Form-Fill-Seal Methodology for Controlled Encapsulation of Small Silver Particles in Hyperbranched Polyglycidol

Production of polar hyperbranched polymers and encapsulation of small particles in the hyperbranched polymers is like forming pouches and then filling these Pouches. Modification of the end-groups Of the hyperbranched polymers with relative apolar groups is like sealing the pouches. In this article, we demonstrated that two methods depending on changed sequences, i.e., Form-Fill-Seal and Form-Seal-Fill methods resulted in different sized small particles with size-depended properties. By using these approaches, small metal nano-particles can be encapsulated inside polar microzones of dendritic-star polymers taking advantage of the difference in partition coefficients instead of strong interactions between the dendritic polymers and ions. We used the methodology to produce small silver particles encapsulated in hyperbranched polyglycidol (HPG). The HPG was synthesized via anionic ring-opening multibranching polymerization of glycidol. The sealing process was fulfilled by polymerization of epsilon-caprolactone initiated from the end groups of HPG. In the Form-Fill-Seal approach, Ag+ was filled inside HPG, and then was sealed before reduction to Ag; whereas the pouch of HPG was sealed at first, and then Ag+ was filled inside HPG by diffusion in the Form-Seal-Fill approach. Mainly nanometer-sized silver particles were formed by the Form-Fill-Seal approach, whereas silver clusters of several atoms were formed in the Form-Seal-Fill approach. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 112: 1209-1214, 2009