Water regain value

The volume of inner solvent, V can be calculated If the dry weight of gel employed and the water regain value of the particular gel are known. Thus... 

EFFECT OF EPICHLOROHYDRIN CONCENTRATION ON WATER REGAIN VALUE (FIXED AMOUNT OF DEXTRAN)... 

Water Regain and Bed Volume Gel chromatography media are often supplied in dehydrated form and must be swollen in a solvent, usually water, before use. The weight of water taken up by 1 g of dry gel is known as the water regain. For G-50, this value is 5.0 0.3 g. This value does not include the water surrounding the gel particles, so it cannot be used as an estimate of the final volume of a packed gel column. Most commercial suppliers of gel materials provide, in addition to water regain, a bed volume value. This is the final volume taken up by 1 g of dry gel when swollen in water. For G-50, bed volume is 9 to 11 mL/g dry gel. 

As with most fibers derived from the vegetable kingdom, the individual fibers vary considerably in strength. Their strain to fracture is about 1.7%. The density of jute is 1.5 g cm. Jute fibers absorb a considerable amount of water, typically showing a regain value of about 15 wt% at 65% relative humidity. 

The water content of a resin is usually expressed as a percent of its swollen weight, but some authorities prefer to express water content as the weight of water taken up by 1 gram of initially dry resin, in which case it is termed water regain. If the water content is W percent and the water regain WR (gH20 per dry gram), the relation between the two values is ... 

Figure 11.1a demonstrates clearly the absence of any correlation between the sorption activity of the water-swoUen polymers and their specific surface area measured in the dry state. On the contrary, the dye uptake obviously rises with the sorbent water regain, reaching a maximum value at the highest swelling that corresponds to a 300% degree of crosshnking. The sorption capacity of Styrosorbs with a nominal 400 and... 

Figure 3. Values of In in different gels at 25° C plotted against In values in Sephadex G-15. See text for discussion. The G-numbers refer to Sephadex gels, DVS-10 is a divinyl sulphone cross-linked dextran gel (water regain = 0.99) and P-2 is polyacrylamide Biogel P-2 (water regain = 1.8).

Cellulose ester Shrinking point, °C mp, °C Water tolerance value s Moisture regain , % Density, g/mL Tensile strength, MPa ... 

With lipases, improved dyeing behavior, water absorption, and oil stain resistance of PET fabrics have been claimed following treatment with enzymes from T. insolens [1, 62, 72, 101] and T. lanuginosus [4, 11, 26]. Treatment of PET fabrics with lipases from Aspergillus spp., Beauveria brongniartii, C. antarctica, C. cylindracea, Rhizomucor miehei, Burkholderia cepacia. Pseudomonas fluores-cens, Rhizopus spp., and porcine (hog) pancreas lipase resulted in increased hydrophilicity, moisture regain, and water absorption values [4,33,38,44,51,52,60,103]. 

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