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71.
Di Michele A Brinchi L Di Profio P Germani R Savelli G Onori G 《Journal of colloid and interface science》2011,358(1):160-166
The critical micelle concentration (cmc) and ionisation degree (α), of micelles of cetyltrimethylammonium bromide (CTABr), cetyltrimethylammonium chloride (CTACl), cetyltripropylammonium bromide (CTPABr) and cetyltripropylammonium chloride (CTPACl) have been measured over a narrow temperature range at 2 degree intervals using electrical conductivity. CTPACl and CTPABr are very soluble in water and were measured in the temperature range 275.15-323.15K. The Krafft temperatures for CTABr and for CTACl are 293.15K and 284.15K, respectively and established a lower temperature limit for our studies on these two surfactants. The cmc vs temperature curves have a smooth minimum near room temperature and α linearly increases with temperature. The changes of cmc and α with temperature are smaller than those associated with the modification of head group size or counterion nature. Using these results, basic thermodynamic quantities associated with the phenomena of micellization have been evaluated. Thermodynamic properties of the surfactant solutions were discussed in terms of temperature dependence of the free energy, enthalpy and entropy of micellization. A close similarity between the effects of change in temperature on protein folding and micellization process appears from the data. 相似文献
72.
Morra S Valetti F Sadeghi SJ King PW Meyer T Gilardi G 《Chemical communications (Cambridge, England)》2011,47(38):10566-10568
[FeFe]-hydrogenases are efficient natural catalysts that can be exploited for hydrogen production. Immobilization of the recombinant [FeFe]-hydrogenase CaHydA was achieved for the first time on an anatase TiO(2) electrode. The enzyme is able to interact and exchange electrons with the electrode and to catalyze hydrogen production with an efficiency of 70%. 相似文献
73.
Cellulose foams, or sponges, are produced from solutions in ionic liquids by the aqueous acid mediated decomposition of 1-alkyl-3-methylimidazolium-2-carboxylates, where the alkyl group and acid may be selected such that the by-product is the ionic liquid solvent: a by-productless foaming. 相似文献
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This communication describes a simple, rapid and cost effective method of embedding a conductive and flexible material within microfluidic devices as a means to realize uniform electric fields within cellular microenvironments. Fluidic channels and electrodes are fabricated by traditional soft-lithography in conjunction with chemical etching of PDMS. Devices can be deformable (thus allowing for a combination of electro-mechanical stimulation), they are made from inexpensive materials and easily assembled by hand; this method is thus accessible to a wide range of laboratories and budgets. 相似文献
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We present a model of a new paramagnetic defect center which results from the interaction of atomic hydrogen with the MgO(1 0 0) surface. DFT calculations have been performed using periodic supercells and embedded cluster models where long-range polarization effects are included explicitly. The H atom promotes the creation of an oxygen vacancy (F center) by formation of the FS+(OH−) defect where an hydroxyl group is adsorbed near an electron trapped in an oxygen vacancy. This new center has some characteristics similar to those of the classical FS+ centers but a smaller formation energy; furthermore, being globally neutral, it can be treated also with supercell methods. 相似文献
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Riassunto Si dà una costruzione di un insieme minimale di generatori omogenei per l'ideale di una curva monomiale proiettiva e una limitazione
per il grado delle equazioni che la definiscono.
Summary A construction of a minimal system of homogeneous generators for the ideal of a monomial projective curve and a degree bound for its defining equations are given.相似文献