Volume 52, Issue 5

Decreasing resource consumption concerning electricity, water and detergents in the framework of automatic dishwashing is not only determined by technical improvements. First and foremost, the use phase, in other words, the consumers and their choices, for example, the type of dishwasher, the kind of dishwashing programmes selected and the method of pretreating dishes, play an important role in terms of saving energy. To investigate the current dishwashing habits in Germany, 4 000 private households were asked about the usage of automatic dishwashers and the general dish treatment in everyday life. The results of the survey have shown a broad range of consumer behavior due to individual dishwashing habits. It also became obvious that consumers who more frequently use the energy saving “eco programme” tend to pretreat some dishes, such as pots and pans, with additional resources more often than the households who use other programmes. Therefore, the study reveals that a holistic view due to all resources consuming dishwashing steps is necessary to deduce adequate consumer recommendations for saving energy, water and detergents.

Micelles are increasingly used as carrier systems. In previous studies, we have shown that the blockcopolymers PEO 13 -PPO 30 -PEO 13 and α s -casein form micelles at distinct temperature and concentration ranges. The aim of the study at hand was to determine the thermodynamics of this micelle formation by isothermal titration calorimetry (ITC). For α s -casein, micelle formation was investigated as a function of temperature from 15 – 30 °C at pH = 6.6, while micelle formation of PE6400 and of mixtures of PE6400 with α s -casein was studied from 29 – 31 °C. In addition, the influence of increasing α s -casein mole fraction from 0.135 × 10 −3 to 3.6 × 10 −3 was examined at 30 °C. In case of α s -casein, the standard experimental approach could be used while we developed a new experimental approach for PE6400 and for the mixture. The results show that the enthalpy of demicellization increases for α s -casein and decreases for PE6400 with increasing temperature. In case of the mixtures, the enthalpy of demicellization was not influenced by either the temperature or the α s -casein mole fraction. The results obtained for α s -casein suggest that the micellization follows a “shell-model”. In the case of the mixtures, α s -casein is likely to form the core of the micelle while the outer part appears to be composed of PE6400. The mixing properties were antagonistic, which was shown by comparing the enthalpies of PE6400 with those of the mixtures. The results show that ITC is a powerful tool to precisely determine micellization properties not only of the single but also of mixed surfactant systems.

Pseudo-ternary phase diagrams of 1-butyl-3-methylimidazolium hexafluorophosphate (bmimPF 6 ) /Tween 80 (polyoxyethylene sorbitan monooleate)/alcohol/toluene systems were constructed with different linear-chain alcohols. The phase diagrams demonstrate that an increase in the surfactant/alcohol weight ratio yields a larger microemulsion domain. The different chain lengths of the alcohols affected the extent of the microemulsion region. Alcohols having short-chain lengths were optimum cosurfactants in bmimPF 6 -based microemulsion. Moreover, the influence on the microstructure of the single-phase area as a function of the alcohol chain was investigated using electrical conductivity. Preliminary investigations suggested that the bmimPF 6 -in-toluene region of systems which contain ethanol was notably magnified, and increasing in alcohol chain length (n = 4 – 10) led to a shrinkage for alcohols with longer chain length.

Two surfactants, namely, dodecanoylglycinate and dodecanoylsarcosinate, differing only in a methyl group vs . a hydrogen atom on the amide nitrogen, have been studied with respect to solution behavior and adsorption at the air–water, oil-water and calcium carbonate-water interfaces. It was found that the ability of the glycinate surfactant of forming intermolecular hydrogen bonds via the amide group leads to tighter molecular packing, which greatly influenced the behavior at interfaces. Based on this molecular observation, potential applications were considered and emulsification, foaming and wetting tests were carried out. It could be concluded from this work that a minor change in the structure of a surfactant molecule can be very significant for technological systems and processes.

The aim of this work was to compare the penetration enhancer effect of newly developed sucrose myristate with the generally used sucrose laurate. Hydrogel formulations containing sucrose esters (SEs) were prepared and the model drug was Ibuprofen (IBU), which has oral side effects, so applying it in a transdermal system could be useful. We evaluated the effect of SE hydrogel formulations on the skin by the noninvasive in vivo test and examined their concentration dependent influence on the penetration of IBU through a synthetic membrane ( in vitro ) by the Franz cell method. The results indicated that sucrose myristate incorporated into hydrogel moistures the skin well and lastingly and showed a better drug penetration enhancing effect at a much lower concentration compared to sucrose laurate. Our results revealed that sucrose myristate could be a promising and effective penetration enhancer in the pharmaceutical field.

Information concerning the use of non-ionic surfactants (NS) in household products is very scanty. Therefore, a qualitative determination of NS in raw sewage is an alternative source of information concerning the presence and manufacture of NS. The aim of this work was to identify NS in raw sewage (in Poznan and Blonie, both Poland) and treated sewage (in Blonie) and to compare the results with those obtained for river water (Warta in Poznan, Poland). LC-MS/MS was used for this purpose. The presence of 116 ethoxamers, being exclusively polydispersal alcohol ethoxylates (AE) containing alkyl moieties from C 10 to C 16 and C 18 , as well as 20 poly(ethylene glycols), was confirmed in the raw sewage, while 68 ethoxamers were found in the treated sewage, including 12 octylphenol ethoxylates. No nonylphenol ethoxylates were identified in the raw or treated sewage.

Two kinds of 1,2,3,4-butanetetracarboxylic acid type gemini surfactants having semifluoroalkyl groups (Rf-(CH 2 ) n -; Rf = C 8 F 17 , n = 2,3,4,5,6,8,11) as diester of 2,3-bis-COOH and 1,4-bis-COOH were prepared from 1,2,3,6-tetrahydrophthalic anhydride as the key material. Their surface properties were studied by surface tension and surface pressure-area (π–A) measurements. Semifluoroalkylated geminis showed excellent surface tension re-ducing ability, but the values of the critical micelle concentration (CMC) and γ CMC remained nearly unaffected by the methylene chain length. From the zero-pressure molecular areas of semifluoro-alkylated geminis and the compression modulus analysis, it was clarified that semifluoroalkylated gemini surfactants having short methylene chains would form more rigid monolayers than those having long methylene chains. But, there were not very large differences in surface properties between two geminis having the same methylene chain length.

Four cationic surfactants have been synthesized in the absence of solvent using triethylamine and four different long chain alkyl halides. Using FTIR, 1 H NMR spectra and elementary analysis the chemical structure of the synthesized surfactants were confirmed. The physio-chemical properties have been evaluated using standard analytical procedures. The corrosion inhibition properties of these four surfactants as additives were evaluated on zinc phosphate conversion coating on mild steel using nano silica as accelerator. The efficacy of the surfactants as corrosion inhibitor increases with increase in the side chain length and surface activity. With the help of X-ray diffraction (XRD), Atomic force microscope (AFM) and Scanning electron microscope (SEM) the surface morphology have been studied. The protective performance of the coatings was evaluated by salt spray exposure studies.

A new thio-based non-ionic surfactant 1-(3-chlorophenyl)-3-te-tradecanoylthiourea has been synthesized from potassium thiocyanate, tetradecanoyl chloride and 3-chloroanaline. The purity of the compound was characterized by techniques like 1 H NMR, 13 C NMR, and FT-IR. The compound was used to detect the toxic metals like copper, mercury and manganese by using UV-Visible spectrophotometric technique. The compound is able to act as a ligand as well to form micelles. Due to this the compound extracts these toxic metals in form of solubilization and complexation. The extracted metals settle down to the bottom in a water tank. The visible change in color with time proves the interaction of the compound with the metals. The compound having carbonyl as well as sulfur groups have soft corner to metal for complexation. This will be used to remove toxic metals from polluted soil and soft drinking surface and underground water. The surfactant is easily synthesized, very economical and environmentally acceptable. The CMC of the surfactant is also determined.

A thin-layer chromatographic system comprising of silica gel as stationary phase and a mixture of methanol, 0.1 % aqueous sodium thiocyanate, acetone and ethyl acetate in 7 : 3 : 2 : 3 ratio as eco-favourable mobile phase has been found most efficient for the separation of ternary mixture of surfactants (alkyldimethylbenzylammonium chloride (ADBAC) + cetyltrimethylammonium bromide (CTAB) + Triton X 100). The separation pattern has been presented as densitogram. Chromatographic parameters like ΔR F , separation factor (α) and resolution (R S ) for the separation have been calculated. The effect of the presence of foreign substances such as metal cations, metal anions, amino acids and vitamins as impurities on the separation has been examined. The mobility trend of the separated surfactants was also examined by replacing methanol with other alcohols. The detection limits for ADBAC, CTAB and Triton X 100 have been determined. The proposed method has been successfully applied for the identification of ADBAC in the household cleaning product “Lizol”.