Chemical modification of hyperbranched ultrathin films on gold and polyethylene

Synthetic methods for modifying the carboxylic acid groups of hyperbranched thin film grafts were studied. Amidation, esterification, reduction, and a lkylation reactions of carboxylic acid derivatives that proceed in high con version (>90%) are described. The stability of ultrathin, hyperbranched fil m grafts attached to self-assembled monolayers on gold to conditions of str ong base, strong acid, heat, and organic solvents is detailed. Practical pr ocedures that can be used to prepare and modify poly(acrylic acid) hyperbra nched grafts on gold, polyethylene film, and powder for use in the synthesi s of cationic polyelectrolyte grafts, for use in the synthesis of poly(ally l alcohol) grafts, for use in the synthesis of poly(allyl ester) grafts, an d for use as substrates for organometallic chemistry and further graft chem istry are discussed. (C) 2000 John Wiley & Sons, Inc.