bluuebunny/crossref_metadata_2025 huggingface dataset:
Aquatic Risk Assessment of Enzymes used in Household Detergents
Authors: Madsen T. , Slothuus T. , Petersen G. I. , Rasmussen D.
Published: December 2013

Exposure and effect assessment including risk characterisation of enzymes used in household detergents were conducted. Predicted environmental concentrations were calculated by use of traditional methods and detailed transport and fate modelling. Predicted no effect concentrations were derived from the results of ecotoxicological studies conducted with subtilisin and other available information on the acute and chronic aquatic toxicity. Risk characterisation ratios were defined as the ratio between the predicted environmental concentration and the predicted no effect concentration. Risk characterisation ratios were calculated for fresh and marine water and were found to be between 0.0002 and 0.06, i.e. all well below 1. This shows that under the given conditions, the use of enzymes in household detergents does not present a risk to the aquatic environment.
One-step Preparation of Comb-like Surfactants Containing Poly(ethylene oxide) Methyl Ether and Linear Alkyl Grafts
Authors: Zhang W. , Du Z. , Wang W. , Wang G. , Lin S.
Published: December 2013

The optimum one-step method for preparing comb-like surfactants with poly(styrene-co-maleic anhydride) (SMA) as backbone was investigated to achieve a commercial way for manufacture. The side chain molecule was introduced into reaction system while the radical copolymerization of styrene (St) and maleic anhydride (MA) in anhydrous inhibitor-free tetrahydrofuran (THF) was finished. The precipitation and purification process of SMA in traditional grafting-onto route was passed over. A series comb-like surfactants with various side chain, poly(styrene-co-maleic anhydride)-g-(poly(ethylene glycol) monomethyl ether) (SMA-M), poly(styrene-co-maleic anhydride)-g-(poly(ethylene glycol) monomethyl ether & dodecane) (SMA-M+C12) and poly(styrene-co-maleic anhydride)-g-(dodecane) (SMA-C12), was prepared via this one step method respectively. The molecular weight of the products was measurement via gel permeation chromatography (GPC). The comb-like structures of the surfactants were confirmed by Infrared Spectroscopy (IR) and 1H nuclear magnetic resonance spectroscopy (1H NMR). The equilibrium surface tension was measured to evaluate the surface activity of comb-like surfactants. The surface activity of the product could be improved by using C12 to carry out a hydrophobic modification. The surface activity of comb-like surfactants could be adjusted by using various side chains with different amphiphilic property.
Volumetric and Diffusion Properties of Water/Surfactant/n-Propanol/4-Allylanisole Micellar Systems
Authors: Fanun M. , Shakarnah A. , Meltzer D. , Schwarze M. , Schomäcker R. , Blum J.
Published: December 2013

Sol-gel encaged [(C8H17)3NCH3][RhCl4] catalyses the double bond isomerization in the flavoring agent 4-allylanisole in aqueous microemulsions. In order to provide optimal composition of the reaction medium water/n-propanol/surfactant/4-allylanisole micellar systems were formulated. The surfactants were sodium dodecyl sulfate, cetyltrimethylammonium bromide, sucrose monolaurate, and polyethylene glycol (7) glyceryl cocoate. The ratio (w/w) of n-propanol/surfactant equals 2/1. The extent of the microemulsions region as function of temperature was determined. The micellar systems were characterized by the volumetric parameters, density, excess volume, ultrasonic velocity and isentropic compressibility. The micellar densities increase with the increase in the water volume fraction. Ultrasonic velocities increase with the increase in water volume fraction up to 0.8 then decrease. Ultrasonic velocities increase with temperature for water volume fractions below 0.8 and decrease for water volume fractions above 0.8. Quantitative analysis of the volumetric parameters enabled the characterization of structural transition along the micellar phase. The particle hydrodynamic diameter of the oil-in-water systems was determined as function of temperature. The particle hydrodynamic diameter decreases in the case of the ionic surfactants while in the case of nonionic surfactants it increases.
Do Pseudomonas Aeruginosa Bacteria Affect the Selectivity of Dolomite/Francolite Separation?
Authors: Elmahdy A. M. , El-Mofty S. E. , Abdel-Khalek N. A. , El-Midany A. A.
Published: December 2013

The similarity of surface properties of dolomite and phosphate minerals leads to limited or no selectivity in their separation by flotation. Many chemical additives were tested; however, a limited success was achieved. Recently, bio-surfactants and bacteria have received much focus not only because of their environmentally friendly behaviour but also for their enhanced selectivity in different processes such as flotation. In this paper, the adsorption of Pseudomonas Aeruginosa (PA) bacteria onto francolite and dolomite was investigated. The adhesion of bacteria was studied by adsorption isotherm, zeta potential, and Fourier Transform Infra-Red (FTIR) spectroscopy to reveal the effect of bacteria on the floatability of each mineral. The proposed adsorption mechanism depends mainly on physical interaction due to Van der Waal's, bridging, electrostatic, as well as hydrophobic forces.
Interfacial Composition and Structural Parameters of Aqueous NaCl(HCl/NaOH)/CnmimBr/1-Pentanol/n-Octane Microemulsions
Authors: Xu L. , Chai J. L. , Zhu M. L. , Liu W. , Shang S. S. , Lu J. J.
Published: December 2013

The interfacial composition, thermodynamic properties and structure parameters of the W/O microemulsion systems containing alkyl-3-methyl imidazolium bromide (CnmimBr, n = 12, 14, 16)/1-pentanol/n-octane/aqueous NaCl (HCl or NaOH) have been studied by a dilution method.

The molar solubility of 1-pentanol in oil phase (Xo
a) and the molar fraction of 1-pentanol at the interfacial layer (Xi
a) were obtained from the dilution equation of the W/O microemulsions. Furthermore, the distribution constant K of 1-pentanol between the interfacial layer and the bulk oil phase was determined, along with the standard Gibbs’ free energy change of transferring alcohol from the continuous oil phase to the interfacial layer, –ΔGo
o→i. Some structure parameters related to the microemulsion droplets were also calculated.

The effects of NaCl, HCl and NaOH on the properties and structures of the W/O microemulsions were also explored. It was found that as the content of the aqueous NaCl (HCl and NaOH) increases, Xo
a and Xi
a would decrease, the formation of the microemulsion would be more thermodynamically spontaneous, and the radius of the water pool significantly increases.
Control of Rheological Behaviour with Oppositely Charged Polyelectrolyte Surfactant Mixtures
Authors: Hoffmann I. , Prévost S. , Medebach M. , Rogers S. , Wagner N. J. , Gradzielski M.
Published: December 2013

Mixtures of the cationic, cellulose based polyelectrolyte JR 400 and the anionic surfactant sodium dodecylbenzene sulfonate (LAS) have been used to control the rheological behaviour of aqueous solutions. Around charge equilibrium precipitation takes place, but both for the surfactant-rich and the polymer-rich side homogeneous solutions are formed. In these monophasic regions the rheology depends strongly on the mixing ratio between the two components and highly viscous systems can be obtained on the polyelectrolyte rich side upon the addition of relatively small amounts of surfactant. Here the viscosity increases by more than four orders of magnitude before reaching the phase boundary of precipitation. Small-angle neutron scattering (SANS) showed the formation of an interconnected network of rodlike aggregates composed of a polyelectrolyte/surfactant complex, which explains the observed high viscosity due to the high degree of interconnection by the polyelectrolyte.
Biosurfactants – Exotic Specialties or Ready for Application?
Authors: Dreja M. , Vockenroth I. , Plath N.
Published: December 2013

Surfactants are the most important ingredients in laundry detergents, hand dish washing liquids and shampoos. It is a major challenge for the industry today to identify alternative materials that are biodegradable, based on renewable resources and that show reasonable cost-performance effectiveness. Biosurfactants are an emerging class of surfactants produced by microorganisms in processes usually running at low temperatures and without large amounts of waste or by-products, therefore complying with the rules of green chemistry and potentially resulting in a lower carbon footprint than conventional surfactants.

We show in our work which biosurfactants can meet or even surpass conventional surfactants today when it comes to properties like interfacial tension reduction and wetting. Taking into account that further optimization and tailoring of materials, unique physicochemical properties and efficient production processes are within reach, the future perspectives for the broader use of biosurfactants are bright.
Two-Phase Titration Method for Cationic Surface Active Agents Determination with Use of 5-(3-Bromo-4-hydroxy-5-methoxyphenyl)-7,7-dimethyl-7H-indolo[1,2-a]quinolinium Perchlorate Dye
Authors: Gąsiorowska M. , Wróblewska E. K.
Published: December 2013

The direct two-phase titration method with use of solvatochromic dye, i. e. 5-(3-bromo-4-hydroxy-5-methoxyphenyl)-7,7-dimethyl-7H-indolo[1,2-a]quinolinium perchlorate (1) for cationic surfactants determination is presented which is the modification of an earlier described procedure for anionic surface active substances detection. The method was tested on standard solution of benzethonium chloride (cationic detergent) which enables to estimate its accuracy as well as on few commercially available products to verify its utility. The influence of pH value of the probe on the titration endpoint determination was discussed and a simple solution of this problem has been proposed.
A new place setting – Consumer-relevant measuring unit for domestic dishwashers
Authors: Brückner A. , Schneider M. , Stamminger R.
Published: December 2013

This study summarises the possible, necessary and recommended steps to align consumer behaviour and the standard place setting used for performance and consumption measurements of domestic dishwashers. The diversity and amount of load items, the composition of the dish materials and the amount of soiling in real life differ from the standard place setting. Through the analysis of secondary data regarding the dishware cleaned in household dishwashers, the development of a new, more consumer relevant place setting was possible. Apart from a reduction of the total amount of load items, new materials and items were introduced. The durability and availability of the dishes has been guaranteed and reproducible and differentiating soiling for the new dish items has been developed. Although laboratory tests revealed that the new place setting caused slightly different cleaning results, it still delivers differentiable results concerning the performance parameters of dishwashers. Finally, it reflects the actual usage of a dishwasher in the household much better than the current place setting, and standard test results may gain in importance for the consumer.
Kinetics and Mechanism of Nucleophilic Substitution in SnR2Cl2 · 2DMSO by Chloride Ions in Micellar Microenvironment
Authors: Moheman Abdul , Yadav Seema , Siddiqi Khwaja Salahuddin
Published: December 2013

The kinetics of nucleophilic substitution of dimethylsulfoxide by chloride ion in bis-dimethyl sulfoxide dimethyltin(IV) dichloride and bis-dimethyl sulfoxide diphenyltin(IV) dichloride in micellar microenvironment (1.0 × 10–2 M SDS in aqueous solution of ethanol (1:1, v/v) has been studied conductometrically. The reactions have been carried out at 25°C. Substitution follows first order path with respect to chloride ion concentration. A millimolar solution of the complexes in ethanolic solution of 1.0 × 10–2 M SDS shows an increase in conductance with time due to solvation of the molecule. Sn(CH3)2Cl2 · 2 DMSO shows high conductance as compared to Sn(C6H5)2Cl2 · 2 DMSO. In the presence of the nucleophilic reagents, C6H5COCl and CH3COCl there is a greater enhancement in conductance due to substitution of DMSO by chloride ion. The data of rate constant for solvation (KS) and for nucleophilic substitution (K1 and K2) have been calculated. It was found that the solvation is a slower process compared to the substitution by chloride ions i.e., K1, K2 > Ks. A possible mechanism has been suggested.
Micellar Catalysis on Pentavalent Vanadium Ion Oxidation of Ethanol in Aqueous Acid Media
Authors: Ghosh Sumanta K. , Ghosh Aniruddha , Saha Rumpa , Mukherjee Kakali , Basu Ankita , Saha Bidyut
Published: December 2013

Vanadium(V) oxidation of ethanol follows a first order dependency on the concentration of ethanol, vanadium(V), H+ and HSO4
–. These observations remain unaltered in the presence of externally added surfactants. The effect of the cationic surfactant (i.e., N-cetylpyridinium chloride [CPC]), anionic surfactant (i.e., sodium dodecyl sulphate [SDS]) and neutral surfactant (i.e., Triton X-100 [TX-100]) has been studied. CPC inhibits the reactions, whereas SDS and TX-100 accelerate the reaction to different extents. Observed effects have been justified by considering the hydrophobic and electrostatic interaction between the surfactants and reactants. SDS and TX-100 can be used as catalysts in the production of acetaldehyde from ethanol.
Effect of Surfactants and Electrolyte on Removal and Recovery of Basic Dye by Using Ficus Carica Cellulosic Fibers as Biosorbent
Authors: Pathania Deepak , Sharma Shikha
Published: December 2013

Natural cellulosic fiber derived from Ficus carica, was used as eco-friendly biosorbent after alkali treatment for methylene blue dye remediation from aqueous system. The biosorbent was characterized by instrumental techniques such as Fourier transform infrared spectroscopy and scanning electron microscopy. The equilibrium behavior of the biosorbent was investigated in presence of electrolyte and surfactants by batch adsorption experiments. It was observed that in presence of ionic surfactants such as sodium dodecylbenzenesulfonate (SDS) and cetyltrimethyl ammonium bromide (CTABr), the adsorption capacity decreased from 38.97 mg g–1 to 35.64 mg g–1 and 36.75 mg g–1 respectively. The equilibrium data were analyzed using the Langmuir and Freundlich isotherm models and were best represented by the Langmuir isotherm model. The pseudo second order kinetic model adequately describes the kinetic data in comparison to first order model. Thermodynamic studies indicated that the adsorption was endothermic and spontaneous. The desorption studies illustrated that the removal of methylene blue dye at optimized condition was 64.95%, out of which 41.53% of methylene blue dye can be recovered by desorption in first cycle. Thus, the biosorbent used in this work proved to be effective materials for the treatment of dye contaminated aqueous systems.
Influence Prediction of Small Organic Molecules (Ureas and Thioureas) Upon Electrical Percolation of AOT-Based Microemulsions Using Artificial Neural Networks
Authors: Montoya Iago Antonio , Astray Gonzalo , Cid Antonio , Manso José Antonio , Moldes Oscar Adrían , Mejuto Juan Carlos
Published: December 2013

In order to predict percolation temperature of AOT-Based microemulsions (AOT/iC8/H2O w/o microemulsions) in the presence of small organic molecules (ureas and thioureas), different Artificial Neural Network architectures (ANN) have been carried out using a Perceptron Multilayer Artificial Neural Network with three entrance variables (W = value of the microemulsion, additive concentration, logP value). Best ANN architecture consists in three input neurons, one middle layer (with two neurons) and one output neuron. Correlation values were R = 0.9251 for the training set and R = 0.9719 for the prediction set.
Study of the Cloud Point of C12EO6 and C12EO8 Nonionic Surfactants: Effect of Additives
Authors: Alibrahim Moussa
Published: December 2013

Significant change in the cloud point of the nonionic surfactant solutions is observed by adding foreign substance. The aqueous solutions of these surfactants show complex phase behaviour including liquid-liquid separation at higher temperature. Electrolytes as well as nonelectrolytes have a large effect on the cloud point (CP) of C12EO6 and C12EO8 nonionic surfactants, because of their effect on water structure and their hydrophilicity. The presence of NaI and KI in the systems leads to a substantial increase in the cloud point of 2 wt% of the C12EO6 and C12EO8 solutions, but the increase is relatively less with KI than with NaI. Moreover, the cloud point decreases in the presence of NaF, NaCl and NaBr, and also similar identical observation was seen in the cloud point with KF, KCl and KBr, respectively. Furthermore, the results show that the addition of the tetramethyl ammonium bromide (TMABr) decreases the cloud point of the C12EO6 and C12EO8, whereas the addition of tetrabutyl ammonium iodide (TBAI) increases the cloud point of the above systems. The clouding phenomenon of the aqueous C12EO6 and C12EO8 systems in the presence of various additives is discussed.
Synthesis and Emulsification Properties of Organosilicone Modified Sodium Sulfonate of Alkanolamide Succinic Acid Monoester with Palm Oil
Authors: Wang Chen , duo Li Tian , yu Feng Sheng
Published: December 2013

Surfactants are widely used in the leather-making processes. The structure and property of surfactant obviously affect the quality and performance of leather. In this paper, a novel anionic surfactant, organosilicone modified sodium sulfonate of alkanolamide succinic acid monoester with palm oil was synthesized. Firstly palm oil was amidated with diethanolamine, then grafted with hydroxy-terminated silicone oil, esterified with maleic anhydride and sulphited with sodium bisulfite in sequence. The emulsification properties and fatliquoring performance of the prepared surfactant were tested. The influence of the mass percentage of reactants, the reaction temperature and time on the surface tension, the emulsifying activity and stability of the prepared surfactant were investigated. The FT-IR spectra analysis showed that under optimised conditions the novel surfactant was obtained. The fatliquoring application experiments showed that the novel surfactant is an excellent leather fatliquor.
Synthesis and Surface Properties of Novel Gemini Surfactants
Authors: Zhang Zhang , Zhen-Xian Zhang , Yu-rong Liu , Yu Zhang , Jie Chen
Published: December 2013

Novel Gemini surfactants containing amide group linkage were prepared with fatty acid, diamine and dihalide by simple organic reaction, and characterized with IR, and elemental analysis (EA). As the results show, the structures of the products obtained correspond to the target compounds designed. By surface tension scanning, these Gemini surfactants have excellent surface activity with low c.m.c. and surface tension, the lowest c.m.c value was 9.12 × 10−6 mol/L for surfactant Bi-18(4).
An Advanced Method for the Preparation of Erucyl Dimethyl Amidopropyl Betaine and Acid Solution Properties
Authors: Lu Hongsheng , Zhang Xuan , Quan Hongping , Dai Shanshan , Zhang Tailiang , Huang Zhiyu
Published: December 2013

In this paper, an improved method for the preparation of erucyl dimethyl amidopropyl betaine (EDAB) was provided. The synthesis conditions were investigated. N,N-dimethyl-N′-erucyl-1,3-propylenediamine was synthesized by the reaction of erucic acid with N,N-dimethyl-1,3-propylenediamine at 170°C for 7 h, and then the intermediate was reacted with sodium chloroacetate in the mixture of methanol and water (3:7 v/v) at 60°C. The product was obtained after 6 h. The compounds were confirmed by IR and 1H-NMR. The properties of EDAB acid solution were also studied. The results indicated that viscosity of acid solution increased with decreasing hydrochloric acid concentration and was mainly controlled by surfactant concentration and temperature. The viscosity of an acid solution was maximum when the concentration of hydrochloric acid was at 15 wt%.
Development and Validation of Micellar-Enhanced Spectrofluorimetric Method for Determination of Sulpiride in Pharmaceutical Formulations and Biological Samples
Authors: Shah Jasmin , Jan Muhammad Rasul , Khan Muhammad Naeem , Inayatullah
Published: December 2013

Sensitive and simple spectrofluorometric method has been developed and validated for the quantification of sulpiride in pure, commercial formulations, human plasma and urine in the presence of sodium dodecyl sulphate (SDS) surfactant micelle. The experimental parameters like buffer, surfactant type and volume were studied. A linear relationship was found between sulpiride concentration and fluorescence intensity in the range of 0.02 μg mL–1–7.0 μg mL–1 containing 0.2 M sodium dodecyl sulphate with λex 292 nm and λem 343 nm with a correlation coefficient of 0.9987. The limit of detection (LOD) and limit of quantification (LOQ) was found to be 1.9 × 10–2 μg mL–1 and 5.9 × 10–2 μg mL–1 respectively. The proposed method was successfully applied for the determination of sulphiride in pure and dosage form; the percentage recoveries agreed well with the label value. The effect of common excipients used as additive in pharmaceutical formulations was studied and no interferences was found. Similarly the effect of some common cations and compounds present in urine and plasma were also investigated and the method was found free of interferences. The method was further extended to the in-vitro determination of sulphiride in spiked human plasma and urine samples with percentage recoveries from 98.33%–99.75% and 95.67%–101.67% respectively. The results of the proposed method have been compared with the literature HPLC method and no significant difference was found between them.
Cleanability of Textile Materials in Liquid CO2
Authors: Dutschk Victoria , Sutanto Stevia , Calvimontes Alfredo
Published: December 2013

Cleanability of well-characterised textile materials of different types – cotton, polyester and wool – in liquid carbon dioxide (CO2) have been systematically investigated under different process conditions. It was found that the soil removal, which is represented with the soiling additional density (SAD), strongly depends on the kind of investigated textile materials. The use of a commercial detergent significantly improved the cleanability of all textile materials under study and slightly reduced the redeposition of soil in the case of wool fabric. In addition, by using optical roughness analysis, some topographical changes in the fabric structure after cleaning were studied.
Preparation and Evaluation of β-Carotene Containing Microemulsion
Authors: Yan Xiuhua , Wang Zhengwu
Published: December 2013

Microemulsions (O/W, W/O and B.C.) formed in Tween80/ethanol/ethyl butyrate/water system were identified by phase diagram determination and conductivity measurement at 25 °C. Comparative studies were made, by means of dynamic light scattering, viscosity and UV measurements, on (1) the difference of viscosity and particle size between β-carotene solubilized and empty microemulsions; (2) the effects of sunlight and temperature on the stability of β-carotene both in microemulsion and in ethyl butyrate solution. It is shown that in β-carotene loaded systems, the mean particle diameter is 82.13 nm and the size distributions were quite broad (PDI = 0.35). Smaller particles (31.75 nm) and narrower particle size distribution of droplets (PDI = 0.14) were obtained in empty microemulsion. The sizes of droplets of both β-carotene loaded and empty ones get shrunk sharply in the first 3 days, then keep remarkable stability even for a month. β-carotene solubilized in microemulsion is much more stable than that solubilized in ethyl butyrate solution.
Synthesis and Interfacial Activity of Novel Sulfobetaines in Aqueous Solutions
Authors: Staszak Katarzyna , Wieczorek Daria , Zielinski Ryszard
Published: December 2013

Fourteen new sulfobetaines with N-alkylmorpholinium moiety have been synthesized using correspording N-alkylmorpholines and propanesultone or butanesultone. Their interfacial activities in aqueous solution were studied by equilibrium and dynamic surface tension measurements. Surface tension measurements provide information about the surface excess concentration, the minimum area per surfactant molecule, the critical micellar concentration (CMC) and the standard Gibbs energy of adsorption. The adsorption properties of these compounds significantly depend on the length of alkyl chain (the number of carbons). The lowest value of critical micellar concentration is obtained for the compound with the longest carbon chain and decrease with increasing of chain length of compounds considered. The same tendency is observed for effectiveness of adsorption.
Micellar Catalysis of Chromic Acid Oxidation of Methionine to Industrially Important Methylthiol in Aqueous Media at Room Temperature
Authors: Basu Ankita , Ghosh Sumanta Kr. , Saha Rumpa , Ghosh Aniruddha , Mukherjee Kakali , Saha Bidyut
Published: December 2013

Oxidation of organic molecule by metal is very important. Selective oxidants require non aqueous media, which is toxic and hazardous. L-methionine is oxidized to industrially important methyl thiol in micellar media by chromic acid. The overall reaction follows a first order dependency on substrate and hexavalent chromium and second order dependency on hydrogen ion. Here, reverse micelle formation is observed. TX-100 increases the rate where as SDS retards the rate of oxidation.
Research on Surfactant Flooding in High-temperature and High-salinity Reservoir for Enhanced Oil Recovery
Authors: Zhou Ming , Zhao Jinzhou , Wang Xu , Yang Yan
Published: December 2013

The aim of this work was to research the solution properties of a new surfactant flooding system for high temperature and high salinity reservoir, which include trimeric sulfonate surfactants 1,2,3-tri(2-oxypropyl sulfonation-3-alkylether-propoxyl) propanes (TTSS-n) and anion-nonionic surfactant NPSO [sodium nonyl phenol polyethyleneoxy ether sulfonate, (EO = 10)]. The critical micelle concentrations (CMCs) of five trimeric sulfonate surfactants were smaller than 400 mg L−1. Furthermore, their interfacial tensions (IFTs) could reach an ultralow value with Tazhong 4 oil at lower concentrations. Through optimized formulation, we found that TTSS-12 had better properties and was selected as the major component of the surfactant flooding system. We designed an optimal formulation of the surfactant flooding system with 1 000 mg · L−1 TTSS-12 and 1 000 mg · L−1 NPSO surfactant. The system with a very small surfactant concentration could reach ultralow IFT with Tazhong 4 crude oils at high temperature (110 °C) and high concentration formation brine (112,228.8 mg/L TDS), which proved that the simpler component surfactant had better reservoir compatibility. NPSO could weaken the disadvantage of the surfactant TTSS-12 in oil/water interface. The stability of this surfactant flooding system was evaluated by aging time, static adsorption and chromatographic separation. All experiments showed that it still keeps ultralow IFT in high temperature and high salinity conditions. Coreflooding experimentation showed that average oil recovery reached 9.8 wt% by surfactant flooding, therefore, it is feasible to use as a surfactant flooding system for enhanced oil recovery (EOR).
Effect of Oil/Water Mass Ratios on the Composition and Solubilization of Microemulsion Systems Containing Tween/Alcohol/Alkane/NaCl Solution
Authors: Liao Qiushi , Chai Jinling , Bai Tingting , Wang Dan , Sun Hao , Liu Ning
Published: December 2013

The composition and solubilization ability of microemulsion systems Tween (Tween 20, Tween 60, Tween 80)/1-butanol/decane/7.5 % NaCl solution at various oil/water mass ratios were studied. As oil/water mass ratios (α) increase, the solubility of the alcohol increases, and for the system containing Tween 60 or Tween 80, the mass fractions of the alcohol in the interfacial layer, AS
, increase, whereas for the system containing Tween 20, the mass fractions of the alcohol in the interfacial layer, AS
, decrease. Also, the solubilization ability (SP∗) of the microemulsion systems decreases. The solubilization ability of the microemulsion systems containing different Tween surfactants in descending order is Tween 60 > Tween 80 > Tween 20. The effects of alcohols and alkanes on the composition and solubilization abilities of microemulsion systems Tween/alcohol/alkane/NaCl solution were also investigated.
Foaming Behavior of Dialdehyde Starch Schiff-base Derivatives
Authors: Wang Xiaojuan , Zhang Shufen , Ju Benzhi
Published: December 2013

A foamable dialdehyde starch-aniline Schiff-base (DAS-AN) was synthesized by the reaction of dialdehyde starch (DAS) and oil-soluble aniline in a homogeneous dimethyl sulfoxide system under N2 atmosphere. The DAS-ANs were characterized by gel permeation chromatography (GPC), Fourier-transform infrared spectroscopy (FT-IR) and NMR spectroscopy. Their foaming behavior and surface tension were investigated. Foaming power and stability tests were performed for solutions of DAS-ANs with different degrees of substitutions with aniline (DS
AN) and concentrations. The maximum foaming power was 2.6 times the initial solution volume of the foam test in 450 mg · L–1 CaCO3 aqueous solution. The most stable foams only decreased by 6% in volume in deionized water after 20 min.
Interaction of Cationic CTAB Surfactant with Curcumin, an Anticarcinogenic Drug: Spectroscopic Investigation
Authors: Sharma Rakesh , Jani Dipti
Published: December 2013

Curcumin, the most active polyphenolic constituent of turmeric cucuminoids obtained from rhizome Curcuma longa, holds a high place in ayurvedic medicine but its role in conventional disease management is also established. Unfortunately, the compound has poor aqueous solubility, which results in poor bioavailability following high doses by oral administration. In order to enhance its effectiveness and improve bioavailability, surfactant assemblies as the colloidal drug carriers with desired properties have been largely utilized. The interaction of curcumin with cetyltrimethylammonium bromide (CTAB) surfactant has been investigated by absorption spectroscopy as a function of surfactant concentration in pre-micellar and micellar range at acidic pH of 6.4. The pre-micellar and micellar region of pure CTAB surfactant at acidic pH of 6.4 is examined through tensiometry and conductometry techniques. Spectral data shows that in presence of curcumin at lower CCTAB, the change in absorbance and peak form initially was assigned to attraction of positive head group of CTAB towards the β-diketone group of drug. In micellar region including CMC, the type of interaction corresponds to the attachment of C16 chains of CTAB to nonpolar aryl groups of drug and simultaneously displacement of polar head group from β-diketone group of the drug. Finally at post micellar CCTAB, the encapsulation of the curcumin into micelles, predominantly in intact monomeric form is observed with the sharp peak at λmax = 423 nm.
Parametric Optimization and Thermo-dynamic Studies on the Influence of Electrolytes on Sodium Salicylate in Aqueous Solution
Authors: Pawar Kiran , Desai Meghal A. , Parikh Jigisha
Published: December 2013

Hydrotropes (amphiphiles) start to aggregate at a certain minimum concentration known as the minimum hydrotrope concentration (MHC), above which an appreciable solubilization of insoluble compounds in aqueous solution is observed. However, the MHC values are very high, thus, limiting the applications of hydrotropes. The salts are found to increase the association tendency of hydrotropes and reduction in the MHC. The present study discusses the effect of various electrolytes (Na+, Mg2+ and K+ series) on the behavior of sodium salicylate at different temperatures. Design of experiment was employed to optimize the process parameters. Furthermore, thermodynamic parameters were investigated to observe the stability of the aggregates at higher temperatures.
MonitoringBase Surfactants – A Database Specifically for Storage of Environmental Data on Surfactants in Europe
Authors: Leonards Pim , Eadsforth Charles , Schowanek Diederik
Published: December 2013

A database has been developed in MS Access™ for storage and retrieval of environmental data of surfactants in Europe, as well as general information on major surfactant monitoring programs. The database contains measured concentrations (about 2100 data points) for 8 surfactant groups collected from scientific literature and unpublished reports. The quality of the monitoring data was evaluated and scored using an approach similar to the Klimisch method for judging ecotoxicology and toxicology data. The assignments involve four “Klimisch”-like categories (reliable without restriction, reliable with restriction, not reliable, not assignable), and are based on six key features of a monitoring study, of which three features were found the most important. The proposed evaluation and scoring approach is widely applicable and can easily be applied for other environmental contaminants.
Removal of Heavy Metals from Aqueous Solution by Adsorption on Biomass Based Adsorbent
Authors: Alam Sultan , Bangash Fazlullah Khan , Amin Noor-ul , Azmatullah
Published: December 2013

Removal of heavy metals i.e. Zn2+and Cd2+from aqueous solution by adsorption onto biomass based adsorbent was investigated as a function of time and different concentrations. The sample was characterized by FTIR, EDS, BET surface area and Zeta potential technique, which was reported earlier. Adsorption kinetics of Zn2+and Cd2+was tested by first order kinetics, Elovich and parabolic diffusion kinetic equations which show that the process of adsorption is diffusion controlled process. The rate of adsorption was high at high adsorption temperature. Thermodynamic parameters like ΔH°, ΔS°and ΔG°were calculated from the kinetic data. The negative value of Gibbs free energy (ΔG°) shows the spontaneous nature of the process. Freundlich, Langmuir, Temkin isotherms and distribution coefficient were found fit to the adsorption isotherm data.
Research of Surface Chemical Properties and Micellization Behavior of Sodium N-Lauroylglycine
Authors: Xu Hujun , Song Chunli , Fang Qing , Huang Yaru , Xu Hao
Published: December 2013

Amphoteric surfactant, sodium N-lauroylglycine, was synthesized and symbolized as SLG. The surface chemical properties and micelle behaviors of SLG in 0–0.5 mol · L−1 aqueous solution of sodium chloride were investigated by surface tension measurements at 298–313 K. The critical micelle concentrations (cmc) of pure surfactant were determined in 0–0.5 mol · L−1 sodium chloride aqueous solution. Fluorescence and micelle aggregation number (N
agg) measurements have been used to investigate the variations of micro-polarity and micellization behavior. The added NaCl has a tendency to increase the attractive interaction between the surfactant molecules in both the micellar phase and the adsorption layer. The Gibbs free energy of micellization (ΔG
m

0
) is negative for all investigated systems, and the thermodynamic parameters of SLG indicate that the micellization of SLG is entropy driven.
Röntgen- und Neutronen — Einblicke in Brennstoffzellen
Authors: Schulze Martin H. , Hartnig Christoph , Manke Ingo , Kupsch Andreas
Published: December 2013

Kurzfassung

Um die Aufklärung und das Verständnis kritischer Transport- und Alterungsprozesse in Brennstoffzellen voranzutreiben, wurden in einem interdisziplinären Ansatz mathematische, natur- und ingenieurwissenschaftliche Kompetenzen aus sechs Instituten gebündelt. Einen Schwerpunkt bildete dabei der Einsatz zerstörungsfreier bildgebender Verfahren zur in-situ Diagnostik von PEM-Brennstoffzellen unter Betriebsbedingungen. Das vorliegende Heft präsentiert wesentliche Ergebnisse des vom Bundesministerium für Bildung und Forschung (BMBF) geförderten Verbundprojekts „Röntgen- und Neutronenbasierte Untersuchungsmethoden für PEM-Brennstoffzellen“ (RuNPEM, 03SF0324, 2007 bis 2010).
Statistischer Größeneinfluss und Bauteilfestigkeit
Authors: Diemar Andreas , Thumser Rayk , Bergmann Joachim W.
Published: December 2013

Kurzfassung

Schwingfestigkeitskennwerte können auf Bauteile anderer Form und Größe mit Hilfe des statistischen Größeneinflusses übertragen werden. Zur Charakterisierung der Größe des hochbeanspruchten Bauteilbereiches wird das Spannungsintegral verwendet. Erfolgt die Ermittlung des Spannungsintegrals durch ein Finite Elemente (FE) Programm, ist die notwendige Zuordnung von Oberfläche oder Volumen zu den Stützstellen der Spannung nur durch spezielle FE-Postprozessoren möglich. Diese unterliegen Einschränkungen bezüglich der Wahl des FE-Programms, der Elemente sowie des Integrationsbereiches (Oberfläche, Volumen). Es wird eine Methode vorgestellt, welche die Zuordnung der Wertepaare Oberfläche und Spannung bzw. Volumen und Spannung durch eine geeignete Wahl von Einheitslastfällen ermöglicht. Mit den erhaltenen Wertepaaren erfolgt die numerische Integration. Diese Methode der Spannungsintegralermittlung aus Einheitslastfällen (SPIEL) ist nicht an ein spezielles FE-Programm gebunden.
Laufende Instandhaltung von Schienenfahrzeugen
Authors: Erhard Anton , Heckel Thomas , Schenk Gottfried , Hintze Hartmut
Published: December 2013

Kurzfassung

Zur Gewährleistung des sicheren Betriebs von Schienenfahrzeugen werden bei der laufenden Instandhaltung die Radsätze (Laufräder und Radsatzwellen) mittels Ultraschall auf Fehlerfreiheit geprüft. Auf Grund der Komplexität der durchzuführenden Prüfungen an der Radscheibe von scheibengebremsten Fahrzeugen ist beim Einsatz konventioneller Techniken eine große Anzahl Ultraschallprüfköpfe erforderlich, deren Reduzierung eine technische Herausforderung darstellt. Auch bei der Prüfung von Radsatzvollwellen sind auf Grund der eingeschränkten Zugänglichkeit unterschiedliche Winkelprüfköpfe erforderlich. Ein Ziel der Untersuchungen bestand darin, die Anzahl der erforderlichen konventionellen Prüfköpfe deutlich zu reduzieren. Dazu kann die Gruppenstrahlertechnik einen Beitrag leisten.
Reflexionsverhalten in fokussierten Schallfeldern
Authors: Boehm Rainer , Erhard Anton , Rehfeldt Thomas
Published: December 2013

Kurzfassung

Angeregt durch experimentelle Arbeiten zur hochauflösenden Ultraschallprüfung mit fokussierenden Prüfköpfen wird mit Hilfe von Modellrechnungen der Einfluss verschiedener Schallfeld- und Reflektorparameter auf die Echohöhe untersucht. Von besonderem Interesse ist dabei das Verhalten typischer Testreflektoren wie der Kreisscheibenreflektor und die Querbohrung in „verformten“ Schallfeldern, die durch Bauteilkrümmungen und Fokussierung entstehen können. Für solche Fälle lassen sich Abstandskurven (DAC) für verschiedene Reflektortypen rechnerisch erstellen und der experimentelle Aufwand erheblich reduzieren. Ein deutlicher Fortschritt wurde durch die Weiterentwicklung des Schallfeldmodells erreicht, das insbesondere für die Entwicklung neuer Typen von Gruppenstrahlerprüfköpfen unverzichtbar ist. Die Gültigkeit des Modells wird durch bisherige Messergebnisse bestätigt.
Mobility of grain boundaries in stress fields
Authors: Winning Myrjam , Badirujjaman Syed
Published: December 2013

The mobility of grain boundaries under certain conditions is a key factor for the evolution of polycrystalline microstructures and material properties. In recent experiments it was shown that grain boundaries can interact with mechanical stress fields and that the motion of planar grain boundaries, low angle as well as high angle grain boundaries, could be induced by an external mechanical stress field [1,2]. Therefore the current study was performed to investigate the details of grain boundary motion and interactions between definite, planar grain boundaries and the mechanical stress field during high temperature low cycle deformation of high purity aluminium bicrystals. The grain boundary planes were in all cases perpendicular to the loading axis. Experiments were made with large as well as small stresses at different temperatures and numbers of cycles. The displacement of grain boundaries was measured by using optical microscopy, and the microstructural features, as well as orientations of individual grains were recorded by the electron backscatter diffraction technique (EBSD) after each deformation experiment.
Fatigue damage accumulation around notches
Authors: Iino Yutaka , Yano Hideo
Published: December 2013

Notched compact tension specimens of type 304 stainless steel (notch tip radius of 1 mm and 4 mm) were low-cycle-fatigued at stress ratio R = −1 and 0.05 in order to investigate the through-thickness fatigue damage accumulation around the notch. The recrystallization-thermal etching technique was used to observe the accumulated plastic zone APZ with the accumulated plastic strain ∊ac above 0.12(APZ0.12) and APZ with ∊ac above 0.02 (APZ0.02) at midthickness, quarter thickness and surface. Both APZ0.12 and APZ0.02 are formed early during the fatigue (before crack initiation) near midthickness and not at less thickness or at the surface. The reason why the fatigue crack initiates near the midthickness of the notch root surface was found to be due to more fatigue damage near midthickness than at the surface. Magnetic permeability(degree of the martensite formation) at midthickness was also higher than at the surface, supporting the above result.
Der Kurzrisseffekt bei der bruchmechanischen Prüfung
Authors: Münstermann Sebastian , Langenberg Peter , Dahl Winfried , Eisele Ulrich , Roos Eberhard
Published: December 2013

Kurzfassung

Unter dem ausgeprägten Kurzrisseffekt versteht man den Anstieg von zähbruchmechanischen Initiierungskennwerten bei reduzierter Ermüdungsrisslänge. Für Bruchmechanikproben mit niedrigem a/W-Verhältnis, also geringer Ermüdungsrisslänge, werden bei Vorliegen eines ausgeprägten Kurzrisseffekts demnach höhere Initiierungskennwerte ermittelt als für Proben mit größerem a/W-Verhältnis. In mehreren Forschungsarbeiten der Vergangenheit wurden teilweise unterschiedliche Ergebnisse zum Kurzrisseffekt bei Stahl erzielt. Ein im vergangenen Jahr durchgeführtes gemeinsames Forschungsprojekt der Materialprüfungsanstalt Uni Stuttgart (MPA) und des Instituts für Eisenhüttenkunde der RWTH Aachen (IEHK) sollte die Ursachen für die unterschiedlichen Ergebnisse klären.
Modeling the effects of mechanical loads
Authors: Uguz Agah , Oka S. Hakan
Published: December 2013

In this investigation, a ball joint, which is the major functional part in a car, has been modeled to predict its fatigue life. In order to confirm the accuracy of the research, initially a modal analysis was performed, so the natural frequency of the structure was verified. It has been found that, the calculated natural frequency of the structure is much lower than its own natural frequency. The results, which were confirmed by experimental studies, have been interpreted by using analysis techniques and compared with theoretical outcomes.
Low cycle fatigue of superalloys
Authors: Aoki Yasuhiro , Arai Mikiya , Zhou Hao , Ro Yoshikazu , Harada Hiroshi
Published: December 2013

Low cycle fatigue (LCF) of a fourth-generation single-crystal (SC) Ni-base superalloy TMS-138 was studied by comparison with typical third-generation (TMS-75) and second-generation (CMSX-4) Ni-base SC superalloys. TMS-138 exhibits improved LCF behaviour under a condition of the R ratio of 0 at temperatures of 1073 K and 1173 K. The addition of refractory elements resulted in a remarkable improvement of the LCF properties compared to those of the reference superalloys due to the different microstructure developed in TMS-138.
Das Master-Curve-Konzept im Rahmen des neuen Sprödbruchsicherheitsnachweises für die EN 13445
Authors: Langenberg Peter , Buchholz Jörg , Dahl Winfried
Published: December 2013

Kurzfassung

Die Stahlauswahl für unbefeuerte Druckbehälter zur Vermeidung von Sprödbruch erfolgt bei Anwendung der europäischen Norm EN13445 auf Basis eines bruchmechanischen Konzeptes, welches in den 80er-Jahren des letzten Jahrhunderts entwickelt wurde. Im Rahmen des europäischen Forschungsvorhabens ECOPRESS (www.ecopress.org) wurden Modifikationen erarbeitet, die sich auf neuere bruchmechanische Erkenntnisse unter Berücksichtigung der Master Curve stützen und es ermöglichen, die Anwendung der Auswahlmethode in der EN13445 auf Stähle mit Streckgrenzen bis 690 MPa auszuweiten.
Monozyten und Makrophagen im direkten Kontakt mit TiAl6V4-Implantaten*
Authors: Warmuth Sybille , Kosmann Michaela , Aigner Joachim , Wintermantel Erich , Scharnweber Dieter , Worch Hartmut
Published: December 2013

Kurzfassung

Im Zentrum neueren medizinischen Interesses steht die phagozyteninduzierte Entzündungsreaktion als ein Ausdruck der zellulären Interaktion im Interfacebereich von Implantaten. Die vorliegende Studie untersucht die Ausschüttung entzündlicher Mediatoren (Zytokine), die von humanen primären Monozyten/Makrophagen nach direktem Kontakt mit verschieden beschichteten TiAl6V4- Implantaten gebildet werden. Die In-vitro-Zellkulturversuche zeigen, dass die verschiedenen Oberflächenmodifikationen unterschiedliche Zytokinexpressionen auslösen und erste Aussagen zum Entzündungspotential von Implantatoberflächen zulassen. Zum vertieften Verständnis der komplexen Wechselwirkungen im Interfacebereich von Implantaten bedarf es weiterer Untersuchungen.
Optimierung der mechanischen und tribologischen Eigenschaften keramischer Schichten*
Authors: Rahm J. , Glien W. , Kieselstein E. , Kreyßig K. , Sommer P. , Auerswald E. , Kremling U.
Published: December 2013

Kurzfassung

Das Optimieren der mechanischen und tribologischen Eigenschaften keramischer Schichten basierte auf den Ergebnissen von Vorversuchen, in denen überwiegend Agglomeratpulver der Systeme Al2O3/TiO2 bzw. Al2O3/ZrO2 zur Anwendung gekommen sind. Das Erreichen der erforderlichen Oberflächenqualität der plasmagespritzten Schichten erfolgte durch eine Schleif- und Polierbearbeitung. Die Untersuchungsergebnisse der Haftfestigkeit und des gravimetrischen Verschleißes der Schichten zeigen, dass die Mischkeramiken Al2O3(70%)/TiO2(30%) und Al2O3(57,5%)/ZrO2(42,5%) die Favoriten für eine weiterführende Schichtoptimierung darstellen. Die Optimierung der Schichtstruktur und -eigenschaften beinhaltet im Schwerpunkt das weitere Homogenisieren der Schichtmorphologie bei gleichzeitiger Erhöhung der Adhäsion.
Multiaxial fatigue – methods, hypotheses and applications
Authors: Zenner Harald
Published: December 2013

The present overview covers the fundamentals of multiaxial loading and the state of the art of the theoretical assessment of fatigue strength.
Entwicklung eines Schadenstoleranz-Konzeptes für Komponenten des Rad/Schiene-Systems am Beispiel von Radsatzwellen
Authors: Zerbst Uwe , Mädler Katrin , Vormwald Michael
Published: December 2013

Kurzfassung

Am Beispiel einer Radsatzwelle wird ein Schadenstoleranzkonzept diskutiert, das am GKSS-Forschungszentrum in Zusammenarbeit mit der DB-Systemtechnik entwickelt wird. Das Konzept greift auf vorhandene Fehlerbewertungsmethoden, v.a. die europäische SINTAP-Prozedur und in Bezug auf die Ermüdungsrissausbreitung die NASGRO/ESACRACK-Prozedur von NASA und ESA, die in Luft- und Raumfahrt weite Verbreitung gefunden hat, zurück. Im Ergebnis der Analyse, die für einen vereinfachten Fall demonstriert wird, ergeben sich quantitative Anforderungen an die zerstörungsfreie Prüfung, welche Fehlergröße für ein gegebenes Inspektionsintervall aufgefunden werden muss.
Present limitations in the assessment of components under multiaxial service loading
Authors: Sonsino Cetin Morris , Küppers Martin , Zenner Harald , Yousefi-Hashtyani Farhad
Published: December 2013

This paper is focused on a research project supported by the German automotive industry and international software producers. Six multiaxially loaded components were tested under random multiaxial service loading conditions and evaluated by different algorithms. The results reveal a large scatter of calculated fatigue lives which are, in most cases, on the unsafe side. The contradictory unsatisfactory results are determined by the complex interaction of the multiaxial stress state with cumulative damage. Therefore, in the case of safety critical components, experimental structural durability tests must be carried out.