Volume 52, Issue 3

Phospholipids and polyphenolic phytoconstituents may form specific molecular complexes ( polyphenolics-phospholipid complexes, phyto-phospholipid complexes ) with definite chemical structure, solubility, thermal and spectroscopic characteristics. Furthermore, such specific molecular entities may self-associate into spherical unilamellar vesicles ( phyto-vesicles, herbosomes ) with size at nano- or microscale. Phyto-phospholipid complexation was recognised as a promising strategy to improve formulation performances and enhance efficiency of herbal polyphenolics with cosmetic relevance in comparison with pure phytoconstituents. This concise review summarizes the current knowledge on preparation methods, physico-chemical properties and aspects of application of the selected phyto-complexes as cosmetic active ingredients.

In the past years some researches were conducted to model laundry washing in the automatic washing machine. The most studies, however, were focused to some aspects of the automatic laundry washing (e. g. spinning cycle) and not on the washing process as whole. In this paper a model of a washing machine is presented that is based on measured data of 9 different washing machines with rated capacity between 5 kg and 11 kg, which are produced by six different manufacturers. The proposed approach is based on multiple linear regression analysis to extract the systematic, model independent behavior of washing machines and is used to calculate the consumption of the water, energy and detergent in dependence of the rated capacity, washing temperature, duration of the main wash, load size and washing performance.

In order to simulate the usage of washing machines by the consumer, a concept of a “virtual washing household” is developed that, to some extent, behaves as a real life household. As essential part of this virtual household is the virtual washing machine in which washing cycles are conducted in dependence of the washing parameters, household size and behavioral parameters. The concept stipulates that a washing cycle is conducted only when the household has enough laundry collected, so that the loading capacity of the washing machine is used, otherwise the houshold waits. Houshold, however, washes the laundry despite the loading capacity restrictions when a certain, waiting time (defined by the houshold) is elapsed. The consequences of all washing cycles during one year are calculated in terms of CO 2 equivalent emissions caused by the energy, water and detergent consumed for reaching a well-defined level of washing performance. This model offers a high range of possibilities to simulate some of the consumer's behavioral patterns and so helps to identify an optimal washing behavior for different sizes of washing machines.

The aim of this study was to develop a repeatable method for the measurement of microbial load reduction factors after hand and machine dishwashing processes that meet the requirements associated with consumer studies, based on non-pathogen test strains. Microorganisms were isolated from tableware, identified and cultured for this purpose, mixed with soiling agents and lyophilised for storage purposes. Detailed instructions for ambient conditions and disinfection, and preparation and application of soiling agents were defined. The method chosen in this study successfully led to repeatable results. The food matrix of the soiling agents used for the application of test strains shows to have a large impact. This is, therefore, the first repeatable method that enables the comparison of microbial load reduction factors after machine with hand dishwashing. In addition, the method was designed in a way that enables further consumer studies.

The standard procedure of non-ionic surfactant detection by using the Bismuth Active Substances method offers low sensitivity, precision and a high consumption of the reagents. A new spectrophotometric (λ max = 460 nm of the visible spectrum) iodobismuthate method was developed, which may be successfully used to determine the presence of non-ionic surfactants at microgram levels. The oxyethylates were precipitated with the modified Dragendorff reagent, filtered, dissolved and afterwards the spectrophotometric determination of the equivalent bismuth amount was carried out. Several key factors, which influence the results of the proposed oxyethylate determination method, were optimized. The consumption of chemical reagents was notably decreased and the sensitivity of the method increased significantly in comparison to the standard method of non-ionic surfactant determination.

Corynomycolic acids have two hydrophilic heads (OH and COOH) and two hydrophobic tails on adjacent carbon atoms. In this work, hybrid type corynomycolic acids ( syn - and anti -isomers) were synthesized via the following three steps: 1) crossed Claisen condensation of t -butyl tridecanoate with ethyl per fluorooctanoate, 2) reduction of C = O to OH, and 3) conversion of COO- t -Bu to COOH using CF 3 COOH. Both hydrophilic groups (OH and COOH) of hybrid corynomycolic acid would dissociate to –O – and –COO – at alkaline condition ( p H = 12) while they remain unchanged at acidic condition ( p H < 3). The effect of hybrid structure on the surfactant properties was investigated by the surface tension and surface pressure-area (π- A ) measurements. Hybrid type corynomycolic acid gave smaller cmc and γ cmc than dialkyl type one due to fluoroalkyl chain. With respect to the stereochemistry, the anti -isomer attained a smaller γ cmc value than the syn -isomer. In π- A measurements, the monolayer of the syn -isomer showed a lower collapsing pressure (∼15 mN m – 1 ) than that of the anti -isomer.

A new series of novel nanostructured poly (aniline-co-m-aminobenzoic acid) copolymer has been synthesized by chemical oxidative in-situ polymerization method using dodecylbenzene sulphonic acid (DBSA) as a soft template. The synthesized copolymers were characterized by Fourier Transform Infrared spectroscopy, Ultraviolet visible spectroscopy, X-ray diffraction and scanning electron microscopy. The infrared spectrum shows the characteristic peaks confirming the formation of the copolymer. The ultraviolet visible spectrum shows the π to π∗ transition and n to π∗ transition. X-ray diffraction pattern confirms the amorphous nature of the polymer. Scanning electron microscopic images show the new morphology of spherical granular sponge like structures in the range of 100 to 200 nm. Conducting properties of the copolymers were studied using four probe method. Copolymers doped with DBSA showed an increased conductivity in the order of 10 –4 S/cm. These copolymers are found to be more soluble in polar solvents comparing to polyaniline homopolymer.

Herein, we have investigated the interaction between a phenothiazine drug promethazine hydrochloride (PMT) and nonionic surfactant t -octylphenoxypolyethoxyethanol (TX-100) in aqueous solutions using a conductometric technique at different temperatures and compositions. The evaluated critical micelle concentration ( cmc ) values are lower than cmc id values suggesting attractive interactions of mixed micelles components. It is observed that with the increase in temperature, the cmc value increases first and after the value decreases at higher temperature. At 298.15 K, the maximum cmc values were attained in presence or absence of TX-100. The bulk properties of solution were studied by means of different theoretical models reported in the literature such as Clint, Rubingh, Motomura, and Rodenas for explanation and comparison of results of different binary mixtures of the drug and TX-100. The negative values of interaction parameter (β) obtained from the regular solution theory (RST) recommend synergistic interactions. Activity coefficients ( f 1 and f 2 ) calculated by all theoretical models used herein were obtained to be always below unity indicating nonideality in all binary mixtures. Thermodynamic parameters (like standard Gibbs energy (Δ G ° m ), enthalpy (Δ H ° m ), and entropy (Δ S ° m )) are also evaluated which propose dehydration of hydrophobic portion of the drug at higher temperatures. The above results obtained may be helpful in model drug delivery systems.

Contact angles of pure water, partially sulphated groundnut oil and different surfactant solutions on glass, Stainless Steel, Teflon and different other polymer surfaces have been measured. The contact angles of oil on various surfaces underwater and under different surfactant solutions were also measured. These two contact angles have been found to be linearly related with a slope close to 1. However, the underwater contact angles have been found to deviate significantly from the prediction based on Young's equations which have been attributed to the possible modifications of the surfaces underwater due to adsorption of surfactants. Based on the observed oil underwater contact angles, comparative efficiencies of fatliquoring have been obtained. Weight gain measurements in various fatliquoring solutions containing surfactants and oil have been carried out with the wet blue leather samples. The results show that the contact angle of oil underwater correlates well with the efficiency of leather wetting.

Dynamic interfacial tension (IFT) behaviors of dialkylbenzene sulfonate (DAS)/heavy alkylbenzene sulfonate (HABS)/dodecylbenzene sulfonate (LAS) ternary mixture solutions against a homologous series of alkanes were studied. On the basis of our experimental results, one can find that the lipophilic ability of DAS was stronger than that of HABS. At the lower content of LAS, the ternary system was oil soluble; at the higher content of LAS, the ternary system was water soluble. An IFT in the 10 – 3 mN/m range can be obtained for the ternary system against long-chain alkanes (decane, dodecane) under the condition that the content of LAS was 30 %. A dynamic IFT of 10 – 4 mN/m order of magnitude was observed against decane. The hydrophilic-lipophilic ability of the surfactant plays an important role in dynamic IFT behavior. With increasing content of LAS, the alkane carbon number of ternary mixture solutions for producing the lower IFT had a tendency to lower.