Surface modification of PMMA films by CHF3 plasma

Abstract

In the production of an optical device, it is indispensable that the refraction index of the core should be higher than the cladding, in order that the signal is transmitted by the device. Some healthy superficial treatment techniques, like plasma fluorination, are very common to obtain different refraction indexes among the materials, whether by deposition or replacement reactions, which creates a layer of fluorinated polymers on a polymer substrate with a modified refraction index. In this paper, the modification of the poly-methyl methacrylate (PMMA) films surface was studied, using the plasma polymerization technique by fluorinated gas. Such films, with 10 m thickness, were obtained by Spin-Coating, starting from a chloroform solution. The films were exposed to the plasma of trifluoromethane (CHF3) following a factorial experimental. The surfaces of the films were characterized through gravimetry, FTIR-ATR spectroscopy, and contact angle.