Concentration Of Surface-active Agent Research Articles

The effect of a surface-active agent on mass transfer in a stirred liquid-liquid extractor

The effect has been observed of small additions of sodium oleyl- p-anisidinesulphonate on the rate of extraction of iodine from aqueous solutions with carbon tetrachloride in an agitated extractor. The results have been analysed by the method of H ixon and S mith [2]. The time required for extracting 90% of the extractable iodine from the aqueous phase increased with the concentration of surface-active agent to a maximum about 70% above the original value at 3 × 10 −5 g/100 ml aqueous solution, and fell on further additions far below the original value. The H ixon lines were curved for the larger additions of surface active agent, indicating a gradual increase in interfacial area.

Solubilizationの製剤学への応用 (第1報)

Solubility of 10 kinds of steroidal hormones in non-ionic surface-active agents, possessing polyhydroxyethylene group, was tested with the following results.1) Solubility of testosterone propionate was approximately proportional to the concentration of surface-active agents.2) Solubilizing efficiency of the above compound was better at a lower concentrations;3) At a very high concentration ranges of the active agents, the solubilizing efficiency increased rapidly.4) When compared at the same weight/volume concentration, the active agents possessing smaller number of hydroxyethylene group possessed better solubilizing efficiency.5) In general, hormones with stronger hydrophilic properties were less soluble, although there were some exceptions.Some simple observations were made on the above characteristics.

THE DYEING OF NATURAL COTTON WITH DIRECT DYES: SOME EFFECTS DUE TO TEMPERATURE, DYE CONCENTRATION, AND ANIONIC SURFACE-ACTIVE AGENTS

The presence of an anionic surface-active agent in the dyeing of natural cotton yarn with a purified direct dye, using a dye-bath containing sodium chloride, is shown to increase the rate of dyeing, and to increase the amount of dye sorbed at equilibrium. The rate-accelerating effect has been studied as a function of the concentration of surface-active agent, using both commercial materials and methanol-extractable fractions of the latter. The effect exerted by an anionic surface-active agent, both on the equilibrium sorption and on the rate of dyeing, decreases as the temperature is increased. An explanation of the data, in terms of an interaction between the fibre and surface-active agent, is advanced.Studies carried out in the absence of a surface-active agent show that with increased temperature of dyeing the rate of dye sorption is increased, but the value of the equilibrium sorption is decreased; the dyeing process in exothermic. The relation between equilibrium sorption and residual dye-bath concentration is expressible by a Freundlich equation, and that between equilibrium sorption and initial dye-bath concentration is linear, at least over the range of concentration studied. The time required to reach a state of equilibrium increases as the initial concentration of dye in the bath is increased.