Metal Chelating Polymer Thin Films by Surface-Initiated ROMP and Modification

摘要

We report the surface-initiated ring-opening metathesis polymerization (SiROMP) of hydroxamic acid-containing, metal-chelating polymer thin films. SiROMP of trans-5-norbornene-2,3-dicarbonyl chloride (NBDAC) is introduced as a versatile platform to achieve many functional polymer films via simple exposure of pNBDAC films to reagents. This modification strategy owes its success to the fast and high-yield reaction of acyl chlorides with alcohols, amines, water, and other molecules. The polymerization of NBDAC is performed with monomer in the vapor phase and exhibits rapid kinetics, producing similar to 400 nm thick films within 5 min. Because of the high reactivity of the acyl chloride groups in the film, the pNBDAC films are easily modified to produce side chains of carboxylic acids, esters, and amides via the reaction of the acyl group with water, alcohols, and amines, respectively. Exposure of the pNBDAC film to hydroxylamine results in a film with hydroxamic acid functionality that is capable of chelating various metal ions. The chelation process effectively cross-links the polymer chains to greatly improve the thermal and pH stability of the film in solution, elevate resistance against water and ion transfer, and alter the mechanical properties to a more solid-like film.