Three different platinum-biopolymer nanocomposites have been prepared independently in the presence of hexachloroplatinic acid and biopolymers like fucoidan, alginic acid and sodium hyaluronate (NaHA) via sodium borohydride reduction. The average particle diameter of platinum nanoparticles using fucoidan becomes slightly smaller, with a decrease of the concentration of fucoidan, ranging from 3.1 to 2.6 nm. On the other hand, the average particle diameter of platinum nanoparticles using NaHA becomes slightly larger, with a decrease of the concentration of NaHA, ranging from 3.4 nm to 3.8 nm. The average particle diameter of platinum nanoparticles using alginic acid is 3.2-3.4 nm which is independent of the biopolymer concentrations. The antioxidant activities of the platinum-biopolymer nanocomposites upon elimination of hydroxyl radicals formed in an H2O2/FeSO4 system have been studied using a spin-trapping method; All the nanocomposites exhibit high catalytic activities that are affected by the concentration and the kind of the biopolymer. In addition, the activities of the platinum-biopolymer nanocomposites are higher than those of the gold-biopolymer nanocomposites. The highest antioxidant activity for the platinum-alginic acid nanocomposites was 110 times higher than that of ascorbic acid.
Cotton was dyed with unsubstituted phthalocyanines (MPc, M = Cu, H2, Ni, Mg, Zn, Co) and halogen-substituted phthaolocyanines using a trifluoroacetic acid/dichloromethane mixed solution containing protonated MPc, resulted in blue and green cotton. The amount of the dye on the cotton increased with the immersion time up to 1 h. Scanning electron micrographs of the dyeing stuff showed that cotton fiber surface was densely covered with CuPc crystallites. The dyeing was explained by the deposition of MPc due to the reaction of protonated MPc with hydroxide substituents of glucose unit in cotton. The results of the tests for color fastness showed that the fabric with CuPc had good fastness. Especially, the fastness to light was excellent as expected from that of CuPc.