نتایج جستجو برای: fumed silica

تعداد نتایج: 37206  

Journal: :Journal of the American Chemical Society 2012
Haiyuan Zhang Darren R Dunphy Xingmao Jiang Huan Meng Bingbing Sun Derrick Tarn Min Xue Xiang Wang Sijie Lin Zhaoxia Ji Ruibin Li Fred L Garcia Jing Yang Martin L Kirk Tian Xia Jeffrey I Zink Andre Nel C Jeffrey Brinker

We have developed structure/toxicity relationships for amorphous silica nanoparticles (NPs) synthesized through low-temperature colloidal (e.g., Stöber silica) or high-temperature pyrolysis (e.g., fumed silica) routes. Through combined spectroscopic and physical analyses, we have determined the state of aggregation, hydroxyl concentration, relative proportion of strained and unstrained siloxane...

Journal: :journal of chemical and petroleum engineering 0
atieh eskandari faculty of chemical, petroleum and gas engineering, semnan university, semnan, i.r. iran. mansoor anbia research laboratory of nanoporous materials, faculty of chemistry, iran university of science and technology, tehran 16846-13114, iran. mansour jahangiri faculty of chemical, petroleum and gas engineering, semnan university, semnan, i.r. iran. fariba mohammadi nejati faculty of chemical, petroleum and gas engineering, semnan university, semnan, i.r. iran.

silicon and aluminum sources are most important reactants in the synthesis of zeolite. the use of the silicon source has an important effect on the crystallization of zeolites. also, it can change the properties of the end product. this work reports the influence of three common commercial silica sources such as colloidal silica (ludox am-30), fumed silica and water glass on the crystallinity o...

Silicon and aluminum sources are most important reactants in the synthesis of zeolite. The use of the silicon source has an important effect on the crystallization of zeolites. Also, it can change the properties of the end product. This work reports the influence of three common commercial silica sources such as colloidal silica (Ludox AM-30), fumed silica and water glass on the crystallinity o...

2008
David Jesson D. A. Jesson A. Arkhireeva

The adsorption of polyester onto organically modified silicas (ormosils) and (commercial) fumed silica has been compared utilising ToF-SIMS. The thermodynamics of each system was examined by constructing adsorption isotherm plots which indicated that the adsorption of polyester onto one of the modified silicas used may be a two stage process. Adsorption onto the fumed silica is in accord with t...

2005
Susmit Basu Himadri Paul Chinnakonda S. Gopinath Sumit Bhaduri Goutam Kumar Lahiri

Anionic platinum carbonyl cluster has been ion paired with cinchonidium groups that are chemically bound to the surface of MCM-41 and fumed silica. In the hydrogenation of methyl pyruvate or acetophenone the fumed silica-based catalyst gives zero enantioselectivity, but under optimum conditions enantiomeric excesses of > 90 and ∼ 40%, respectively, are obtained with the MCM-41-based catalyst.

Journal: :RESOURCES PROCESSING 1991

1998
Jiang Fan Srinivasa R. Raghavan Saad A. Khan Peter S. Fedkiw Jun Hou Gregory L. Baker

We report results from our studies on composite polymer electrolytes based on novel surface-modified fumed silicas. The electrolytes were prepared by dispersing fumed silica in a matrix formed by methyl-capped polyethylene glycol and lithium salt. Silicas with widely different surface chemistries were synthesized in order to study the effects of surface modification, with the attached surface g...

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...

2016
Pavlo O. Kuzema Iryna V. Laguta Oksana N. Stavinskaya Olga A. Kazakova Mykola V. Borysenko Tudor Lupaşcu

Silica-Enoxil nanobiocomposites with 13 %w of Enoxil were prepared either by mechanical mixing of corresponding powders or by sorptive modification of fumed silica powder with aqueous Enoxil solution under fluidized bed conditions. The interaction of fumed silica with Enoxil and the properties of silica-Enoxil composites have been investigated using IR spectroscopy, thermogravimetric analysis, ...

1998
Srinivasa R. Raghavan Michael W. Riley Peter S. Fedkiw Saad A. Khan

Dynamic rheological techniques are used to probe the microstructures present in fumed silica-based composite polymer electrolytes. These electrolytes are obtained by dispersing hydrophobic fumed silica in a poly(ethylene glycol)-lithium salt solution and display high conductivities (σ298K > 10-3 S/cm), mechanical stability, and easy processability. The materials behave as soft solids (gels) und...

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