Particle diameters, gelatin solutions

Photon Correlation Spectroscopy Studies. In order to investigate possible aggregate formation between the gelatins at 40°C photon correlation spectroscopy was used. The following pairs of Type A and Type B gelatin solutions (0.5% w/v) were prepared and studied by PCS both individually and as mixtures and the values obtained for the average particle diameter and the polydispersity were compared ... 

Particle Diameter and Polydispersity of 0.5% w/v Solutions of Type A and Type B Gelatin, Before and After Mixing at 40°C (Equal Concentrations)... 

Solution Filtration. The polymer solution, free of unacetylated ceUulose, rigid particle contaminants, and dirt, must pass through spinnerets with holes of 30—80 ]lni diameter. Multistage filtration, usuaUy through plate-and-frame filter presses with fabric and paper filter media, removes the extraneous matter before extmsion. Undesirable gelatinous particles, such as the hemiceUulose acetates from ceUulose impurities, tend to be sheared into smaller particles rather than removed. The solution is also aUowed to degas in hoi ding tanks after each state of filtration. 

Glass fiber paper, Whatman grade GF/B (W. R. Balston Ltd., Maidstone, Kent, U. K.) is the most suitable for use in immunoassay. This has an optimum flow rate of 10 ml/min through a disk 1 cm in diameter, and the pore size is such that all particles over 0.5 pw are retained. The filter should be prewashed immediately before use with a protein solution, such as aqueous 0.25% albumin or gelatin in order to minimize protein adsorption. 

---