Poly-paraxylylene

Originally, the effect of charge state of nanostructures on their catalytic activity was recognized from analysis of the experimental data on the catalytic properties of metallic nanoparticles immobilized in the matrix of a poly-paraxylylene polymer [13-15,24]. It was found that the dependence of the catalytic activity (and, in some cases, of the selectivity) of copper, palladium, and iron nanoparticles on the metal content of these structures has a maximum. This maximum exists not only for the specific (related to unit weight) activity, but also for the absolute activity. More specifically, for copper and... 

Poly-paraxylylenes are deposited by a thermal CVD process popular in the microelectronics industry as the "Gorham process"." The starting material for this deposition process (precursor) is usually a paracyclophane dimer (DPX). The dimer dissociates to form reactive monomer species, which then undergoes nucleation and growth leading to polymer thin film formation. The following reaction ensues ... 

Figure 25.4 MIR absorption spectrum measured on a free standing 7 pm thick poly-paraxylylene (PPX) film. The sharp peaks originate from vibronic excitations of the polymer and the periodic modulation attributed to Fabry-Perot oscillations.

Fig. 2 The families of polymers currently deposited using CVP (a) paraxylylene, (b) polyimide, (c) poynapthalene, (d) poly p-phenylene vinylene, and (e) polyazomethine.

Poly(monochloro-paraxylylene) Union Carbide Reg. trademark. k Allied Chemical, amorphous nylon film. 

Poly(monochloio-paraxylylene) Union Carbide registered trademark. 

F. R. Denton III, A. Sarker, P. M. Lahti, R. O. Garay, and F. E. Karasz, Paraxylylenes and analogues by base-induced elimination from 1,4-bis(dial-kylsulfoniomethyDarene salts in poly( 1,4-arylene vinylene) synthesis by the Wessling soluble precursor method, J. Polvm. Sci. Part A Polvm. Chem. 30 2233 (1992). 

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