family

I don't own a single album or song by any of these bands.

Thursday, May 06, 2010

Mistaken Identity

I thought I might have run into an old buddy the other day, flow-induced crystallization, but I was in error. [1] I was running a constant temperature DMA on some new plastic materials under development and in the plot of viscosity over time saw this:
Many materials will show an increase in viscosity over time – any system that cures (epoxies, reactive polyesters, styrene-ester systems…), as well as materials that crosslink upon excessive heat. But this was a simple thermoplastic that wasn’t expected to have such a reaction running around. So what was causing this massive increase at a temperature in which the polymer was molten?

One possibility was flow-induced crystallization (FIC), a term that describes crystallization that results from flow. [2] Without the flow, the crystallization would not have occurred as the temperature of the polymer would be too high. The flow field is able to partially orient the polymer, (extensional fields work so much better for this than shear fields) and in doing so, reduce the entropy change in the transition from melt to crystal. Now recall with me from your wonderful days in chemical thermodynamics that at equilibrium,

DS = DH/T

Since DS has decreased while DH hasn’t, T must increase. i.e., the temperature at which the melt crystallizes is higher than normal. And so the flow field can cause crystallization at temperatures higher than those at which it would normally occur.

The sample was being sheared continuously during the testing, so it is possible that this might have induced crystallization. [3] However, a few more tests allowed us to rule this out. First, the viscosity increases that we saw occurred faster as the temperature increased - even in the somewhat odd world of flow-induced crystallization, this doesn't happen anymore than it happens in the quiescent world. The real killer however, was what we saw when the plastic sample was kept at the constant temperature without the shear for most of the induction period noted above, and then the shear was started up: the initial viscosity was already at the elevated level, forcing us to conclude that the oscillatory shear was in fact inhibiting the viscosity climb.

So what I thought was an old buddy was actually a case of mistaken identity.

[1] I say old buddy as my dissertation was in the area of flow-induced crystallization. I have run into it more than a few times in my professional career, so this buddy does call from time to time, but it’s not like I’ve friended him on Facebook or anything.

[2] “Flow” in this case is a broad term meaning any applied mechanical stress or strain. Some researchers will even use the specific terms “strain-induced” or “stress-induced”. It’s still the same phenomenon underneath.

[3] The shear was oscillatory and I was working in the linear region. Both of these constraints that would have made it more difficult to create the orientation needed.

Wednesday, May 05, 2010

GM up to its old tricks?

I can read a lot into this headline:

Can you?

If you are familiar with GM and the buying strategies they have used in the past, then this is not a surprise. The automaker is looking to have a list of pre-approved resins – worldwide at that – from which they will allow their parts to be made.

From the company’s perspective, they claim they will gain many advantages:
  • worldwide coordination of supplies
  • common shrinkage to control tolerances (?!?!)
  • faster design of new parts

  • Here’s my thoughts on these three ideas:
  • Since GM will be buying larger quantities of fewer materials, they will be able to exert even more price pressure on the suppliers. And since the suppliers will really want their resins to continue to be on the approved list, it will be significant pressure. Same old same old.
  • What drugs are they taking? This is absolutely insane. Amorphous plastics inherently – meaning that it is a fundamental physical property – shrink less than crystalline polymers. Crystals are more densely packed than glasses, so the same mass of a crystalline plastic will occupy less space than an amorphous, glassy material, so there will always be differences in shrinkage.
  • You can design the parts as fast as you want, the testing of the parts will determine the viability. Some of the testing can be simulated (tensile testing) but no computer model will be able to tell you the survivability of a plastic exposed to hot oil or antifreeze or brake fluid. These are the real world simulations that are needed to ensure product durability, not something that can be run on a FEA model.

  • Having worked in a large corporation that also tried to cut down on the number of raw materials it was using, I predict that the list will quickly fail. Some designer will need a resin, and find that some resin not on the list will work and will work at a lower cost than some resin on the list. While the approved resin will initially be used, a period of cost-cutting will quickly follow and the alternate resin will get added to the list. And so the list will grow.

    At the end of the day, the only thing left from the wish list above will be the somewhat improved purchasing power of GM, something that they have been known for for decades. Bankruptcy has not changed their modus operandi.

    The Pink Flamingos are coming home

    Most people think of “intellectual property” as heady stuff – state-of-the-art patents, trade secrets…Not pink flamingos. Apparently that is not the case. As reported in Plastics News (May 3, 2010), a Massachusetts company has purchased “…the intellectual property rights to the pink flamingo, as well as more than 200 blow molds and injection molds…”

    I imagine the IP is the design, trademarks and copyright, which in some cases is quite valuable. Maybe not so here. I suspect that this is also one of those legally allowed monopolies that exist throughout the country, where there is only one manufacturer, but it is not an issue for the government since the demand is small and elastic.

    The flamingos were originally made in Massachusetts, but production moved to New York in 2006 after the original manufacturer went bankrupt, so this is a move home for the kitschy artwork.

    The Big Oil Leak

    Most news outlets provide very little technical details on the engineering issues of the leaking oil rig. I found "The Oil Drum" to be a very good site, and this article in particular (although all of their articles seem pretty good). If you're reading this blog, you have the fluid mechanics necessary to understand the issues.

    Tuesday, May 04, 2010

    Photocatalytic Reduction

    Sure enough, reduction can occur occur on photocatalysts. I had previously seen only oxidation, but something as simple as conversion of CO2 to CH4 can be done on TiO2 surfaces. And there's lots more examples out there. So now I know. (You too.)

    Graphical Abstracts

    When graphical abstracts first appeared a few years ago, they were exciting as they appeared to provide at a glance information about a research report, all without having to read the abstract, which was also designed to provide quick information about a research report without having to read the report. So now the chain of events is 1)look at the picture 2) if that looks good, look at the title, 3) if that looks good, look at the abstract, 4) if that looks good, read the article. Steps 1 and 2 can be interchanged of course, and in my experience, step 4 can be broken into additional substeps 4a) download the article 4b) print out the article 4c) put the article one of the big stacks of other previously downloaded articles 4d) eventually forget about the article until it is rediscovered at some future date which ransacking the piles looking for an article that I recalled having.

    Far more than article titles, their abstracts and even the articles themselves, the quality of the graphical abstracts varies greatly. Look at this one from Macromolecules: It certainly is eye catching with the colored liquids, but what does it tell you about the research? The chemical structure that is drawn on the two pictures obviously cleaves the COOH group, forming CO2 which is then driven to the container on the right[*]. But what happens to the H atom? It appears to transfer to the ketone, so then how does the Na2CO3 on the right become NaHCO3? Why is there an unbalanced equation in the graphical abstract?.

    Regardless, all of this represents a lot of thought, not what is supposed to happen with the graphical abstract. I get the feeling that it is one of those "supply the caption" contests where a cartoon is drawn but without a caption.

    Or look at this graphical abstract for comparison: Not very helpful on its own, but at least it isn't confusing as the one above is. It's a Ramen spec of whatever polymer was being studied.

    Graphical abstracts can be a welcomed addition. I find them vary helpful in communication chemical structures - the picture can quiokly tell about the molecule far quicker than the name. But in many or even most cases, they are not helpful and are a waste of space - electronic, cellulosic or otherwise. The RSS feed from the ACS only has the title and the graphical abstract, so I either have to click through to the abstract (often finding that the article only a short communication without an abstract) or play this guessing game.

    [*] I don't know about you, but I think that if my polymerization reaction is generating CO2, I certainly don't want that going on when I am preparing a solid polymer such as the PMMA being formed on the left. How do I know it is PMMA? I read the abstract..

    Monday, May 03, 2010

    Lost Golf Balls

    Golf balls are almost purely polymeric, what with the Surlyn coatings, the rubber windings and the rubber enclosing the liquid. (I used to love cutting open golf balls when I was young - except for the solid one-piece balls which were boring. Compare that with the excitement of having stretch rubber flying everywhere as you rapidly attack the ball with a hacksaw.)

    And yet very few golf balls are disposed of in the trash. Maybe the pros can keep a ball long enough that they decide to toss it, but for the rest of us, we shoot them until we lose them. And that ends up being a huge amount of balls, some 300 million in the US alone. And since very few are kept or disposed of in the trash, I have to believe that 299 million of those are lost every year.

    Of course, the ultmate lost golf balls would be the two golf balls on the moon - although I would guess that after 29+ years of continuous exposure (even with half of it was during the long lunar nights) very little resiliancy is left in them. All the polymer chains must be scissioned into near nothingness.

    Recycling Bubblegum


    There is no breakthrough technology here. It's just a simple concept, but points out the tremendous value of good design: a gum recycling bin which itself is made from recycled gum and appropriately call "The Gum Drop". Looking at the designer's website, it is clear that she is an innovative designer, forever emphasizing simplicity and understanding how humans interact with the materials in their environment. She also is not afraid to use plastics.