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.

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.

Poly(vinyl chloride) (PVC) samples for the conformation and structural relaxation studies were prepared by freeze-extracting the solutions in various solvents and with varying concentrations. The partially disentangled PVC samples could be obtained by freeze-extracting very dilute PVC/tetrahydrofuran (THF) and PVC/dimethyl phthalate (DMP) solution (0.05 wt %), while the PVC sample remains in an entangled state after freeze-extracting the concentrated solutions in THF and in DMP. Surprisingly, the extent of interpenetration of PVC chain decreases, even in concentrated solution in dioctyl phthalate (DOP) (5 wt %), which is contrary to accepted theories. DSC and infrared spectroscopic studies showed that a higher ordered conformation could be achieved for the disentangled specimens recovered from concentrated solution in DOP than for the entangled samples prepared from THF and DMP. DSC heating curves showed strong and sharp endothermal peaks for the disentangled polymer after sub-Tg annealing. The structural relaxation behavior of the disentangled PVC freeze-extracted from DOP solutions is more predominant, which is in good agreement with the modeling predictions.

The partially disentangled poly(vinyl chloride) (PVC) samples were prepared by freezeextracting from dilute PVC/THF solutions. The conformation of these samples was investigated by infrared and Raman spectroscopy. The structural relaxation behaviors were studied by differential scanning calorimeter (DSC). The results showed that the PVC samples prepared from dilute solutions with concentrations lower than 0.25% were in the expanded state with fewer entanglements. The conformation and structural relaxation of PVC depended strongly on the entanglements in polymers, and the structural relaxation rate increased with decreasing chain entanglements, which is in good agreement with the modeling predictions.

The laser-induced chemical reactions on the surface of a polymer film were investigated by surface-enhanced Raman scattering (SERS) using chemically deposited silver as the SERS activating layer on the surface of the film. The silver-catalyzed pyrolysis at the outermost surface of the polyacrylonitrile film under laser radiations with different wavelengths was investigated by this SERS technique. The extremely low carbonization temperature at room temperature under laser implies several responsible mechanisms.

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.