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High Hydrophobicity (high + hydrophobicity)
Selected AbstractsStructure,fungitoxicity relationships of some volatile flavour constituents of the edible mushrooms Agaricus bisporus and Pleurotus floridaFLAVOUR AND FRAGRANCE JOURNAL, Issue 4 2001Eugene Sebastian J. Nidiry Abstract The fungitoxicity of the diethyl ether extracts of two basidiomycete mushrooms, Agaricus bisporus and Pleurotus florida, and 14 flavour constituents present in these mushrooms is being reported. Median effective molar concentrations (EC50) of the compounds for the mycelial growth inhibition of Colletotrichum gloeosporioides on potato,dextrose,agar (PDA) medium were computed and compared. Among the constituents tested for fungitoxicity, 1-octanol exhibited the highest activity. Structure,activity relationship studies of the constituents revealed that high hydrophobicity of the alkyl moiety, the presence of the primary alcoholic group and the absence of branching of the alkyl group are responsible for the high activity of 1-octanol. Copyright © 2001 John Wiley & Sons, Ltd. [source] Chemical modification of polyethersulfone nanofiltration membranes: A reviewJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2009B. Van der Bruggen Abstract Polysulfone (PS) and poly(ether)sulfone (PES) are often used for synthesis of nanofiltration membranes, due to their chemical, thermal, and mechanical stability. The disadvantage for applying PS/PES is their high hydrophobicity, which increases membrane fouling. To optimize the performance of PS/PES nanofiltration membranes, membranes can be modified. An increase in membrane hydrophilicity is a good method to improve membrane performance. This article reviews chemical (and physicochemical) modification methods applied to increase the hydrophilicity of PS/PES nanofiltration membranes. Modification of poly(ether)sulfone membranes in view of increasing hydrophilicity can be carried out in several ways. Physical or chemical membrane modification processes after formation of the membrane create more hydrophilic surfaces. Such modification processes are (1) graft polymerization that chemically attaches hydrophilic monomers to the membrane surface; (2) plasma treatment, that introduces different functional groups to the membrane surface; and (3) physical preadsorption of hydrophilic components to the membrane surface. Surfactant modification, self-assembly of hydrophilic nanoparticles and membrane nitrification are also such membrane modification processes. Another approach is based on modification of polymers before membrane formation. This bulk modification implies the modification of membrane materials before membrane synthesis of the incorporation of hydrophilic additives in the membrane matrix during membrane synthesis. Sulfonation, carboxylation, and nitration are such techniques. To conclude, polymer blending also results in membranes with improved surface characteristics. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 [source] Physicochemical and biological evaluation of plasma-induced graft polymerization of acrylamide onto polydimethylsiloxaneJOURNAL OF APPLIED POLYMER SCIENCE, Issue 4 2008A. Parvin Abstract Polydimethylsiloxane (PDMS) rubbers exhibit good mechanical properties for biomedical and industrial applications, but their inherently high hydrophobicity limits biomedical applications of this material despite its favorable mechanical properties. In this work, surface modification of PDMS by radio-frequency glow discharge and subsequently graft polymerization of acrylamide was studied. PAAm-grafted, oxygen plasma-treated, and control (untreated) PDMS rubbers were characterized using attenuated total reflectance Fourier transform infrared, scanning electron microscopy, dynamic mechanical thermal analyses, zeta potential, and contact angle techniques. Fibroblast (L929) cell attachment and growth onto these surfaces were examined by optical microscopy. The data from in vitro assays showed that cell attachment onto control surface was very negligible while significant cell attachment and growth was observed onto oxygen plasma-treated and PAAm-grafted PDMS surfaces. The method developed in this work offers a convenient way of surface modifications of biomaterials to improve attachment of cells onto substrates. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008 [source] Biosynthesis of peptide fragments of eukaryotic GPCRs in Escherichia coli by directing expression into inclusion bodiesJOURNAL OF PEPTIDE SCIENCE, Issue 5 2010Leah S. Cohen Abstract Biosynthesis of peptides in heterologous systems is often a prerequisite to biophysical analyses. Large amounts of peptides, in particular portions of membrane proteins, are needed to optimize conditions for secondary and tertiary structure analysis. Chemical synthesis of these peptides is limited by their high hydrophobicity and also due to the need to incorporate isotopic labels for high resolution NMR analysis. In this protocol, we describe a method for the heterologous expression and purification of unlabeled and isotopically labeled peptide fragments of Ste2p, an integral membrane G protein-coupled receptor. Copyright © 2010 European Peptide Society and John Wiley & Sons, Ltd. [source] Sulfonated poly(ether sulfone)s with binaphthyl units as proton exchange membranes for fuel cell applicationJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 21 2009Kazuya Matsumoto Abstract Sulfonated poly(ether sulfone)s containing binaphthyl units (BNSHs) were successfully prepared for fuel cell application. BNSHs, which have very simple structures, were easily synthesized by postsulfonation of poly(1,1,-dinaphthyl ether phenyl sulfone)s and gave tough, flexible, and transparent membranes by solvent casting. The BNSH membranes showed low water uptake compared to a typical sulfonated poly(ether ether sulfone) (BPSH-40) membrane with a similar ion exchange capacity (IEC) value and water insolubility, even with a high IEC values of 3.19 mequiv/g because of their rigid and bulky structures. The BNSH-100 membrane (IEC = 3.19 mequiv/g) exhibited excellent proton conductivity, which was comparable to or even higher than that of Nafion 117, over a range of 30,95% relative humidity (RH). The excellent proton conductivity, especially under low RH conditions, suggests that the BNSH-100 membrane has excellent proton paths because of its high IEC value, and water insolubility due to the high hydrophobicity of the binaphthyl structure. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5827,5834, 2009 [source] | |||||||||||||