نتایج جستجو برای: supercritical carbon dixide

تعداد نتایج: 289203  

2005
Teresa Castelo-Grande Paulo A. Augusto Domingos Barbosa

The aim of this research project is to study the applicability of supercritical extraction with carbon dioxide to the decontamination of soils containing pesticides. In this work, after a brief but important introduction to the subject, the results of a preliminary study of the extraction of atrazine from sand with supercritical carbon dioxide are reported. These results, which were obtained wi...

2009
C. Y. Kong M. Nakamura K. Sone T. Funazukuri S. Kagei

The binary diffusion coefficients of ferrocene and 1,1’-dimethylferrocene at infinite dilution in supercritical carbon dioxide, D12, were measured by the chromatographic impulse response (CIR) method at temperatures from 308.2 to 323.2 K and pressures from 9 to 40 MPa. The D12 data for ferrocene were also measured by the Taylor dispersion method. The diffusion data of ferrocene measured by the ...

2002
Yukihiko Matsumura

Two wet biomass gasification processes, supercritical water gasification and biomethanation, were evaluated from energy, environmental, and economic aspects. Gasification of 1 dry-t/d of water hyacinth was taken as a model case. Assumptions were made that system should be energetically independent, that no environmentally harmful material should be released, and that carbon dioxide should be re...

Journal: :Chemical communications 2011
Byeongno Lee Seung Hee Kang Donghyeon Kang Kyu Hyung Lee Jaeheung Cho Wonwoo Nam Oc Hee Han Nam Hwi Hur

A solid hydrazine was isolated as a crystalline powder by reacting aqueous hydrazine with supercritical CO(2). Its structure determined by single crystal X-ray diffraction shows a zwitterionic form of NH(3)(+)NHCO(2)(-). The solid hydrazine is remarkably stable but is as reactive as liquid hydrazine even in the absence of solvents.

Journal: :Physical review. E, Statistical, nonlinear, and soft matter physics 2009
J Martí J Sala E Guàrdia M C Gordillo

We report the results of a series of molecular dynamics simulations of water inside a carbon-slit pore at supercritical conditions. A range of densities corresponding from liquid (0.66gcm;{-3}) to gas environments (0.08gcm;{-3}) at the supercritical temperature of 673K were considered. Our findings are compared with previous studies of liquid water confined in graphene nanochannels at ambient a...

2002
John E. Chateauneuf Jingsheng Zhang Joshua Foote Jeffery Brink Marc W. Perkovic

We present our initial results on the use of supercritical carbon dioxide as both a reactant and as a reaction medium to photo-chemically produce carboxylic acids from polycyclic aromatic hydrocarbons via radical anion intermediates. In the present work, we have found that photolysis of anthracene in supercritical carbon dioxide produces up to 57% yield of 9,10-dihydroanthracene-9-carboxylic ac...

Journal: :Langmuir : the ACS journal of surfaces and colloids 2011
Christopher A Barrett Ajay Singh Joseph A Murphy Catriona O'Sullivan D N Buckley Kevin M Ryan

Colloidal carbon spheres were synthesized by the carbonization of squalane, a nonvolatile hydrocarbon solvent, in supercritical carbon dioxide. Precise pressure modulation of the fluid medium led to size controlled growth of carbon spheres ranging from 300 to 1500 nm in diameter. This unique synthetic approach of carbonizing a hydrocarbon suspension in supercritical fluid is found to suppress a...

Journal: :Chemical & pharmaceutical bulletin 2002
Young Hae Choi Ki-Pung Yoo Jinwoong Kim

Supercritical fluid extraction using carbon dioxide modified with methanol, methanol-diethylamine, or methanol-triethylamine was used to extract vinblastine from the aerial portions of Catharanthus roseus. An HPLC-electrospray ionization (ESI)/MS analysis method was also developed to quantify the alkaloids in these extracts. Of the supercritical solvents evaluated, carbon dioxide-methanol-triet...

2003
Sheng-Meng Wang Yong-Chien Ling

The gas-like mass transfer properties and liquid-like solvation characteristics of supercritical fluid make it a promising medium in performing extractory and chromatographic separations, i.e., supercritical fluid extraction (SFE) and supercritical fluid chromatography (SFC), respectively. The tunable solvation properties of supercritical carbon dioxide not only improve SFE's efficiency and spe...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2009
Jie Ke Wenta Su Steven M Howdle Michael W George David Cook Magda Perdjon-Abel Philip N Bartlett Wenjian Zhang Fei Cheng William Levason Gillian Reid Jason Hyde James Wilson David C Smith Kanad Mallik Pier Sazio

Electrodeposition is a widely used materials-deposition technology with a number of unique features, in particular, the efficient use of starting materials, conformal, and directed coating. The properties of the solvent medium for electrodeposition are critical to the technique's applicability. Supercritical fluids are unique solvents which give a wide range of advantages for chemistry in gener...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید