nanosilica periodic acid (nano-spia) is found to be a new, powerful, and reusable heterogeneous catalyst for the rapid synthesis of 2-naphtholazo dyes via diazotization of aromatic amines and followsazo coupling with 2-naphthol under solvent-free conditions at room temperature by grinding. eco-friendly, heterogeneous reaction conditions, high stability of diazonium salt, simple experimental pro...

In this work, polyamide (PA)/silica nanocomposite films prepared by dissolution method of composite mixing were investigated. The morphology of nanocomposite films were characterized using scanning electron microscope (SEM), reveals that nano silica powder were uniformly dispersed on PA silica nanocomposite film. Chemical composition of film was confirmed by Fourier transform infrared spectrosc...

silica exists in rice husk, an agriculture waste, as a naturally occurring phase. in first step, acidic pre-treatment and calcination of the rice husk were performed to obtain nano-silica, in which various sizes of the nano-silica, totally with sizes under 80 nm, were achieved. second, to reduce nano-silica to elemental si and subsequently formation of the composite, mg used as the reducing age...

Two simple protocols for the synthesis of three-component condensation reaction of an aldehyde, β-ketoester and urea or thiourea to obtain the 3, 4-dihydropyrimidin-2(1H)-ones (thiones) using nano silica phosphoric acid are reported. Short reaction times, high yields, reusability of catalyst and easy workup are some advantages of these protocols.

An efficient and environmentally benign   method for the synthesis of aryl iodides have been developed by diazotization of aromatic amines with NaNO2 and nanosilica periodic acid (nano-SPIA) as a green catalyst via grinding followed by a sandmeyer iodination by KI under solvent-free conditions at room temperature. The ensuing aryl diazonium salts supported on nano-SPIA were sufficiently stable ...

Diatoms are single-celled algaes that make photonic-crystal-like silica shells or frustules with hierarchical micro& nano-scale features consisting of two-dimensional periodic pores. In this paper, we present an innovative label-free optical sensor based on a biological-plasmonic hybrid nanostructure by self-assembling silver (Ag) nanoparticles into diatom frustules. The photonic-crystal-like d...

Diatoms are single-celled algaes that make photonic-crystal-like silica shells or frustules with hierarchical micro- & nano-scale features consisting of two-dimensional periodic pores. This article reports the use of diatom frustules as an integration platform to enhance localized surface plasmon resonances of self-assembled silver nanoparticles (NPs) on the surface of diatom frustules. Theoret...

This paper describes the synthesis and chromatographic and morphologic characterization of two monolithic silica nano-columns (50 µm i.d.) prepared by sol-gel processes, using hydrophilic interaction (HILIC) mode separations to evaluate their performance. Two types of monoliths were prepared by varying the precursors (tetraethoxysilane or a tetraethoxysilane-methyltrimethoxysilane mixture) and ...

in this paper the influence of two different sizes of silica particles (micro-silica and nano-silica) was studied on mechanical properties of sulfur and sulfur composite. to improve the structural properties, sulfur was plasticized using dicyclopentadiene (dcpd) and methyl styrene (mst). plasticized sulfur composite was prepared by melt blending of plasticized sulfur and silica particles. the i...