Nano@Tech welcomes, Professor Seth Marder, director of the Center for Organic Photonics and Electronics at Georgia Tech, on "Tailoring the Properties of Interfaces with Organic Chemistry" as part of the educational seminar series.

If you plan on attending this seminar, please register here.

Abstract:
I will describe some work on the modification of surfaces with phosphonic acids, that can be used to improve compatibility of nanoparticles in polymers for fabrication of capacitors, as well as modification of the work function and surface energy of transparent conducting oxides for applications in organic electronics.

I will also discuss thermochemical nanolithography (TCNL), which has the potential for patterning of materials to sub-10-nm resolution. The capability to modify the chemical properties of surfaces with nanoscale control can be beneficial in a wide range of applications. Here a heated scanning probe tip is used to activate the local chemical deprotection of amine groups at the surface of a specially designed polymer, spin-coated on a substrate. These amine groups are then converted into different functionalities using standard protocols and used for the subsequent attachment of nano-objects. We demonstrate that co-existing patterns of up to three different chemical species (amine, thiol, aldehyde, biotin) in independent and arbitrary designs can be obtained on the same surface by iteration of the writing and conversion steps. Several strategies to attach proteins and DNA to the chemical nanopatterns are demonstrated, including the co-patterning of two bioactive proteins. This chemical nanopatterning approach uses heat transport and molecular recognition rather than mass transport to chemically functionalize surfaces and then attach nano-objects. This approach is therefore unique in its high-speed (> 1mm/s with a single probe), flexibility in the substrate choice, and versatility in generating orthogonal functionalities on the same surface.