Ellipsometry studies of albumin films on tantalum oxide and SiO2

The adsorption of (1) bovine serum albumin in acetate buffer, (2) albumin followed by glutaraldehyde crosslinking, (3) albumin followed by exposure to an albumin/glutaraldehyde solution, and (4) albumin after the surface was subjected to treatment (3), has been studied using Ta oxide/Ta chips and SiO₂/Si wafers as substrates. The films were washed, air dried and measured in air using an automatic laser ellipsometer, 6328 Å. The films formed from treatment (3) and treatment (4) have a lower refractive index and are thicker than films formed from treatment (1) and treatment (2). The adsorption of albumin on SiO₂/Si wafers seems to be slower than that on the Ta oxide/Ta surfaces.     

Miscibility maps for copolymer - copolymer blends: A comparison of theoretical predictions to experimental studies of poly(styrene-co-vinyl phenol) blends with poly(ethylene-co-methyl acrylate)

We report the results of theoretical and experimental studies of random amorphous styrene-co-vinyl phenol (STVPh) copolymer blends with ethylene-co-methyl acrylate (EMA). This work is a natural extension to our recently reported studies of the phase behavior of analogous STVPh blends with an homologous series of poly(n-alkyl methacrylate) homopolymers, where we employed an association model together with parameters obtained from studies of miscible homopolymer blends. Here we emphasize that there is no conceptual difference between the average chemical repeat of a random copolymer and that of an analogous repeat unit of a homopolymer containing the same number and type of functional groups. The theoretically calculated miscibility maps for STVPh - EMA copolymer blends are in outstanding agreement with experiment.     

An infrared spectroscopic study of a hyperbranched,dendrimer-like,polyester and its blends with poly(4-vinyl phenol)

A dendrimer-like hyperbranched polyester is characterized by infrared spectroscopy. By converting and labeling the terminal groups by acetylation with ¹³C acetic anhydride, the relative accessibility of core and terminal functional groups to solvents and linear polymers can be measured by counting the number of hydrogen bonds formed between the complementary functional groups found in these materials. The terminal groups form hydrogen bonds as readily as the same groups in linear polymers, but the core groups are highly screened. These results suggest that in these mixtures the dendrimer is extended, with the terminal groups located near the periphery of the molecule.