Cloud points of aqueous solutions of homogeneous poly(oxyethylene)dodecyl ether derivatives (C12(OE)n : 1"/= 2-8) and the apparent theta temperature TO ap were determined from the abrupt changes in optical transmittance and the temperature dependence of the second viriai coefficient obtained by light scattering measurements. It was found that the lower critical solution temperature (LCST) shifts to a lower temperature and lower concentration as the number of oxyethylene units in a molecule decreases. Because of this behavior of LCST, the modified Flory-Schultz plot of phase separation was applied to the present nonionie surfactant-water system, and its theta temperature obtained. The dependence of TO ap on the number of oxyethylene units suggests that the polyoxyethylene chain has different effects on the solubility of C12(OE)n in water for n less than or equal to 3 from those for n greater than or equal to 4.

Porous nickel oxide (NiO) nanofibers, structured with and composed of linearly oriented NiO nanoparticles, were synthesized via a simple method using a solution containing ethanol, H2O, NiCl2, and P123 (Pluronic P123, a triblock copolymer H(OCH2CH2)20(OCH(CH3)CH2)70(OCH2)20OH). By adjusting the concentration of P123, this method allows for the control of the fiber morphology and the nanoparticle size.

Polyvinyl alcohol (PVA) has been used to prevent flaking of paint pigments on traditional Japanese Shohekiga painted screens and panels. However, over time these PVA coatings whiten. To date, the mechanism of this whitening has not been studied from the point of view of polymer degradation. In this study, a piece of whitened PVA was obtained from a painted wooden panel. The PVA whitening mechanism was studied in this piece using scanning electron microscopy (SEM) and functional group analysis by Fourier transform-infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). SEM showed that the surface of the whitened PVA thin film was irregular and rugged, and many micrometer-sized cracks were observed. This suggests that efficient scattering of all visible light from the cracks causes whitening. FT-IR and XPS measurements revealed that inter-and intra-chain dehydration and chemical crosslinking (C-O ether linkage) occur on the surface of the whitened PVA.

The hydrolytic behavior of heat-set poly ( ethylene terephthalate) (PET) fibers is compared in the presence and absence of a quaternary ammonium compound, do decylbenzyldimethylammonium chloride (DBDMAC). Alkaline hydrolysis without DBDMAC depends on the heat-setting temperature, showing a minimum weight loss at around 140°C and becoming more marked with increased NaOH concentration, hydrolysis temperature, and time. Alkaline hydrolysis is accelerated by DBDMAC for all PET fibers over the whole range of heat-setting temperatures. The fibers set at lower temperatures, however, have much larger increases in weight loss than those set at higher temperatures by alkaline hydrolysis in the presence of DBDMAC. The rate en hancement of alkaline hydrolysis by DBDMAC decreases with increased heat-setting ' temperature or degree of crystallinity of the fiber, and may preferentially occur in the amorphous regions of the fiber.

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