Recent Applications of Ionic Liquids in the Sol-Gel Process for Polymer–Silica Nanocomposites with Ionic Interfaces

Abstract

Understanding the organic–inorganic interphases of hybrid materials allows structure and properties control for obtaining new advanced materials. Lately, the use of ionic liquids (ILs) and poly(ionic liquids) (PILs) allowed structure control from the first sol-gel reaction steps due to their anisotropy and multiple bonding capacity. They also act as multifunctional compatibilizing agents that affect the interfacial interactions in a molecular structure-dependent manner. Thus, this review will explore the concepts and latest efforts to control silica morphology using processes such as the sol-gel, both in situ and ex situ of polymer matrices, pre-polymers or polymer precursors. It discusses how to control the polymer–filler interphase bonding, highlighting the last achievements in the interphase ionicity control and, consequently, how these affect the final nanocomposites providing materials with barrier, shape–memory and self-healing properties.