The surface-active (surface tension, adsorption, molecule cross-sectional area in the adsorption monomolecular layer) and colloidal (viscosity, critical micelle concentration, solubilization) properties in aqueous and hydrochloric acid solutions of anionic surfactant alkylbenzenesulfonic acid (ABSA) were studied. Surface activity of ABSA increases in the presence of hydrochloric acid. Two inflections were established on adsorption isotherms with inorganic acid content of 5 and 10 wt. %, which are indicative of stepwise micelle formation. The ABSA dissociation is suppressed in the presence of hydrochloric acid, and therefore it behaves as a nonionic surfactant, forming micelles at lower concentrations. Mixed micelles, formed by dissociated and non-dissociated surfactant particles, are organized with an increase of ABSA content in mixture. The value of the surfactant limiting adsorption increases significantly at small hydrochloric acid amounts in comparison with an aqueous solution. The formed monomolecular layer is denser in the presence of inorganic acid than in an aqueous solution. The solubilization of Sudan I dye in alkylbenzenesulfonic acid increases with increasing in solution acidity. The extremum points on isotherms of solubilizing ability with 5 and 10 wt. % HCl content are observed at surfactant concentrations corresponding to the beginning and end of the formation of micelles containing alkylbenzenesulfonate ion.
The effect of isobutyl and isoamyl alcohols on the surface-active characteristics of SAFOL 23 nonionic sur-factant was studied. The surface tension isotherms (STI) of an aqueous solution of surfactant and its water-alcohol compositions are obtained. The structure of mixed micelles and the values of the surfactant interac-tion factor in the micelle, based on the STIs of SAFOL 23 – alcohol – water systems, were calculated. The dependence of surface activity on the SAFOL 23: alcohol ratio passes through a maximum, which is associat-ed with the transition of alcohol from co-surfactant to co-solvent due to the increase in its quantity. The wet-ting process of high dispersed polytetrafluoroethylene (PTFE) by SAFOL 23 – alcohol – water compositions was studied, contact angle isotherms were constructed. The PTFE surface was hydrophilized by compositions at ratios which comply with surface activity maximum. SAFOL 23 is more adsorbed on the surface of the sol-id phase than on the liquid-gas interface. The appending of alcohol into an aqueous solution of surfactant changes the ratio between hydrophilic and lipophilic groups of the composition, which affects cloud point. It significantly expands the range of application of surfactants and allows the use of SAFOL 23 as a solubilizer, emulsifier and wetting agent.
According to the estimates of the World Health Organization, the share of medications based on medicinal plant materials is increasing from year to year. Along with industrial drugs, the population widely uses medicinal plants harvested on their own. However, medicinal plants growing in unfavorable environmental conditions can cause serious harm to health. Thus, it is necessary not only to control raw materials but also to study the areas where harvested medicinal plants grow, which in most cases are located in the immediate vicinity of industrial facilities. The purpose of this work was a comprehensive study of the ecological state of Zakurye Island in the town of Chusovoy and its plant communities. When planning the research work, the study area was zoned in accordance with the distance from the alleged source of pollution. In the process of work, we used standard methods of preparation and drying of medicinal plant materials, sampling of soil and water. Chemical analysis was carried out with the use of generally accepted and approved methods. A conclusion is made about a significant degree of pollution with pollutant metals of the surface and deep layers of the Chusovaya River, as well as of soil and medicinal plants near Zakurye Island. Most likely, environmental pollution is associated with poorly maintained dumps of blast-furnace slag from the Chusovoy Metallurgical Plant, located along the river bank.
The effect of isopropyl alcohol on the surface-active characteristics of SAFOL 23 nonionic surfactants was explored. The surface tension isotherms of an aqueous surfactant solution and its water-alcohol compositions were obtained. Based on a series of tension isotherms of a number of surfactant – alcohol – water systems, the compositions of mixed micelles and the values of the surfactant interaction factor in the micelle were calculated. The dependence of the surface activity of a water-alcohol composition on its composition was found and studied. The dependence of surface activity on the ratio of surfactant has the following form: alcohol is not monotonic and passes through a maximum, which is associated with a change in the function of alcohol with an increase in its content and a transition from co-surfactant to co-solvent. A feature of the adsorption process of surfactant – alcohol systems on highly dispersed PTFE was studied, namely, the free surface energy of the polymer was calculated, and isotherms of the contact angle were constructed. The cloud point of the systems was calculated and the characteristic of the hydrophilic-lipophilic balance was found. The introduction of alcohol changes the hydrophilic-lipophilic balance of SAFOL 23, which allows it to be used as a solubilizer, emulsifier.
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