How to Kill a Project

We've been at the point where you keep working on a project and not getting the results that you want, so you keep trying. With more and more chemicals available all the time, (and more literature to read too), it's pretty tough to completely run out of ideas and call it quits. If you ever do throw in the towel, there will always be that nagging thought that if you had just given it one more try, it might have worked out. Or worse yet, if someone else had come along, they might have tried something that we overlooked. [*]

But I managed to find a true "deader than a vampire with a silver stake in it's heart" solution to one such nagging project last week.

For reasons that will remain largely unnamed, I was trying to use UV light to crosslink a protein with the hope of achieving a certain rheological result. After trying endless amounts of photosensitive chemicals and failing to achieve what I wanted, I was starting to get the feelings I stated above: is this ever going to work and how would I know when to stop. Then it hit me: go for the acid, go for the throat, let's pin this guy to the mat and see if it still can get up.

Glutaraldehyde is well known for crosslinking proteins with a vengeance.

It's fast (enough), effective and has been used since the '50s for this purpose. And now you might see where I was going: I used glutaraldehyde to crosslink the protein. At that point, I still didn't see the rheology results I wanted, so I knew that there was no hope from the UV approach.

Glutaraldehyde is also rather dangerous, as it doesn't really care whether the protein is dead or alive, so proper handling of the chemical is essential, and that's why I never used it in the first place - our client was not set up to handle such a chemical. Adding UV crosslinking agents (and crosslinking them) is different - the chemicals are a much lower risk and UV lights can be effectively shielded against with minimal PPE and training.

So in the end, I got the result I wanted, well not really. I would have loved to see the project succeed, but in this case, I could confidently walk away from it and know that it would never work - and I have the proof I needed. That is something all to rare in this profession.

[*] We certainly have plenty of clients who have said "we tried that approach and it didn't work". I love hearing that as what it really means is that "we tried whatever we could think of and it didn't work", and it is amazing how many times we can get it to work.

Highly Accelerated Aging

There's a report out (open access for all of 2011) about a new technique for rapidly accelerating the UV aging of coatings, in this particular study, exterior acrylic paints. Small pieces of paint (0.75 mm diameter) are exposed to UV light (Xe-Hg lamp) in a pyrolysis tube attached to a GCMS, allowing for analysis of the coating. One of the claimed results is quite amazing: that 10 hours of exposure to the Xe-Hg lamp is equal to 1000 hours exposure [*] to a metal halide lamp!

I have two issues with the report. 1) A natural exposure was never run, and 2) there was no discussion or even mention of what the exposed paint looked like!

Long-time readers of this blog will know that I am always leery of any claims of huge acceleration factors (huge being anything in double digits or more), so a 100x increase over an already accelerated exposure (the metal halide lamp irradiance between 300 and 400 nm was 75 mW/cm² = 750 W/m² which already 10x the normal exposure levels) is particularly challenging to swallow without further support - a control tested to actual outdoor exposure.

But how about including a snapshot or two of what the final exposed paint looked like? I'd love to know if what was left even looked like paint or was it more like the Flanders fields in 1918?Just one image of the final paint could be enough to justify the extreme exposures given to the samples and the corresponding claims. Until then, I remain a skeptic.

[*] The exposure time was broken into 8 hour cycles with 4 hours of irradiation followed by 4 hours of moisture condensation and no irradiation.

Self Selection of a Polymer Career

One brief line in last week's post on a career in polymer science/engineering needs further comment. I said

"Just the fact that you are interested in polymers will offset you from everyone else."

but I'm wondering if this is still as true as it was 20 years ago. At that point in time, polymers were considered this dirty little, problematic area. The fact that a polymer didn't have a precisely defined molecular weight certainly put off many people to start with, and then add in the non-Newtonian fluid mechanics and you pretty much had huge walls around the subject, and so that is why I reached the conclusion that I stated above. If you were interested in polymers, you could do it because few others would express the interest.

An example: One of my contemporaries in grad school did his work in surface science, but was able to garner a job for a large polymer company because 1) he had taken an undergraduate class in polymers and 2) told the recruiters he was interested in returning to the field. I was amazed that they took him in (and even more so since I had interview for the same job. Ouch!).

So my question is this: have things changed? Does polymer science/engineering still have the skull-and-crossbones signs labeled "KEEP OUT (THIS MEANS YOU)!" at the entrance? Do people look at you weird and shake their heads when they find out your career choice? Or have things gotten better?

How to (not) Become a Polymer Engineer

What is reported at this website is certainly not the advice I would give.

Step One: Obtain a Bachelor's of Science in Engineering
...The first step for becoming a polymer engineer is to complete a bachelor's of science degree program in engineering. Many schools offer chemical engineering degrees that will give potential engineers a good basic overview of polymers, but some schools offer even more highly specialized degrees in polymer engineering. A degree program in polymer engineering will provide students with in-depth knowledge into the behavior of polymer materials during processing.

Can't argue with any of that. If you can get an undergraduate degree in polymers, go for it, otherwise ChemE or MechE is a good option, but be sure to take whatever classes in polymers that you can (not overlooking a polymer chemistry class that might be available in the chemistry department). Just the fact that you are interested in polymers will offset you from everyone else.

Step Two: Find an Internship
Finding an internship will provide a potential polymer engineer with a competitive edge on the job market. The appropriate internship may be found in many different research laboratories for companies and manufacturers working with polymers. According to the University of Oregon, nearly 70% of all chemists and chemical engineers work in the polymer industry (www.uoregon.edu). During an internship potential engineers will see how scientists conduct their studies and apply their knowledge to solve actual problems.

This is step 2? This should be done while you are still in school, not afterwards. And what's up with this 70% figure? There is no way that that number is that high. If it were, there would be little point in this article as the odds are nearly 3-to-1 that you will end up working in polymers anyway.

Step Three: Consider Licensure
Although it is not a requirement for polymer engineers to become licensed, earning a Professional Engineer (PE) title will provide an engineer with more career options and the possibility for greater responsibilities. As a PE, an engineer is able to submit bids for government grants, work as a consultant and work with the public on projects.

Don't. I can't see that would do you any good. What public works are so heavily polymer oriented? Sure, polymers are being used more and more by civil engineers - adhesives for instance, and oh boy do CivE's need to know more about how they work and fail, such as what happened in the Big Dig a few years back, but if you are going to be doing work like this, you will be first and foremost a Civil Engineer, not a polymer engineer. So no, I would not recommend licensure.

Step Four: Find Entry-Level Work
The many different positions held by polymer engineers create a wide variance in the requirements for job openings. Polymer engineers may be employed by local, state or federal government agencies to aid in the regulation and clean up of polymers deemed harmful to the environment. The many companies that use polymers in the manufacturing of their products often employ a team of polymer engineers to help them use polymers in safe, effective and profitable ways.

Now we're talking. But a polymer engineer being used to "clean up polymers deemed harmful to the environment"? Is this environmental correctness being taken to an extreme?

Step Five: Consider a Graduate Degree in Engineering
Many upper level research and teaching positions will require a polymer engineer to go on to earn a postgraduate degree. Depending on the position desired after school, an engineer would need to complete either a Master's of Science or a Doctor of Philosophy (Ph.D.) in polymer engineering. These programs are found at most major universities and teach students the complex functions and applications of polymers.

Right on. This worked out well for me, but I recognize that grad school is not for everyone, and certainly have an advanced degree can make it seem like you have fewer options than if you didn't have one, so I would definitely emphasize the word "consider".

So, in summary, step two should be done simultaneously with step one and skip step three entirely. And remember that your employment options are far more than what few choices were given above.

A Single Phase Gel from Buckyballs?

Gels are one of the rheological nightmares: not only are they more difficult to make measurements on, but even defining a gel is a unresolved issue. The great P.J. Flory, in his 1974 Introductory Lecture for the Faraday Discussions pretty much gave up on a literal definition and went with a working definition, breaking gels into 4 classes. One issue that he also mentions, but doesn't resolve is the need for 2-phases as was proposed by Hermans (oh it is so much fun to do such name dropping today!). Flory wasn't a fan of the 2-phase requirement as he thought vulcanized rubber, aerogels and other 1-phase materials should be considered gels too. While there hasn't ever been a clear resolution to the matter, the existence of 1-phase gels and their supporters are clearly in the minority. [*]

Regardless of the definition, there is a new report (open access) that C₆₀, a.k.a. Buckyballs, are capable of forming a gel just by themselves. At least in a computer simulation that lasted only 100 ns. Still, this is something that should be looked into further - it should be relatively easy to do. Assuming the gel state can be verified, would it be good for anything? Given the track record for C₆₀, probably not. But are there other materials out there for which a 1-phase gel state would be useful? That is the real question.

[*] Personally, I support the 2-phase concept. I'd call 1 the one-phase materials listed above as "gellable", but that is very much me. I am comfortable with whatever terms people are already using, except for those that use the term too broadly (a whole other subject).

Mud Rheology and Dinosaur Tracks

A new report (pay-per-view) discusses why there are so few dinosaur tracks: in order for a track to form, the rheology of the mud has to be "just right", with the "just right" conditions being different for each dinosaur.

Admittedly I have not read the report (sorry, we don't have subscription to it here at work and I don't think I can convince anyone here that it is work related either), but based on the abstract and a popular press article you can put some of the pieces together, although I wish I could see more about what they used for the rheology properties of the mud. For instance, the abstract states:

Ideal, semi-infinite elastic–plastic substrates displayed a ‘Goldilocks’ quality where only a narrow range of loads could produce tracks, given that small animals failed to indent the substrate, and larger animals would be unable to traverse the area without becoming mired.

But I would imagine that if the mud were very soft, it would also relax and destroy the track. Swallowing up an entire animal would be something that could happen only in a deep mud pit.

Maybe I'll just have to ask a few of my older colleagues around here about what it was really like.

Not Invented Here, or Not?

You certainly heard the phrase before: "Not Invented Here", referring to the way that product developers have disdain for what their competitors make. I've thought it results largely from pride. We certainly see it in our work here at Aspen with a few clients - we are not consultants (we work for a living!) but we are still an outsider and so whatever we propose can sometimes be met with icy cold resistance. (Granted, in some cases, it is because the client's technical staff perceives us as a threat - we are doing something that they were hired to do and so they wonder how long the client will keep them around if we solve all their problems.) But as I said, this attitude is very pervasive and has been around for decades. It also can be good money for us. We have one client right now who decided in a big way to get into a market that has many little players in it. Rather than copying and slightly improving what exists, they have decided to start fresh. Consequently, they are repeating the entire learning curve that their competitors have already been through.

What is less common and even more shocking to me however, is the "Invented Here" attitude, where people have profound adoration for a competitor's ideas and products, and feel nothing but contempt for their own. I've only seen it only a couple of times, and it is quite strange, usually arising where sales/marketing/management has been burned too many times (i.e., once) by the technical team, and are unwilling to take another chance on them again. What I never understand is if the internal trust isn't there, why are the sales/marketing/management people still there? Why not move over to the competitors that they so admire? I suspect that even if such changes were made, it wouldn't be long before the "Invented Here" syndrome would take over again. It's just something that seems to be genetic and can't be avoided. And there is also good money in these situations too, as anything we bring in fits the requirements that it be from outside the company.

Top Killing with Oobleck?

Physics Review Letters has a new research article (open access) suggesting, no, make that strongly suggesting that the Deepwater Horizon oil spill this last summer could have easily been stopped by a top kill of cornstarch and water - that magical mix of dilatancy commonly call Oobleck, a term invented by Dr. Suess.

The research is fairly simple: they found that when the mixture is poured into a column of mineral oil, the strand doesn't break up, a critical requirement for achieving a top kill. As long as the fluid stays together, it will eventually fill the well and block flow.
I think the article is a little strange in that it is so oriented towards a top kill and not on what was really discovered. Additionally, there are huge gaps between this initial discovery and the intended application, including temperature (this work was done at RT, the external conditions at the bottom of the Gulf were near freezing, while the exuding petroleum was probably pretty warm although I don't know this for a fact)and also the large differences both chemically and rheologically between crude oil and mineral oil. It's a nice first step and others can certainly begin to study the applicability further for the next time a top kill is needed, which hopefully is not for a very long time.

Gluing Feathers on a Bird

Hopefully this poor little bird doesn't end up as a modern day Icarus: A kestrel bird was recovered from captivity in Australia and was found to have it's wings clipped. There is a planned "recovery" to allow the bird to return to the wild of it's own powers:

"Feathers from a dead kestrel will be spliced with bamboo pins and epoxy resin to the feathers of the young bird, which should be able to fly again within a few days of the operation."

No the question is which epoxy is being used. Certainly the sales and marketing people behind the manufacturer would love to know, giving them so good PR and maybe even a new marketing tagline. Something like "you can soar with the eagles with our epoxy".

Peanut Butter Rheology

Soft Matter, has short report [1] (3 pages) about the rheology of peanut butter, but from a rather odd perspective, that of a metallurgist [2]. We all know that peanut butter has a yield point, a point (defined by either a stress or a strain) that the material needs to be deformed beyond in order for it to flow. Here the authors of this report go one step further and put a good deal of time into showing that peanut butter (creamy, not chunky) also shows work hardening - once the "flow" regime is reached, the material now has a higher yield point than it initially did.

I used the phrase "good deal of time" for a reason: they let the peanut butter sit in the rheometer for 2 hours before making any measurement. This was necessary to let any residual stress from the sample preparation completely relax.

I would imagine that chunky peanut butter would give similar results, but making the measurements would be much more challenging. Both creamy and chunky peanut butter have a base made up of a large amount (64 wt.% in this case) of fine peanut particles (3.9 μ), but the large chunks could be quite a hassle to work with in a rheometer - they sample thickness needs to be significantly larger than the largest chunk size so that it doesn't protrude from on either edge.

So next time you are making a PB & J sandwich for your significant other or your children (grilled ones, of course, are the best), be sure to tell them all about the work hardening that is occurring right in front of their eyes. They'll thank you for the knowledge and be even more impressed with your intellect, won't they?

[1] Open access until March 4, 2011, but only after free registration Tip of the hat to the Soft Matter blog for highlighting the article and providing open access. The Royal Society of Chemistry is doing this for all their journals, something that should be emulated on this side of the pond. It's another reason I am only too happy to review articles for the RSC.

[2] Given that I work with 3 metallurgists, I am perfectly entitled to say they have a rather odd perspective on rheology. They do!!

Polymers and Divorce

The title is quite the odd combination don't you think?

And yet it is appearing more and more across the internet. Last week there was the Polymer Game, a "cooperative-competitive game for couples [*], and last fall Plastics News reported that extruder operators were #5 on the list of occupations with the highest divorce rate.

Very odd. Very, very odd.

[*} and what does this have to do with polymers at all?

Withholding Information

My wife and I love to cook. Over the weekend, we discovered something about a famous chef that we thought was a little unusual: this chef's best recipes are in the books that he/she publishes; the recipes available (for free) on line are not anywhere near as good in quality. We both thought this was a really good way to trash your branding.

But then the thought occurred to me: do I do this with this blog? Give out better advice to paying clients than the free stuff available here? (And for that matter, do other bloggers?)

My first thought is no, although the longer I think about it, the more I temper it. Certainly if I do water down the information here, it is not deliberate; it is not an effort to withhold information with the thought that if you want to get it all, you have to pay up. Rather, I think it is a compromise to the restraints of the media. Blogs have only limited space for conveying information, and I expect that readers have only a short time period to read any particular post. I know I do. Long diatribes that require hitting the vertical scroll bar more than once scare me off (particularly if I'm at work) and so I suspect it is the same for others. I try and portray the information accurately, but completely?, well that is just not going to happen.

I think (hope) that most of you can appreciate the difference. A chef publishing second rate recipe is totally different, as a proper recipe could be published in just as easily as the diminished one. Scientific completeness? Even entire books about a subject are never complete, but not by choice.

Bye Bye Mercury Thermometers

In what is probably the final death knell for mercury thermometers, the National Institute of Science and Technology will no longer calibrate them. Unlike the passing of many other artifacts from my youth, I don't think I will miss them very much, although kids these days now are taught to be so paranoid of elemental mercury that they will never know the pure fun of rolling quicksilver around on a countertop.

Being made of glass, they were prone to breaking, and then cleaning them up could be quite the mess. I recall TAing the unit operations lab class at Illinois where we had a large (30 foot (?)) glass distillation column that had tongues into which mercury thermometers were placed to measure the temperature at various elevations in the column. Of course they broke often and the mercury pooled at the bottom, exposed to the heat of the column until we pulled it out with a vacuum.

During that same time period, another researcher in our group gathered up all the mercury that he could find in the department and took it to the recycling center. He ended up with quite a bit of money which then provided the donuts for a couple of years worth of group meetings.

Aspen Research is Dead! Long Live Aspen Research!

Breaking News:

"February 3, 2011
To Our Valued Customers and Partners:
I am pleased to announce that Aspen Research Corp. has finalized a sale agreement with Aspen Acquisition Corp. (AAC), a local investor group made up of very experienced and successful business professionals. We have been working with AAC for several months and are extremely excited to have completed this transaction with them. It is clear to me and to all of us here that they have a deep appreciation for this organization, its mission and its many talented associates. This transaction will greatly enhance our ability to develop and deliver unique solutions to you. In the days and weeks ahead, we will communicate more about the exciting opportunities that are unfolding.

Your experience working with us will not change. Our name remains the same, as does our physical location and our professional team. We will continue to deliver sound science and cutting edge technical solutions. However, we want you to know that during a brief period from Friday afternoon (February 4) until Tuesday morning (February 8) you might experience temporary phone and e-mail interruptions during the switch-over of our telecommunications and Internet services.
During this period, if you cannot reach us and need to speak to someone immediately please call (651) 436-1340 or email us at innovationman@comcast.net.

On February 7th our new main phone number will be (651) 842-6100 and our fax will be (651) 842-6199. All the e-mail addresses will be the same as they are today. We will send out more contact information once our technical transition is completed.

For 25 years, Aspen Research Corp. has delivered customized research, product and material solutions to meet the needs of our customers. We thank you for your continued support during this new and exciting time. We look forward to speaking with you about your needs now and in the future."

While I've never been threw a spin-off before, I can state that we are all pretty amped about this - there is real excitement in my colleagues. It would be endless fun to publish a vitriolic spree on all the examples of poor stewardship provided by our previous owners, but what's the point? [*] The new guys are already spending money on new equipment and see the potential value that all of us here have seen for decades, so it seems like a great match. It's time to fly!

As you read, internet connectivity might be spotty for me for a few days and so it might be for blogging too. The most important question to me is: will we get a new logo?

[*] It's also been amazing to me how many clients have expressed concern that we were owned by Andersen, despite there truly being a full arm's length between us (and 14 miles of terrain!). As part of the sale, we can't do any fenestration work for 2 years, so sorry to Marvin, Pella and all the others. We'll be in touch in 2013.

Nitrogen Filling Tires

I had heard of filling tires with nitrogen, but pretty much blew off the whole subject as just a new way for people to be separated from money that can be better spent elsewhere. A massive 6 page article on a segment of the subject appears in the January 24, 2011 issue of Rubber and Plastics News, focusing mostly on the diffusion of oxygen and nitrogen into and out of a tire. I won't get into most of the details [1], but I am far more interested in the complexity of the subject that I never had given much thought to.

Surprisingly, the subject appears to have been ignored by serious academic researchers. It's mostly independent consulting engineers who have done the research, but in scrolling through their efforts, I really am not convinced any of it has been done correctly.

My interest would be almost entirely on whether internal oxidation [2] can be avoided by filling the tire with nitrogen, although I'm not even sure that this is that significant of a issue. I don't recall and haven't ever met anyone who lost a tire due to internal oxidation, although arguably some blowouts may have been the result of it. I would speculate that 99.999+ percentage of tires are replaced because of tread wear and external damage that cannot be repaired. So on that basis alone, is it even worth the effort to study it?

As I said, the complexity of the problem certainly would make it an interesting academic exercise, but that complexity is pretty much ignored by those who have studied it so far. The most common approach has been to take a tire, fill it with varying amounts of O₂ and N₂, heat it to 60 ^oC and see what happens. Nice try, but anyone who has worked with accelerated aging test knows that these tests, in the words of the Wicked Witch of the West, have to be done "Carefully...carefully". Jungle tests - exposing a part to extreme conditions - can produce totally erroneous results, something I've seen here at Aspen Research, including one client who we helped win millions in a lawsuit from their supplier.

Let me give you one example: olefins under a UV light are routinely exposed to a 18 minute dark period in every 2 hour cycle. Why? It produces more accurate results. Without the dark cycle, the oxygen levels at the surface can become reduced, thereby producing a decrease in the oxidation rate, despite the increase exposure to the UV light.

So if you are going to test a tire, do it right. Cycle the temperatures up and down to simulate real world conditions until you can prove that a consistent high temperature is just fine.

But to me, the crux of the whole issue is to ignore all of the variables and focus on just one question: how much oxygen is needed to do damage? The surface area of a tire is limited, and unless the whole tire is completely evacuated of oxygen and kept that way in the future by topping it off with 100% nitrogen, there will be more than enough oxygen present to form a monolayer on the inner surface of the tire. That should be enough to initiate the oxidation and start the damage, which can propagate quite fine on its own for a while. But regardless of the purity of the nitrogen inside the tire, oxygen will continually diffuse into the tire so that a fresh supply will always be available to keep things moving along.

I'm not too optimistic about the outcome of this experiment, but it certainly should be run, as science is based on data and experimentation, not logical thoughts.

[1] As an aside, I question the validity of the results, as one of the main equations used in the calculations, #3, is flawed (dimensionally inconsistent) as presented. It may be a typo, or not; for today, it really doesn't matter.

[2] Oxidation on the external surfaces is going to happen no matter what you fill the tire with.

More on Baroplastics

Having only in the last week personally discovered baroplastics - diblock copolymers that flow when put under pressure - I happily ran across a use of these materials yesterday. A Korean team is using them as a mechnical information storage device, basically pressing the polymer with an AFM tip to create holes in the film. This invention also required the development of a new baroplastic that flows at only 60 bar pressure, much lower than the 300 bar pressure that all other baroplastics require.

As an aside, there are a few idiosyncracies in the article that appears to have been translated from Italian (or maybe Spanish), given that the materials of interest of called "baroplasticos". There is also another zinger at the end of the third paragraph: In discussing alternative technologies that previously accomplished the same end, the sentence reads "The big drawback was that the technology was really hot, she only worked at temperatures between 300 and 400 ° C." (Emphasis added)

My Kingdom for a Thermodynamicist

Rheology and thermodynamics are two areas of science that have some unique characteristics. They both are subjects that cut across wide ranges of science, rearing their ugly little heads in physics, chemistry, biology and wide ranges of engineering. This suggests their extreme importance. And yet, despite this importance and wide applicability, it is impossible (as far as I know) to earn a degree explicitly in those subjects. Sure, you can specialize in those areas while doing your doctorate, but have you ever see anyone with a Ph.D. in Thermodynamics, or a Masters in Rheology? Kinda odd, don't you think?

I've tried to come up with similar fields in this situation. The whole realm of "transport phenomenon" and the various subsets (heat, mass and momentum transfer [1] for those of not trained as chemical engineers) are one, although I'm not as convinced on the subsets by themselves. On the other hand, I've ruled out the idea of the Grand Unification Theory - any of the various attempts to unify the 4 fundamental forces (gravity, electromagnetism, strong nuclear force and weak nuclear force) as being just a part of physics [2] and not really applicable to chemistry, biology... Ditto for the String Hypothesis [3].

Scholarly journals present a mixed view of this matter. There are several journals devoted to just rheology (Journal of Rheology, Rheologica Acta,...) along with many scholarly societies devoted to rheology but thermodynamics isn't quite as well represented and I am not aware of any thermodynamics societies. And transport phenomena (as a whole) is totally without any journals or professional organizations, while the subsets are well represented.

As for the industrial world, I don't ever recall seeing job opening where these specializations are the leading or major component of the job description. Certainly you can see "rheology" far down the list for some positions, but have you ever see a job for a thermodynamicist? Even the people that are rheologist tend to carry that around as a sub-description as they usually have primary interests in a chemical/physical situation that gives rise to the rheology of interest.

So what does this all mean? What is the impact on us? All of us carry mental constructs around in our heads which we use to divide the world up and thereby give us a perspective on how we see things. Would the world be better off if you could major in thermodynamics? If we did have thermodynamicists?

[1] momentum transfer = fluid mechanics
[2] To anyone wanting to argue that chemistry and biology are both just applied physics, I've dealt with that reductio ad absurdum before.
[3] How can anyone call it String "Theory" when it hasn't been put it up to any experimentation yet?