out of town

You may have noticed that my posting has been less than usual this month. I have been out of town at a wedding/family trip, and looking for work. So, forgive me, this will have to be a slow month.

TiO2

TiO2. Used for so many things. A report a couple of weeks ago in C&E news talked about how it is used in sunscreen. But I'd like to talk more about the compound in general here. What is it? How does it work?
Firstly-what is it?
A combination of titanium and 2 oxygen atoms. A solid crystal with a crystal structure.
How does that work? Shouldn't I have listed a structure? The way it works is that TiO2 has a variety of forms. The three most common ones are rultile and anatase and brookite. Anatase and Rutlie are tetrahedral. Brookite is orthorombic. Control over these forms can usually be accomplished in the design stage through temperature control at synthesis.
Which form do you want? That depends on your application.
Anatase is generally more reactive. The article I linked to above contains interesting experiments about sunscreens on metal. Anatase TiO2 was seen to increase radical production.
It is also used in solar cell designs.
Rutile is what seems to be better for sunscreens. Less reactive, it sticks to reflecting. Another common use is white paint. Reflecting all wavelengths of light ends up looking white. The UV reflectance gives TiO2 sunscreen capabilities.
Brookite, the last of our forms, is not white. It is a rare form, and doesn't seem to be commonly commercially used

Tensions in green classes

So, these past two weeks, I took the Society of Mechanical Engineers' Green Specialist certificate classes. Taking the test will be at some future time. One of the classes was "green chemistry". Now, I am in support of this idea-a lot of pretty harsh solvents don't need to be used nearly as much as they are, and looking for ways around that can be both good business sense and environmentally important. Because let's be honest, a 2 step process with 77% yield is an improvement on a 5 step process with 44%.
My problem, however, is the assumption in that class, and in the sustainability community in general that chemical free is even a legitimate term.
Water is a chemical. You can't sell something chemical free. Fear marketing like that is the reason I won't buy anything from Burt's Bee's-they have some ideas that I like(tea tree oil works better on my pimples than salicylic acid, but I'll get my own oil and mix it in other company's products-and this is as much personal info as needed on this blog) because I won't give them money to promote fear of my industry.
My other concern about the class is the image of chemists as misguided, not knowing what we do that may be harmful to the environment, "not understanding some of the risks". I would argue that most chemists have a better understanding than the public about the risks of most chemicals. We look at the MSDS. We have to learn what protective measures are important.
This idea also erases the contribution by many chemists looking specifically to do things like find a safer/more efficient route to synthesize ibuprofen, or looking to develop environmental remediation technologies. Or people like professors Vicki Grassian and Mark Young that I used to work with that study the effects of what we put in the atmosphere on the many process happening up there.

Things to take down

Maybe I'm just in a contrary mood today, but I am considering a list of chemical things that are annoying me.
This order is the order that I think of them, not meant to indicate anything else.
#1-Chemical free anything. A particular offender of this is Burt's Bee's. If you have something to put in your tube, it has a chemical.
#2-100% pure, when we're talking about a combination product. This usually seems to mean "pure"="natural" I don't know. But unless we're talking a single thing, pure seems like the wrong choice here.
#3 hair oil advertised as "sulfate free". Because there are no surfactants there anyway. This is technically true, so it annoys me a little bit less.
#4 Trans fat free skim milk. Really? Once again with the technically true, but I dream of enough scientific literacy in our population that this isn't an effective advertising strategy

Small

I worked with nanoscale materials-zeolites and magnetic iron- and just really enjoy tiny, hard to see particles. I tried to get my students to see atoms when teaching our AFM lab. So I've got a couple of reports on small things
1. Carbon nanotubes may not save the world-or specifically, may be linked to cancer

I know we're all shocked here, and I have suspicions about any single new cool technology. Nothing is perfect. That said, there are also a lot of things that can be linked to cancer. If I spent my days going around doing nothing that has ever been linked to cancer. . . well, I'd be stuck just in terms of vitamin D-too much sun=cancer. Not enough sun=not enough D=cancer. So I'm not convinced that we can live in a perfectly safe world, much as we'd like to.
Cool concept-actual 3D imaging of nanoparticles.
anyone seen the details?

Interesting question

Yet another C&E news post. They had an article in the July 4th issue about encouraging research in an environment like pharmaceutical development, where the stakes are reputed to be so high, and everything must go perfectly. And I have to wonder how much of that comes from this US living and dying by the stock market, by perceptions, and by the idea that stocks must only go up and up, and that short term loss, or even lack of short term gain is unacceptable. What do you think is the solution? Is there a better way to do this? How do we encourage people to come up with truly new ideas, if we have to admit that some truly new ideas don't work?

Question about sustainability that touches on chemistry

I got a link to the following that makes me . . . curious.

I find the basic concept, that worrying about only one thing is not actually indicative of overall sustainability or greenness very important. I rant a lot about the concept of food miles as the only ecological value of food(an extreme example of some locavore arguments, but not beyond the realm of possibility) and carbon as the only measure of product waste a lot. Some of that comes because a particular factor is easy to measure and easy to track. There is merit in tracking things that have numbers associated with them, particularly in the green movement. At least, that's my opinion as a scientist. Numbers and data ground observations in reality.
I am, though, not convinced that packaging doesn't matter, though. I feel like waste can be at least moderately prevented by careful buying. Do we really need to buy 2 weeks worth of groceries every time? Call me suspicious