Volume 57, Issue 5

Antioxidant substances are used not only in food and beverages, but also in soap formulations which are known to be effective in skin cleansing, and are also used as ingredients in the detergent and cosmetics market. The aim of this study was to determine the bactericidal effects of plain and antibacterial soaps containing Punica granatum flower (PGF), Carrot seed (CS, Daucus carota ), Lavender (LV, Lavandula officinalis L.) extracts which are known for their high antioxidant activity. Antioxidant properties were determined by using the cupric ion reducing antioxidant capacity (CUPRAC) and Ferric reducing antioxidant power (FRAP) for all soap samples. The effectiveness of soaps which are prepared using PGF, CS and LV extracts on gram positive and gram negative bacteria was investigated. From the findings obtained, all plant extracted soaps had antibacterial activity and it was determined that soap containing carrot extract caused a significant decrease in bacterial levels compared to other soaps. As a result, it has been concluded that the use of antimicrobial and antioxidant compounds as soap formulation components is extremely important for increasing the effectiveness of soap against bacteria.

In this work, we report the application of coconut oil derived N-acyl prolinate surfactant as a potential ingredient in laundry detergent formulation using biological, physicochemical and molecular docking approach. The properties of the sodium cocyl prolinate surfactant 2 were compared with those of sodium cocoate surfactant 1 , a sodium salt of fatty acids from coconut oil, as well as the conventional surfactant sodium dodecyl sulphate (SDS) which is commonly used in the detergent industry. Sodium cocyl prolinate surfactant 2 showed a lower foaming ability compared to SDS and was found to exert a better detergency at a much lower temperature (25°C) compared to surfactant 1 and SDS. The coconut oil based surfactants 1 and 2 displayed a better antibacterial activity against gram positive strains compared to SDS. In view of studying the effectiveness of the surfactants against the severe acute respiratory syndrome corona virus 2, SARS-CoV-2 (COVID-19) which might remain on the surface of contaminated clothes, molecular docking of surfactants 1 and 2 with the spike protein of SARS-CoV-2 was carried out. Surfactant 2 showed an optimum interaction with the amino acid residues of the spike protein which is responsible for the binding of the virus with the host receptors. Molecular docking with savinase, an enzyme used in laundry formulation showed that sodium cocyl prolinate surfactant 2 and SDS displayed comparable interactions with the enzyme. Overall, this study has shown that sodium cocyl prolinate surfactant 2 can be a potential candidate in laundry detergent formulation for machine washing due to its relatively low foaming ability and good detergency properties at a much lower temperature (25°C), making it more energy-efficient. Surfactant 2 was also found to be a promising antimicrobial agent in laundry detergent due to its moderate antibacterial activity and its interaction with the spike protein of SARS-CoV-2, which can help to reduce the spread of any epidemic or pandemic diseases.

Two series of well-defined dimeric metallo-bolaamphiphiles (bola surfactants) with the coordinated metal ions (Cu, Co, Zn) were prepared. These oligomeric surfactants consist of simple monomeric cationic surfactant fragments which are coupled via the hydrophilic ammonium chloride head groups by C 6 and C 12 spacer groups of different lengths. FTIR and 1 HNMR identification techniques confirmed the obtained products. Measurements of surface tensions showed that the synthesized Bola amphiphiles have the desired, relatively low critical micelle formation concentrations (CMC). Bola amphiphiles with long spacer groups (C 12 ) have a pronounced surface activity. The properties of these cationic surfactant oligomers in aqueous solution such as micellization and surface activity were discussed in relation to spacer group. In addition, the synthesized compounds were examined for their anti-microbial activity using the agar diffusion technique.

We have studied the effect of NaCl and CaCl 2 on phase behavior of foaming aqueous dispersions containing mixtures of silica nanoparticles (Ludox CL) and sulfobetaine (LHSB). At the evaluated ratio, the phase behavior results show that at a low CaCl 2 concentration, sedimentation occurs, whereas a stable aqueous dispersion could be achieved when the CaCl 2 concentration reaches to 20%. The adsorption experiments show that high concentrations of both NaCl and CaCl 2 reduce the adsorption of LHSB to CL. In the CaCl 2 dispersion the adsorption decreases significantly and only a few LHSB molecules can be adsorbed on the CL surface. Therefore, without the lower hydrophobicity of LHSB adsorption less CL could adsorbed at the air/water interface. The results on gas permeability show that aqueous dispersions containing mixtures of CL and LHSB show no obvious difference to aqueous systems containing only LHSB. The surface dilatation module of the LHSB and CL system in CaCl 2 solution also shows a similar variation to the system with LHSB alone, which is significantly different from the system with 20% NaCl. Finally, foam flow tests in a porous medium show that compared to a 20% CaCl 2 dispersion with the LHSB and CL system in 20% NaCl, a finer foam and a higher pressure difference could be achieved.

It is important to study the mechanism of wettability of Zhaozhuang coal with surfactant compoundings in order to prevent dust disaster in the process of coal seam mining. By means of molecular simulation, the amounts of water absorbed by different systems, which are composed of monomer surfactant molecules and Zhaozhuang coal molecules or compounding surfactant molecules and Zhaozhuang coal molecules, were compared in this paper. The simulation results show that the system composed of 0.2% sodium dodecyl benzene sulfonate (SDBS) and 0.3% alcohol polyoxyethylene ether (AEO 3 ) had the maximum water absorption amount of 479, which is significantly better than that of other compounding methods and of each monosurfactant system. Analysis results show that the interference of non-ionic surfactant can greatly reduce the electrostatic repulsion between ionic surfactants and make the adsorption sites on the Zhaozhuang coal molecule more compact. The experimental results show that the decreasing percentage of the contact angle of this type of compounding solution on Zhaozhuang coal was 83.74%, which is the best of the six compounding methods. It has a high degree of consistency with the simulation results, and the molecular simulation method applied in this paper shows that it is convenient and accurate. This research plays a guiding role in dustproof work in Zhaozhuang coal mining.

The present study is an investigation of the solubilising ability of natural and conventional surfactants saponin (sapindus saponin or reetha saponin), Rhamnolipids (RLs) and N-cetylpyridinium chloride (CPC) respectively via dye-surfactant interaction. The ionic dye Congo Red was examined by absorption spectroscopy method for the study. The dye interacted strongly with oppositely charged surfactant N-cetylpyridinium chloride in the pre-micellar concentration range and formed a stable dye-surfactant complex. The thermodynamic parameter, free energy change for all the systems was calculated at a constant temperature of 25°C. The ΔG 0 value for N-cetylpyridinium chloride is found to be −33.269 kJ/mol while for saponin and rhamnolipids the values were −16.084 kJ/mol and −26.006 kJ/mol respectively. The values clearly indicate the efficiency of N-cetylpyridinium chloride surfactant compared to the other two surfactants. The present study aims to understand the dye solubilization in surfactant media in order to develop environmentally friendly, green and cost effective techniques.

The formulation of gypsum foaming agents using alkyl polyglucosides (APG) as main surfactant was studied. The foaming behavior of the foam compound system and the stability of the foam were determined by experiments. The foaming property of APGs with various carbon chain lengths and of APGs in mixtures with other surfactants, such as cocoamidopropyl betaine (CAB), sodium lauryl amphoacetate (SLA) and sodium alcohol ether sulphate (AES) was investigated. The influence of some polymers used as foam stabilizers, such as hydroxypropyl methylcellulose (HPMC), polyethylene glycol (PEG), polyvinyl alcohol (PVA) was also examined. Foaming times, foaming stability and bleeding ratio change were tested in order to investigate the properties of foaming and foam stability. Results indicated that the best foam performance was obtained by the composition based on APGs mixed with SLA and PVA. The optimal condition was as following: m (APG0810): m (APG1214): m (SLA) = 4: 1: 2, and PVA accounted for 10% ( w / w ) of total. After 1 minute, the foam multiplier was 4.35. Due to the improved mix system, it remained at 3.65 even after 15 min, with a mass fraction of 0.2%, a stirring speed of 1800 rpm and a stirring time of 3 min.

In the present study, three amide Gemini surfactants of different chain lengths were synthesized, namely N,N-bis-dodecyl-2,6-pyridinium dimethylamide propionate sodium (DLP-12), N,N-bis-tetradecyl-2,6-pyridinium dimethylamide propionate sodium (DLP-14) and N,N-bis-hexadecyl-2,6-pyridinium dimethylamide propionate sodium (DLP-16). Their chemical compositions and structures were characterized by FTIR, 1 H NMR and mass spectrometry. Moreover, tensiometry, Langmuir monolayer and conductivity measurements were performed to investigate the micellization and chemical surface properties of the surfactants. The results of the characterization proved that the synthesis of DLP-12, DLP-14 and DLP-16 was successful. Among the investigated surfactants DLP-16 had optimum properties such as a higher emulsification ability as well as a lower surface tension. Furthermore, by calculating the critical packing parameter (CPP), the aggregation morphology of the DLP-12, DLP-14 and DLP-16 was also predicated in this study.

The synthesis of branched-chain alkyl polyglucosides (APG) from 2-butyl-1-octanol, a Guerbet alcohol, in an acid/phase transfer catalyst (PTC) system was studied. Under optimized conditions the conversion rate of this reaction was 98.4% and the selectivity 16.5:1 (APG to polysaccharide, w/o). The APG was characterized by HPLC, LC/MS and 1 HNMR. The surfactant properties showed that the wetting time was 17.9 s, and the emulsification time of a 0.15% aqueous solution with soybean oil was 22 min 44 s and with liquid paraffin 11 min 05 s. The critical micelle concentration (CMC) was 5 · 10 −4 mol/L, and the surface tension was 25.87 mN/m with a 1% aqueous solution. It is a low foaming surfactant.

The kinetics of the reaction methionine+cumene hydroperoxide in the presence of nonionic surfactant was studied both in the pre-micellar and post-micellar regions at different temperatures by iodometry. It was established that the rate of the methionine + cumene hydroperoxide reaction depends on the molecular/ionic/micellar form of surfactant in the reaction system. In the post-micellar region the rate of methionine+cumene hydroperoxide reaction slows down due to solubilization of the reacting substances in the micelles. Quantification of solubilization of cumene hydroperoxide and methionine in the micelles has been studied by HPLC analysis. It was obtained that about 30% of cumene hydroperoxide, which is more hydrophobic than methionine, is solubilized in the micelles, as a result the concentration of cumene hydroperoxide in the reaction environment decreases and the rate of reaction in the post-micellar region also decreases. Based on the kinetic studies the reaction rate constant was determined and the value of activation energy was obtained.