Viscosity of gelatin solutions

The Role of Alum in Historical Papermaking. .. and other Polyvalent Metals on the Viscosity of Gelatin Solutions. Journal of the Science of Food. .. WF et al. "The Effect of Alum and pH on Sheet Acidity , go to the following web site http //palimpsest.stanford.edu... 

The viscosity of gelatin solutions is vital to the control of the thickness of the cast film. Viscosity is measured on a standard 6 % w/w solution at 60°C in a capillary pipette and generally the range of 30-60 millipoise is suitable. 

Domenek et al. (2008), released measurement of the intrinsic viscosity of gelatin type B in water solution at 42°C, where given values were of 27 cm /g and 70 cm / g. 

All values were calculated for intrinsic viscosity of gelatin B solutions to 37.4°C and compared against the value of Huggins, normally used as standard. It is noteworthy that each method has a relative error percentage and low for methods of more than four pair s values (Er% > 0.30). 

Hot, demineralized water is used in the preparation of the dipping solution. Initially, a 30 40% w/w solution of gelatin is prepared in large stainless steel tanks. Vacuum may be applied to assist in the removal of entrapped air from this viscous preparation. Portions of this stock solution are removed and mixed with any other ingredients, as required, to prepare the dipping solution. At this point, the viscosity of the dipping solution is measured and adjusted. The viscosity of this solution is critical to the control of the thickness of the capsule walls. 

There exist instances where an increase in the viscosity of nitrocellulose solutions is recommended as in the product intended for manufacture of blasting gelatine, i.e. for the solution of nitrocellulose nitroglycerine. The solution must have the consistency of firm gelatine. 

Collodion nitrocotton for manufact uring blasting gelatine and dynamite, also called dynamite cotton or dynamite collodion, is characterized by the very high viscosity of its solutions in organic solvents. It is produced by selecting a suitable cellulosic raw material, and performing the nitration at a low temperature, followed by a brief stabilization boil in a neutral or nearly neutral medium. The most important factor is the choice of suitable raw material. 

The only satisfactory method for synthesizing hydrazine was devised by Raschig1 and involves the oxidation of ammonia by sodium hypochlorite in the presence of some such catalyst as glue or gelatin. The purpose of the catalyst is to raise the viscosity of the solution and to inhibit the effect, by adsorption, of traces of metallic ions which cause decomposition of the hydrazine formed.2 It is therefore advisable to use distilled water. Since free chlorine, if present in the hypochlorite solution, oxidizes ammonia to nitrogen, special care must be taken in the preparation of the oxidizing solution. The hypochlorite solution should be distinctly alkaline. %... 

Figure 3. Viscosity of equilibrium solutions after formation of coacervates from gelatin and gum arabic at various pH values. Initial viscosity and concentrations of gelatin and gum arabic solutions taken as 100% (X).

The viscosity of gelatin and glue is affected by the acidity of the material, by the age of the solution, and by other factors. A method of testing glues suggested by Lenk consists in measuring the time of gelatinisation in minutes at fH 7 0—7>5. He proposes the... 

The enzyme-membranes were placed in a well-agitated 1-2 wt % pigskin gelatin (pi — 8.5 where pi is the pH of the isoelectic point of the gelatin) solution at 25°C and also at 37°C. After varying periods of time the reduced viscosity of the solution was measured with a Cannon-Ubbelohde No. 1 capillary viscometer. The decrease in viscosity of the gelatin solutions containing enzyme-membranes was compared to the viscosity decrease of control solutions and solutions to which a known amount of soluble enzyme was added. 

The styrene-DVB copolymer beads are prepared by suspension (pearl) polymerization technique. The monomers are mixed and a polymerization catalyst such as benzoyl peroxide is added. The mixture is then dispersed into small droplets in a thoroughly agitated aqueous solution that is kept at a temperature required for polymerization (usually 85°C-100°C). A suspension stabilizer (gelatin, polyvinyl alcohol, sodium oleate, magnesium silicate, etc.) in the aqueous phase prevents agglomeration of the droplets. The size of the droplets depends chiefly on the stabilizer, the viscosity of the solution, and the agitation, and it can be varied within wide limits. As polymerization takes place, the droplets are transformed into polymer beads. For most purposes, a bead size of 0.1-0.5 mm is preferred, but beads from 1 pm to 2 mm in diameter can be prepared without much difficulty. 

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