نتایج جستجو برای: silica gel

تعداد نتایج: 136948  

Abolfazl Farahani Farzad Khajavi Parvin Baghai Ravanbakhsh Shirdam,

The aim of this research is to develop a silica gel and alumina column chromatography for separation of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) into two groups. This is achieved by optimizing the cut-off volume of eluting solvent and weight ratio of silica gel and alumina. In this process mixture of PAHs and PCBs divide in two groups and simultaneously o...

Journal: :Talanta 2003
Anupama Goswami Ajai K Singh B Venkataramani

The silica gel modified with (3-aminopropyl-triethoxysilane) was reacted with 5-formyl-8-hydroxyquinoline (FHOQ(x)) to anchor 8-quinolinol ligand on the silica gel. It was characterised with cross polarisation magic angle spinning (CPMAS) NMR and diffuse reflectance infrared Fourier transformation (DRIFT) spectroscopy and used for the preconcentration of Cu(II), Pb(II), Ni(II), Fe(III), Cd(II),...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 2007
ravanbakhsh shirdam abolfazl farahani farzad khajavi parvin baghai

the aim of this research is to develop a silica gel and alumina column chromatography for separation of polycyclic aromatic hydrocarbons (pahs) and polychlorinated biphenyls (pcbs) into two groups. this is achieved by optimizing the cut-off volume of eluting solvent and weight ratio of silica gel and alumina. in this process mixture of pahs and pcbs divide in two groups and simultaneously other...

2016
Cristina Lavinia Nistor Raluca Ianchis Marius Ghiurea Cristian-Andi Nicolae Catalin-Ilie Spataru Daniela Cristina Culita Jeanina Pandele Cusu Victor Fruth Florin Oancea Dan Donescu

The present study describes for the first time the synthesis of silica nanoparticles starting from sodium silicate and oleic acid (OLA). The interactions between OLA and sodium silicate require an optimal OLA/OLANa molar ratio able to generate vesicles that can stabilize silica particles obtained by the sol-gel process of sodium silicate. The optimal molar ratio of OLA/OLANa can be ensured by a...

2016
Mónika Sándor Cristina Lavinia Nistor Gábor Szalontai Rusandica Stoica Cristian Andi Nicolae Elvira Alexandrescu József Fazakas Florin Oancea Dan Donescu

A series of aminopropyl-functionalized silica nanoparticles were prepared through a basic two step sol-gel process in water. Prior to being aminopropyl-functionalized, silica particles with an average diameter of 549 nm were prepared from tetraethyl orthosilicate (TEOS), using a Stöber method. In a second step, aminopropyl-silica particles were prepared by silanization with 3-aminopropyltrietho...

2017
Sivalingam Ramesh Heung Soo Kim Young-June Lee Gwang-Wook Hong Joo-Hyung Kim

It is demonstrated in this paper that silica nanoparticles coated with core/shell gold provide efficient thermal, optical, and morphological properties with respect to the cellulose-polyhedral oligomeric silsesquioxanes (POSS) hybrid system. The one-step synthesis of a silica/gold nanocomposite is achieved with a simultaneous hydrolysis and reduction of gold chloride in the presence of formic a...

2015
Muhammad Aqeel Ashraf Aysha Masood Khan Mushtaq Ahmad Maliha Sarfraz

Microencapsulation has become a hot topic in chemical research. Technology mainly used for control release and protection purposes. The sol-gel micro encapsulation approach for fragrance and aroma in porous silica-based materials leads to sustainable odorant and flavored materials with novel and unique beneficial properties. Sol-gel encapsulation of silica based micro particles considered econo...

2013
Baris R. Mutlu Sujin Yeom Ho-Wang Tong Lawrence P. Wackett Alptekin Aksan

A method is developed for encapsulation of bacterial biocatalysts in silica gels formed by silica nanoparticles (SNP) and a silicon alkoxide crosslinker. Formulation of the gel was optimized by changing the SNP size, SNP to crosslinker ratio and crosslinker functionality. Hydrolysis and condensation reactions of silicon alkoxide were controlled by water to alkoxide ratio (r) and pH of the solut...

Journal: :Chemistry 2009
Laura Contessotto Elena Ghedini Francesco Pinna Michela Signoretto Giuseppina Cerrato Valentina Crocellà

Pure and modified silica materials were synthesised by a sol-gel process and used as carrier for the controlled release of ibuprofen, selected as model drug. A one-step synthesis was optimised for the preparation of various silica-drug composites by using tetraethoxysilane and 3-aminopropyltriethoxysilane as precursors at different molar ratios. The presence of aminopropyl groups on the silica ...

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