الفهرس Only 14 pages are availabe for public view
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Abstract
Creating predicting model that provides possibility to synthesize xerogels with controlled physiochemical properties thus controlled drug release according to chosen conditions is our goal. We studied the simultaneous effect of pH of the precursor solution, water: Tetraethylorthosilicate (TEOS) molar ratios, temperature, Polyethylene glycol (PEG) as additive and aqueous ammonia as aging solution on physiochemical properties of silica xerogel: surface area, total pore volume mesopore volume ,%of weight loss and total enthalpy, The silica xerogel was synthesized via acid catalyzed sol-gel method. Using 2 ⁵⁻² fractional factorial design to analyze the data. Samples were characterized by X-ray diffraction (XRD), High scanning electric microscopy (SEM), Fourier transformed infrared spectroscopy (FTIR), gas adsorption (N₂ at 77 K) and thermal analysis including; thermogravimetric analysis, differential thermal analysis and Differential scanning calorimetry (TGA, DTA and DSC)