نتایج جستجو برای: nano silica

تعداد نتایج: 86088  

2014
Ludovic F. Dumée Fenghua She Mikel Duke Stephen Gray Peter Hodgson Lingxue Kong

Meso-porous metal materials have enhanced surface energies offering unique surface properties with potential applications in chemical catalysis, molecular sensing and selective separation. In this paper, commercial 20 nm diameter metal nano-particles, including silver and copper were blended with 7 nm silica nano-particles by shear mixing. The resulted powders were cold-sintered to form dense, ...

In this research work, silica nano-porous thin films were deposited on glass substrates by layer by layer method. The thin films were calcinated at various calcination temperatures (200, 300, 400, and 500 °C). The morphology, surface characteristics, surface roughness and hydrophilic properties of the thin films were investigated by field emission scanning electron microscopy, attenuated total ...

Marziyeh Bagheri Mostafa Karimkoshteh,

Nano silica-H2SO4 is an efficient and mild catalysis system for the regeneration of aldehyde from aldoximes. Ketoximes are converted to amides by Beckmann rearrangement in the presence of nano silica-H2SO4. The reactions are carried out in solvent-free conditions under microwave irradiation (600 W) within 50-120 sec in good yields.

Journal: :Nanoscale 2012
Oleg I Lebedev Stuart Turner Shiquan Liu Pegie Cool Gustaaf Van Tendeloo

Using template-containing silica microspheres as a precursor, novel ordered mesoporous silica nanoparticles with a narrow pore size distribution and high crystallinity have been synthesized by various hydrothermal merging processes. Several architectures like chains, dumbbells, triangles, squares and flowers have been discovered. The linking mechanisms of these interacting silica spheres leadin...

2016
Marwa Elkady Hassan Shokry Hassan Aly Hashim

A novel nano-hybrid was synthesized through immobilization of amine-functionalized silica gel nanoparticles with nanomagnetite via a co-precipitation technique. The parameters, such as reagent concentrations, reaction temperature and time, were optimized to accomplish the nano-silica gel chelating matrix. The most proper amine-modified silica gel nanoparticles were immobilized with magnetic nan...

Journal: :Chemical communications 2010
George Hasegawa Kazuyoshi Kanamori Kazuki Nakanishi Teiichi Hanada

Hierarchically porous carbon monoliths with high specific surface areas have been fabricated by removing nano-sized silica phase from carbon/silica composites pyrolyzed from bridged polysilsesquioxane. This activation method improves the homogeneity between inner and outer parts of the monoliths compared to the conventional thermal activation methods.

Journal: :جنگل و فرآورده های چوب 0
حسین جلالی ترشیزی استادیار گروه فناوری سلولز و کاغذ دانشکدة مهندسی فناوری‏های نوین دانشگاه شهید بهشتی، تهران، ایران سعیده زارع بیدکی کارشناس ارشد گروه فناوری سلولز و کاغذ دانشکدة مهندسی فناوری‏های نوین دانشگاه شهید بهشتی، تهران، ایران امید رمضانی استادیار گروه فناوری سلولز و کاغذ دانشکدة مهندسی فناوری‏های نوین دانشگاه شهید بهشتی، تهران، ایران حمیدرضا رودی استادیار گروه فناوری سلولز و کاغذ دانشکدة مهندسی فناوری‏های نوین دانشگاه شهید بهشتی، تهران، ایران

various kinds of chemicals are used in papermaking to enhance paper properties and to improve efficiency of the production process. in the presence of cationic starch as an anionic charge catcher, effects of nano silica/cationic polyacrylamide complex on retention, drainage time, water volume drained by dynamic drainage jar and properties of paper recycled from old corrugated container were inv...

Phosphosulfonic acid as a multi solid site was easilyprepared from the reaction of ammonium dihydrogen phosphatewith chlorosulfonic acid in CCl4and for improved its catalyticactivity was supported nano Silica was extracted from husk ricecontains about 95% of Silica the size of extracted nano silica wasdetermined by SEM efficiency of this solid acid in four componentcondensation reaction of arom...

2015
S. D. Eder K. Fladischer S. R. Yeandel A. Lelarge S. C. Parker E. Søndergård B. Holst

Silica (SiO2) is one of the most common materials on Earth. The crystalline form α-quartz is the stable silica polymorph at ambient conditions although metastable forms exist. α-quartz is a piezoelectric material, it can be produced artificially and is widely used for example in electronics and the biosciences. Despite the many application areas, the atomic surface structures of silica polymorp...

2009
Jitender P. Sharma

The effect of addition of nano size fumed silica on the conductivity and viscosity behaviour of polymer gel electrolytes containing polyethylene oxide (PEO), ammonium hexafluorophosphate (NH4PF6) and propylene carbonate (PC) has been studied. The addition of PEO increases the viscosity of electrolytes alongwith a small increase in conductivity and polymer gel electrolytes with conductivity high...

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