Some properties of polysulfone, chlorometylated polysulfone and quaternized polysulfone were studied by viscometry, interferometry and dialysis equilibrium. Modification of intrinsic viscosity, preferential and total adsorbtion coefficients explained the changes of the hydrodynamic dimensions with solvent quality. POLYM. ENG. SCI., 46: 827–836, 2006. © 2006 Society of Plastics Engineers

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Novel quaternized polysulfones (PSFs) with two ionic chlorine contents were investigated, namely, their morphology and antimicrobial activity. Atomic force microscopy (AFM) studies on their membranes showed ordered domains, in which pores and nodules of different sizes and intensities were distributed. The charge density of the quaternized PSFs and the history of the membranes formed from solutions in solvent/nonsolvent mixtures influenced the different aspects of the surface images. The adhesion of Escherichia coli ATCC 10536 and Staphylococcus aureus ATCCC 6538 microorganisms to solutions of the modified PSFs is discussed in correlation with the hydrophobic/hydrophilic properties of the studied polymers and microorganisms.

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ABSTRACT:The conformational behavior and unperturbed dimensions of polysulfone and chloromethylated polysulfone with different degrees of substitution were investigated by viscometry in N,N-dimethylformamide; we intended to use these results with more complicated structures with different properties and applications. The effects of concentration and temperature on the coil densities and dimensions and of chlorine content on the unperturbed dimension parameters are discussed.

Nicotine (from cigarette smoke) and caffeine (from coffee) have analgesic effects in humans and experimental animals. We investigated the combined effects of coffee drinking and cigarette smoking on pain experience in a group of moderate nicotine-dependent, coffee drinking, young smokers. Pain threshold and pain tolerance were measured during cold pressor test following the habitual nocturnal deprivation of smoking and coffee drinking. Smoking increased pain threshold and pain tolerance in both men and women. Coffee drinking, at a dose that had no independent effect, doubled the increase in pain threshold induced by smoking. The effect could not be explained by a cumulative raise in blood pressure. Our data suggest that caffeine enhances the analgesic effect of nicotine.

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Modification of intrinsic viscosity and the preferential adsorption coefficients of quaternized polysulfones with various contents of ionic chlorine in N,N-dimethylformamide/water and methanol/water mixed solvents was investigated at different compositions and temperatures. The polyelectrolyte effect induced by an enhanced dissociation of the ionizable groups determines both the modification of the swelling degree of the polymer coil and the difference in composition of the mixed solvent inside and outside the coil. The results obtained were correlated with the interaction parameters of the above-mentioned polymer/solvent/solvent systems.