PURPOSE The aim of the present study was to synthetize and characterize novel sol-gel organic-inorganic hybrid materials to be used for controlled drug delivery application. MATERIALS AND METHODS Organic-inorganic hybrid class I materials based on poly(epsilon-caprolactone) (PCL 6, 12, 24 and 50 wt%) and zirconia-yttria (ZrO2-5%Y2O3) were synthesized by a sol-gel method, from a multicomponent...

Previous studies have shown that the barrier effect and the performance of organic-inorganic hybrid (OIH) sol-gel coatings are highly dependent on the coating deposition method as well as on the processing conditions. However, studies on how the coating deposition method influences the barrier properties in alkaline environments are scarce. The aim of this experimental research was to study the...

Sol–gel chemistry is an efficient tool to control the morphology and reactivity of solids. Drying is the crucial step due to the capillary forces exerted during the classic ambient drying process, which induces the collapse of the wet gel porosity. The use of N, N-dimethylformamide (DMF), a newly found DCCA were found to be effective in the sol–gel synthesis of crack-free silica gel monolith fr...

An optical urea biosensor was fabricated by stacking several layers of sol-gelfilms. The stacking of the sol-gel films allowed the immobilization of a Nile Bluechromoionophore (ETH 5294) and urease enzyme separately without the need of anychemical attachment procedure. The absorbance response of the biosensor was monitoredat 550 nm, i.e. the deprotonation of the chromoionophore. This multi-laye...

We report that oxidized multiwalled carbon nanotubes (MWCNTs) can be synchronously dispersed and functionalized in TiO2 sol via an in situ sol-gel process. Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and atomic force microscopy (AFM) were used to characterize the functionalized MWCNTs. The results revealed that the hydrolysis and condensat...

Sol-gel and polymeric membrane electrodes, based on thiacalix[4]arene as a neutral carrier, weresuccessfully developed for the detection of VO2+ in aqueous solutions. The sol-gel and PVCmembrane electrodes exhibited linear response with Nernstian slopes of 29.3 and 28.4 mV perdecade, respectively, within the vanadyl ion concentration ranges from 1.0 × 10-6 to 1.0 × 10-1mol dm-3 and from 1.0 × 1...

INTRODUCTION A sol-gel preparation involves f m t the formation of a sol, which is a suspension of solid particles in a liquid, then of a gel, which is a diphasic material with a solid encapsulating a liquid. The liquid can be removed from a gel by either conventional drying (such as by using an oven) to obtain a plojiict kLown as e xercgel, or hy drying with supercritical extraction (often ref...

The sol-gel method produces amorphous or crystalline thin gel films of metallic solid compounds by solidifying a sol formed by hydrolyzing and polymerizing a solution containing metallic compounds. Sol-gel processes are widely employed in the field of chemistry to prepare ceramic powders and thin films of hafnium oxide (HfO2) (Nishide et al., 2000) and zirconium oxide (ZrO2) ( Liu et al., 2002)...

For detection of phenolic compounds a simple amperometric biosensor based on tyrosinase immobilized in titania sol-gel/Nafion composite was employed. Titania sol-gel was mixed with Nafion (v/v) in ratios 1:1 (TiO2/NF-1/1) and 2:1 (TiO2/NF-2/1), v/v. Morphology of immobilization composites was characterized by scanning electron microscopy. Analytical performance of biosensors with Nafion and bas...

Three kinds of lipases (from Candida antarctica, Pseudomonas cepacia, and Pseudomonas fluorescens) were encapsulated in inorganic matrices by the sol-gel method in order to synthesize chiral compounds by kinetic resolution. Sol-gel lipases prepared with vinyltriethoxysilane had higher hydrolysis activity for 2-octyl acetate than those with other silane precursors: tetramethoxysilane, methyltrim...