Probing the Sol-to-Gel Transition in the Gel Structure

Abstract

The sol- to-gel transition in a bulk gel is a macroscopic event, which can be followed using different analytical methods, even if an accurate determination of the gelation time is always a difficult task. It is possible to obtain reliable measures especially by a combination of techniques. The liquid phase of the gel remains, even after gelation, a peculiar chemical environment with a specific microviscosity which evolves during drying while diffusion inside the pores is always possible. This chapter is dedicated to a brief overview of the methods used to probe this microenviroment and sol-gel transition in thin films.