NEW INSIGHT INTO MECHANISMS OF SOL-GEL PROCESS AND NEW MATERIALS AND OPPORTUNITIES FOR BIOENCAPSULA-TION AND BIODELIVERY

摘要

The review considers principal mechanisms in solution transformations, hydrolysis and condensation of alkoxysilanes and metal alkoxide complexes and the pathways of further transformations of the thus formed colloid systems. The versatility of silica sol-gel is provided by the possibility to direct the kinetically controlled process towards either polymeric or micellar colloids. The hydrolysis of metal alkoxides is kinetically unhindered and results in formation of Micelles Templated by Self-Assembly of Ligands (MTSALs) under the local equilibrium conditions. The morphology, reactivity, long term stability and biocompatibility of MTSALs can be efficiently controlled by the choice of metal cations, ligands and the conditions of hydrolysis. Application of the MTSAL concept for the synthesis of hierarchically porous materials and the prospects of their use in bio-encapsulation and biodelivery for water and soil remediation processes are discussed.