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Water in gel

Stabilizers work with emulsifiers to prevent the fats and oils from separating. They can be emulsifiers themselves, or they can be large molecules, such as vegetable gums, that lock up the water in gels. [Pg.135]

Wiggins, P.M. 1995. High and low density water in gels. Progr. Polymer Sci. 20, 1121-1163. [Pg.102]

Gel formation inhibits hydrolysis of the inulin (Silva, 1996). At low concentrations (i.e., below gelling), inulin may be hydrolyzed at a pH below 3 and at very high temperature due to the presence of free water. In gel form, inulin is stable in acidic and high temperature conditions due to the lack of available water. [Pg.69]

Solvent-replacement drying involves replacement of water in gels or precipitates with special organic solvents and removal of the organic solvents. [Pg.709]

AHf= Hf - H j l is the difference between partial molar enthalpy of solvent (water) in gel and pure liquid solvent (water) in surrounding Contrast this with the equation for water in the solid state (iee) ... [Pg.345]

Woessner et al. [24] and other workers reported from NMR [24-30] and DSC [31] studies on agar [23,24], dextran [32], and poly(vinyl alcohol) [31] that there are three kinds of waters in gels of hydrophilic polymers and most of the water in gels is free water which does not interact with polymers. [Pg.379]

Polymer gels are different from normal solids and liquids and show various characteristics and behaviors. It is known, for example, that the water in gels exists in several different forms non-freezable water even at very low temperature that exists close to the network and has a strong interaction with the network bound water that freezes at —10 to —20°C and free water that has the same properties as normal water. There is also the phase transition phenomenon in which a gel is nonlinear. Phase transitions caused by solvent composition, temperature changes, pH... [Pg.13]

Fig. 3 Time-dependent changes of T2 of water in gel A ( ) and gel B (O) during heating. Fig. 3 Time-dependent changes of T2 of water in gel A ( ) and gel B (O) during heating.
HI - Hqi is the difference between partial molar enthalpy of solvent (water) in gel and... [Pg.354]

A diffusion mechanism is also used in dialysis as a means of separating colloids from crystalloids. The rate of diffusion of molecules in gels is practically the same as in water, indicating the continuous nature of the aqueous phase. The diffusion of gases into a stream of vapour is of considerable importance in diffusion pumps. [Pg.137]

Konjac flour, derived from the konjac plant tuber, has a long history of use in the Ear East, but is a newcomer to the United States. It reacts with many starches to enhance the viscosity of both, and is used in gels that are stable in boiling water. [Pg.119]

The fluid is formulated from a premium mineral od-base stock that is blended with the required additive to provide antiwear, mst and corrosion resistance, oxidation stabdity, and resistance to bacteria or fungus. The formulated base stock is then emulsified with ca 40% water by volume to the desired viscosity. Unlike od-in-water emulsions the viscosity of this type of fluid is dependent on both the water content, the viscosity of the od, and the type of emulsifier utilized. If the water content of the invert emulsion decreases as a result of evaporation, the viscosity decreases likewise, an increase in water content causes an increase in the apparent viscosity of the invert emulsion at water contents near 50% by volume the fluid may become a viscous gel. A hydrauHc system using a water-in-od emulsion should be kept above the freezing point of water if the water phase does not contain an antifreeze. Even if freezing does not occur at low temperatures, the emulsion may thicken, or break apart with subsequent dysfunction of the hydrauHc system. [Pg.263]

When the hydrosol ceases to flow like a Hquid (the gel time), it is termed a hydrogel (Fig. 11a). As formed, the pores are filled with the medium (usually water) in which the gel is prepared. The hydrogel may be washed to remove the by-product salt and sold in that form, in which case it may consist of up to 70% water. Because the water is trapped in the pores, the final product can stiU be a relatively free-flowing powder. [Pg.478]

Water is softened by removing calcium and magnesium ions from hard water in exchange for sodium ions at sites on cation-exchange resin. Water softeners typically use a gel polystyrene sulfonate cation-exchange resin regenerated with a 10% salt brine solution (25). [Pg.186]

H2O/100 kg of adsorbent. At equilibrium and at a given adsorbed water content, the dew point that can be obtained in the treated fluid is a function only of the adsorbent temperature. The slopes of the isosteres indicate that the capacity of molecular sieves is less temperature sensitive than that of siUca gel or activated alumina. In another type of isostere plot, the natural logarithm of the vapor pressure of water in equiUbrium with the desiccant is plotted against the reciprocal of absolute temperature. The slopes of these isosteres are proportional to the isosteric heats of adsorption of water on the desiccant (see... [Pg.515]

Polymer-based, synthetic ion-exchangers known as resins are available commercially in gel type or truly porous forms. Gel-type resins are not porous in the usual sense of the word, since their structure depends upon swelhng in the solvent in which they are immersed. Removal of the solvent usually results in a collapse of the three-dimensional structure, and no significant surface area or pore diameter can be defined by the ordinaiy techniques available for truly porous materials. In their swollen state, gel-type resins approximate a true molecular-scale solution. Thus, we can identify an internal porosity p only in terms of the equilibrium uptake of water or other liquid. When crosslinked polymers are used as the support matrix, the internal porosity so defined varies in inverse proportion to the degree of crosslinkiug, with swelhng and therefore porosity typically being more... [Pg.1500]

The products are available as tablets, capsules, liquids (in the form of solutions, suspensions, emulsions, gels, or injectables), creams (usually oil-in-water emulsions), ointments (usually water-in-oil emulsions), and aerosols, which contain inhalable products or products suitable for external use. Propellants used in aerosols include chlorofluorocarbons (CFCs), which are being phased out. Recently, butane has been used as a propellant in externally applied products. The major manufactured groups include ... [Pg.78]

Aqueous solutions of dyes ean also be employed instead of water. In the ease of hydrophilic dyes such as methylene blue or patent fast blue the transparent background of the TLC/HPTLC plate is stained blue. Pale spots occur where there are nonwetted zones. Dauble [89] detected anion-active detergents in this way on silica gel layers as pale zones on a blue background with palatine fast blue GGN... [Pg.42]


See other pages where Water in gel is mentioned: [Pg.221]    [Pg.311]    [Pg.304]    [Pg.304]    [Pg.345]    [Pg.232]    [Pg.182]    [Pg.145]    [Pg.265]    [Pg.267]    [Pg.273]    [Pg.221]    [Pg.311]    [Pg.304]    [Pg.304]    [Pg.345]    [Pg.232]    [Pg.182]    [Pg.145]    [Pg.265]    [Pg.267]    [Pg.273]    [Pg.866]    [Pg.3]    [Pg.139]    [Pg.258]    [Pg.431]    [Pg.436]    [Pg.359]    [Pg.299]    [Pg.478]    [Pg.490]    [Pg.185]    [Pg.228]    [Pg.253]    [Pg.257]    [Pg.291]    [Pg.85]    [Pg.215]    [Pg.387]   
See also in sourсe #XX -- [ Pg.304 ]




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