Templating silver nanoparticle growth using phosphonated calixarenes

摘要

Very small (~ 2 nm) silver nanoparticles can be readily prepared using p-phosphonated calixarenes as templating agents and surfactants, at the same time allowing the use of hydrogen gas as an environmentally benign reductant.rnMetal nanoparticles have many potential applications, including use in biomedical, optoelectronic and catalysis systems, which relate to their size-dependent properties. Silver nanoparticles, in particular, have remarkable properties, interacting with light better than any known chromophore, and displaying antimicrobial and catalytic activity, with small nanoclusters of silver showing fluorescence with a relatively high quantum yield. Typically, silver nanoparticles are produced when metal salts of silver are reduced in the presence of a strong reductant with a stabiliser to passivate the surface and prevent agglomeration. The reductants used are usually toxic materials such as borohydrides or hydrazine, although there are recent examples in the literature focussing on the use of environmentally benign reductants such as ascorbic acid and glucose.