A novel substrate, whose silver particles were deposited on both sides of a slide, was made by silver mirror reaction. Its two sides had different thinness and reflectivity and they were suited for the test of surface enhanced Raman spectroscopy (SERS) and reflection absorption infrared spectroscopy (RAIR) technique respectively.
The interface between a-PMMA thin film and silver mirror substrate was investigated using surface-enhanced Raman scattering (SERS). It is found that the molecular chain axis of a-PMMA tends to parallel the substrate in the interface. When the sample is annealed at different temperatures, some interesting changes appear in the SERS spectra. The spectra differences and their transition are due to the surface geometry change of the ester group.
Filming process of polystyrene nano-latex (NPS) particles was studied by a combination of various methods. For a constant annealing time of 1 h, the AFM images showed that the deformation and sintering temperatures for NFS particles were ca. 90 ℃ and 100 ℃ respectively. In spin-lattice relaxation measurements of solid state NMR, it is found that TIL, T1S and /1L/I0 increased significantly after annealing at 90℃ and above. DSC results showed that there was an exothermic peak near Tg after annealing for 1 h at the selected temperatures below 95℃; otherwise, the exothermic peak disappeared after annealing at 100℃ or above. The apparent density of NPS increased suddenly in the temperature range. The results implied that the macromolecules in NPS particles are in a confined state with higher confor-mational energy and less cohensional interactions which are the drive force for the sintering at a lower temperature compared with the multichain PS particles and the bulk polymer.
The polyelectrolyte multilayer films were prepared by the layer-by-layer deposition of polyelectrolytes on the charged surfaces substrates. A simple process was developed to create a large area and discrete microporous thin films based on PDDA/NaPSS multilayer films by using immersing the multilayer film into pure water at an appropriate temperature and period. The microporous morphology of the multilayer film is controlled by temperature and time, and observed by atomic force microscopy. It is observed that the total area of the micropores in the films increased with immersing temperature and time. In addition, the microporous process of PEM films in hot pure water is discussed. This unique way to fabricate the microporous films has potential applications to the fields from microelectronic materials to biomaterials.
The miscibility and structure ofA-B copolymer/C homopolymer blends with special interactions were studied by a Monte Carlo simulation in two dimensions. The interaction between segment A and segment C was repulsive, whereas it was attractive between segment B and segment C. In order to study the effect of copolymer chain structure on the morphology and structure of A-B copolymer/C homopolymer blends, the alternating, random and block A-B copolymers were introduced into the blends, respectively. The simulation results indicated that the miscibility of A-B block copolymer/C homopolymer blends depended on the chain structure of the A-B copolymer. Compared with. alternating or random copolymer, the block copolymer, especially the diblock copolymer, could lead to a poor miscibility of A-B copolymer/C homopolymer blends.Moreover, for diblock A-B copolymer/C homopolymer blends, obvious self-organized core-shell structure was observed in the segment B composition region from 20% to 60%. However, if diblock copolymer composition in the blends is less than 40%, obvious self-organized core-shell structure could be formed in the B-segment component region from 10 to 90%.Furthermore, computer statistical analysis for the simulation results showed that the core sizes tended to increase continuously and their distribution became wider with decreasing B-segment component.
