Volume 61, Issue 5

In recent years, the massive use of pharmaceuticals has led to the detection of a large number of relevant residues in water. As emerging contaminants, pharmaceuticals residues in the environment pose a major threat to human health and ecosystems. Covalent organic polymers (COPs) possess high stability, uniform pore size, and easy functionalization, which have attracted great attention in water treatment. In this study, a novel covalent organic polymer was successfully studied by a simple synthesis method, combining p -phenylenediamine (Pd) and isophthalaldehyde (Is) via a Schiff-base (referred to PdIs-COP), which was used as an absorbent for the removal of indomethacin from aqueous solutions. The composite was characterized with scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) specific surface area and thermogravimetric (TGA) analysis. The effect of changes in the pH values and the adsorption time on the adsorption capacity was also investigated. The results of this study indicated that the absorbent had a high adsorption capacity for indomethacin. The adsorption capacity of PdIs-COP for indomethacin is 92.86 mg g −1 at pH of five and a contact time of 2 min. This shows that PdIs-COP is a novel material with good affinity for pharmaceuticals.

The implementation of the EU CLP Regulation for mixtures in 2015 led to a reduction of the cut-off levels for mixtures containing severely irritating or corrosive ingredients. As a result, most everyday detergents would be required to carry the same corrosive pictogram on the label as caustic or highly acidic specialty cleaners. However, in most cases, calculation-derived skin and eye hazard classifications do not reflect in-market experience and consumer understanding of the hazardous properties of household detergents. The detergent industry responded to this situation by forming the Detergent Industry Network ‘DetNet’. It is a transparent process that supports mixture classification decisions by sharing data, expertise, and best practices between manufacturers of detergent and cleaning products. At the core of DetNet is its database providing access to compositional information and toxicological data on more than 240 detergents and cleaning products. This paper describes and discusses the main features of DetNet, its organisational structure and database. Based on a case study, the process and functioning of DetNet to support a scientifically sound classification of an untested mixture for skin and eye effects based on data available for similar mixtures is demonstrated.

Optimizing the energy efficiency of household appliances is crucial to appliance manufacturers, energy suppliers, governments and, almost importantly, consumers. For the reliable cleaning of normally soiled dishes, consumers can save energy by using Eco-programs instead of Intensive- or Auto-programs, but this means that they have to accept cleaning times of up to 4 h. Consequently, the acceptance for these programs is not very high, despite consumers’ high willingness to save energy and water. Short-cycles that run for less than 55 min and use equal to less energy on average than Eco-programs have a high consumer potential. However, according to manufacturers, these are rather designed for lightly soiled or pre-treated dishes. Considering the Sinner’s circle, the cleaning result depends on the interaction of temperature, time, mechanics and chemistry, so we investigated the extent to which using a commercially available detergent, thus fully exploiting the “chemistry” component of the Sinner’s circle, can save time, temperature, water and, most importantly, energy in the end. Our results show that there are Short-program combinations using a commercially available detergent that reliably clean normally soiled dishes in less than 55 min and typically 30–40 min with significantly lower energy consumption than average Eco-cycles.

Routine household tasks, such as laundry or dishwashing, are complex socio-technical systems in which a variety of factors and actors interact, including manufacturers, technologies, regulators, consumer practices, cultural norms and infrastructures. A deep understanding of these socio-technical systems is necessary to find the right recommendations on how to optimise this system in order to achieve relevant savings in resource consumption without requiring a complete renewal of the infrastructure installed. In our case, we focus on automatic dishwashing in the United Kingdom and try to find out what an optimised consumer use of the dishwashers installed can look like and how many savings can be achieved. Accordingly, we modelled the base of dishwashers installed and conducted a consumer survey on dishwasher usage behaviour in sufficient detail to understand the interplay between the various factors. By simulating a change in usage behaviour, we find a potential energy saving of 21.3 % simply by following basic rules for selecting the appropriate programmes without the risk of a loss of performance.

Polyglyceryl polyricinoleate (PGPR) is an emulsifier produced by esterification of polyricinoleic acid and polyglycerol. Polyricinoleic acid is derived from ricinoleic acid, which is expensive compared to other fatty acids. Therefore, analogues of polyricinoleic acid should be made from less expensive fatty acids, such as oleic acid. Therefore, oleic acid was converted to polyhydroxy estolide (PE) by a reaction with hydrogen peroxide and acetic acid. The PE was used as a substitute for polyricinoleic acid to produce PGPR analogues by direct esterification with polyglycerol and various fatty acids. The direct reaction between polyglycerol and PE produced a polyglyceryl estolide (PGE) with high viscosity and hydroxyl value, which limited its suitability as an emulsifier for the isopropyl myristate (IPM) and water system. Conversely, PGE prepared from lauric acid, polyglycerol and PE showed lower viscosity and hydroxyl value, resulting in a broad region of emulsion stability on a phase diagram when evaluated as a water-in-oil emulsifier for the IPM/water system. Similarly, other PGE made with oleic acid also displayed good emulsion stability for systems with higher IPM concentrations. In contrast, PGE prepared with stearic acid was a semi-solid at room temperature. Most of the prepared PGEs showed promising potential as emulsifiers for water-in-oil emulsions.

Branched-chain surfactants have lower equilibrium surface tension, superior wettability and emulsifying performance, making them suitable for exclusive applications. Linear α -olefins are rich in coal-based Fischer–Tropsch synthesized liquid products and are promising building blocks for the synthesis of branched-chain surfactants via dimerization and subsequent C=C bond functionalization. Herein, a new series of branched ethoxylate non-ionic surfactants (MDC 6 E n ) were prepared using 2-butyl-1-octene (1-hexene dimer, DC 6 ), obtained by the dimerization of coal-based Fischer-Tropsch synthesized 1-hexene, as the hydrophobe via hydroxylation and ethoxylation. In particular, the hydroxylation of DC 6 was carried out in a one-pot tandem hydroformylation and hydrogenation over unmodified Co 2 (CO) 8 under mild conditions (140 °C and 4–8 MPa, CO:H 2 = 1:1). A thorough investigation of their surfactant properties was carried out, including equilibrium surface tension, dynamic surface tension, foaming properties, wetting power, and emulsifying power. The results indicate that MDC 6 E 9 performs comparably to a commercially available branched-chain surfactants, the iso-tridecyl alcohol ethoxylates (MULTISO 1390). This research provides a new direction for the synthesis of branched nonionic surfactants using Fischer–Tropsch synthesized products, further promoting the development of coal-based fine chemicals.

A novel viscoelastic surfactant (VES) micelle system was developed by using a new tetrameric polyhydroxy cationic surfactant (STPC) as a thickener in combination with sodium chloride (NaCl). The flow curves, thixotropy, viscoelasticity, viscosity-temperature relationship, temperature and shear resistance, and thermal thixotropy of the micelle system were further investigated. The results showed that the new four-parameter rheo kinetic model accurately described the viscosity versus shear time curve of the micelle system. The established four-parameter viscosity-temperature relationship model could be used to characterize the viscosity versus temperature curve of the micelle system. Meanwhile, the Carreau model could also be fitted to the flow curve of the STPC/NaCl micelle solution. The effects of counterion salt concentration and surfactant concentration on the rheological properties of the viscoelastic STPC/NaCl micelle solution were clarified and the optimum mass ratio of 5 wt%/5 wt% for the STPC/NaCl solution was determined. The viscoelastic modulus versus temperature curves of the STPC/NaCl (5 wt%/5 wt%) micelle solution showed that it exhibited thermal thixotropy. This study extends on the types of thickeners and VES micelle systems and provides a rheological reference for the application of viscoelastic tetrameric cationic surfactants in oil fields.

The Dynamic Light Scattering (DLS) measurements have been performed on quercetin with dioctyl sodium sulfosuccinate (Aerosol OT, AOT), Triton X-100 in 1,4-dioxane, as well as on the solutions containing water in the core of suitable reversed micelles; the water amount was calculated using the relation R = [H 2 O]/[surfactant], defining the ratio of water to surfactant concentration. The amount of quercetin in the studied systems as well as the effects of the water presence on the size of the micelles and diffusion effects were discussed. A significant effect of the research was the determination of the maximum amount of water that can be introduced into the AOT micelles in the studied systems.

The physicochemical properties of cadmium and neodymium soaps (caprylate) have been studied by infrared spectroscopy, X-ray diffraction, and thermal analyses in the solid state. The infrared analysis indicates that the fatty acid is present in a dimeric form due to interactions facilitated by hydrogen bonding. Additionally, it suggests that the soaps have properties of a partially ionic nature. The X-ray diffraction data were used to determine the long spacing, confirming the double-layered configuration of the cadmium and neodymium soaps. It was observed that the decomposition reaction proceeds with zero order kinetics, indicating a constant reaction rate regardless of changes in concentration. Furthermore, the activation energy for this process was determined to be 0.401 kJ mol −1 and 0.226 kJ mol −1 , respectively A comparative evaluation of the different analytical methods is provided, highlighting the distinct advantages of each method, at the same time delineating the limitations identified through careful study of reference materials and their practical application in sample analysis contexts.

The release of the dye Disperse Blue 35 (DB35) into water has serious environmental and health consequences, due to its toxicity and resistance to degradation. This paper investigates the effectiveness of cloud point extraction (CPE) to remove this industrial dye from aqueous solution by Lutensol AO7 and Triton X-114, two environmentally friendly nonionic surfactants. First, the partial phase diagrams of the water–surfactant binary systems are constructed. Then, the effects of pollutants, sodium sulfate and cetyltrimethylammonium bromide on the cloud point temperature ( T c ) are determined. The experimental results are expressed by four responses: Extraction efficiency ( E ), residual concentrations of solute and surfactant in the dilute phase ( X s,w and X t,w , respectively) and the volume fraction of coacervate ( Ф c ). An empirical smoothing method was applied. For each parameter, the results obtained were modeled using the response surface methodology (RSM) and represented on three-dimensional diagrams. The results show that the efficiency of dye extraction with Lutensol AO7 and Triton X-114 at a concentration of 6 wt% is about 95 % and 82 %, respectively. The influence of salt and ionic surfactant on the effectiveness of CPE for the removal of DB 35 dye was determined. The regeneration of surfactant was only achieved by pH adjustment.

The molecules of Gemini surfactants are dimeric and consist of two monomeric surfactant units linked by a spacer. Among them, cationic Gemini surfactants have a wide range of application in various industrial sectors such as pharmaceuticals, home and personal care, corrosion inhibition, etc. Various methods of synthesis have been investigated and tested for the synthesis of cationic Gemini surfactants. The surface properties of Gemini surfactants are highly dependent on various factors like spacer, headgroups, counterions, etc. The cationic Gemini surfactants have lower CMC values as compared to their monomeric analogues. This review highlights the different methods for the synthesis of cationic Gemini surfactants and the applications of these surfactants in different fields are presented.