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The size of aggregates formed by poly(acrylic acid)‐block‐poly(methyl methacrylate) block copolymers was determined and the applicability of these block copolymers as stabilizers in emulsion polymerization was investigated. The analytical methods included transmission electron microscopy, light scattering, and analytical ultracentrifugation. Polymers with a hydrophilic poly(acrylic acid) block of equal or larger size than the hydrophobic poly(methyl methacrylate) block are efficient as stabilizers down to block copolymer‐to‐monomer ratios of less than 1 wt.‐%. From the influence of the block copolymer‐to‐monomer ratio on the latex particle size, from the relation between the number of block copolymer molecules per latex particle and the aggregation number of the block copolymer micelles, and from fluorescence studies we conclude that micelles consisting of block copolymers with 35 or more hydrophobic MMA units act as a seed in the emulsion polymerization of acrylic and methacrylic monomers.

Binary monolayers of octadecyltrichlorosilane (OTS) and ll-(2-naphthyl)undecyltrichlorosilane (2-Np) were prepared by backfilling of partial monolayers of one component as a result of exposure to solutions of the other component. The comparison with coadsorbed monolayers shows that both procedures lead to the same kind of binary monolayers. The ratio of the UV-absorption bands at 224 nm (Bb) and 280 nm (La) of the naphthalene chromophore in UV spectra of binary monolayers is independent of composition, indicating constant orientation of the chromophore. Thus, the UV absorbance of the naphthalene tag in backfilled monolayers could be used to determine the surface composition and thus the original coverage of the partial monolayers. The transient growth process monitored in this fashion does not follow irreversible first-order kinetics. This is proposed to be the result of the rinsing process that is carried out after removing the substrates from the adsorption solution. Part of the monolayers are removed by this process and the portion of removable material depends on surface coverage. Partial monolayers exhibit a liquid character as shown by orientational disorder (UV), reduced lateral interaction of alkyl chains (FTIR), and the occurrence of the full-sandwich excimer in partial monolayers of 2-Np. Backfilling solidifies the monolayers. In such systems the naphthalene chromophores become oriented, the alkyl chains show higher lateral interaction and the full-sandwich excimer disappears in favor of the partial-overlap excimer. Backfilled monolayers show less defects with lower surface density. This is proposed to be the result of the second immersion in a fresh alkyltrichlorosilane solution that contains more monomeric silanetriols to fill vacancies in the monolayer.

The microstructure and thermal stability of multilayer thin films of rodlike polyglutamate copolymers having flexible aliphatic side chains have been studied with X-ray and neutron reflectometry. The complementary sensitivity of X-rays and neutrons and the use of four different sequences of protonated and deuterated molecules provides an enhanced level of structural discrimination. Within bilayers formed upon deposition, the backbones are located preferentially near the center, with backbones from the two layers overlapping strongly. The side chains of molecules in adjacent layers belonging to different bilayers interdigitate substantially, and interdigitation between layers within a bilayer is seen as well. Upon annealing at 70 or 84 °C, the backbone positions within each bilayer relax. However, there is no ascertainable interlayer interdiffusion and the nature of the side chain interdigitation does not change. No evidence is found for the formation, with annealing, of a three-dimensional ordered structure.