Volume 62, Issue 1

Despite the fact that dishwashers have been optimised in recent decades in response to policy requirements, consumers still use more energy and water than necessary. This has been deeply investigated by two research groups with complementary approaches and published in this journal. When translating these scientific findings into recommendations, it is essential to ensure that these recommendations can be easily integrated into consumers’ everyday lives and do not lead to significant failures or disappointments that result in compensatory behaviours among consumers and consume even more resources. In this context, the authors suggest the introduction of a ‘short eco’ programme, which is just as economical as the ‘eco’ programme, but, achieves similar cleaning results in a much shorter time when using a high-performance detergent. This would overcome one of the biggest limitations that consumers currently have when using the ‘eco’ programme. The authors discuss the possible consequences of this proposal and invite readers for comments.

The physicochemical property of surfactants that is widely used to study their behavior is the critical micellar concentration (CMC). The value of this property is specific to each surfactant as it depends on a number of external factors and the chemical composition of the surfactant. This research focused on using two new machine learning approaches, Random Forest (RF) and Support Vector Machine (SVM), to predict the logarithmic CMC value of 10 ionic surfactants. The same database from the previous study (a total of 258 experimental cases) was used with the same input variables – those defining the mixture of the organic solvent-water: T, molecular weight, molar fraction and log P; and the chemical composition of the surfactant: number of atoms of each element of the surfactant – to develop the predictive models. The best RF and SVM models were then compared with the best ANN model developed in the previous study. According to the results, the normalized models were those that presented the lowest RMSE values in the validation phase. Finally, the two approaches proposed in this research are suitable tools, together with the ANN, for the prediction of CMC and as possible alternative methods to replace expensive experimental laboratory measurements.

To further improve the foaming properties, foam stability, salt and temperature resistance, betaine surfactants were combined with sodium dodecyl sulphate-derived multifunctional surfactants synthesized in laboratory. Sodium dodecyl sulphate-derived multifunctional surfactants (HSDS) was synthesized and the changes in performance before and after the addition of hexadecyl betaine (HB) to hydroxymethylated sodium dodecyl sulfate were comprehensively compared by carrying out experiments such as such as measuring foam volume and surface tension. The foaming volume of hexadecyl betaine (HB) compounded with HSDS-4 is found to reach 475 mL with a half-life of 7.72 min. The temperature resistance test shows that the foam volume of HS-4 at 70 °C is 22.9 mL. At a salt content of 200 g L −1 , the foam volume of HS-4 is still 355 mL with a half-life of 6.13 min. Finally, the microstructure of the foams produced by the different compounds was measured. The foam produced by HS-4 had the lowest defoaming rate compared to the other compounds. The effectiveness of the compounded product in improving the recovery rate is shown, providing support for the further innovation and utility of this technology.

To investigate the effect of amphiphilic nanoparticles and nonionic surfactants on the stability of emulsions, SiO 2 nanoparticles were first locally surface modified with organosiloxanes of different carbon chain lengths to prepare amphiphilic nanoparticles with different hydrophobic properties, and then the effects of surfactant type and concentration, interfacial tension and its composite system with the amphiphilic nanoparticles on the stability of emulsions was investigated. The experimental results demonstrate, the OP-50 exhibits the most effective emulsification properties at a concentration of 0.1 %. However, the emulsion stability is significantly compromised. The emulsification effect of OP-50 with amphiphilic nanoparticles at a concentration of 0.1 % remained unaltered, while the emulsion stability was markedly enhanced compared to that of a single system. The modulus of expansion of OP-50 was 11.8 mN m −1 , while that of OP-50 compounded with C8-10:1 was 120 mN m −1 . The incorporation of modified nanoparticles with varying lengths of carbon chains was shown to effectively enhance the modulus of expansion of the oil–water interfacial interface. The results of this study are informative for the application of oil repellents in the mechanism of enhanced recovery.

For the enrichment of photosensitive micelle systems, several novel types of UV light viscoelastic photosensitive micelle systems were prepared by compounding oleamidopropyl dimethylamine (PKO–O) and trans - o -methoxy-cinnamic acid ( trans -OMCA). The flow curves and viscoelastic properties of the micelle systems were investigated before and after UV irradiation at a wavelength of 365 nm. The concentration of PKO–O was controlled at 1.0 wt% and 2.0 wt%, with a fixed molar ratio (MR) of PKO–O to trans -OMCA of 1:0.75, after exposure to UV light, the zero shear viscosity ( η 0 ) of the optimal micellar system decreased by more than 99 %. Furthermore, when the mass concentration of PKO–O ranged from 3.0 wt% to 5.0 wt%, while maintaining the same molar ratio, the optimal micelle system achieved a more than 15-fold increase in η 0 . These phenomena are attributed to the isomerization of trans -OMCA to cis -OMCA under UV light irradiation. The Carreau-Yasuda model effectively describes the flow curves of the PKO–O/OMCA micelle systems. The viscoelastic response of the micelle systems can be well characterized by the Maxwell model. Furthermore, the four-parameter rheokinetic model was used to accurately describe the variation of η 0 with UV light exposure time. This study promises to explain the irreversible photosensitive thickening and thinning of tertiary amine viscoelastic micellar systems, while also providing valuable rheological references.

There is a growing interest in dietary materials to explore their therapeutic activities. Ellagic acid is considered as a dietary supplement and is naturally present in fruits and other foods. It has anticancer, antimalarial, antiviral, antioxidant, and anti-inflammatory activities. These activities can be enhanced with nanoformulations, which can increase its oral bioavailability. However, there is a need for an economical, simple, sensitive, and robust analytical method for the estimation of entrapped ellagic acid in the nanoformulations. Therefore, the present study presents the development and validation of a UV–visible spectroscopy method for the estimation of EA in nanoformulations. The phosphate buffer (pH 7.2) and the detection wavelength of 253.5 nm were used for the method development, and its validation was performed according to the ICH Q2A (R1) guidelines. The coefficient of determination value of the developed method was found to be 0.9988 in the concentration range of 1 μg mL −1 to 6 μg mL −1 . The method was found to be linear, precise, sensitive, and robust. This method can be used for the estimation of EA in nanoformulations, bulk dosage forms, and other pharmaceutical formulations.

Surfactants offer a promising alternative for the efficient and environmentally friendly removal of organic pollutants and toxic heavy metal ions from various media. Their high efficiency and environmental compatibility make them a valuable option for remediation efforts. This study focuses on the cloud point extraction (CPE) of ions from aqueous solutions using biodegradable nonionic surfactants combined with ionic surfactants instead of chelating agents. Phase diagrams of binary surfactant/water systems were first constructed. The effects of salt, inorganic contaminants, and ionic surfactants on the cloud point (T c ) were then investigated. At temperatures above the cloud point, two distinct phenomena were observed and monitored over time: phase separation and phase clarification. The kinetic process was studied using the Turbiscan Lab Expert. Extraction results were evaluated based on four responses: extraction yield (E%), residual concentrations of solute (X s,w ) and surfactant (X t,w ) in the dilute phase, and volume fraction of coacervate at equilibrium ( Φ C ). Empirical modelling gives a satisfactory agreement between experimental and calculated values. The capacity of CPE to simultaneously remove an organic pollutant and a toxic heavy metal was demonstrated.

The technology of oil and gas well plugging and profiling currently represents a favourable means of promoting the development of water injection and ensuring stable production from oil reservoirs in oil fields. The use of emulsified asphalt is significantly limited by several factors, including its insufficient resistance to high temperatures, demanding requirements for sealing strength, and susceptibility to destabilisation in high salinity conditions. Nevertheless, it presents favorable injection performance and does not cause soil contamination. To improve the selective water plugging in seam-hole reservoirs with high salt content and temperature, a novel high softening point emulsified asphalt blocker was developed in this work using petroleum asphalt powder, sodium lauryl diphenyl ether disulfonate, and propylene glycol alginate as the primary monomers. The stability of the system in terms of temperature and salt resistance as well as the sealing performance under different permeable seam hole layers were investigated. The studies showed that the novel blocking agent remained stable for at least 20 days at room temperature and remained fluid for at least 3 h at 130 °C. The system exhibited excellent salt resistance and maintained a suitable viscosity in highly mineralized conditions. With an injection volume of 1 PV and a permeability ranging from 2,014 mD to 3,321 mD, the slit reservoirs achieved an average blocking rate of 88.9 %.

The hydrophilic-lipophilic balance (HLB) of any surfactant determines its solubility. Selection of the ideal surfactant for a given application appears to be facilitated by a thorough understanding of the relationship between accurately measured or calculated HLB and physicochemical properties. In this study the HLB values of the mono-, bi- and bolaphilic derivatives of F -alkylated cyclic polyethylene glycol succinate were determined using the Griffin technique. It was investigated how the different applications of these surfactants can be distinguished by their HLB values.