Tunable Structure and Connectivity of Organosilica Hybrid Films by Using Different Epoxy Based Precursors in Atmospheric Plasma Deposition

Abstract

Organosilica hybrid films and fluorinated organosilica hybrid films have been successfully deposited using atmospheric plasma deposition. Different precursors, which incorporates epoxy groups in their molecules, were used to obtain connected structures with tunable chemistry and connectivity. The study demonstrated the capability of tuning the chemical composition, connectivity and mechanical properties of organosilica films by selecting the precursors and operational parameters of the process. The use of (3-glycidiloxypropyl) trimethoxysilane (GPTMS) and 2-(3,4-epoxy-cyclohexylethyl) trimethoxysilane (TRIMO) as precursors made possible the deposition of hybrid films with high organic character, increasing the relative C content up to 20 at% and 40 at%, respectively, due to the lower fragmentation caused during the deposition by atmospheric plasma. The obtained structures had higher concentration of symmetric cages than those obtained from precursors without epoxy groups, which lead to a more compact structure and higher stiffness than conventional organic films. The combination with a fluorinated molecule also had a strong influence in the resultant structure caused by the preferential orientation of fluorinated molecules due to the low surface energy of FDTS that causes migration of fluorinated tails to the film-air interface during the film growth.