Surface modification of Ar-plasma-pretreated polyimide (PI) films (Kapton® HN films) via UV-induced graft copolymerization with 1-vinylimidazole (VIDz), 4-vinylpyridine (4VP), and 2-vinylpyridine (2VP) under atmospheric conditions was carried out to improve their adhesion with the electrolessly deposited Cu. The surface compositions of the graft-copolymerized PI films were characterized by X-ray photoelectron spectroscopy. The adhesion strength of the electrolessly deposited Cu on the surface-graft-copolymerized PI film was affected by the type of monomers used for graft copolymerization and the graft concentration. T-peel adhesion strengths of about 15, 10, and 6?N/cm were obtained for the Cu/graft-modified PI assemblies involving, respectively, the VIDz, 4VP, and 2VP graft-copolymerized PI films. These adhesion strengths are much higher than those obtained for assemblies involving electrolessly deposited Cu on pristine or on Ar-plasma-treated PI films. The adhesion strengths involving the VIDz and 4VP surface-graft-copolymerized PI films are also higher than those involving PI films modified by chemical etching. The cohesive failure inside the PI substrate of the Cu/graft-modified PI assemblies during delamination suggested that not only were the grafted polymer chains covalently tethered on the PI film, they were also incorporated into the metal matrix during the electroless plating process. 相似文献
Summary: Molecular dynamics simulations of a coarse‐grained bead‐spring model of flexible macromolecules tethered with one end to the surface of a cylindrical pore are presented. Chain length N and grafting density σ are varied over a wide range and the crossover from “mushroom” to “brush” behavior is studied for three pore diameters. The monomer density profile and the distribution of the free chain ends are computed and compared to the corresponding model of polymer brushes at flat substrates. It is found that there exists a regime of N and σ for large enough pore diameter where the brush height in the pore exceeds the brush height on the flat substrate, while for large enough N and σ (and small enough pore diameters) the opposite behavior occurs, i.e. the brush is compressed by confinement. These findings are used to discuss the corresponding theories on polymer brushes at concave substrates.
Snapshot picture of a brush grafted inside of a cylinder, for , , displaying different chains in distinct colors in order to be able to distinguish them. Top shows a side view of the cylinder, and the lower part a view of the cross‐section. Note that the particles forming the cylindrical wall are not displayed. 相似文献
Scaling predictions for bottle‐brush polymers with a rigid backbone and flexible side chains under good solvent conditions are discussed and their validity is assessed by a comparison with Monte Carlo simulations of a simple lattice model. It is shown that typically only a rather weak stretching of the side chains is realized, and then the scaling predictions are not applicable. Also two‐component bottle brush polymers are considered, where two types (A,B) of side chains are grafted, assuming that monomers of different kind repel each other. In this case, variable solvent quality is allowed. Theories predict “Janus cylinder”‐type phase separation along the backbone in this case. The Monte Carlo simulations, using the pruned‐enriched Rosenbluth method (PERM) give evidence that the phase separation between an A‐rich part of the cylindrical molecule and a B‐rich part can only occur locally. The correlation length of this microphase separation can be controlled by the solvent quality. This lack of a phase transition is interpreted by an analogy with models for ferromagnets in one space dimension.
