solubility of high molecular weight n-paraffins in supercritical carbon dioxide has been a matter of interest to many researchers. however, not sufficient solubility experimental data are available although the methods by which the experimental data are obtained have many varieties. utilizing cubic equations of state is an effective method for solubility prediction of n-paraffins in supercritic...

during last two decades, polysaccharides such as alginate (alg) alone and in combination with other biopolymers are widely used in vaccine and drug delivery systems. the aim of the present work was to investigate the potential utility of microparticles made of alginate (alg) as new vehicles for improving nasal vaccine delivery. for this purpose, diphtheria toxoid (dt) was chosen as a model anti...

a mixture  of  sodium  lauryl  sulfate  (sls)  as  ionic  emulsifer  and  stearyl alcohol as non-ionic emulsifer was employed in a vinyl chloride emulsion polymerization  reaction  to  study  the  infuence  of  various  interactive parameters involved in the reaction system. it was found that the particle size was dependent on the amount and type of emulsifer. the average particle size of polyv...

The physical properties of a polyethylene resin are mainly though not exclusively dependent on basic molecular properties such as short chain branching, average molecular weight and molecular weight distribution. These basic properties in turn are controlled by the size, structure and uniformity of the polyethylene molecules. Ethylene is a gaseous hydrocarbon composed of two carbon atoms and fo...

Five narrowly distributed fractions of phenolphthalein poly(ether sulfone) (PES-C) were studied in CHCl3 by both static and dynamic laser light scattering (LLS) at 25 °C. The dynamic LLS showed that the PES-C samples contain some large polymer clusters as in previously studied phenolphthalein poly(ether ketone) (PEK-C). These large clusters can be removed by a 0.1-ím filter. Our results showed ...

The intrinsic viscosities and osmotically estimated number-average molecular weights of a series of cellulose acetate fractions have been measured. It was found that within t he range of chain lengths investigated (number-average molecular weight, lvin, up to 130,000) the number-average molecular weights are proportional to the intrinsic viscosities in acetone solu t ions, in agreement with Sta...

A series of approximately 50:50 mol % poly(L-lactide-co-ε-caprolactone) copolymers were synthesized by bulk copolymerization of L-lactide (LL) and ε-caprolactone (CL) using stannous octoate (Sn(Oct) 2 ) and diethylene glycol (DEG) as the initiating system. The resulting P(LL-co-CL) copolymers were characterized by various analytical techniques including dilute-solution viscometry, GPC, H/C NMR ...

High-molecular-weight deoxyribonucleic acid (DNA) of Saccharomyces carlsbergensis has been fractionated by sucrose density gradient centrifugation. The main DNA fraction has an average molecular weight of about 500 x 106. A major fraction of the DNA molecules containing sequences homologous to ribosomal ribonucleic acid (RNA) sediments as material of this molecular weight. The remainder sedimen...

Hot water extraction of hemicelluloses from aspen wood chips of different sizes and wood meal was performed, and the extracted hemicelluloses were characterized. With decreasing wood chip size, the total sugars and total polyand oligosaccharides extracted with hot water increased. The dissolution of hemicelluloses was mainly limited by diffusion in the fiber wall and mass transfer from fiber to...