Fabrication of silica films using Langmuir Blodgett technique for sensing applications

The present work reports the fabrication of monodispersive silica nanoparticles films using Langmuir Blodgett technique. The synthesized silica nanoparticles were characterized by using dynamic light scattering (DLS), scanning electron microscopy (SEM), Fourier transform-infra red (FTIR) and UV-visible spectroscopy. The DLS and SEM measurements clearly showed successful formation of approximately 350 nanometer (nm) sized monodispersive silica nanoparticles. We have fabricated films with varied surface pressure ranges from 12 mN/m-22 mN/m under the solid phase region of Langmuir's surface pressure versus area isotherm. We have also investigated the effect of 350 nm sized silica nanoparticles concentration on the lift of area in the Langmuir’s pressure-area isotherm. FTIR spectra of synthesized silica exhibited several peaks corresponding to various structural units indicating the formation of silica nanoparticles. The UV-visible spectra of fabricated films showed remarkable absorption in 400-450 nm wavelength range. Special optical properties of these films have potential applications in fields including photonics, sensors, electro-optics, electronics, and medical science.