Volume 49, Issue 1

Surfactants are the most important ingredients in laundry detergents, hand dish washing liquids and shampoos. It is a major challenge for the industry today to identify alternative materials that are biodegradable, based on renewable resources and that show reasonable cost-performance effectiveness. Biosurfactants are an emerging class of surfactants produced by microorganisms in processes usually running at low temperatures and without large amounts of waste or by-products, therefore complying with the rules of green chemistry and potentially resulting in a lower carbon footprint than conventional surfactants. We show in our work which biosurfactants can meet or even surpass conventional surfactants today when it comes to properties like interfacial tension reduction and wetting. Taking into account that further optimization and tailoring of materials, unique physicochemical properties and efficient production processes are within reach, the future perspectives for the broader use of biosurfactants are bright.

Two novel imidazoline gemini surfactants quaternary ammonium salts of di(2-undecyl (heptadecyl)-1-formyl aminoethyl imidazoline) hexanediamine (SUAEIHDI/SHAEIHDI) were synthesized in this article, and their interfacial properties were studied. It was found that SUAEIHDI had a higher CMC value than SHAEIHDI in distillated water at constant temperature (12 ± 2) °C, indicating that it was easier for SHAEIHDI to form micelles in water. The symmetrical molecular structure of SUAEIHDI/SHAEIHDI is composed of lipophilic group and hydrophilic group comprising many active elements i. e. O, N and two imidazoline rings. The novel imidazoline gemini surfactants can be viewed as block-like copolymers, whose surface-modifying effects on nanomaterials are promising.

The direct two-phase titration method with use of solvatochromic dye, i. e. 5-(3-bromo-4-hydroxy-5-methoxyphenyl)-7,7-dimethyl-7H-indolo[1,2-a]quinolinium perchlorate (1) for cationic surfactants determination is presented which is the modification of an earlier described procedure for anionic surface active substances detection. The method was tested on standard solution of benzethonium chloride (cationic detergent) which enables to estimate its accuracy as well as on few commercially available products to verify its utility. The influence of pH value of the probe on the titration endpoint determination was discussed and a simple solution of this problem has been proposed.

This article reports the reduction of methylene blue (MB) by ascorbic acid (H 2 As) in basic aqueous and micellar solutions. Ascorbate ion (As 2 –) is found to be an effective reducing agent for the decolorization of methylene blue under ambient condition. Effects of salting-in and salting-out agents have been investigated for real-time application in the reduction process. The salting-in agent urea has been found to uniquely enhance the rate of the reduction of MB by As 2 – in the presence of micelles. Detailed kinetic and thermodynamic aspects have been considered to realize the interaction between methylene blue and ascorbate ion. Kinetic studies revealed that the reaction follows pseudo first order reaction kinetics.

Green oxidation of cyclohexane by molecular oxygen was carried out over ZrO 2 and noble metals (Pd and Pt) supported on zirconia in solvent free conditions. Studies have been carried out in a typical three-necked batch reactor. Reaction products were identified by GC and UV spectrophotometer. Reaction rates were determined as a function of temperature, partial pressure of oxygen, amount of catalyst, volume of reactants, agitation and reaction duration. The agitation effect and activation energy revealed the absence of mass transfer resistance. Experimental results unveiled the effect of morphology of ZrO 2 on catalysis. 1.0 wt.% noble metal/ZrO 2 (m) was found more selective for cyclohexanol production at low temperature, agitation 900rpm and partial pressure of 101.325 KPa while at high temperature cyclohexanol was further oxidized to cyclohexanone. Comparison of Pt/ZrO 2 and Pd/ZrO 2 catalysts was made on the basis of reactivity and selectivity. Catalysts were characterized by using BET surface area and pore size analyzer, XRD and SEM. To conclude shortly, for the oxidation of cyclohexane, platinum or palladium supported on zirconia are selective, recyclable and could behave as truly heterogeneous catalysts.

The oxidation/degradation of benzyl alcohol in artificially contaminated water under atmospheric pressure by molecular oxygen/air over ZrO 2 (m) catalyst was investigated. Monoclinic phase ZrO 2 was synthesized and characterized by modern techniques. Oxidation of benzyl alcohol in aqueous medium was carried out in a typical three necked double walled batch reactor equipped with thermometer and condenser. The rate of oxidation was affected by different reaction parameters such as speed of agitation, catalyst loading, temperature, concentration of substrate solution (46.3 – 185 mmol/L) and partial pressure of oxygen. Major products were detected with GC and UV spectrophotometer. Optimal conditions were setup for better catalytic activity of ZrO 2 (m). To sum up, catalytic oxidation of benzyl alcohol in aqueous medium by ZrO 2 (m) is a useful and cheaper method for the conversion of benzyl alcohol to valuable products as well as for the removal of benzyl alcohol from industrial waste water.

One pot facile synthesis of ordered mesoporous alumina-supported zirconia with high thermal stability and large pore sizes by evaporation-induced method was systematically investigated. The strategy based on a sol-gel process associated with nonionic triblock copolymers PPO-PEO-PPO as templates in ethanolic solution. Small-angle XRD, TEM, and nitrogen adsorption and desorption results showed that these composites possessed an ordered 2D hexagonal mesostructure, resisted to high temperature up to 1000 °C, and had large surface areas and narrow pore-size distributions. Loaded with palladium, the mesoporous alumina-zirconia composite exhibited high catalytic activity in Suzuki coupling of 2-bromotoluene with phenylboronic acid.

This study summarises the possible, necessary and recommended steps to align consumer behaviour and the standard place setting used for performance and consumption measurements of domestic dishwashers. The diversity and amount of load items, the composition of the dish materials and the amount of soiling in real life differ from the standard place setting. Through the analysis of secondary data regarding the dishware cleaned in household dishwashers, the development of a new, more consumer relevant place setting was possible. Apart from a reduction of the total amount of load items, new materials and items were introduced. The durability and availability of the dishes has been guaranteed and reproducible and differentiating soiling for the new dish items has been developed. Although laboratory tests revealed that the new place setting caused slightly different cleaning results, it still delivers differentiable results concerning the performance parameters of dishwashers. Finally, it reflects the actual usage of a dishwasher in the household much better than the current place setting, and standard test results may gain in importance for the consumer.

In this paper a new protocol to support comparative testing of European laundry detergents is described. This protocol has been developed by A.I.S.E., the International Association for Soaps, Detergents and Maintenance products, to assess the primary (i. e., stain removal) and key secondary performance (whiteness, colour safety and colour transfer) of Household Laundry Detergents and Laundry Additives. The main purpose of designing and supporting a minimum test protocol across A.I.S.E. members and external stakeholders has been to improve the available comparative testing methodologies, while it is not intended to become a standard methodology in the detergent industry. This was carried out by setting minimum requirements for a reliable comparison of detergent quality which is particularly important for test institutes and consumer organisations running comparative performance tests.