Characterization of the interfacial interaction between polyacrylamide and silicon substrate by Fourier transform infrared spectroscopy

The formation of the interface between the polyacrylamide (PAL) Spin-coated thin films and the silicon (Si) substrates was characterized by Fourier transform infrared spectroscopy, (FTIR). The increase in the peak intensity and the decrease in the peak frequency of the Si-O stretching vibration at 1107 cm(-1) support that the hydrogen bonds are formed between the hydrogen atoms in the PAL amino groups and the oxygen atoms in SiO2 on the Si substrate. Compared to the PAL casting film on the Teflon surface, the orientation of PAL carbonyl groups parallel to the substrate Sur-face for the spin-coated PAL thin films was found. This side-group orientation is believed due to the inter-facial interaction.