SYNTHESIS OF METAL NANOCLUSTERS WITHIN MICROPHASE-SEPARATED DIBLOCK COPOLYMERS - SODIUM CARBOXYLATE VS CARBOXYLIC-ACID FUNCTIONALIZATION

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 a cetates, chlorides, nitrates, and sulfates. A[MTD](400)[NORCOONa](50) film was subjected to four consecutive Ag+ loading and reduction seque nces, 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 Angstrom were estimated following the first, second, third, a nd fourth, loading and reduction sequences, respectively. During a sin gle loading and reduction sequence, cluster size (ca. 30 Angstrom) wit hin [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 pol yNORCOOH, consistent with a nucleation-controlled cluster formation pr ocess. (C) 1998 Elsevier Science Limited.