Thin films of Al2O3 have been deposited on ITO-coated glass substrates by a sol-gel dipcoat process. Aluminium isopropoxide (Al(OC3H7)3) was used as the Al source material. X-ray diffraction measurements show that these films are amorphous. Scanning electron microscopy and atomic force microscopy images of the films have revealed a relatively flat surface with no cracks. The dielectric properti...

The electrochemical entrapment of polyaniline (PANI) onto sol-gel derived tetraethylorthosilicate (TEOS) films deposited onto indium-tin-oxide (ITO) coated glass has been utilized for immobilization of lactate dehydrogenase (LDH). The performance of these sol-gel/PANI/LDH electrodes has been investigated as a function of the lactate concentration, applied potential, pH of the medium and interfe...

Colloidal suspensions are used to generate polymers or particles from which ceramic materials can be made by the sol-gel process. The precursors for preparation of a colloidal suspension consist of a metal element surrounded by various ligands (attached groups not including another metal). For example, common precursors for sol-gel synthesis of aluminum oxide include inorganic salts such as Al(...

Galactomannan extracted from seeds of Cassia grandis with 0.1M NaCl, followed by ethanol precipitation, presented a yield of 36 ± 8%. The polysaccharide has a constant mannose/galactose ratio (2.44:1). Methylation analysis, one and two dimensional NMR spectroscopy confirmed that the polysaccharide has a central core composed of 4-linked β-mannose units, with branches of galactose, linked to the...

We report on the fabrication of diffraction gratings in photosensitive sol–gel thin films by direct contact printing using a UV-mercury lamp. Titanium amplitude masks were used to replicate diffraction gratings into photosensitive sol–gel films by contact printing with an incoherent UV-light source. Gratings with 1-mm period were fabricated in sol–gel films. The diffraction efficiencies of each...

The overall objective of this research is to enhance the bioactivity of cellulase enzymes as well as the stability of the enzymes to increase it reusability through immobilization of the enzymes in the microenvironment of porous inorganic-organic hybrid sol-gel polymers. Recently, we have discovered that the microenvironment of these sol-gel polymers markedly increases the bioactivity of immobi...

The sol-gel method is a simple and facile wet chemical process for fabricating advanced materials with high homogeneity, high purity, and excellent chemical reactivity at a relatively low temperature. By adjusting the processing parameters, the sol-gel technique can be used to prepare hollow sphere and 1D structural materials that exhibit a wide application in the fields of catalyst, drug or ge...

Dynamic light scattering and oscillatory rheology experiments were performed to study the effects of various salts on the hydrogel consisting of an oligomeric electrolyte gelator, poly(pyridinium-1,4-diyliminocarbonyl-1,4-phenylenemethylene chloride) (1-Cl). Sol-gel transition temperature increased with increasing salt concentration that suggested the salt-in behavior. The concentration depende...

A water vapor sensor based on a combination of sol-gel processing and planar optical waveguide technologies has been developed. The indicator erythrosin B was entrapped in a thin sol-gel film (thickness ∼100 nm) prepared from methyltriethoxysilane, dimethyldiethoxysilane, and tetraethoxysilane. This dye exhibits an increase in absorbance in the presence of liquid or gaseous water. The sol-gel l...