Water affinity

Metal-solution interface, quantum mechanical calculations for (Kripsonsov), 174 Metal-water affinity, 177 Micro-balance, quartz crystal, 578 Microwave circuit, 446 for Faraday rotation, 454 Microwave conductivity... 

The preferred choice of a water-selective membrane up to now has been hydrophilic membranes because of their high water affinity. However, recently Kuhn et al. reported an all-silica DDR membrane for dehydration of ethanol and methanol with high fluxes (up to 20kg m h ) and high selectivities (H20/ethanol 1500 and H20/methanol 70 at 373 K) in pervaporation operation. The separation is based on molecular sieving with water fluxes comparable to well-performing hydrophilic membranes [51]. 

Probably the most common distillation method used as a form of sample preparation for chromatographic analysis is steam distillation [31,32]. Solvent extraction and gas phase stripping methods are generally inefficient procedures for isolating polar, acidic, or basic compounds in an aqueous matrix due to the low efficiency of water immiscible solvents for the extraction of these compounds and their low volatility and high water affinity which results in a very slow transfer to the gas phase using... 

Washing with water may be used for the dissolution of soluble metallic ions and desorption of adsorbed metals and organics (such petroleum products), as long as the soil has high water affinity. 

The relative wettability of soil by oil and water determines the relative affinity of soil to oil and water, which in turn determines the level of retention of oil or water in the soil. A soil is hydrophilic (i.e., it has water affinity) if water has more affinity to the soil than the oil, although soil may also to a certain degree be somewhat wetted by oil. A soil is called hydrophobic if oil has more affinity to the soil than water. 

Choose a disintegrant that has high water affinity and solubility, to facilitate tablet breakup. 

The Flory-Huggins interaction parameter, x, indicates the water affinity of the polymer while Ch is a measure of the fraction of bound water in the... 

Swelling capability is directly related to water affinity. It is reasonable to assume that most, if not all, of the mechanical softening, as well as the degradation of the material, is induced by the free water rather than the bound water. The absorption of water molecules onto the polar groups is expected to occur without a substantial change in the polymer stmcture and thus no appreciable reduction in the mechanical strength or increase in... 

Type Structure Surface area K/g) Products Desorption Compounds tested (Starting at b.p.) Polarity Thermal stability Water affinity... 

Because of its hydrophilic nature even unmodified BC shows great potential to separate azeotropes such as EtOH/FbO. It adsorbs seven times more water than ethanol. This selectivity and a reasonable flux increase with growing temperature and thinning of the membrane. In addition, the BC membranes also show a high water affinity in aqueous binary mixtures of organic solvents. 

Phosphorylcholine (PC) coating is a polymer that mimics the human chemistry of the cell membrane surface. The PC polymer is biocompatible, because it has hydrophobic areas that stick to each other and to the metal, and it is also cross-linked for strength, Its high water affinity allows for water to be attracted to its surface, PC-coated devices have a permanent water layer on the surface, again serving as a potentially biocompatible surface. 

Polysaccharides, remarkable for their water affinity, can embody many times their weight or volume of this solvent—hence the name hydrocolloids. Polysaccharide dispersions are either hydrosols, hydrogels, or xerogels (de-... 

Moisture was known to increase the mobility of the surface groups of protein as measured by solid-state nuclear magnetic resonance spectroscopy The distribution of water between the protein and the excipients in a freeze-dried powder depends on the crystalline or amorphous nature of the excipients. For example, if a protein is formulated with an amorphous excipient and stored in a sealed container, water would distribute according to the water affinity of the protein and excipients.When the amorphous excipient crystallizes (e.g., because of elevated temperatures), it will expel its sorbed water, which may cause stability problems in the protein. ... 

A high degree of hydrophobic character is an almost unique characteristic of silicon-rich or pure-silica-type microporous crystals. In contrast to the surface of crystalline or amorphous oxides decorated with coordinatively unsaturated atoms (in activated form), the silicon-rich zeolites offer a well-defined, coordinatively saturated sur ce. Such surfrces, based on the strong covalent character of the silicon-oxygen bond and the absence of hydrophilic centers, display a strong hydrophobic character unmatched by the coordinativeiy unsaturated, imperfect surfaces. Also, hydrophobic zeolite crystals have been reported to suppress the water affinity of transition metal cations contained in the zeolite pores. This property permits the adsorption of reactants such as carbon monoxide or hydrocarbons in the presence of water. 

Behavior of Hydroxypropylmethylcelluloses of Different Molecular Structure and Water Affinity at the Air-Water Interface... 

The objective of the present work was to evaluate the impact of the degree and type of substitution and the water affinity of different HPMCs on the structure and dynamics of structure formation of the air-water film. 

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