Synthesis of metal nanoclusters within microphase-separated diblock copolymers: sodium carboxylate vs carboxylic acid functionalization

Abstract

Conversion of carboxylic acid groups, within the morphologies of [MTD] 400[NORCOOH] 50 diblock copolymers, to the sodium carboxylate form, [MTD] 400[NORCOONa] 50, results in large increases in both the rate and extent of transition metal and rare earth ion uptake from metal acetates, chlorides, nitrates, and sulfates. A[MTD] 400[NORCOONa] 50 film was subjected to four consecutive Ag + loading and reduction sequences, resulting in a cumulative loading of approximately 26 wt% Ag in the overall polymer/Ag composite. Mean crystal diameters of 37, 50, 64, and 65 Å were estimated following the first, second, third, and fourth, loading and reduction sequences, respectively. During a single loading and reduction sequence, cluster size (ca. 30 Å) within [MTD] 400[NORCOOH] 50 was found to be relatively insensitive to the extent of Ag + uptake, for loadings between 40 and 500 mg Ag +/g polyNORCOOH, consistent with a nucleation-controlled cluster formation process.