Wednesday, January 30, 2008

Nanocoils

My husband works in what I consider to be the materials side of chemistry (he is currently the only chemist in a group of physicists), so even though I am an organic chemist at heart, I really enjoy reading about new developments in nanotechnology. Yesterday I came across a paper entitled "Conductive One-Handed Nanocoils by Coassembly of Hexabenzocoronenes..." and I actually thought it was pretty interesting. Coiled nanofibers have been made previously, but little is known about their conducting properties. This is mostly due to the fact that coiled assemblies of aromatic molecules are not overwhelmingly stable. If one could create coiled, single-handed, electroconductive nanostructures that were also stable, it would be possible to create tiny little electromagnets. Cool, huh?

Hexabenzocoronene (HBC) with alkyl and triethylene glycol substituents can self assemble into nanotubes; appending norbornene groups at the end of the triethylene glycol chains leads to the formation of both right- and left-handed helical nanocoils upon self assembly (1). While these nanocoils can be stabilized by subsequent ring-opening methathesis polymerization (ROMP) of the norbornene groups, they are actually only the kinetic product of self assembly. Without the ROMP stabilization, they are eventually converted into the more thermodynamically stable nanotubes. This all seems fascinating enough, but members of the Aida lab were able to take things a step further using what they call the "sergeant and soldier effect" to control the formation of left- or right-handed nanocoils. Doping the original HBC/norbornene construct (1) with as little as 20% of HBC with a shortened linker containing a chiral handle (either R or S) produced single-handed coils (S enantiomer --> left-handed coils, R-enantiomer --> right-handed coils). After doping with I2, the coils are also conductive. It only takes a few sergeants to control an army!


Sunday, January 27, 2008

Periodic Table of Sentiments

While elements like 18Is (I'm sorry) and 49Ty (Thank you) are certainly made up, I think that any chemist would get a chuckle out of receiving one of these lovely periodic table of sentiments cards from Pink Loves Brown...

Sunday, January 20, 2008

Chemistry on TV...

Today when I looked in the newspaper, I just happened to see an advertisement for this new show on AMC. I was so happy that both bromine and barium were pictured with the correct atomic number. Yay for the proper use of chemistry in the media!! Since I don't have cable, I won't be watching tonight, but from some of the pictures online, it seems that at least some chemistry might actually appear in the first episode. Bunsen burners, Erlenmeyer flasks, electron configurations, all that good stuff. Unfortunately safety doesn't seem to be a high priority. In the first picture, the high school chemistry teacher on "Breaking Bad" is shown in front of a flaming Bunsen burner without goggles. But I forgive them this time, as I did enjoy this quote from the show's blog: "Electrons change their energy levels. Molecules change their bonds. Elements combine and change into compounds. But that's all of life, right? It's the constant, it's the cycle." Yes, chemistry is life.

Friday, January 11, 2008

PCR, when you need to find out who the daddy is...

A biologist in my lab sent this out yesterday. It's from the Biorad website and only gets better the longer you listen. Enjoy.


video

Tuesday, January 8, 2008

Priceless...

My husband made a nice little visual aid to go along with the post from yesterday...

Monday, January 7, 2008

How much are you worth?

Some recent information to absorb (all rounded to the nearest thousand):

An average graduate student in the chemical sciences earns per year before taxes: $22,000 (wow, do i really get paid that much? it doesn't feel like it.)

Tuition paid per year on behalf of the graduate student: $12,000

Facilities and overhead paid per year on behalf of the graduate student: $13,000

Misc. expenses paid on behalf of the graduate student ("fringe"): $1,000

Being told that an average Ph.D. (assuming a full five year service) costs more than a quarter of a million dollars: PRICELESS