in the present investigation surface modification of silica nanoparticles by alumina was carried out by sol-gel process. fourier transform infrared (ftir) and x-ray fluorescence (xrf) confirmed the synthesis of silica and the surface modification as alumina is anchored to silica surface. field emission scanning electron microscopy (fesem) and transmission electron microscopy (tem) investigation...

as we know sol-gel is one of the most important techniques for thin film preparation. in this paper, high transmission silica thin films have been prepared by dip-coating process from a new silicon-alkoxide solution. the prepared sol was stable for 45 days which is very important to characterize the coating process. the optical properties as a function of aging time, withdrawal rate, and heat t...

in this article, hybrid organic-inorganic materials were prepared by free radical copolymerization of 2-hydroxyethyl methacrylate (hema) and 3-methacryloxy-propyltrimethoxysilane (mptms) via sol-gel process. the methoxysilane-containing copolymer precursors were synthesized at different compositions. these copolymer precursors were then hydrolyzed and condensed to produce phema-sio2 nanocomposi...

we have modified one of the most useful methods of protein separation; namely, two dimensional gel electrophoresis (2-de). this modified version of 2-de is not only simpler and easier but also faster than all the currently available methods. in this method, isoelectric focusing is carried out in the first dimension using a vertical sodium dodecyl sulfate polyacrylamide gel electrophoresis (sds-...

The dynamics of a thixotropic silica aerosil gel dispersed in an octylcyanobiphenyl liquid crystal were directly probed by x-ray intensity fluctuation spectroscopy. For all samples, the time-autocorrelation function of the gel was well described by a modified-exponential function over the q range studied. Compared to a pure gel sample, a dilute (0.06 g cm(-3)) gel embedded within the liquid cry...

Ten indole alkaloids from the chloroform extract of stalk of Tabernaemontana australis (Muell. Arg) Miers were tentatively identified by GC-MS, viz., coronaridine (1), voacangine (2), voacangine hydroxyindolenine (3), rupicoline (4), ibogamine (5), ibogaine (6), ibogaline (7), desethyl-voacangine (8), voachalotine (9), and affinisine (10). Of these, the first four were isolated by silica gel op...

Egyptian Petroleum Research Institute, Nasr City, Cairo, Egypt. Chemistry Department, Faculty of Science, Taif University, KSA. __________________________________________________________________________________________ Abstract Inverse gas chromatography (IGC) has become an accurate, versatile and fast method to study the physicochemical characteristics of the modified silica gels. The use of t...