bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of Surfactants on Release of Chlorhexidine from Hydrogels
Authors: Vitková Z. , Oremusová J. , Vitko A. , Bezáková Ž. 
Published: December 2013

Abstract
In Slovakia chlorhexidine is available in dosage forms of solutions, creams and pastes but not in the form of hydrogels, though they are modern drug forms with many positive properties. Therefore, in this article possibilities of its formulation into hydrogels are studied. In particular, two research aims were followed. The first consisted in study of an influence of surface active agents on the release of chlorhexidine dihydrochloride from chitosan hydrogels and the second one was to design a formulation of hydrogels for local delivery of chlorhexidine to the oral cavity. To this end, surfactants from the group of alkyltrimethylammonium bromides with the length of alkyl chain C6–C18 which occupy a dominant position in the indication group of antiseptics and disinficients were analyzed with intention to use them in preparation of hydrogels. Hydrogels were prepared with 2.5% (w/w) gel-forming agent chitosan. Both the active agent and surfactants were used in 0.1% (w/w) concentration. It is shown that the surface active agents with short alkyl chain are suitable for development of chlorhexidine dihydrochloride hydrogels with controlled release.
Kinetics and Adsorption Isotherms for the Removal of Tartrazine from Aqueous Solution by Coal Ash
Authors: Ishaq M. , Saeed K. , Nadeem S. 
Published: December 2013

Abstract
The coal ash (Φ) was used as an adsorbent for the removal of tartrazine from aqueous solution at room temperature. The adsorption capacity of tartrazine increased as the adsorption time was increased and then remains constant after 30 min adsorption duration. It was found that the Φ removed more than 40% of tartrazine from the aqueous solution within 1 h contact time. The equilibrium adsorption was also analyzed by Langmuir isotherm and it was found that the data followed the Langmuir isotherm models.
Influence of Surfactants on the Morphologies of CdS Nanorods
Authors: Sridevi D. , Rajendran K. V. 
Published: December 2013

Abstract
CdS nanorods have been successfully synthesized by using different surfactants such as cetyltrimethyl ammonium bromide (CTAB), sodium dodecyl sulphate (SDS), and poly ethylene glycol (PEG) via hydrothermal method. The products were characterized by means of powder X-ray diffraction (XRD), Scanning electron microscopy (SEM), and Transmission electron microscopy (TEM). The influences of surfactants on the morphologies of CdS nanorods are discussed.
AOT-Vesicles Produced at the Oil-Water Interface
Authors: Kubatta E. A. , Rehage H. 
Published: December 2013

Abstract
Vesicles can be found in many applications like drug delivery or as models for cell membranes. It is often necessary to produce vesicles which are easy to adjust in size and which can be filled with different types of ingredients. In this publication we used phase transfer techniques in to form well defined vesicles. The synthesis of these particles occurred in three different steps. First, a water phase was covered by an oil phase containing surfactants. A water-in-oil emulsion was then added to the oil phase. In the third step the phase transfer was stimulated by sedimentation or centrifugation processes. In a series of experiments we measured the vesicle sizes and encapsulation efficiencies. Giant vesicles, formed by sedimentation processes had typical sizes between 1–10 μm. Smaller vesicles between 100–500 nm were observed after centrifugation processes. With both methods we could produce vesicles with encapsulation amounts about 10%.
Effects of Electrolytes on Interfacial and Micelle Properties of C.I. Reactive Orange 16 – Dodecylpyridinium Chloride Binary System
Authors: Akbaş H. , Aydemir M. 
Published: December 2013

Abstract
The effect of electrolytes on the interaction between the anionic dye C.I. Reactive Orange 16 and the cationic surfactant dodecylpyridinium chloride was investigated using surface tension measurement in a certain concentration range. The influence of the concentration of electrolyte on critical micelle concentration (CMC) values was observed in the following order; 0.1 M NaCl > 0.5 M NaCl > 1.0 M NaCl. Also, the influence of the electrolyte cations was observed as Na+ > Mg2+ > K+. An increase on CMC values of dye-surfactant solution with increasing electrolyte concentration is explained as charge screening and also the decrease in these values for higher concentration of electrolyte is attributed to the change of micelle shape. Furthermore this change is due to ionic polarizability, valency and hydrated radius. Using Rubingh's regular solution theory, the values of micellar interaction parameters (β), were found as negative in all studied mixtures.
Biosurfactant in Planar Chromatography of Transition Metal Ions: Mixed Micelles Activated Separations
Authors: Moheman A. , Husain A. , Siddiqi K. S. 
Published: December 2013

Abstract
Sodium deoxycholate (a biosurfactant) in planar chromatography has been used to investigate the separation and migration behavior of transition metal ions. The chromatographic system comprised of soil-cellulose (3:7, w/w) as stationary phase and mixed micellar solution (sodium deoxycholate-sodium dodecyl sulfate, 1.0% each in 1:1 ratio) containing M5-acetonitrile in 3:2 ratio (v/v) was identified as the best mobile phase for separation and migration of transition metal ions. The Rf value for the metals follows the order, Cu(II) (0.15) < Ag(I) (0.57) < Au(III) (0.91) which also happens to be the order of increasing atomic weight of the metal ions in the periodic group. The detection limit of Cu(II), Ag(I), and Au(III) was found to be 0.22, 1.48, and 7.76 μg zone−1 respectively. The proposed method is robust, sensitive, easy, and reproducible. It has been used for successful identification and separation of above mentioned cations in sample matrices.
Synthesis of Bisphosphodiester Surfactants Derived from Tetradecanol and Different Methylene Chains as a Spacer Derived from α-ω-Alkyl Dibromides
Authors: Tyagi P. , Tyagi R. 
Published: December 2013

Abstract
Bisphosphodiester surfactant is a name assigned to a family of synthetic amphiphiles possessing a hydrocarbon chain attached to another hydrocarbon chain via different methylene chains as a spacer derived from α-ω-alkyl dibromide (1,4-DBB, 1,6-DBH and 1,8-DBO). In the present study, a series of bisphosphodiester surfactants having C14 hydrophobic tail and different methylene chains as a spacer derived from α-ω-alkyl dibromide have been synthesized at 35°C. The effect of reaction variables like temperature, duration and molar ratios of mono tetradecyl phosphate, tetramethyl ammonium hydroxide and spacer on the yield of bisphosphodiester surfactants has also been reported. Modern instrumental techniques viz. FT-IR, 1HNMR, and 13CNMR were utilized to characterize the functional groups presence in synthesized bisphosphodiester surfactants. Elemental analysis of synthesized bisphosphodiester surfactants was also carried out. Surface active properties viz. surface tension, interfacial tension, critical micelle concentration and aqueous properties viz. foaming stability, wetting ability, emulsifying ability and dispersing power of synthesized gemini surfactants were also determined. Among all synthesized bisphosphodiester surfactants IIIb had maximum anionic content of 78.9%; and showed highest foaming ability (70 ml), superior dispersing ability (45.7%), whereas IIIc showed low CMC values (0.00026 mmol/l); minimum surface tension and interfacial tension (37.3 mN/m and 31.6 mN/m) respectively.
Synthesis, Characterization and Surface Activity of Trioctyl Hydroxyethyl Ammonium Chloride
Authors: Li Y.-L. , Li Q.-X. , Zhi L.-F. , Zhang M.-H. 
Published: December 2013

Abstract
Trioctyl hydroxyethyl ammonium chloride was synthesized from trioctylamine, hydrochloric acid and ethylene oxide by a two-step process. The structure of the quaternary ammonium salt was characterized by FTIR and 1H NMR. The surface tension at the critical micelle concentration was measured to investigate the surface activity of it.
Aquatic Risk Assessment of Enzymes used in Household Detergents
Authors: Madsen T. , Slothuus T. , Petersen G. I. , Rasmussen D. 
Published: December 2013

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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.