Micropatterning of non-crystalline methylsilsesquioxane–titania hybrid films based on their structural changes with UV irradiation

Non-crystalline, transparent methylsilsesquioxane–titania hybrid films for application in micropatterning were prepared from methyltriethoxysilane and titanium tetrabutoxide by the sol–gel method. The hybrid films were heat-treated at 100 8C for 1 h and then irradiated with UV light using an ultrahigh-pressure mercury lamp. The refractive index of the film increased as the amount of incorporated TiO2 increased. No changes in hardness were observed for the films lacking TiO2 during UV irradiation, whereas adding a small amount of TiO2 caused the hardness to increase significantly following UV irradiation. These changes in the physical properties of the films with UV irradiation were caused by the cleavage of Si–C bonds in the films induced by the photocatalytic effect of TiO2.On the basis of the changes in surface profiles, and optical, chemical, and mechanical properties induced by UV irradiation, it is concluded that the methylsilsesquioxane–titania films are promising for micropatterning by photolithography

Micropatterning of non-crystalline methylsilsesquioxane–titania hybrid films based on their structural changes with UV irradiation

Non-crystalline, transparent methylsilsesquioxane–titania hybrid films for application in micropatterning were prepared from methyltriethoxysilane and titanium tetrabutoxide by the sol–gel method. The hybrid films were heat-treated at 100 8C for 1 h and then irradiated with UV light using an ultrahigh-pressure mercury lamp. The refractive index of the film increased as the amount of incorporated TiO2 increased. No changes in hardness were observed for the films lacking TiO2 during UV irradiation, whereas adding a small amount of TiO2 caused the hardness to increase significantly following UV irradiation. These changes in the physical properties of the films with UV irradiation were caused by the cleavage of Si–C bonds in the films induced by the photocatalytic effect of TiO2.On the basis of the changes in surface profiles, and optical, chemical, and mechanical properties induced by UV irradiation, it is concluded that the methylsilsesquioxane–titania films are promising for micropatterning by photolithography

Mechanical properties comparison of phenylsilsesquioxane–methylsilsesquioxane hybrid films by indentation

Sol­gel derived phenylsilsesquioxane (PhSiO3/2)­methylsilsesquioxane (MeSiO3/2) films were prepared on soda-lime-silicate (SLS) glass substrates by dropping and spreading method. The mechanical properties of the pure MeSiO3/2 and 20PhSiO3/2· 80MeSiO3/2 (inmol%) films were measured as a function of heat treatment times and temperatures using a nanoindentation test with a Berkovich indenter. The relative residual depth (²r)offilms decreased and the film hardness (HM)significantly increased with increasing heat treatment times and temperatures. The mechanical properties of the films well reflect the changes in the chemical structures and the evolution of siloxane networks with the heat treatment

Influence of UV irradiation on mechanical properties and structures of sol–gel-derived vinylsilsesquioxane film

The influence of ultraviolet (UV) irradiation on vinylsilsesquioxane (ViSiO3/2) films was investigated using a nanoindentation technique, and the structural changes were analyzed. Solid-state 13C cross-polarization magic-angle-spinning nuclear magnetic resonance and infrared spectra of the films confirmed the polymerization of C=C bonds and formation of a C­C bridge structure upon UV irradiation. Since the vinyl group is a photosensitive organic component with a short organic chain, it is expected to show a large improvement in mechanical properties as a result of the formation of an organic network under the influence of UV irradiation. It is shown that varying the intensity of the UV irradiation leads to changes in the hardness and elasticity. The irradiation energy was found to determine the mechanical properties of the ViSiO3/2 films, regardless of the effects of different UV intensities on the hybrid films

High-pressure (GPa) impedance measurements based on an indentation-induced local stress field

International audienceElectrical measurements of conducting and dielectric materials under high pressures (in the order of GPa) reveal important information regarding orbital overlaps, electronic states, changes in transition temperatures, and activation volumes (Delta V). In this study, we demonstrate a new method for high-pressure impedance measurements, up to 4 GPa, utilizing an indentation-induced local stress field. The current system does not require any pressure mediums or pressure calibrations. The Delta V for O2- ion conduction in 10 mol\% Y2O3-doped zirconia at 500 degrees C was estimated to be 3.0 cm(3) mol(-1). Delta V increased with increasing temperatures from 500 to 600 degrees C. The technique also allows the concurrent determination of the effective elastic modulus by fitting the experimental data obtained from the indentation load-depth profile curve with the Hertzian elastic model. The experimental values were consistent with the theoretical values. (C) 2013 Elsevier B.V. All rights reserved