Cationic photopolymerization of liquid fullerene derivative under visible light

We describe the synthesis and cationic photopolymerization of a C₆₀ derivative bearing a 2,4,6‐tris(epoxynonyloxy)phenyl moiety (FB9ox). Rheological analysis of monomer indicates that temperature of 130 °C yields sufficiently low viscosity for polymerization. A thin film of the liquid monomer has been cationically photopolymerized with a photoinitiator system of curcumin and p‐(octyloxyphenyl)phenyliodonium hexafluoroantimonate, which harvests 424 nm light instead of commonly used ultraviolet light. The degree of polymerization was determined with ATR‐IR. The reaction is the first recorded photopolymerization of a fullerene derivative thin film. The polymer exhibits good mechanical and chemical stabilities. The polymerization can also be achieved by annealing at 150 °C without illumination, but with a smaller degree of polymerization. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5194–5201, 2008     

Photo‐Induced Cross‐Linking of Divinyl Ethers by Using Diphenyliodonium Salts With Highly Nucleophilic Counter Anions in the Presence of Zinc Halides

This study describes the use of diphenyliodonium salts with highly nucleophilic counter anions to photoinitiate the cationic cross‐linking of divinyl ethers. Both direct and indirect initiating modes are used. In the direct acting system, only a diphenyliodonium salt with a highly nucleophilic counter anion and a zinc halide are employed as initiator and activator, respectively. In the indirect systems, in addition to direct system components, photosensitive additives such as anthrecene, perylene, 2,2‐dimethoxy‐2‐phenyl acetophenone, benzophenone, and thioxanthone, which absorb the energy of the incident light and activate the iodonium salt, are used to initiate polymerization. All systems employed in this study initiated quite vigorous polymerizations.

     

XPS and AFM characterization of the self‐assembled molecular monolayers of a 3‐aminopropyltrimethoxysilane on silicon surface,and effects of substrate pretreatment by UV‐irradiation

The self‐assembled (SA) molecular monolayers of a 3‐aminopropyltrimethoxysilane (3‐APTS) on a silicon (111) surface, and the effects of ultraviolet (UV) pre‐treatment for substrates on the assembling process have been studied using XPS and atomic force microscopy (AFM). The results show that the SA 3‐APTS molecules are bonded to the substrate surface in a nearly vertical orientation, with a thickness of the monolayer of about 0.8–1.5 nm. The SA molecular monolayers show a substantial degree of disorder in molecular packing, which are believed to result from the interactions of amine tails in the silane molecules used with surface functionalities of the substrates, and the oxygen‐containing species from the ambient. UV irradiation for silicon substrates prior to the self‐assembly reaction can enhance the assembly process and hence, significantly increase the coverage of the monolayer assembled for the substrates. Copyright © 2010 John Wiley & Sons, Ltd.