917 resultados para water-soluble compounds


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A water soluble hygroscopic powder has been isolated from squilla in good yield, ranging from 3.5 to 5.0% of the fresh raw material, by a simple direct method. The process consists of homogenising squilla with an equal quantity of water, removal of chitinous matter from the slurry by filtration, heating the filtrate at 0.7 kg/sq.cm steam pressure for 15-20 minutes, removal of the precipitated protein by filtration and concentration and final drying in vacuum of the filtered cooled liquor. The pale brown powder so obtained consists mainly of peptones and proteoses and has been found to be comparable to BDH peptone for growth of bacteria, ability to serve as source for tryptophan for indole production and to provide substrate for the production of hydrogen sulphide. Comparative studies have been made on similar water soluble fractions from two species of prawns, namely, Metapenaeus affinis and Parapenaeopsis stylifera.

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We report a new approach for the synthesis of fluorescent and water-soluble Ag nanoclusters, using the common polyelectrolyte poly(methacrylic acid) as the template.

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Selective extraction-separation of yttrium(Ill) from heavy lanthanides into 1-octyl-3-methylimidazolium hexafluorophosphate ([C(8)mim][PF6]) containing Cyanex 923 was achieved by adding a water-soluble complexing agent (EDTA) to aqueous phase. The simple and environmentally benign complexing method was proved to be an effective strategy for enhancing the selectivity of [C(n)mim] [PF6]/[Tf2N]-based extraction system without increasing the loss of [C(n)mim](+). (c) 2007 Elsevier B.V. All rights reserved.

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An anionic, phosphonate-functionalized polyfluorene, i.e., poly(9,9-bis(3'-phosphatepropyl)fluorene-alt-1,4-phenylene) sodium salt (PFPNa), has been synthesized by copolymerization of phosphonic acid-substituted 2,7-dibromofluorene and phenyldiboronic ester via direct Suzuki polycondensation reaction in DMF/water. Polymer PFPNa is highly soluble and emissive in water with a solubility of 60 mg/mL and a photoluminescence quantum yield of 75%. The absorption and fluorescence spectra of PFPNa are strongly dependent on pH value owing to the partial protonation of phosphate groups and the aggregation of the polymer chains.

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A novel water-soluble electroactive polymer, aniline pentamer crosslinked chitosan (Pentamer-c-Chi), was prepared by condensation polymerization of the terminal carboxyl groups in aniline pentamer with the amino side groups in chitosan in aqueous solution. The carboxyl groups were activated by N-hydroxysuccinimide (NHS) and N,N'-dicyclohexylcarbodiimide (I)CC). The electrochemical behavior of aniline pentamer in this kind of crosslinked polymer was studied in acidic aqueous solution by means of cyclic voltammetry (CV), UV-vis, and electron spin resonance (ESR) spectroscopy.

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Water-soluble tetra-p-sulfonatocalix[4]arene, acting as a four-connected node, bridges the rare earth cations into a 3D porous MOF in which 1D smaller circular hydrophilic channels and larger quadratic ones are lined up along the c axis and interconnected to each other by the calixarene cavities and other interstices.