bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerische Berechnung einer integrierten Wärmebehandlung für präzisionsgeschmiedete Bauteile
Authors: Behrens B.-A. , Bach Fr.-W. , Bouguecha A. , Nürnberger F. , Schaper M. , Yu Z. , Klassen A.
Published: December 2013

Precision forging is a production process used for manufacturing of near-net shaped, highly loaded components with low proportion of forging degrees and reduced necessity of post processing. In comparison to the conventional forming and the machining production processes, an important improvement in material savings and a significant shortening of the process chain can be obtained. The near-net shape forging allows an integrated heat-treatment from the hot-forming heat. In this paper, a numerical calculation of the forging process and a heat-treatment process following forging are shown at the example of the pinion shaft. A challenge lies in the coupling of the simulation model for the forging process and the model used to calculate the temperature and microstructure development during quenching and tempering process. This coupling in addition to the illustration of the entire process, enable optimization of spray cooling parameters which leads to the diesired hardness profile.
The simultaneous efect of extrusion and T6 treatment on the mechanical properties of Al-15wt.%Mg2Si composite
Authors: Soltani N. , Bahrami A. , Moghimi F. M. , Pech-Canul M. I. , Hajaghasi A.
Published: December 2013

This article investigates the simultaneous efect of extrusion ratio and T6 heat treatment on microstructure and mechanical properties of in-situ Al-15wt.%Mg2Si composite. his composite has already been introduced as a new class of light materials but the brittle structure of the primary Mg2Si which is formed during solidiication limits its application. As-cast composite was directly extruded as rod by using three diferent dies. Ater T6 heat treatment on extruded samples, microstructure was studied by optical and scanning electron microscopy. Results demonstrated that extruded and heat treated composite possesses considerably higher strength and enhanced ductility in comparison with the as-cast samples. It was also found that heat treatment and extrusion processes change the primary Mg2Si morphology considerably and its size increases as extrusion ratio decreased. Fracture surface examinations revealed a transition from brittle fracture mode in as-cast composite to ductile fracture in heat treated and extruded specimens. his can be attributed to the changes in size and morphology of Mg2Si intermetallics and porosity content.
Verzugsentstehung bei Scheiben aus 20MnCr5 – Einfluss von Umformung und Gefügestruktur
Authors: Rentsch R.
Published: December 2013

Kurzfassung

Für die Zahnradfertigung werden zunächst aus warmgewalzten Stangenabschnitten Scheiben geschmiedet. Die Scheiben aus 20MnCr5 (AISI 5120) werden anschließend auf Maß gedreht und auf einer Wälzfräsmaschine verzahnt. Nach dem Einsatzhärten wird mit dem Verzahnungsschleifen die genaue Geometrie der Zähne hergestellt. Enge Toleranzen von wenigen Mikrometern sind für die Erfüllung der Verzahnungsqualitäten von Hochleistungsgetrieben sowie für stabile Fertigungsprozesse einzuhalten.

Experimentelle Analysen zeigen, dass der Stofffluss in scheibenförmigen Zahnradrohlingen signifikant variieren kann. Zusätzlich zeigten detaillierte WDX-Messungen eine Makroseigerung am Querschnitt der zylindrischen Stangenabschnitte, aus denen die analysierten Scheiben hergestellt wurden. Beides ist für die Zahnradherstellung von Bedeutung, da eine Korrelation zwischen dem Scheibenverzug nach dem Einsatzhärten der Scheiben und dem jeweils im Zahnrad ausgebildeten Stofffluss für diesen Stahl gefunden wurde. Neben den experimentellen Analysen wurden FE-Analysen zum Einfluss von Prozessparametern und Prozessstörungen auf den Scheibenverzug durchgeführt. Als ein wesentlicher Faktor für den Scheibenverzug wurde ein Temperaturgradient über der Höhe der Zylinderabschnitte identifiziert, der über den Stofffluss auf das Verzugsverhalten der Scheiben nach dem Einsatzhärten zum Tragen kommt.
Elektrochemische Korrosionsprüfung verschleißbeständiger Schichten∗
Authors: Haase B.
Published: December 2013

Kurzfassung

Verschleißbeständige Schichten auf Stahl sollten auch korrosionsbeständig sein. Mangelhafte Korrosionsbeständigkeit beruht auf mangelnder chemischer Beständigkeit unter Mitberücksichtigung mechanischer sowie thermischer Beanspruchung im Einsatz. Die chemische Beständigkeit hängt nicht nur von der chemischen Zusammensetzung, sondern auch von der Struktur der verschleißbeständigen Schicht ab, die durch den Herstellungsprozess kontrolliert wird. Wenn allein die chemische Beständigkeit nicht ausreichend ist, erfolgt der Korrosionsangriff gleichmäßig; wenn die Schicht Poren oder Risse aufweist, führt das zu lokalem Korrosionsangriff. Verfahren der Korrosionsprüfung sind meistens nicht zerstörungsfrei, aber zeitaufwendig, denkt man an Methoden wie den Salzsprühtest. Elektrochemische Methoden haben einen geringen Zeitbedarf und können mit nicht-korrosiven Elektrolyten auch zerstörungsfrei sein. Die verschiedenen Methoden lassen Rückschlüsse zu auf die Oxidierbarkeit einer Metalloberfläche (potenziostatische Verfahren wie Bestimmung des Ruhepotenzials oder OCP, open circuit potential) oder auf die Oberflächenwiderstände, die der Ladungsübertragung vom Metall zu Komponenten im korrosiven Medium entgegenstehen (potenziodynamische Verfahren und Elektrochemische Impedanzspektroskopie, EIS). Die letztgenannten Messmethoden werden in Hinsicht auf Anwendung und Aussagefähigkeit verglichen.
Influence of short-cycle heat treatment conditions on the hardness-toughness-relationship of the steels 51CrV4, 74NiCr2 mod. and 100Cr6∗
Authors: Steineder K. , Schneider R.
Published: December 2013

The paper covers the effect of various heat treatment conditions, with a focus on short-cycle heat treatment, on the mechanical properties (hardness and toughness) of the steels 51CrV4, 74NiCr2 mod. and 100Cr6. To determine this property-relationship, micro-impact samples were heat treated under various conditions in a dilatometer. Afterwards the samples were tested regarding their impact toughness and Vickers hardness. Furthermore, additional investigations of the microstructure (optical), the retained austenite content (XRD) and the fracture behaviour (SEM) were performed. Selected dilatometric measurements on the transformation behaviour after short austenizing durations completed the investigation program. Tempering at temperatures in the range of 200 °C always provided a favourable property-relationship. While short-cycle heat treatment conditions only lead to a slightly reduced toughness at similar hardness, overheating resulted in a more significant loss in toughness with different severity for the three steel grades. Microstructural investigations provide additional information to explain this behaviour.
Einsatzhärten im Fertigungstakt∗
Authors: Heuer V. , Löser K. , Schmitt G. , Ritter K.
Published: December 2013

Kurzfassung

Um die geforderten Festigkeitseigenschaften von Getriebekomponenten sicherzustellen, müssen diese in vielen Fällen einsatzgehärtet werden. Dies wird traditionell in den Zentralhärtereien der Betriebe durchgeführt. Aus der räumlichen Trennung zwischen Fertigungslinie und Wärmebehandlung resultiert jedoch ein enormer logistischer Aufwand. Daher wird seit vielen Jahren nach Möglichkeiten gesucht, die Wärmebehandlung in die mechanische Fertigungslinie zu integrieren. Durch den Einsatz neuer Wärmebehandlungstechnologien, wie der Niederdruckaufkohlung mit Hochdruck-Gasabschreckung, ist es inzwischen möglich, die Wärmebehandlung zumindest in räumlicher Nähe der Fertigung durchzuführen. Um zukünftig die Wärmebehandlung direkt in den Fertigungsfluss zu integrieren und mit ihm zu synchronisieren, wurde ein neues Wärmebehandlungsmodul entwickelt. Gemäß der Fertigungsphilosophie “One Piece Flow” werden die Bauteile in diesem Wärmebehandlungsmodul einzeln von der Grünbearbeitung der Wärmebehandlung zugeführt, im Takt der Weichbearbeitung wärmebehandelt (synchrone Wärmebehandlung) und dann einzeln von der Wärmebehandlung an die Hartbearbeitung übergeben. Die für diese Technologie notwendigen werkstofftechnischen, prozesstechnischen und anlagentechnischen Innovationen werden vorgestellt. Zudem wird anhand von Beispielen gezeigt, welche Bauteilqualitäten mithilfe des neuen Wärmebehandlungsmoduls erzielt werden. Dabei wird besonderes Augenmerk auf die erzielten Härteprofile, die Aufkohlungsgleichmäßigkeit sowie auf die Maß- und Formänderungen gelegt.
Charakterisierung des Oberlächenzustands metallischer Dauerformen für das Druckgießen im Produktionsprozess
Authors: Wüst S. H. , Gebauer-Teichmann A. , Scholtes B.
Published: December 2013

Kurzfassung

Im Druckgießprozess wirken gleichzeitig unterschiedliche Verschleißmechanismen. Da die Oberläche direkt den Beanspruchungen im Produktionsprozess ausgesetzt ist, nimmt sie einen entscheidenden Einluss auf die Werkzeugstandzeit. Wesentlich für die Qualität von Druckgussteilen sind Schmelzeanhatungen an dem Werkzeug sowie Verschleißerscheinungen, die Ausgangspunkte für Risse darstellen können. Der Schädigungsverlauf von Druckgießwerkzeugen aus dem Warmarbeitsstahl X37CrMoV5-1 (Werkstofnummer 1.2343) wurde an zwei baugleichen Werkzeugen in Abhängigkeit des Oberlächenzustands (geschlifen, poliert) in der betrieblichen Praxis untersucht. In Abhängigkeit der Anzahl der Gießzyklen wurde die Werkzeugoberläche an besonders stark beanspruchten Bereichen durch Makroaufnahmen sowie durch hochaulösende Silikonabrücke dokumentiert. Dadurch konnte die Schädigungsentwicklung kontinuierlich analysiert und durch die Entwicklung der Rauheit charakterisiert werden.
Experimental characterization and simulation of a wire drawing process and related distortion potentials∗
Authors: da Silva Rocha A. , Nunes R. M. , de Souza T. F. , Soares C. A. T. , Haenisch S. , Tekkaya A. E. , Hirsch T.
Published: December 2013

In this investigation a DoE (Design of Experiments) analysis of distortion for a typical manufacturing process of pre-straightened, cold drawn and induction hardened AISI 1045 cylindrical steel bars was carried out. A careful characterization of the material, including residual stresses and geometrical changes was done for the different manufacturing steps. The variables included the drawing process itself with two different drawing angles, a stress relief treatment which was applied to one part of the samples and finally an induction heat treatment with two different case depths applied to identify effects and correlations on distortion. Simulation of the drawing process was also used as tool to clarify possibilities and limits of this kind of analysis, depending on the available input data. Different influences on the distortion of the induction hardened samples were found and discussed, as for example the marked dependence of the distortion on drawing angle.
Einfluss der Umwandlungsplastizität bei der Simulation des partiellen Presshärtens∗
Authors: Lütjens J. , Hunkel M.
Published: December 2013

Kurzfassung

Der Einsatz pressgehärteter Bauteile im Automobilbau hat in den letzten Dekaden stark zugenommen [1]. Diese Bauteile bieten dabei eine vorteilhafte Kombination aus hoher Festigkeit und großer Formgenauigkeit bei gleichzeitiger Einsparung von Gewicht. Eine Verfeinerung des Presshärtens stellt das partielle Presshärten dar, bei welchem lokal temperierte Werkzeuge verwendet werden, um verschiedene Temperaturverläufe und damit Gefüge-Gradienten im Bauteil zu erzielen [2]. Dabei kann es auch zu einer kurzzeitigen lokalen Wiedererwärmung des Bauteils kommen. In der Folge kommt es zu komplexen Temperatur- und Lastverläufen, was wiederum die Anforderungen an die Modellierung des Prozesses erhöht. In den letzten Jahren wurden bei einer Reihe von Simulationsprogrammen Fortschritte auf dem Gebiet des konventionellen und partiellen Presshärtens erzielt [3]. Dies beinhaltet Materialmodelle (z. B. thermophysikalische Effekte wie Phasenumwandlungen oder latente Wärme), aber auch Randbedingungen wie druckabhängige Wärmeübertragungskoeffizienten [4]. Dieser Beitrag behandelt eine Verfeinerung der thermomechanischen Modellierung des Presshärtens, indem ein Fokus auf den Einfluss der Umwandlungsplastizität gelegt wird. Experimentelle Untersuchungen an einer 22MnB5-Güte liefern die Grundlage für eine Sensitivitätsstudie, in der der Einfluss der Umwandlungsplastizität auf ein Beispiel für das konventionelle sowie das partielle Presshärten dokumentiert wird.
Application of Column Flotation for Egyptian Graphite
Authors: Abd EL-Rahiem Fatma H.
Published: December 2013

This paper focuses on the graphite flotation from Bent Um Qureia ore at Eastern desert of Egypt. Minerals in ore were evaluated by XRD. The sample was crushed in jaw crushing. The sample was ground minus 74 μm and the product was then sieved +45 and −45 μm. The conventional and column flotation were used to float the graphite. In two flotation techniques, kerosene was used as a collector. Factor affecting the graphite grade was investigated. The rougher concentrate was cleaned in both conventional cell and column to compare the performance. The effects of different variables were evaluated in both cases and the conditioned were optimized to achieve better grade and recovery. The results indicate that column can give superior performance compared to conventional cell by either reducing the number of stages of operation or by improving grade and recovery.
Gypsum Scale Formation on Heat Exchanger Surfaces: The Influence of Natural and Synthetic Polyelectrolytes
Authors: Amjad Z.
Published: December 2013

The precipitation and deposition of calcium sulfate dihydrate (gypsum) on brass heat exchanger surfaces from aqueous solutions has been studied using a highly reproducible technique. It has been found that gypsum scale formation takes place directly on the surface of the heat exchanger without any bulk or spontaneous precipitation in the reaction cell. A variety of natural and synthetic polyelctrolytes such as fulvic acid, tannic acid, poly-(acrylic acid) and acrylic acid — based copolymers containing sulfonic group(s) have been examined for their effects on the rate of scale formation. The results indicate that the amount of gypsum scale formed on heat exchanger surface is strongly affected by polyelectrolyte architecture and concentration of polyelectrolyte. Scanning electron microscopic investigations of gypsum crystals grown in the presence of polyelectrolytes (natural and synthetic) show that structures of these crystals are highly modified.
Dynamic Interfacial Behavior of Decyl Methylnaphthalene Sulfonate Surfactants for Enhanced Oil Recovery
Authors: Zhao Zhongkui , Ba Yan , Li Zonghsi , Qiao Weihong , Cheng Lübai
Published: December 2013

The high purity decyl methylnaphthalene sulfonate (DMNS) was synthesized, the purity was determined by HPLC and the structure was confirmed by IR, UV and ESI-MS. Dynamic interfacial tensions (DIT) between DMNS flooding systems and crude oil were measured and the effects of sodium carbonate concentration, surfactant concentration and sodium chloride concentration on the DIT behaviors were investigated. It's found that the surfactant concentration, alkali concentration and the salinity have obvious influences on DIT behaviors. DMNS possessed outstanding capacity and efficiency of lowering the DIT between oil and water. The minimum dynamic interfacial tension could reach 6.35×10−6 mNm−1 at a lowconcentration for added surfactant. DMNS might be used in Enhanced Oil Recovery with lowcosts and high efficiency.
Mesoscale Computer Simulations on the Phase Behavior of the Non-Ionic Surfactant C12E5
Authors: Schulz S. G. , Frieske U. , Kuhn H. , Schmid G. , Müller F. , Mund C. , Venzmer J.
Published: December 2013

Dissipative Particle Dynamics is a mesoscopic simulation method which allows to predict the self-assembly of amphiphilic polymers and surfactants. It was possible to reproduce the phase behavior of the non-ionic surfactant C12E5 in water. The three different phases L1, La and L2 could be characterized with Dissipative Particle Dynamics.
Nonionic Tenside Ligands and its Application in Biphasic Catalysis
Authors: Zilin Jin , Cuilan Feng , Yanhua Wang
Published: December 2013

This review article mainly surveys our research results of biphasic catalysis with nonionic tenside ligands. Emphasis is given to the synthesis and property of cloud point of the nonionic tenside ligands, the general principles of thermoregulated phase-transfer catalysis (TRPTC) and thermoregulated phase-separable catalysis (TPSC). It also explores the applications of TRPTC and TPSC in the hydroformylation of higher olefins and CO selective reduction of nitroarenes. The introduction of TRPTC to biphasic systemis free from the shortcomings of classical aqueous/organic two-phase catalysis, in which the application scope is restrained by the water solubility of the organic substrate. The biphasic catalysis with nonionic tenside ligands was characterized by homogeneous catalysis coupled with convenient biphasic separation.
Synthesis of δ Layered Sodium Disilicate with High Framework Stability
Authors: Dong Jinxiang , Xu Hong , Zhang Gaoyong , Li Jinping , Lian Genwang
Published: December 2013

In this paper, δ layered sodium disilicate with high framework stability has been synthesized by adding the salts of divalent and trivalent elements. In these salts AlCl3had the best effect for leaving the phase transformation of δ-Na2Si2O5. XRD, SEM, Ca2+ion binding capacity and clean experiment were used for measuring their properties. The data proved that Al-δ-Na2Si2O5had good framework stability. δ phase was still major phase after Al-δ-Na2Si2O5was treated in hot water (80°C) for 60 minutes. And Ca2+ion binding capacity may keep at 305 mg CaCO3/g through the treatment. The cleaning experiments showed that Al-δ-Na2Si2O5had good washing ability.
Cleavable Ortho Ester Type Surfactants
Authors: Hellberg P.-E. , Ginkel C. G. van
Published: December 2013

With the focus on quaternary ammonium compounds, this paper describes how the ortho ester chemistry can be used as a versatile tool for synthesis of cleavable surfactants of various types. This class of chemodegradable surfactants hydrolyzes rapidly under mild acidic conditions at the same time as they are long-term stable in alkaline aqueous solutions.

Further, the rate of cleavage can be modified by varying the structure of the surfactant. An additional feature is the possibility to design surface active compounds that release a daughter surfactant with different properties upon cleavage. Ortho ester-based surfactants could be of use in a large number of applications as exemplified in the paper.

Good biodegradation data are of importance for virtually all types of surfactants nowadays. However, there actually seem to exist very few, if any, investigations regarding the biodegradation of cleavable surfactants under both hydrolytical and non-hydrolytical conditions.

Data from the initial part of such a study on cationic ortho ester surfactants are presented and discussed in this paper. The results strongly indicate rapid biodegradation for this class of compounds under varying conditions.
Microemulsions Containing Polyethylene Glycol
Authors: Miller D. J. , Henning T.
Published: December 2013

It is well known that some water/oil/surfactant systems can be optimised to give three phases. The middle phase is a thermodynamically stable microemulsion. Three-phase systems can also form when most of the water is replaced by polyethylene glycol (PEG). The phase behaviour of such PEG-based systems with undecyl and oleyl ethoxylates as surfactants has been studied. The PEG reduces the temperature sensitivity and shifts the optimum to higher EO numbers, i. e. higher HLB values. In single phase O/W microemulsions the polyethylene glycol also reduces temperature sensitivity, though the effect seems to be less than for three-phase systems. It also promotes the solubilisation of higher molecular weight oils, such as triglycerides.
Temperature Effects in Anaerobic Biodegradation of Soaps in Anaerobic Screening Tests
Authors: Galvañ P. Varó , Rico D. Prats , Pastor M. Rodríguez
Published: December 2013

Fatty acid salts (soap) are a widely used class of anionic surfactants. The applications are in fabric washing products, fabric conditioners, laundry additives and surface and toilet cleaners. The levels of soap found in the detergents applications ranges from approximately 10–15%. In this work, the percentage of biodegradation of two soaps, Na-laurate and Na-stearate has been determined under anaerobic conditions. The experiments carried out included the analysis of the effect of the temperature on the degradation of the soaps. A bath test system containing municipal digester sludge as a source of anaerobic bacteria, based on the method proposed by the ECETOC, has been applied.

Based on the experimental results in the anaerobic ECETOC test, soaps tested (Na-stearate at 20°C, 35°C, 55°C and Na-laurate at 35°C, 55°C) can be regarded as ultimately biodegradable compounds, and it can expected that they are completely biodegraded under anaerobic conditions if time period allows for that. On the other hand, Na-laurate at 55°C in concentrations of 200 and 400 mg C/L was not degradaded at test conditions.
Dynamic Properties of Surfactants: Influence on Processes and Technologies
Authors: Oetter G. , Nörenberg R. , Hess S.
Published: December 2013

Industrial processes become faster and faster. The corresponding formulations have to keep pace with new technical solutions like spray coating in paper production or the substitution of isopropanol in fountain solutions for offset printing. Fast diffusion of amphiphiles to interfaces and the formation of interfacial films to lower the interfacial energy are the fundamental molecular mechanisms which have to be optimised for all high speed spraying and wetting processes. Our results show that the interfacial tension at water/air and at water/solid interfaces primarily depends on the concentration of free surfactants. Micelles act as depots for free surfactants which adjust the concentration in solution as soon as surfactants disappear by interface adsorption. By using synergistic mixtures it is possible to extend the application range of dynamic surfactants towards detergency by combining fast adsorption at interfaces with micellar properties.
Cleanability of Plastic Flooring Materials Related to their Surface Properties
Authors: Pesonen-Leinonen E. , Kuisma R. , Redsven I. , Sjöberg A.-M. , Hautala M.
Published: December 2013

The purpose of this study was to test the feasibility of contact angle measurement in evaluating soilability and cleanability of 11 different surfaces of flooring materials. The surface properties were examined using an expanding contact angle technique and the cleanability was evaluated colorimetrically. The values of advancing contact angles θAwere related to the soil residues on particle-soiled surfaces and oil-soiled surfaces. The results indicate the potential of contact angle measurements to evaluate cleanability of flooring materials.
Foam Film Characterization of Commercial Surfactants and their Mixtures
Authors: Hristova E. , Khristov Khr. , Exerowa D.
Published: December 2013

The properties of microscopic foam films formed by two commercial surfactants, sodium alkylethoxy sulfate and linear alkylbenzene sulfonic acid as well as by their mixtures are studied. The results obtained refer to the following dependences: surface tension on surfactant concentration at three different electrolyte concentrations; film thickness on electrolyte concentration at constant surfactant concentration; film thickness on surfactant concentration at constant electrolyte concentration; disjoining pressure on film thickness (disjoining pressure isotherms). Calculated are the following physicochemical parameters: the diffuse electric layer potential, surface charge, molecule area for the respective surfactant and close packing surface concentration of the adsorption layer. The data obtained provide an option to link the model foam film experiments with the real processes and systems.
New Detergency Aspects through Visualisation of Soil Release Polymer Films on Textile Surfaces
Authors: Calvimontes A. , Dutschk V. , Koch H. , Voit B.
Published: December 2013

Soiling degree and cleanability of different polyester textile materials before and after impregnation with a soil release polymer (SRP) has been systematically investigated. The use of an imaging instrument for the optical roughness analysis operating on the principle of chromatic aberration allowed visualisation of a transparent SRP film on impregnated textile surfaces. Through visualisation of the SRP film and quantification of its relative area, a possible mechanism of cleanability due to impregnation with SRP is proposed.
Preparation and Surface Activities of Novel Sodium Sulfated Aryl Oleic Acid Alkanolamides
Authors: Zhigang Xu , Bing Yuan , Jie Yan , Zongshi Li , Weihong Qiao , Cheng Lubo
Published: December 2013

Novel sodium sulfated aryl oleic acid alkanolamide surfactants (SSAOAA) with different hydrophobic groups are prepared. An aromatic ring introduced to a long alkyl chain has a significant effect on the effectiveness in reducing water surface tension. The critical micelle concentration (c.m.c.) of one product and the surface tension (γc.m.c.) at the c.m.c. are investigated. Surface active properties of sodium sulfated aryl oleic acid alkanolamides are compared to those of conventional sulfated fatty acid alkanolamides. Results show that the c.m.c. decreases with increasing the sizes of alkyl chains.
Synthesis and Surfactant Properties of New Ester-capped Poly(oxyalkylated) Alcohols
Authors: Nowicki J. , Wasilewski J. , Poskrobko J.
Published: December 2013

A new group of nonionic ester surfactants was synthesized. New esters were obtained in high yields from commercially available poly(oxyalkylated) alcohols and fatty acid chlorides under mild reaction conditions. Their structures were confirmed by GPC and HPLC chromatography. The surface properties such as critical micelle concentration (c.m.c.), surface excess concentration, Gc.m.c., and surface area per molecule, Ac.m.c., were determined. The emulsification properties of the new esters were investigated.
Ultrasonic Extraction and TLC Determination of Surfactants in Laundry Wastewaters
Authors: Rezić I. , Bokić Lj.
Published: December 2013

Standard method of surfactant determination is UV/VIS determination and a long time — consuming standard flask extraction with chloroform, in which very large quantities of harmful organic solvent are employed. In this work, ultrasonic solvent extraction of anionic, cationic and non-ionic surfactants was compared with the traditional shake-flask extraction method and both methods were applied on laundry wastewater samples. Separation, identification and quantification of surfactants were done by thin layer chromatography and video densitometry. Ultrasonic extraction procedure was optimized with regard to the amount of solvent and duration of extraction. This extraction method proved to be much better because it was faster and more efficient. Due to the application of much less organic solvent, it is both economically and ecologically favorable.
Effect of Counterions and Temperature on the Association and Partition Balances of Hexadecylpyridinium Halides in Aqueous Solutions
Authors: Oremusová J. , Greksáková O.
Published: December 2013

The effect of counterions and temperature on the association (critical micelle concentration, thermodynamics of micellization) and partition balances (experimental partition coefficient) of three quarternary ammonium surfactants (CPX) having a common hexadecylpyridinium cation and different anions (chloride, bromide, iodide) were studied in aqueous solutions at the temperature range 20–50°C, using conductometry, potentiometry, UV spectroscopy and measurement of surface tension. All methods used gave closely similar values for critical micelle concentration. From calculated thermodynamics parameters the process of micellization was found to be spontaneous and exothermic. Experimental partition coefficient of hexadecylpyridinium halides increased from chloride to iodide.

The objective of this work was to check whether surfactant counterions can affect the micellization and partition processes. From the results obtained it seems that the differences found in micellization and partitioning of all compounds studied, may be attributed to the different physicochemical properties of chloride, bromide and iodide anions as their differences in mobility etc.
Oxo-Alcohol Ethoxylates: Surface and Thermodynamic Properties and Effect of Various Additives on the Cloud Point
Authors: Duarte L. J. N. , Canselier J. P.
Published: December 2013

In this study the thermodynamic properties of various Oxo-alcohol ethoxylates related to their adsorption at the air/water interface and to their micellization have been studied. The effect of various additives, including electrolytes, alcohols, polar aromatic solutes, and ionic and nonionic surfactants on the cloud point of aqueous solutions of the same surfactants has also been investigated. Salting-out electrolytes lower the cloud point while salting-in species raise it. Except for the totally water-miscible alcohols, most hydroxylated compounds lower the cloud point. Phenols, aromatic alcohols, and amines seem to interact preferentially with the ethylene oxide groups of the micelles, leading to strong dehydration, and consequently lowering the cloud point. On the contrary, by forming mixed micelles, an anionic surfactant strongly raises the cloud point of the nonionic.
Revision of the Adsorption Behavior of the Non-ionic Surfactant Tetraoxyethylene Decylether C10E4at the Water/Air Interface
Authors: Schulze-Schlarmann J. , Stubenrauch C. , Miller R.
Published: December 2013

The adsorption kinetics of the non-ionic surfactant C10E4was studied by maximum bubble pressure (MPT-2) and drop/bubble shape analysis tensiometry (PAT-1). The two methods complement each other and show good agreement in the overlapping time range if the problem of the so-called initial load at the drop/bubble surface is considered properly. The adsorption appears to be diffusion-controlled, giving an average diffusion coefficient of the order of 110−10m2s−1. At higher surfactant concentrations, the adsorption rate tends to change to a non-diffusional mechanism, which is possibly caused by surface active impurities.
Reaction Kinetics of the Heterogenous Decomposition of Hydrogen Peroxide in Microemulsions
Authors: Nadia Yousef , El-Sousy Khaled M. , EL-Aila Hisham J. Y. , Mhesen Fatheya
Published: December 2013

Kinetic study for the heterogeneous decomposition of hydrogen peroxide over different non-soluble metal oxides (CuO, Fe2O3 and PbO2) was taken as a model reaction, mainly in normal micellar, inverse micellar microemulsion of sodium dodecyl sulfate (SDS). Other micellar phases of different surfactants [sodium dioctylsulfosuccinate (AOT), cetyle trimethyl ammonium bromide (CTAB) and triton X100] have been studied. Different organic solvents have been investigated. A promotional effect was generally observed. The reaction rate determining step was estimated. Reaction rate constants and thermodynamic parameters (ΔG*, ΔH* and ΔS*) were calculated. It was found that the highest promotional influence was observed in the case of (SDS/Fe3O4) in micellar and inverse micellar micro-emulsion media.
Vesicular Phase Behaviour in Ionic Surfactant Systems with Organic Counter-ions
Authors: Friman R. , Backlund S. , Teixeira C. V. , Linden M.
Published: December 2013

Phase diagrams at 298.2 K were determined for aqueous systems of alkylamines and alkanoic acids in equimolecular ratio, i.e. for alkylammonium alkanoates. The bilayer structural evolution for these ionic surfactants with organic counter-ions in water was studied using transmission electron microscopy (TEM), optical microscopy, small-angle X-ray scattering (SAXS) and rheological measurements. The formed vesicles are highly viscoelastic and have a yield stress value. In the pentylammonium nonanoate-water system at higher contents, the vesicles collapse to micelles, while in the hexylammonium nonanoate-water and in the pentylammonium decanoate systems, a transition to a fully expressed lamellar phase is observed. The results are discussed in terms of electrostatic interactions and membrane flexibility.
Polymeric Surfactants from Beechwood Glucuronoxylan
Authors: Skalková P. , Sroková I. , Sasinková V. , Ebringerová A.
Published: December 2013

Polymeric surfactants were prepared from two beechwood glucuronoxylans, differing in the uronic acid content, molecular mass and solubility, by transesterification with vinyl laurate under homogeneous and heterogeneous reaction conditions and with methyl laurate under solvent-free conditions. The water-soluble derivatives exhibit significant emulsifying efficiency comparable to that of the commercial surfactants Tween 20 and Slovasol 245. The performance tests indicated good washing power and very low antiredeposition efficiency. Water-soluble glucuronoxylan laurates can be prepared from both xylan preparations with non-toxic esterification agents as well as under “solventfree” reaction conditions.
New Family of Trisiloxane Surfactants
Authors: Zhang Guodong , Han Fu , Zhang Gaoyong
Published: December 2013

The interfacial properties of a series of novel aqueous trisiloxane of the general formula Me3SiOSiMeROSiMe3[R=(CH2)3N(CH2CH(OH)CH2(OCH2CH2)nOCH3)2n=1,2] were studied. The physicochemical parameters of these trisiloxane were discussed. These surfactants reduced the equilibrium surface tension of water to a minimum value of approximate 21∼22 mN/m at concentration levels of 10−4mol·L−1.
Influence of Natural and Synthetic Additives on Calcium Carbonate Precipitation and Crystal Morphology
Authors: Amjad Z.
Published: December 2013

The pH-stat technique has been used to study the influence of several natural and synthetic additives containing carboxyl, phenolic, and sulfonic groups on the precipitation of calcium carbonate from supersaturated solutions (Ca=HCO3 = 5.50 mM, NaCl=0.10 M, pH 8.50, 35°C). The additives investigated were natural i.e., green tea extract, GTE; sodium lignosulfonate, SLS and synthetic i.e., poly(acrylic acid), P-AA; poly(2-acrylamido-2-methyl-propane sulfonic acid), P-SA. It has been found that addition of low concentrations of additive has three fold effects: a) it delays the precipitation of calcium carbonate, b) it inhibits the rate of precipitation, and c) it influences the calcium carbonate polymorph. Based on the results obtained under the test conditions, the ranking in terms of decreasing effectiveness is: P-AA ≫ GTE>SLS ∼ P-SA. The results also indicate that the delay in precipitation increases with increasing additive concentration. SEM and X-ray diffraction studies of calcium carbonate precipitated in the presence of additives reveal that whereas P-AA and P-SA favor the formation of vaterite, GTE and SLS influence the formation of calcite. By contrast, the predominant polymorph formed in the absence of additive is vaterite. Kinetic analysis suggests Langmuir-type adsorption of added additive ions on the active growth sites of CaCO3 crystals.
Force Measuring Methods for Determination of Surface Tension of Liquids: A Comparison
Authors: Richter L. , Vollhardt D.
Published: December 2013

Three methods for the determination of the surface tension of liquids based on force measurements namely, the vertical plate method of Wilhelmy, the frame method of Lenard and the ring method of du Noüy are compared and studied in respect of a common principle of correction. It is shown that these three most important force-based methods allow the determination of the surface tension under static conditions. The force components of the corresponding liquid column below the measuring wire obtained for the straight part of the withdrawal curve up to the transition in its curved part provides exact surface tension values. The experimentally accessible value of the force component describes the physical background of the measured value correction contrary to the approximate equations obtained by mathematical way. Usually the determination of surface tension of liquids is based merely at the vertical plate method on exact equations thermodynamically derived whereas in the case of the frame and ring methods correction factors in approximate equations are used. At usual application of the force-based methods under the non-static condition of the withdrawal of a liquid column, the force maximum measured at withdrawal of the measuring object (plate, frame, or ring) is the basis for the determination of surface tension. In these cases, the measured surface tension values are compensated by correction equations for the frame and ring methods which are based on an correction factor and correction tables empirically obtained. The surface tension values obtained in this usual way agree with those obtained by using the force component of the corresponding liquid column below the measuring wire for the straight part of the withdrawal curve up to the transition in its curved part. Problems arising at the force measurements with increasing thickness of the measuring wires inside and outside the rings are discussed.
Different Tracer Stain Systems for Testing Laundry Detergent Performance
Authors: Hilgers T. , Ophüls A. , Bohnen J.
Published: December 2013

A wide range of test methods are used worldwide for testing the performance of laundry detergents. Principally, all methods need tracer stains. Uniformly stained standard tracer stains are occasionally considered ‘artificial’ while manually prepared or circular stains are at the same time accepted as ‘natural’. This distinction is not helpful, it is even incorrect. Uniformly stained tracer stains were developed to improve reproducibility. Only few existing stains are additionally heat treated or represent combinations of several stain substances ((effect stains)). All tests are supposed to provide performance results reflecting reality (i. e. consumer perception); suitability of any of the model systems depends solely on their ability to provide results for reliable performance assessment. Extensive comparative tests using different stain systems confirmed that preparation of small batches using different fabric substrates, finish and pre-treatment is beneficial for testing e. g. soil release polymer performance. Apart from that, uniformly soiled standard stains in general showed better reproducibility while providing comparable performance results. We could confirm that standard stains are a good solution for addressing issues with dissatisfactory reproducibility.
The Synthesis and Properties of High Pure δ Layered Sodium Disilicate
Authors: Dong J.-X. , Li L.-P. , Xu H. , Deng F. , Zhang G.-Y. , Li J.-P. , Ai X.-J.
Published: December 2013

δ layered sodium disilicate (δ-Na2Si2O5) is a single layer silicate and has good properties as detergent builder. However, it is difficult to synthesize high pure δ-Na2Si2O5. In this paper, a feasible and simple technology was found by decreasing Na content in liquid sodium silicate (water glass). The crystalline time was short and no seed needed. The suitable synthesis conditions were Si/Na = 1.05–1.10, calcining at 720 °C for 5 minutes. The synthesis conditions are of industrial value. XRD and29Si NMR data proved that synthesized samples were δ-Na2Si2O5without impure phase. High pure δ-Na2Si2O5exhibited good ions binding ability and reached 312 to 338 mg CaCO3/g.
Is the EU Ecolabel DID List a Useful Environmental Evaluation Tool for Detergent-like Consumer Products?
Authors: Nitschke L. , Malcomber I. , Tibazarwa C. , Steber J.
Published: December 2013

For comparing the environmental relevance of household and personal care products, the Critical Dilution Volume (CDV) originally developed for the EU Ecolabel of detergents is an often used key criterion. The EU Ecolabel Detergents Ingredient Database (DID) is a publicly available information basis for derivation of product CDV by providing data on key descriptors for the environmental fate and effects of chemical substances used in consumer products. The alterations of the CDV-relevant descriptors in the revised DID list (2004) have led, in many cases, to an unrealistic depiction of the environmental behaviour of product ingredients and to inadequate product evaluations. The paper reports on the framework of and the experiences with a novel DID list developed by an expert group of the German Hauptausschuss Detergentien (HAD) enabling an environmentally more realistic comparison of products.
Synthesis and Characterization of a Series of Novel Anionic Fumaric Polymerizable Surfactants
Authors: Zhu M. , Qiao W. , Sun Y. , Liu H. , Li Z.
Published: December 2013

A series of novel anionic fumaric polymerizable surfactants with different lengths of carbon chains (C8–C14) were synthesized. The chemical structure of the surfactants was confirmed by 1H NMR, IR and MS. The values of critical micellar concentration (cmc) and γcmc of the surfactants were determined. The surface properties of this series of designed polymerizable surfactants show their potential application in the emulsion polymerization to improve the stability of the latices and water sensitivity of the films.
The Influence of Different Ether Carboxylic Acids on Polyester Fibre Friction
Authors: Dutschk V. , Myat S. , Brünig H. , Märtin J. , Stolz M. , Breitzke B. , Cherif Ch. , Heinrich G.
Published: December 2013

The influence of different surface active ether carboxylic acids as spin finishes on polyester fibre friction has been studied. The fibre friction was indirectly assessed through measurements of yarn tensile forces during the melt-spinning process. After manufacturing, the friction of fibre against steel was evaluated using the method of inclined plane. Results for the static fibre-steel friction coefficient obtained are in good agreement with the yarn tensile force data. The influence of different finishing agents as lubricants on the fibre friction was revealed.
A Comparative Analysis between Different Ether Carboxylic Acids with Respect to Wettability and Surface Topography of Abrasively Treated Polyester Fabrics
Authors: Dutschk V. , Myat S. , Märtin J. , Stolz M. , Breitzke B. , Cherif Ch. , Heinrich G.
Published: December 2013

Wetting properties and surface topography of different polyester fabrics have been determined before and after their mechanical abrasion. As protective finishes, different surface active ether carboxylic acids were used. The influence of different weave types of the fabrics – woven and knitted – on their abrasive resistance was revealed. A comparative analysis between different ether carbon acids with respect to wettability of fabrics, surface topography parameters and mechanical treatment by abrasion was done.
Hydrolysis of α, β-Layered Sodium Disilicate in Ions Binding Process
Authors: Dong J.-X. , Li L.-P. , Xu H. , Li J.-P.
Published: December 2013

In different type water, the hydrolysis of α, β-Na2Si2O5was investigated near washing clothing concentration by XRD, SEM chemical analysis and residual solid yield. β-Na2Si2O5changed to kanemite in distilled water. In water with Ca2+or Mg2+, β-Na2Si2O5transformed to a mixture of kanemite, Ca(OH)2and amorphous silicate or a mixture of kanemite (NaHSi2O5·3 H2O), Mg(OH)2and amorphous silicate. α-Na2Si2O5changed to an unknown phase in distilled water. In water with Ca2+or Mg2+, α-Na2Si2O5transformed to a mixture of unknown phase, Ca(OH)2and amorphous silicate or a mixture of unknown phase, Mg(OH)2and amorphous silicate. The experimental data showed that the divalent cation binding process of α, β-Na2Si2O5belongs to a mixture process with divalent cations exchange with Na+cation and precipitation in form of insoluble amorphous solid.
Synthesis and Characterisation of Antifungal Agents Containing Copper(II) Soaps and Derived from Mustard and Soyabean Oil
Authors: Sharma R. , Tank P. , Saxena M. , Bhutra R. , Ojha K. G.
Published: December 2013

The solid copper(II) soaps derived from Mustard oil and Soyabean oil and their complexes with ligands containing nitrogen and sulphur atoms like urea, thiourea and 2-amino-6-chloro benzothiazole have been synthesized and characterised by elemental analysis, IR, NMR, ESR spectroscopy and magnetic moment studies. From the analytical data, the stoichiometry of the complexes have been observed to be 1: 1 (metal: ligand). The magnetic moment studies suggest the dimeric nature of the complexes. IR, NMR and ESR spectral details confirm that complexation has taken place successfully. The results indicate that the complexes possess elongated octahedral geometry. Conductometric studies suggest that the soaps and complexes are non-electrolytic in nature. The fungi toxicities of these ecofriendly and biodegradable soaps and complexes have been investigated.
Conductivity Measurements as a Method for Studying Ionic Technical Grade Surfactants
Authors: Carey E. , Patil S. R. , Stubenrauch C.
Published: December 2013

The critical micellar concentrations (cmc) of cationic alkyltrimethylammonium bromides (C10TAB – C16TAB) and of anionic alkyl sulfates (SDS, technical grade Sulfopon 12G and Sulfopon 1214G) were determined using specific conductivity and surface tension measurements. While the cationic surfactants were purified, the anionic surfactants were used as received. In the former case, surface tension and conductivity measurements lead to the same cmc values. In the latter case, measuring the specific conductivities (bulk property) proved to be superior compared to measuring the surface tensions (surface property) because the presence of highly surface active impurities creates a pronounced minimum in the surface tension isotherm, which makes it impossible to determine an accurate value for the cmc. On the other hand, these impurities do not influence the conductivities, i. e. that the conductivities can be used to determine cmc values of impure and technical grade ionic surfactants, respectively. Moreover, an evaluation of the specific conductivities allows for the determination of the degree of micelle ionization (α) of the ionic surfactant solutions and thus provides additional useful information.
Phase Separation Study of a Surface-Active Drug, Promazine Hydrochloride, in Presence of Surfactants and Ureas
Authors: Kabir-ud-Din  , Al-Ahmadi Mohd. D. A. , Naqvi A. Z. , Akram Mohd.
Published: December 2013

As clouding in drugs causes high concentration of drug at a particular site which may prove harmful to the body, the clouding behaviour of a tricyclic phenothiazine drug promazine hydrochloride (PMZ) in aqueous solutions has been studied in the presence of surfactants and ureas. The cloud point (CP) decreases with increase in pH due to deprotonation of the drug molecules. Addition of non-ionic and cationic (conventional as well as Gemini) surfactants increased the CP whereas anionic surfactants showed a peaked profile. The urea family additives influenced the CP in both ways that depended whether they contain >C=O or >C=S moiety: the former interacts with the micelles and lowers the CP while the latter (due to its electropositive character) may not interact and hence CP increases. Dye solubilization results indicate micellar growth with the addition of surfactants in PMZ solutions. The results are interpreted taking cognizance of mixed micelle formation, hydrophobic interactions, and/or change in solvent structure.