Influence of the polymer molecular weight on the microstructure of hybrid materials prepared by γ-irradiation

• The influence of PDMS Mw was investigated in hybrid materials of fixed composition.
• As PDMS Mw increases, the size and structure of the inorganic regions changes.
• PDMS Mw influences the microstructure of the hybrids.

Hybrid materials have been the object of intense research due to their potential for biomedical applications as well as in other fields. They are usually prepared by sol–gel but the method of gamma irradiation of the precursors is an alternative avoiding the addition of any other chemicals. The study of the hybrids prepared by this method has been progressing to understand the impact of different variables on the microstructure. In this work, the influence of the polymer׳s molecular weight on the microstructure of the materials is investigated. Hybrids were obtained from a mixture of polydimethylsiloxane (PDMS) silanol terminated, tetraethylorthosilicate (TEOS) and zirconium propoxide (PrZr) in the wt% composition 20PDMS–73TEOS–7PrZr varying only the PDMS molecular weight. The obtained materials are homogeneous, transparent and flexible and their microstructure was analysed by Scanning Electron Microscopy (SEM) and Small-Angle Neutron Scattering (SANS). It was found that different microstructures were obtained, depending on the polymer molecular weight.