Fabrication and Characterization of an Optical Nano-hybrid Sol-gel Derived Thin Film on the PMMA Substrate

A TEOS-GPTMS nano-hybrid thin film was deposited on the polymethyl methacrylate (PMMA) substrate by a sol-gel dip coating method. Morphology, roughness and surface chemical bonding of the thin films were evaluated by X-ray diffraction (XRD), field emission scanning electron microscopy(FE-SEM), atomic force microscopy, and Fourier transform infrared spectroscopy methods, respectively. UV-vis spectrophotometer was used to measure the transmittance spectra of the samples. Also, the adhesion and hardness of the coatings were investigated using pencil hardness the adhesion tape test and the test, respectively. XRD results proved that the thin film had an amorphous structure. Also, FE-SEM images indicated that addition of GPTMS to the TEOS yielded a crack-free thin film. Based on the UV-vis spectroscopy results, the transmittance of the polymer substrate in the visible region was increased by the deposition of the nano-hybrid coating. Moreover, the hardness of the PMMA substrate was increased from 3H to 6H by the deposition of the nano-hybrid thin film. Also, tape test confirmed the high adhesion of the nano-hybrid thin film on the PMMA substrate. Consequently, the transparent organic-inorganic GPTMS-TEOS hybrid coating can be used as a scratch resistant coating on the PMMA substrate.