Nanophase Materials

Chris Phoenix is providing live blog coverage for us on all the presentations from an important conference on Productive Nanosystems: Launching the Technology Roadmap...

Next talk: "Nanophase Materials. A Persistent Enabler" - Dennis W. Smith, Jr., Department of Chemistry, Clemson University

Welcome to the second day of live-blogging the Productive Nanosystems conference. The first talk is about "recent examples of functional nanosystems related to polymer synthesis and applications in photonics, energy conversion, and renewable materials." (By the way, the agenda for the day can be found on the SME website.)

Dennis does polymer chemistry. A good quote: "Dear Colleague, Leave the concept of large molecules well alone ... there can be no such thing as a macromolecule." Advice given to Hermann Staudinger, future Nobelist, in 1920. Mike Treder starts his talks with a bunch of quotes about how flying machines are impossible and the world only needs five computers. This might be a good quote to add to the list, especially since a diamondoid nanomachine component is essentially a *really* large, highly crosslinked, macromolecule.

A diblock copolymer is two different polymer molecules joined together. They self-assemble into intricate semi-regular structures. Most pictures of them look pretty randomly wavy, but he showed a couple of pictures of "guided self-assembly" with very straight lines and sharp angles. That's cool.

Diblock copolymers may be useful for fuel cell membranes; they can create several different "zones" in the material.

Polymeric nanocomposites are about putting nanoparticles in plastics instead of larger "fillers" that have been used for a while. They can make the plastic work better. Nanotubes can have more interesting chemistry than e.g. carbon black (also a nanoparticle). There's apparently a chemical interaction going on between the nanotube and the polymer (polyaniline) - not just non-covalent interaction. And you can make clear, electrically conductive polymers. In a piezoelectric plastic, 0.05% nanotubes increases performance by seven-fold.

BODA can be turned into aromatic molecules, then reacted with carbon nano-onions (which hasn't been done before, because the onion surface is very graphite-like), which is nice because it solubilizes the onions, and onions are photoreceptive.

Can make carbon nano foams for electrolytes.

Can make photonic materials by putting spheres into an array. You can put polystyrene into rubber(?), making a photonic crystal. Then when you stretch it, the bandgap (color) changes. You can make versions that respond to solvent.

Can build polymers that detect specific anions. Sulfonate membranes to make fuel cells. Functionalize nanoparticles. Build low surface energy materials (nano-roughness) (so dirt doesn't stick) (may also have useful optical properties, I think).

POSS: well-defined molecules that are big enough to be nanoparticles. Fluorinated POSS is especially interesting. They dissolve well in fluoropolymers (e.g. Teflon) and make it easier to handle and give it interesting properties.

So, there's lots of materials and chemicals and substances with tweakable properties. Most of this doesn't seem directly relevant to general-purpose molecular manufacturing, but any little thing may turn out to be useful. I'm guessing that this sort of work will feed into basic science for spinoff designs, rather than bulk polymers being incorporated directly into atom-precise nanomachines.

Chris Phoenix

Tags: nanotechnology nanotech nano science technology ethics weblog blog