title: A new cross-linking route via the unusual collision kinematics of hyperthermal protons in unsaturated hydrocarbons: the case of poly(trans-isoprene).
abstract: The bombardment of a approximately 18 nm film of poly(trans-isoprene) molecules (approximately 300,000 carbon atoms per molecule) with a mass-separated proton beam at 10 eV has been shown to induce highly efficient cross-linking of several macromolecules per incident proton. In this new method using physical means to conduct synthetic chemistry, the hyperthermal protons preferentially cleave C-H bonds because of their unusual kinematics in hydrocarbons, and the carbon radicals thus created initiate a polymerization chain reaction of the isoprene C[double bond, length as m-dash]C bonds. The method produces ultrathin polymeric films via cross-linking with a dry process having high chemical selectivity and reactivity but requiring no thermal cost and no chemical additives, conditions that are commonly required in the fabrication of microelectronics and photonics.
authors.affiliation: Institute of Surface Micro and Nano Materials, Xuchang University, Xuchang, 461000, China.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Zheng
authors.forename: Wai Man
authors.initials: WM
authors.lastname: Kwok
authors.forename: Woon Ming
authors.initials: WM
authors.lastname: Lau