Trimethylsilylation of a variety of alcohols and phenols, in the presence of silica chloride, using hexamethyldisilazane (HMDS) in solution and under solvent-free conditions is reported. Trimethylsilyl ethers were formed in excellent yields both for aliphatic alcohols and phenols without having an electron-withdrawing group. In addition, SiO2-Cl can be recovered and reused after drying.

Objective(s): Enzyme immobilization via nanoparticles is perfectly compatible against the other chemical or biological approximate to improve enzyme functions and stability. In this study lactoperoxidase was immobilized onto silica-coated magnetite nanoparticles to improve enzyme properties in the presence of cadmium chloride as an inhibitor. Materials and Methods:  The process consists of the ...

nano-silica supported boron trifluoride (bf3.sio2) is an efficient, reusable and eco-friendly catalyst for chemoselective thioacetalization of aldehydes and ketones. so, this catalyst was applied for transthioacetalization of acetals and acylals into their corresponding 1,3-dithiolanes or 1,3-dithianes  in good to excellent yields. the reactions were carried out at room temperature under solven...

A simplistic green and neat procedure was developed for the synthesis of arylmethyl and heteroaryl phosphonates or phosphinates by silica gel supported Lewis acid catalyst, CeCl3.7H2O-SiO2 through Michaelis-Arbuzov reaction under conventional as well as microwave irradiation methods. Herein, tetraalkyl 1,4phenylenebis(methylene)diphosphonates 5(a-d)/dimethyl 1,4-phenylenebis(methylene)bis (phen...

an efficient green route for the preparation of naphthoxazinones, applying a three-component one-pot condensation reaction of 2-naphthol, aromatic aldehyde and urea in the presence of nano silica supported ferric chloride under solvent-free conditions has been developed. the present procedure offers several advantages such as short reaction time, simple workup, recovery and reusability of the c...

this study focuses on the preparation and modification of a thin-film composite (tfc) hollow fiber polyamide membrane fabricated by the interfacial polymerization of piperazine (pip) and trimesoyl chloride (tmc) on a porous polysulfone substrate. the effects of triethylenetetramine (teta) and silica nanoparticles (sio2) contents in the aqueous phase (as the additives) on the morphology and perf...

We tested the hypothesis that activation of inwardly rectifying potassium (KIR) channels and Na(+)-K(+)-ATPase, two pathways that lead to hyperpolarization of vascular cells, contributes to both the onset and steady-state hyperemic response to exercise. We also determined whether after inhibiting these pathways nitric oxide (NO) and prostaglandins (PGs) are involved in the hyperemic response. F...

The activation of dihydrogen on silica, silver, and silica-supported silver (9 wt% Ag) was investigated. Both, silica and silver are individually able to dissociate dihydrogen. Silanol groups on silica undergo H→D exchange at 393 K in D2 as detected by IR spectroscopy. HD is observed in temporal analysis of products (TAP) experiments when H2 and D2 are sequentially pulsed on silver at 673 K; ev...

In this paper, silica gel supported titanium dioxide particles (TiO2/SiO2) prepared by acid-catalyzed sol–gel method was as photocatalyst in the degradation of acid orange 7 (AO7) in water under visible light irradiation. The particles were characterized by X-ray diffraction, BET specific surface area determination, and point of zero charge measurement. The supported catalyst had large surface ...

Silica, silica/polydimethylsiloxane and silica/polydimethylsiloxane/ calcium xerogels were examined as polymeric carriers for the controlled release of drug—Metronidazole. Characterization assays comprised analysis of the matrix by Fourier transform infrared spectroscopy (FTIR), determining the specific surface area of solids (BET) and scanning electron microscope (SEM) techniques and further m...