Optical quality, polymer film preparation

Optical quality polymer film preparation. The H, CN, NO2, and CH3O substituted azophenol polymers were soluble in most polar organic solvents. 

Good optical quality thin films of PAV have been prepared through a new precursor polymer that is soluble in organic solvents [16]. For example, PTV thin film can be fabricated as follows. Polymerisation of a sulfonium monomer, 2,5-thienylene bis(methylene-dimethyl-sulfonium chloride), is carried out in a methanol-water mixture... 

Layer-by-layer (LbL) technique can be apphed to form the smooth multilayer films based on PDMS. Using this method the covalently bound, robust multilayer films of optical quality were obtained from 3-aminopropyl-terminated homobifunctional PDMS and poly(ethylene-alt-maleic anhydride) (PEMA) on silica surfaces [48]. Due to the differences in solubility of the polymers used, the polymer layers were deposited from different solvents PEMA layers were prepared from tetrahydrofuran solution, while the PDMS layers were deposited from toluene. The multilayer assemblies show a solvent memory for swelling and de-swelling when immersed in the corresponding solvent for each polymer. Films prepared under these conditions were smooth up to 60 nm of thickness, as demonstrated by small angle X-ray reflectometry, and do not visibly scatter the incident light. Thicker films showed very homogeneous... 

In Figure 8-1 we show the chemical structure of m-LPPP. The increase in conjugation and the reduction of geometrical defects was the main motivation to incorporate a poly(/ -phenylene)(PPP) backbone into a ladder polymer structure [21]. Due to the side groups attached to the PPP main chain excellent solubility in nonpolar solvents is achieved. This is the prerequisite for producing polymer films of high optical quality. A detailed presentation of the synthesis, sample preparation,... 

Three kinds of PAV films was prepared using methoxy pendant precursors. The chemical structures and synthetic route of the PAV films used in this study are shown in Fig. 19. The details of synthesis of the methoxy pendant precursors have been described in refs. 29 and 30. The precursors were soluble in conventional organic solvents, for example, chloroform, dichloromethane, benzene and so on. The precursor polymer thin films were spin-coated on fused quartz substrates from the chloroform solutions. The precursor films were converted to PAV films by the heat-treatment at 250 0 under a nitrogen flow with a slight amount of HC1 as a catalyst. This method provided high performance PAV films with excellent optical quality. 

E. C. Venancio, P.-C. Wang, O. Y. Toledo, and A. G. MacDiarmid, First preparation of optical quality films of nano/micro hollow spheres of polymers of anihne, Synth. Met., 157, 758-763 (2007). 

Note that the sol-gel materials based on polysiloxane have been known for their durability and good optical quality. If functionalized with azobenzene moieties, they exhibit nonlinear optical properties and photoinduced anisotropy. There are a few examples of SRG inscribed onto materials (Kim et al., 2006b Chaput et al., 2000 Frey et al., 2000 Darracq et al., 1998). The gratings could be inscribed only in freshly prepared films, whereas in aged films, the cross-linking of the polymer completely hindered SRG formation. 

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