Micro continuous flow-through synthesis of triangular silver nanoprisms and their incorporation in complexly composed polymer microparticles

Abstract

The micro fluid segment technique is used for the continuous-flow synthesis for small silver nanoparticles by reduction of silver ions with sodium borohydride in aqueous solution and for the growth of triangular silver nanoprisms. In result, triangular nanoprisms are obtained in very high yield and high homogeneity. The tuning of the in-plane dipole plasmon resonance can easily be controlled by choosing suited flow rate ratios of silver salt solution and colloidal solution of seed nanoparticles or by different silver salt concentrations. The colloidal aqueous solutions of metal nanoparticles can be used for the preparation of mixtures with water-soluble monomers as acrylamide and for the formation of hydrogel-polymer composite particles in a droplet-based photopolymerization process. Beside spherical composite particles, Janus particles with a hydrophilic nanoparticle-containing composite part are prepared by a combined photopolymerization of the aqueous acrylamide reaction mixture together with embedded droplets of an acrylate-based monomer (Tripropylene Glycol Diacrylate, TPGDA) mixture in a micro co-flow twin arrangement. The components of the mushroom-like particles can easily be distinguished by optical microscopy due to their light-scattering and fluorescence behavior.