Volume 44, Issue 4

The influence of polymers as stabilizing additives for iron and manganese ions was investigated in an aqueous system. The polymers tested include: homo-polymers of acrylic acid, maleic acid, methacrylic acid, 2-acrylamido-2-methylpropane sulfonic acid; co-polymer of acrylic acid: vinyl acetate, acrylic acid: hydroxypropyl acrylate, acrylic acid: carbitol acrylate, acrylic acid: 2-acrylamido-2-methylpropane sulfonic acid; and ter-polymer of acrylic acid: methacrylic acid: acrylic acid: acrylic acid: 2-acrylamido-2-methylpropane sulfonic acid: sulfonated styrene, acrylic acid: 2-acrylamido: t-butylacrylamide. It was found that polymer architecture i. e., monomer type, monomer charge, molecular weight, and polymerization solvent, strongly influences the performance of polymer as iron and manganese ions stabilizing additives. The stabilization data reveal the following order in terms of decreasing polymer performance: ter-polymer > co-polymer > homo-polymer.

Heat flow calorimetry has been evaluated as an alternative technique to conventional stability testing of sodium percarbonate [15630-89-4] (SPC) based on analysis of the hydrogen peroxide content. Stability tests were performed with different SPC samples as well as under various experimental conditions. In general, stable samples exhibiting high concentration of hydrogen peroxide were accompanied by low heat flow values. It was found that the results obtained by heat flow calorimetry and conventional stability testing were in agreement. It was also demonstrated that the long-term stability could be predicted from heat flow data obtained during the initial stage of decomposition. Furthermore, different manufacturing and experimental conditions were manifested as a change of the heat flow curve. The results indicate that the rate of heat production is closely associated with the stability of sodium percarbonate, i. e. the rate of decomposition of sodium percarbonate. In presence of zeolite the stability of sodium percarbonate was reduced, particularly under humid conditions.

Using anionic surfactant sodium alkyl epoxy ethylene carboxylate as structure-oriented agent mesoporous titanium dioxide was direct prepared at ambient temperature via hydrolysis precipitation. The synthesized products were characterized by XRD and N 2 -adsorption. XRD analysis indicates that the TiO 2 exhibits anatase phase and its pore disappears at 550 °C calcinations temperature. N 2 -adsorption results shows that high surface area of 324 m 2 /g, pore volume of 0.211 cm 3 /g and pore size of 3.5 nm were obtained in no heat-treated sample.

When the sanitary ware (ceramicplus) was launched it was one of the first product in consumer market that offered a surface based on nanotechnology. (ceramicplus) is a ceramic material that is modified by sol-gel methods, the so called wet-chemical nanotechnology thus creating a material of very low surface energy which results in a particularly dirt-repellent and easy-care surface. A further innovative surface is called (activecare). This ceramic glaze contains small quantities of antibacterial silver ions which prevent the build-up of bacteria and ensures hygienic cleanliness. Independent tests by renowned research institutes have verified the properties and long-term effect of (ceramicplus) and (activecare). Because of its water- and dirt-repellent properties (ceramicplus) requires minimum care without influencing the established good properties typical of ceramic materials. The roughness and hardness of ceramicplus is not significantly different from those of conventional ceramic glaze for sanitary ware. Scrubbing tests have proven that only the long-run use of highly abrasive cleaning agents – like scouring powder – may scratch the surface and impair the properties of (ceramicplus) as well as conventional ceramics. Thanks to the easy-care properties of these functionally modified ceramic surfaces such aggressive cleaning agents are not required for cleanliness.

A series of novel anionic fumaric polymerizable surfactants with different lengths of carbon chains (C 8 –C 14 ) were synthesized. The chemical structure of the surfactants was confirmed by 1 H NMR, IR and MS. The values of critical micellar concentration (cmc) and γ cmc of the surfactants were determined. The surface properties of this series of designed polymerizable surfactants show their potential application in the emulsion polymerization to improve the stability of the latices and water sensitivity of the films.

In this study the interfacial as well as the surface tensions, the partition coefficients K p , the interfacial elasticities, and the stabilities of o/w-emulsions of the same systems were measured and compared to find a quantitative correlation which can help to control the emulsion stability. The systems in question contain water, paraffin oil and one of four non-ionic technical surfactants commonly used as emulsifiers. While a clear correlation between emulsion stability and equilibrium interfacial tension was found, the different emulsifying capacities cannot be explained by the partition coefficients K p or the surface tension. However, combining the K p results with the surface tension data allows us to estimate which emulsifier is more effective in solubilising a given amount of dispersed phase. Another method to classify emulsifiers is to carry out interfacial rheology measurements over a frequency range as broad as possible. Again a clear correlation between interfacial rheology and emulsifying capacity was found. This correlation, however, was restricted to surfactants of the same class. No correlation between interfacial rheology and emulsifying capacity could be found for emulsifiers of different molecular structure.