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For the past 12 years Expert's research efforts have been directed toward the development of liquid crystalline and polymeric materials for nonlinear optical (NLO) applications. Thin films (1 - 100 micrometers) of these materials have very attractive mechanical and electronic properties such as fast response times, high polarizability, and processability, which facilitate their use in optoelectronic devices. The preparation of a material with a useful second order susceptibility, such as would be required for electro-optic modulation or second-harmonic generation (SHG), requires the removal of its inversion symmetry. Electric field poling of guest-host and chromophore-attached polymeric films has proven to be a successful procedure for removing the inversion symmetry. Among the many issues to address for these materials are the generation and retention of the orientation of the NLO chromophores. The research involves several experimental steps including preparation of polymers, spin-coating or casting of thin films of the polymers onto microscope slides, corona poling to align NLO chromophores, use of ordinary polarized linear-optical absorption measurements to monitor orientational orders and their temporal decay, and the use of a YAG laser to do the SHG measurements.

In the summer of 1988, he worked as a Research Scientist at the Materials Laboratory, Wright-Patterson AFB. There, he was responsible for the selection of a new nonlinear optical material to be used by the Air Force for the purpose of laser protection of pilots and sensors. After a literature search and testing, the material chosen, phthalocyanines, became one of the most-researched materials by all the military branches during the next few years...especially the Naval Research Laboratory. This is one of the most stable, optically nonlinear materials available today. He also set up a new gas chromatograph with a space-head sampler for analyzing vapors emitted from polymeric thin films.

While at the Phillips Laboratory, Expert set up a computerized optical table for frequency-doubling measurements, and performed these measurements on nonlinear optical polycarbonate samples prepared by his graduate students at WTAMU. He co-authored an article for the Journal of Applied Physics as a result of this effort.

For most of Expert's career, his research interests were in magnetic properties of polymetallic transition metal complexes. His early research involved the synthesis of new transition metal compounds and the characterization of them by various physical methods including magnetic susceptibility, EPR, UV-VIS, and IR. His interests soon focused on the magnetic properties of these compounds. On arriving at WTAMU in 1970, he built three magnetic susceptibility balances, one Gouy and two Faraday. The Faraday balances are equipped to measure temperature dependent magnetic properties from 1 - 400 K. Magnetic and EPR data were used to study electron spin coupling and structural properties of these compounds.

His research interests at WTAMU have been primarily with applications of information gained from spectral and magnetic investigations of transition metal complexes and structural and bonding problems in coordination chemistry.

During 1969-70 he conducted postdoctoral research at the University of North Carolina at Chapel Hill on magnetic and spectral properties of transition metal complexes. Considerable attention was given to systems with electron spin coupling; several first-example triplet ground state systems were investigated.

Expert started applying his background of magnetic and electronic properties of transition metal complexes to the synthesis and characterization of analgesic drugs. The purpose of this research was to prepare metal-containing drugs that would have at least the same or greater analgesic effect as the established drug, but would not irritate the stomach lining. The first metal-containing compound of ibuprofen, copper(II) ibuprofenate, was made and characterized in 1980. The first iron compound of aspirin was made in 1981. Other similar first-examples were studied (1983) and (1985).