Fourier transform Raman spectroscopy of a thiophene solution shows a reduction of aromaticity of the thiophene ring by the interaction with a solvated Lewis acid, which lowers the oxidation potential of the monomer. Low-potential electrochemical deposition of polythiophene was carried out in the presence of a Lewis acid in a solvent with a suitable donor number. High quality conducting polythiophene films were prepared at low potential in BF3-ethyl ether. The conductivity parallel to the film surface is more than 104 times that across the film thickness. This anisotropy is related to the orientation of polythiophene chains. The molecular arrangement of polythiophene on a stainless steel electrode was investigated by surface-enhanced Raman scattering and infrared reflection-absorption spectroscopy.

The morphology and crystallization behavior of freeze-extracted isotactic polystyrene (iPS) derived from concentrated solutions in solvents of middle molecular size were characterized by the wideangle X-ray diffraction, infrared spectroscopy, and differential scanning calorimetry. It was found that the freeze-extracted iPS sample is poorly crystallized, but the chains are in an ordered 31 helix conformation, which can be easily transferred to a highly crystalline state upon heating. It can easily crystallize even cooled from the melt. The ordered 31 helix structure could be maintained even after melting at 520 K, which is 30 K higher than the melting point, but diminished at 530 K. The metastable property of the freeze-extracted sample from concentrated solutions in solvent of middle size can be attributed to fewer interchain entanglements, like the behavior of collective particles from very dilute solution in benzene.

Depletion interaction of added additional polymer latex was reported to drive self-aggregation of particles in suspension or on a hard wall (Yodh, A. G.; Lin, K. H.; Crocker, J. C.; Dinsmore, A. D.; Verma, R.; Kaplan, P. D. Philos. Trans. R. Soc. London A 2001, 359, 921). We describe an experimental investigation of controlling the optimal geometrical arrangement for the adsorbed molecules by depletion interaction between the adsorbent and the metal wall. Bipyridine and a polymer of amino acid were found to form ordered structures that covered silver after adding a depletant of low molecular weight poly(ethylene glycol) (PEG) into their solutions in ethanol. The adsorbed molecules were investigated by surface enhanced Raman scattering (SERS) spectroscopy, which provided information about morphology at the molecular level. The PEG-mediated depletion interaction with the wall contributed to the entropic force for supramolecular assembling of these adsorbents on substrate.

Polythiophene (Pth) was electrochemically deposited onto stainless steel substrate from freshly distilled boron fluoride-ethyl ether containing 10 millimoles of thiophene per liter. The free-standing Pth film obtained at an applied potential of 1.3 volts (versus Ag/AgCl) had a conductivity of 48.7 siemens per centimeter. Its tensile strength (1200 to 1300 kilograms per square centimeter) was greater than that of aluminium (1000 to 1100 kilograms per square centimeter). This Pth film behaves like a metal sheet and can be easily cut into various structures with a knife or a pair of scissors.

A semiconducting pyrrole-styrene block copolymer film was electrochemically synthesized in nitromethane. The product polymer was confirmed to be a copolymer of pyrrole and styrene and not a composite or a blend of PPy and PSt through electrochemical, spectral, and dissolving experiments.