Homofunctionalized polymer surfaces formed by selective plasma processes

Several possibilities exist to produce a modified polymer surface with a hi gh density of only one sort of functional group such as: (i) the plasma gra fting of unfragmented monomer molecules and their polymerization forms OH, NH2, COOH groups, etc. in concentrations of approximately 25 groups per 100 C atoms; (ii) selective plasma bromination provides 10-25 CBr groups; (iii ) the plasma oxidation of polymer surfaces in an O-2 plasma followed by the chemical reduction of all O-containing groups to OH groups by diborane, vi tride (TM) (Na complex) or LiAlH4 yields 9-14 OH groups per 100 carbon atom s; and (iv) the grafting of spacers with different endgroups onto OH or CBr groups produces 7-10 spacer molecules/100 C. This work was focused on the formation of thin plasma deposited polymer layers with a maximum of (homo)f unctional groups and with a minimum of chemical irregularities using the pu lsed plasma technique. The monomers were allylalcohol, allylamine, acryloni trile and acrylic acid. The further intent was to study the interactions of functional groups (OH, COOH, NH2) and deposited metals (Cr, Al, Ti). It wa s expected that more basic (NH2), weakly basic or neutral (OH) or more acid ic (COOH) groups would show different interactions and chemical reactions w ith metal atoms. (C) 2001 Elsevier Science B.V. All rights reserved.