Volume 57, Issue 3

Under the aspect of strict environmental regulations, hydrotropy is accepted as an environmentally friendly (“green”) approach to solubilise hydrophobic compounds. Above the minimum hydrotrope concentration (MHC), hydrotropes are capable of self-aggregation; the MHC is considered the minimum requirement for solubilisation. In this article a comprehensive overview of the aggregation behaviour of different hydrotropes is presented. Details about the methods used for aggregation are given. The role of additives is discussed with respect to their influence on the MHC. Thermodynamic studies are used to evaluate the stability of a hydrotrope at different temperatures. A modern approach to the solubilization mechanism using hydrotropes is also presented in this review article. The aim of this article is to provide guidance for conducting such studies on a number of hydrotropes.

The application of phosphate compounds as a builder in a detergent formulation created eutrophication that encouraged industry to produce more eco-friendly detergents. To overcome that problem, phosphate can be substituted by zeolit that is more effective in cleaning and also biodegradable. In this study, zeolite was synthesized from rice husk ash using a melting method followed by hydrothermal processes. Effervescent detergent tablets were prepared with the following formulations: 3 formulations containing zeolite (F1–F3), 3 formulations containing sodium tripolyphosphate (STPP: P1–P3) and 1 control formulation. The synthesized zeolit was analysed by XRD (X-Ray Diffraction), FTIR (Fourier-Transform Infrared Spectroscopy), SEM (Scanning Electron Microscopy) and cation exchange capacity (CEC). Furthermore, all detergent formulas were characterized for flowability, compressibility, compatibility, disintegration time, pH, cleaning action and biodegradability. The results of FTIR, XRD and SEM characterization showed that the synthesized zeolite was an amorphous type-A crystal and the predominance of the amorphous phase with a cubic structure and CEC value of 95.71 cmol (+) kg −1 . In this study the formulation F1 with 15-% zeolite was found to be the best formulation with granule flow rate parameters of 13.6 g/s, stationary angle of 22.0°, compressibility of 16.6-%, detergent tablet hardness accounted to 0.81 kgf/cm 2 , crushed time of tablet detergent of 1.5 min, pH 6.7, and biodegradability value of 70.3-% in BOD 5 test. A higher concentration of zeolite provided a better cleaning effect of the detergent tablets.

Olive oil was selected as the oil substrate and hydrolyzed by Candida sp. 99–125 lipase. The hydrolysis rate of olive oil was used as an indicator. Based on the single factor experiment, the effects of dosage of Candida sp. 99–125 lipase, reacting temperature, pH value and water-oil ratio were investigated. Box-Behnken center combination and response surface methodology were utilized to optimize the hydrolysis rate. The results showed that the significant differences of each single factor on lipase hydrolysis of olive oil on the oil-water interface were different. pH value is the first significance factor, and the significance of water oil ratio on lipase hydrolysis of olive oil is second only to pH value. Finally, the mechanism of Candida sp. 99–125 lipase hydrolyzing olive oil at the oil-water interface was discussed.

In this work, we have investigated the washing performance of sodium oxalate-based detergents containing different enzymes (protease, lipase and cellulase). The results show that sodium oxalate-based detergents with enzymes have a better washing performance than formulations containing the conventional builder STPP and zeolite 4A. For sodium oxalate-based with protease, the amount of sodium oxalate and protease have a significant effect on the detergency. Lipase can improve detergency of sodium oxalate-based detergents after “first washing” in the presence of different anionic surfactant (LAS, MES and AES). For cellulase, only sodium oxalate in the presence of LAS has a detergency increase.

Hemp seed oil has a very better effect of sunscreen, repair, anti-allergy and anti-aging, as a result of which it is a high-quality raw material for skin care products. In this study, the oxidation degree of hot-pressed and cold-pressed hemp seed oil which was stored in five different environments, was evaluated. The results showed that the long-chain unsaturated fatty acids were oxidized. The oxidation products of hemp seed oil were analyzed by headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC/MS) and high performance liquid chromatography (HPLC). All hemp seed oils which were stored at low-temperature protected from light and outdoor environment contained aldehydes, ketones, and alcohols, which have a negative impact on the health of consumers. Furthermore, hemp seed emulsion was prepared with different HLB values. After the 2 nd month, hemp seed oil emulsion exhibited a good stability without stratification.

In this paper, three kinds of aliphatic alcohol polyoxyethylene ethers (AEO) with different molecular weight distribution were used as raw materials, and aliphatic alcohol polyoxyethylene ether phosphate (AEP) was obtained by P 2 O 5 process. FT-IR and 31 P-NMR were used to characterize the structure of the product, confirming the formation of the product. HPLC-ESI was used to probe the molecular weight distribution of the sample. The surface activity, wetting properties and application properties of the samples were measured. Wetting and permeability were found to increase with decreasing EO addition, and N-AE 7 P is optimal, which is related to the spatial structure of the molecule. The surface activity, washing performance and foaming properties of C-AE 9 P are better as that of the other investigated compounds because of the synergistic effect between the complex components.

Non-ionic carbohydrate based gemini surfactants with rigid aromatic spacer CH 2 -Ar-CH 2, which carry two hydrophobic tails of different tail lengths (C 12 , C 14 and C 16 ) and two sugar moiety polar head groups were synthesized and their reverse micellar behavior for solubilization of some aromatic α-amino acids viz . histidine (His), phenylalanine (Phy), tyrosine (Tyr) and tryptophan (Trp) in n-hexane were studied by spectroscopic analysis. The head group of these gemini surfactants consists of sugar moiety connected to C-6 of tertiary amines. Amino acids form complexes in order of His > Phy > Tyr > Trp, and in all cases it was found that the D-enantiomers solubilize better in comparison to the L-enantiomers. Moreover, more hydrophobic surfactants i.-e. surfactants with longer hydrocarbon tails show greater complex formation tendency towards D- and L-enantiomers of aromatic α-amino acids.

Herein, we investigated the micelle formation of mixed systems of the antipsychotic drug, chlorpromazine hydrochloride (CPZ), and the bile salt, sodium deoxycholate (NaDC), both in the absence and presence of NaCl by tensiometry. To understand the aggregation behaviour of the mixture of these two amphiphiles, we calculated various micellar and interfacial parameters using the theories of Clint, Rubingh, Rosen and Motomura. The calculated interaction parameters indicate an attractive interaction between the two amphiphiles both in the absence and presence of salt. The results were discussed with regard to the use of bile salt as a promising drug carrier for CPZ and the improvement of its bioavailability.

The surface properties of the binary mixture of cetyl diphenyl ether disulfonate (C 16 -MADS) and linear alkylbenzene sulfonate (LAS) have been investigated by salinity and hardness tolerance, equilibrium surface tension, wettability, foam and emulsification measurements. The results show that with increasing mass ratio of LAS in the C 16 -MADS/LAS mixed system, the ability to reduce the surface tension of the solution is improved. The wetting performance is also improved. The critical micelle concentration (CMC) values are increased first, then decreased, and are higher than the ideal CMC values, which indicates that there is an antagonistic effect that is not conducive to the formation of mixed micelles between C 16 -MADS and LAS. In addition, the C 16 -MADS/LAS system improves the hard water resistance of LAS and reduces the foam properties of LAS.

Chitosan is an abundant and renewable natural biopolymer which exhibits a variety of beneficial properties. Quaternized chitosan compound was extensively studied as an antistatic agent in cosmetics and hair care products such as in hair conditioners and fabric softeners. However, the low solubility of chitosan in water limits its applications. This paper describes a novel way to synthesize quaternized derivatives which were further used as cationic amino sugar based surfactants. The quaternized derivatives of chitosan were synthesized and characterized on the basis of various properties. The resulting derivatives have excellent solubilities in aqueous solutions. In the present work the cationic quaternized surfactants were synthesized under microwave irradiation. Compared to a conventional synthesis the compound N,N,N-trimethyl chitosan (TMC) was obtained with higher yield from the reaction between chitosan and methyl iodide using N-methyl-2-pyrrolidone (NMP) as a solvent. We also synthesized it by adding dimethyl sulfate (DMS) under conventional as well as microwave irradiation method. The characterization of the quaternized derivatives of chitosan was done by FTIR spectra, 1 H NMR, TLC and XRD analysis. Thus, a cationic amino sugar surfactant using a biopolymer was successfully synthesized under microwave irradiation with an efficient yield.