نتایج جستجو برای: supercritical water impregnation

تعداد نتایج: 562532  

2010
I. Kikic

A supercritical fluid can be used in substitution of the original organic solvent for the preparation of pharmaceutical forms. The steps involved in the preparation are essentially similar to those of the traditional preparation but in this case the final purification is not required. The interest in the supercritical fluid impregnation of polymeric materials stems from the opportunity to utili...

2000
S. G. Kazarian

Supercritical fluids have a unique and valuable potential for the enhanced processing of many materials. This review describes research in the applications of supercritical fluids to polymer processing. The ability of supercritical carbon dioxide to swell and plasticize polymers is crucial to the impregnation, extraction, and modification of polymeric materials. This plasticization also reduces...

Journal: :The Journal of antimicrobial chemotherapy 2004
Franck Furno Kelly S Morley Ben Wong Barry L Sharp Polly L Arnold Steven M Howdle Roger Bayston Paul D Brown Peter D Winship Helen J Reid

OBJECTIVES Implantable devices are major risk factors for hospital-acquired infection. Biomaterials coated with silver oxide or silver alloy have all been used in attempts to reduce infection, in most cases with controversial or disappointing clinical results. We have developed a completely new approach using supercritical carbon dioxide to impregnate silicone with nanoparticulate silver metal....

Journal: :International journal of pharmaceutics 2005
M Perrut J Jung F Leboeuf

In this second of two articles, we show that several supercritical processes have been developed to prepare composite particles of poorly soluble active ingredients. Microencapsulation, cyclodextrin inclusion and impregnation allow to incorporate poorly soluble materials in fast-dissolving hydrophilic excipients, leading to promising results in terms of dissolution rate enhancement.

2008
V. N. Bagratashvili

Various thermoplastic polymers (polyethylene, polypropylene, PMMA, polycarbonate) were impregnated with spiroxazine photochrom (-1,3,3-threemethylspyro (indoline-2,3-3Нantrazeno[2,1-b] [1,4] oxazin) (SAO) dissolved in supercritical CO2 SAO molecules have usually stable unexcited form (A) that transfers to unstable “colored” form (B) under the action of UV light. It was found that, unlike other ...

2001
H. D. Cochran S. Karaborni

Cochran, H.D., Cummings, P.T. and Karaborni, S., 1992. Solvation in supercritical water. Fluid Phase Equilibria, 71: 1-16. The aim of this work is to determine the solvation structure in supercritical water compared with that in ambient water and in simple supercritical solvents. Molecular dynamics studies have been undertaken of systems that model ionic sodium and chloride, atomic argon, and m...

Journal: :International journal of pharmaceutics 2006
Ana Rita C Duarte Mariana Sousa Costa Ana Luísa Simplício Maria Margarida Cardoso Catarina M M Duarte

Ethylcellulose/methylcellulose blends were produced using different precipitation techniques and impregnated with naproxen, a non-steroidal anti-inflammatory drug (NSAID). Solvent-evaporation technique was used not only for the preparation of ethylcellulose/methylcellulose microspheres but also to encapsulate naproxen. Supercritical fluid (SCF) impregnation was also performed to prepare naproxe...

2006
D. M. Bartels

The direct measurement of the chemistry in reactor cores is extremely difficult. The extreme conditions of high temperature, pressure, and radiation fields, are not compatible with normal chemical instrumentation. There are also problems of access to fuel channels in the reactor core. For these reasons, all reaction vendors and many operators have extensively used theoretical calculations and c...

Journal: :The Journal of chemical physics 2010
T Tassaing P A Garrain D Bégué I Baraille

The present study is aimed at a detailed analysis of supercritical water structure based on the combination of experimental vibrational spectra as well as molecular modeling calculations of isolated water clusters. We propose an equilibrium cluster composition model where supercritical water is considered as an ideal mixture of small water clusters (n=1-3) at the chemical equilibrium and the vi...

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