Phosphoric-acid-swollen

Figure 10. Product distribution from the incubation of enzymes (produced by T. reesei QM 9414 in response to sophorose) with phosphoric-acid swollen cellulose (PSC). Incubation time in this figure indicates the length of incubation of T. reesei mycelia in the presence of ImM sophorose. Enzymes produced at those times were incubated with PSC for 15 hr, and the products analyzed by HPLC (18/...

PMOs are supposed to be active only on (semi)ctystalline polysaccharides and not on short soluble oligosaccharides (DP 2-5). Harris et al. tried a whole variety of substrates and concluded that mixed substrates like PCS (pre-treated corn stover) generate higher activities than pure cellulose substrates like Avicel (microcrystalline cellulose) or PASC (phosphoric acid swollen cellulose).However, hemicellulose substrates do not tend to be more efficiently degraded by PMO addition. The first successful experiments with real pre-treated biomass, namely pre-treated spruce, were recently performed. ... 

Endoglucanases hydrolyze 3-l,4-glycosidic linkages randomly. They do not attack cellobiose but hydrolyze cellodextrins, phosphoric-acid swollen cellulose and substituted celluloses such as carboxymethyl (CM)- and hydroxyethyl (HE)-cellulose. Trichoderma seems to secrete a number of respective enzymes into the medium, of which two (EG I, EG III) have been the subject of a more detailed investigation. It should be noted that some confusion has arisen in the past from the fact that EG III was termed EG II by several authors from the US. However, this has been overcome now. 

Various additives have been added to PFSA membranes to either replace the water or to retain the water at higher temperatures. Nafion has been swollen with phosphoric acid and a conductivity of 0.05 S/cm has been achieved at 150°C. Unfortimately, the anode fails after a short period of time in these membranes so no successful FC tests have been run. 1-Butyl,3-methyl imidazolium triflate and tetrafluoroborate have also been used to swell Nafion giving a conductivity of 0.1 S/cm at 180°C. Nafion has also been swollen with heterocycle solutions, imidazole, and imidazolium salts in trifluoroacetate and trifluoro methane sulfonate solution, although the reported conductivities are more modest, 10 S/cm at 100°C. Acetic acid and tetra-n-butylammonium chloride solutions of the heteropoly acid (HPA), 12-phosphotungstic acid (PTA), have all been used with Nafion giving improved FC performance at 110°C and 120°C, respectively, vs. the undoped PFSA. ... 

Cotton linters were swollen to an increasing extent by means of phosphoric acid of increasing concentration, Using a number of simple sugars plus a series of dextran molecules ranging in M.W. from 180 to 2,4 X 107 and diameter from 8 to 1600 A, it was possible to measure the pore volume and calculate the surface area within the swollen fibres accessible to all the molecules within this range. The substrates reacted with a commercial cellulose enzyme preparation, and the initial rate of reaction was compared with the accessibility of the substrate to molecules of various sizes. There was found to be a linear relationship between the initial reaction rate and the surface area within the cellulose gel which was accessible to a molecule of 40 A, diameter. 

Cellulose-Cellulase System. In Figure 10 are shown the accessibility curves of the cotton which had been swollen to different extents by phosphoric acid. The fiber saturation point, given by the amount of water inaccessible to a very large molecule, is seen to increase from 0.48 ml./ gram for cotton treated with water alone to 1.40 ml./gram for cotton swollen in 78.8% acid. The median pore size increased from 23 A. to 52 A. 

Water-soluble cellulose phosphate of high viscosity and a D.S. was prepared by Katsuura et al. by treating pulp, pre-swollen with zinc chloride, with phosphoric acid in molten urea at 150°C (42). 

R. T. NATARAJAN. What is the role of phosphoric acid in the spinning system P. W. MIHGAN. It is added to the bath in wet-spinning to neutralize the base quickly to get coagulation. If you spin into water, you will go through a slow process of getting a more and more dilute base solution - b rt a polymer solvent nevertheless, so the step from polymer solution to a coagulated state is relatively slow. The resvilt could be a very soft, swollen fiber or perhaps no fiber at all. 

Acrylonitrile butadiene styrene (ABS) is a common thermoplastic that combines the strength and rigidity of the acrylonitrile and styrene polymers with the toughness of the polybutadiene rubber. ABS polymers are resistant to aqueous acids, alkalis, concentrated hydrochloric and phosphoric acids, alcohols and animal, vegetable and mineral oils, but they are swollen by glacial acetic acid, carbon tetrachloride and aromatic hydrocarbons and are attacked by concentrated sulfuric and nitric acids. They are soluble in solvents such as esters, ketones and ethylene dichloride. 

A portion of the Step 5 product was swollen with 2 ml of CH2CI2, washed consecutively with 5 ml of 1M HCl, and 10 times with 5 ml of THF and water to give the free sulphonic acid. The resin was then washed consecutively with CH2CI2, methanol, and THF before drying under high vacuum. The material was then suspended in CH2CI2 and treated with excess phosphorous pentachloride. The mixture was suspended for 2 hours, filtered, and washed with CH2CI2, and THF, and the product was isolated. 

---