Development of Optical barrier films on flexible polymer substrates

Silicon monoxide, SiOhas been deposited on Low-Density Polyethylene (LDPE) surface using Physical Vapor Deposition (PVD) technique. Several thickness films (200, 500 and 700 nm) were prepared. The obtained films were identified and characterized by Fourier transform infrared spectroscopy (FTIR), ultraviolet–visible spectroscopy (UV-VIS) and atomic force microscopy (AFM). At specific coating thickness, far infrared radiation transmittance was prohibited while the ultraviolet–visible transmittance is allowed and that will be explained in details. AFM results showed homogenous and smooth silicon mono oxide thin films. The mean grain size, average roughness (Ra) and root mean square (RMS) roughness values for SiO films were estimated from AFM. Optical measurements show that the coated films prevent the transmission of IR radiation near 9.5μm and allow UV-VIS transmission during the sun-shining time.