My research centers on making and understanding the physical properties of materials applicable to nanomolecular devices. The challenge lies in assembling molecules on surfaces and understanding the behavior of 1-, 2- and thin 3-dimensional (1-, 2- and thin 3-D) materials. The ultimate goal is to build surface structures with special optical and electronic properties, such as the ability to convert electrons to photons through electrochemiluminescence (ECL)
Thin 3-D layered materials are formed by stacking simpler pieces, i.e. 2-D monolayers or the electrosynthesis of surface bound polymers. The monolayer approach uses an interface to align and orient individual molecules into close-packed single molecule thick layers. These macromolecular layers are stacked using a combination of evaporation, self-assembly and/or Langmuir-Blodgett techniques. While most researchers have used saturated hydrocarbons to produce monolayers, my research has shown the ability of rigid rod aromatic molecules to form close packed monolayers.
These molecules by virtue of their low ionization potentials and high electron affinities have very unusual condensed phase properties such as strong near infrared absorptions (NIR). The study of NIR (4,000-10,000 cm-l) absorbing films can be justified by their importance to optoelectronic applications of inexpensive semiconductor lasers. New areas of research include films composed of inorganic complexes having polyaromatic ligands and poly aromatic heterocycles. Our objective here is to establish the criteria necessary to form new, organized 2-D materials, with the specific emphasis on the role of molecular size and shape on orientation and molecular packing in 2-dimensions.
The second method uses electrochemistry to produce polymer films in situ.. The oxidative coupling of aromatic amine monomers leads to polymeric materials that are oxidatively reversible, semiconductive and have intense vibrant color changes. We use this knowledge to design devices like thin layer batteries, photovoltaics, frequency doublers and electrochromic windows.
Click here to see an ELECTROCHROMIC WINDOW based on DNTD polymers
Recent Publications:
Balasubramanian, K.K.; Cammarata, V. "Langmuir-Schaefer Films of Distyrylphenanthrolines and Rhenium Tricarbonyl Chloride Complexes: Headgroup Influence on Anisotropy" Langmuir, 1996, 12, 4882.
Wang, L.; Cammarata, V.; "Electropolymers Based on Diphenylamine: ¹-Stacking in Cationic Benzidine Units" Thin Solid Films, 1996, 284-285, 297.
Balasubramanian, K.K.; Cammarata, V.; "Polymerization and Characterization of Distyryl Bipyridines in Solution and Langmuir-Schaefer Films: Effect of Preorganization" Langmuir, 1996, 12, 2035.
Wang, L.; Goodloe, G.W.; Stallman, B.J.; Cammarata, V.; "Synthesis, Electroxidation and Char-acterization of Bis(diphenylamine)naphthalene Diimide" Chem. Mater., 1996, 8, 1175.
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Last Updated: 30 April 1997 -- Maintained by Vince Cammarata (cammavi@mail.auburn.edu)