Water swelling

Cold- Water Swelling Starches. Special physical treatment produces starch granules that will sweU in water without heating. Molecular dispersions can be formed by appHcation of shear to the swoUen granules. 

Water-swell resistance Fair Excellent Excellent Excellent Fair to Excellent Excellent Excellent Excellent... 

When a cucumber is pickled water moves out of the cucumber by osmosis into the concentrated brine solution. A prune placed in pure water swells as water moves into the prune, again by osmosis. 

The affected area should be cooled by holding in cold, clean running water. Swelling is liable to occur so jewellery or clothing likely to cause constriction must be removed. The... 

For removal of an organic component from water, swelling of the organophillic membrane would result in a higher flux and lower a. At organic levels below about 10 percent, that has not been a major... 

In the previous paper (7) we have described the synthesis, characterization, and certain diffusional characteristics of poly(N V-methylacrylamide)-l -polyisobutylene amphiphilic networks exhibiting a relatively high degree of swelling in both water and n-heptane. It was of interest to prepare further neutral amphiphilic networks of lower water swelling for sustained drug delivery systems. One candidate for this... 

The cubic phases with Somatostatin were allowed to swell to the water swelling limit, while the Desmopressin preparations were of the lamellar phase type, i.e. with low water content, and were therefore assumed to swell in vivo. Approximately 0.5 g of either cubic or lamellar phase was injected, corresponding to 2.5-3.0 mg peptide per kg body weight. 

Fine particle migration can occur in the absence of water-swelling clays. Migrating fines can include the migrating clays kaolinite, illite, chlorite, and some mixed layer clays and fine silica particles (162,163). Fine particle migration is promoted when the... 

More recently certain quaternary ammonium salt polymers have been claimed to be effective in substantially reducing fine particle migration even in the absence of water-swelling clays (1). However, there is little information readily available concerning... 

Other minerals beside water-swelling clays have been found to undergo fines migration. The permeability damage caused by essentially non-swelling clays such as kaolinite and chlorite is a well-known phenomenon. Silica fines have been identified as a potential source of permeability damage in various poorly consolidated U.S. Gulf Coast formations (1). Other minerals identified as constituents of mobile fine particles include feldspar, calcite, dolomite, and siderite (4,5). 

Results indicated that swelling clay stabilizers such as poly (DMA-co-EPl) which do not possess a quaternary nitrogen atom in a pendant chain may not be very effective at preventing permeability damage due to fines migration in the absence of water-swelling clays. 

Cell membranes or synthetic lipid vesicles with normal low permeability to water will, if reconstituted with AQP1, absorb water, swell and burst upon exposure to hypo-osmotic solutions. The water permeability of membranes containing AQP 1 can be about 100 times greater than that of membranes without aquaporins. The water permeability conferred by AQP1 (about 3 billion water molecules per subunit per second) is reversibly inhibited by Hg2+, exhibits low activation energy and is not accompanied by ionic currents or translocation of any other solutes, ions or protons. Thus, the movement of water through aquaporins is an example of facilitated diffusion, in this case driven by osmotic gradients. 

Cold-water swelling starches, 4 722 Cold work, 23 473, 496... 

As water swells cellulose in an intercrystalline way (i.e. only within the non-crystalline amorphous regions), a relationship would be expected between accessibility and moisture uptake, and this is indeed found (Figure 5.5). Refining causes cellulosic fibres to swell and it would therefore be expected to cause a change in the water adsorption isotherm. This is indeed observed (Figure 5.6). 

More expensive than commodities such as polyolefins, PVC and polystyrene brittle when dry, sensitive to water (swelling up to 10%, decrease in mechanical and electrical properties) opaque or translucent require UV and weathering protection significant shrinkage after moulding inherent flammability (but FR grades are marketed). 

In an early study, Mauritz et al. investigated anion—cation interactions within Nation sulfonate membranes versus degree of hydration using FTIR/ ATR and solid state NMR (SSNMR) spectroscopies. An understanding of the dynamic ionic—hydrate molecular structures within and between the sulfonate clusters is essential for a fundamental understanding of the action of these membranes in ion transport. This information can be directly related to the equilibrium water swelling that, in turn, influences molecular migration. 

Connectivity of hydrophilic phase at high sulfonic acid content yields membranes with very high water swelling and thus low mechanical properties... 

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