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General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Physicochimie de surface, Surface physical chemistry, Etat colloïdal et états dispersés, Colloidal state and disperse state, Propriété physicochimique, Physicochemical properties, Propiedad fisicoquímica, Activité, Activity, Actividad, Ammonium, Amonio, Antibactérien, Antibacterial agent, Antibacteriano, Epoxyde, Epoxide, Epóxido, Propriété surface, Surface properties, Propiedad superficie, Synthèse, Synthesis, Síntesis, Tension superficielle, Surface tension, Tensión superficial, Antibacterial activities, epoxy quaternary ammonium salt, and surface tension

Epoxypropyl dodecyl dimethyl ammonium chloride (EPDDMAC) was synthesized with N,N-dimethyl dodecyl amine (DMDA) and epichlorohydrin (EPIC). Diethyl-2,3-epoxypropyl-[3-methyldimethoxyl)] silpropyl ammonium chloride (DEEPSAC) was synthesized with N,N-diethyl-aminopropyl-methyldimethoxysilane (DEAPMDES) and epichlorohydrin (EPIC). The products were characterized by infrared and elemental analysis and 1H NMR spectroscopy. The surface tension, conductivity, and antibacterial activities of EPDDMAC and DEEPSAC were studied.

General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Physicochimie de surface, Surface physical chemistry, Etat colloïdal et états dispersés, Colloidal state and disperse state, Agent surface ionique, Ionic surfactant, Agente superficie iónica, Cycle 6 chaînons, Six membered ring, Ciclo 6 eslabones, Hétérocycle azote, Nitrogen heterocycle, Heterociclo nitrógeno, Propriété physicochimique, Physicochemical properties, Propiedad fisicoquímica, Agent surface cationique, Cationic surfactant, Agente superficie catiónico, Caractérisation, Characterization, Caracterización, Conductivité, Conductivity, Conductividad, Propriété surface, Surface properties, Propiedad superficie, Pyridine, Piridina, Stabilité thermique, Thermal stability, Estabilidad térmica, Synthèse, Synthesis, Síntesis, Tension superficielle, Surface tension, Tensión superficial, Agent de surface gemini, Gemini surfactant, 4-dimethyl amino pyridine, Conductivity and thermal stability, gemini surfactants, surface tension, and synthesis

New pyridinium gemini surfactants have been synthesized by esterification of renewable fatty acids with mercaptoethanol furnishing respective esters (mercaptomethyl decanoate, mercaptomethyl dodecanoate, mercaptomethyl tetradecanoate, mercaptomethyl hexadecanoate) followed by their subsequent treatment with 4-dimethyl amino pyridine resulting in the formation of title gemini surfactants: 1-(5-(decanoyloxy)-2-hydroxypentyl)-4-((5-(decanoyloxy)-2-hydroxypentyl)dimethyl ammonio)pyridin-1-ium chloride (9), 1-(5-(dodecanoyloxy)-2-hydroxypentyl)-4-((5-(dodecanoyloxy)-2-hydroxypentyl)dimethyl ammonio)pyridin-1-ium chloride (10), 1-(5-(tetradecanoyloxy)-2-hydroxypentyl)-4-((5-(tetradecanoyloxy)-2-hydroxypentyl)dimethyl ammonio)pyridin-1-ium chloride (11), and 1-(5-(hexadecanoyloxy)-2-hydroxypentyl)-4-((5-(hexadecanoyloxy)-2-hydroxypentyl)dimethyl ammonio)pyridin-1-ium chloride (12). Their identifications are based on infrared, 1H NMR, 13C NMR, distortionless enhanced polarization transfer, co-relational spectroscopy (COSY), and mass spectral studies. Their surface active properties are also evaluated on the basis of surface tension and conductivity measurements. Thermal stability of these long chain cationic gemini surfactants have been measured by thermal gravimetric analysis under nitrogen atmosphere.

General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Physicochimie des réactions induites par rayonnements, particules et ultrasons, Physical chemistry of induced reactions (with radiations, particles and ultrasonics), Photochimie, Photochemistry, Etat colloïdal et états dispersés, Colloidal state and disperse state, Composé de métal de transition, Transition element compounds, Activité, Activity, Actividad, Caractérisation, Characterization, Caracterización, Electrofilage, Electrospinning, Electrohilado, Matériau composite, Composite material, Material compuesto, Nanofibre, Nanofiber, Nanofibra, Oxyde de titane, Titanium oxide, Titanio óxido, Photocatalyse, Photocatalysis, Fotocatálisis, Synthèse, Synthesis, Síntesis, Ag/TiO2 nanofibers, electrospinning, and photocatalytic activity

Ag nanoparticles (Ag NPs) embedded titanium dioxide (TiO2) nanofibers were fabricated by colloidal sol process, electrospinning, and calcination technique. Calcination of the electrospun nanofibers were heat treated at 600°C for 180 minutes in air atmosphere. X-ray diffraction patterns exhibited that the anatase phase and silver coexisted in the resulted Ag NPs/TiO2 nanofibers; transmission electron microscopy demonstrated Ag NPs well spread in the porous microstructure of composite fibers. The prepared nanofibers were utilized as photocatalyst for degradation of methyl orange. The degradation rate of methyl orange dye solution containing Ag/TiO2 composite nanofibers is 99% only after irradiation for 3 hours. It is proposed that these new Ag NPs/TiO2 composite nanofibers will have potential application in water pollution treatment.

General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Etat colloïdal et états dispersés, Colloidal state and disperse state, Propriété physicochimique, Physicochemical properties, Propiedad fisicoquímica, Agent surface, Surfactant, Agente superficie, Cinétique, Kinetics, Cinética, Huile, Oil, Aceite, Récupération, Recovery, Recuperación, Synthèse, Synthesis, Síntesis, Tension interfaciale, Interface tension, Tensión interfacial, EOR, interfacial tension, kinetics, and surfactants

The synthesis of CO2 philic surfactant using maleic anhydride and 4-tert-butylbenzyl alcohol is reported. We reacted maleic anhydride with 4-tert-butylbenzyl alcohol to form bis(4-(tert-butyl)benzyl) fumarate and sulfonated the produced diester. The esterification reaction was optimized for a maximum yield of 98% of bis(4-(tert-butyl)benzyl) fumarate. First-order reaction kinetics with respect to acid was observed. The activation energy was found to be 55.62 kJ/mol. The sulfonated product of diester was obtained by the sulfonation reaction and the yield of 82% of surfactant was achieved. The in-house developed surfactant effectively lowered down the IFT between CO2/brine to 4.2 mN/m. This surfactant is targeted for CO2-EOR applications.

General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Physicochimie des réactions induites par rayonnements, particules et ultrasons, Physical chemistry of induced reactions (with radiations, particles and ultrasonics), Photochimie, Photochemistry, Etat colloïdal et états dispersés, Colloidal state and disperse state, Composé benzénique, Benzenic compound, Compuesto bencénico, Composé de métal de transition, Transition element compounds, Hydrocarbure, Hydrocarbon, Hidrocarburo, Activité, Activity, Actividad, Dégradation photochimique, Photochemical degradation, Degradación fotoquímica, Oxyde de titane, Titanium oxide, Titanio óxido, Stabilité, Stability, Estabilidad, Styrène, Styrene, Estireno, Synthèse, Synthesis, Síntesis, Aqueous styrene, N-TiO2, photocatalytic degradation, and visible light

Nitrogen-doped TiO2 (N-TiO2) were prepared by the impregnation method using urea as a nitrogen source and TiO2-P25 as precursor. N-TiO2 was characterized by x-ray diffraction (XRD), UV―vis diffusion reflectance spectra (UV―vis DRS), Fourier transform infrared spectroscopy (FTIR), and x-ray photoelectron spectroscopy (XPS) techniques. XPS analysis indicates the incorporation of nitrogen in TiO2 lattice as O―Ti―N linkage. DRS spectra reveal the extended absorption to the visible range. Photocatalytic performance of the N-TiO2 was studied by testing the degradation rate of aqueous styrene under visible light. Also, the degradation kinetics of aqueous styrene and possibility of cyclic usage of N-TiO2 were investigated.

General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Etat colloïdal et états dispersés, Colloidal state and disperse state, Micelles. Lames minces, Micelles. Thin films, Acrylamide polymère, Acrylamide polymer, Acrilamida polímero, Agent surface non ionique, Non ionic surfactant, Agente superficie no iónica, Agent surface, Surfactant, Agente superficie, Copolymère, Copolymer, Copolímero, Eau, Water, Agua, Micelle, Micela, Polymère, Polymer, Polímero, Synthèse, Synthesis, Síntesis, Polyacrylamide, polymeric surfactant, and thermo-associative polymer

A novel cationic-nonionic bifunctional polymerizable surfactant (PEP) was prepared by the quaternarization of poly (ethylene oxide-propylene oxide) block polymers (PEO-PPO) having terminal tertiary amine group with chloropropene. Polymeric surfactant (PAM-g-PEP) was prepared by the copolymerization of acrylamide and PEP in water and the product was confirmed by FTIR. PAM-g-PEP has exhibit excellent surface and interfacial activity and its surface tension and interfacial tension at cmc are 40.13 mN/m and 11.69 mN/m, respectively. The influence of temperature on the micellar behavior of the PAM-g-PEP in water was studied by the dynamic laser scatting (DLS) and ultraviolet spectroscope. The results showed that PAM-g-PEP in water is thermo-associative. In diluted PAM-g-PEP solution, the Rh of the polymeric surfactant increases with the temperature due to the interpolymeric aggregations are formed. In the case of concentrated PAM-g-PEP solution, the light transmittance of PAM-g-PEP aqueous solution decreases with the increasing temperature, which is may be caused by the increase of the number of the interpolymeric PEP chain aggregates.

General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Physicochimie de surface, Surface physical chemistry, Etat colloïdal et états dispersés, Colloidal state and disperse state, Agent surface ionique, Ionic surfactant, Agente superficie iónica, Alcool, Alcohol, Composé benzénique, Benzenic compound, Compuesto bencénico, Propriété physicochimique, Physicochemical properties, Propiedad fisicoquímica, Activité, Activity, Actividad, Agent surface anionique, Anionic surfactant, Agente superficie aniónico, Agent surface non ionique, Non ionic surfactant, Agente superficie no iónica, Carboxylate, Carboxilato, Ether, Eter, Interface, Interfase, Phénol, Phenol, Fenol, Phénols, Phenols, Fenoles, Salinité, Salinity, Salinidad, Synthèse, Synthesis, Síntesis, Tension interfaciale, Interface tension, Tensión interfacial, Anionic-nonionic surfactant, interfacial tension, salinity, and synthesis

In order to study the interfacial activity of the anionic-nonionic surfactant, five nonyl phenol polyoxyethylene ether carboxylates were synthesized and mass spectra were used to characterize their structures. The tensions of the anionic-nonionic surfactant aqueous solutions against crude oil were measured and the effects of the surfactant structure, concentration, and salinity on the interfacial activities were discussed. It was shown that nonyl phenol polyoxyethylene (6) ether carboxylate can produce ultralow interfacial tension when the concentrations are not lower than 0.10%, exhibiting a high interfacial activity and a good anti-dilution resistance. Moreover, it was proved that there exists synergism between NaCl and MgCl (or CaCl2), which is crucial to achieve the ultralow interfacial tension.

General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Etat colloïdal et états dispersés, Colloidal state and disperse state, Etudes physiques et chimiques. Granulométrie. Phénomènes électrocinétiques, Physical and chemical studies. Granulometry. Electrokinetic phenomena, Emulsions. Microémulsions. Mousses, Emulsions. Microemulsions. Foams, Agent surface, Surfactant, Agente superficie, Argile, Clay, Arcilla, Emulsion, Emulsión, Huile, Oil, Aceite, Nanoparticule, Nanoparticle, Nanopartícula, Particule, Particle, Partícula, Stabilisation, Stabilization, Estabilización, Clay nanoparticles, nonaqueous emulsions, pickering emulsions, and reactive surfactants

Although surfactants and particles are often used together in stabilization of aqueous emulsions, the contribution of each species to such stabilization at the oil-water interface is poorly understood. The situation becomes more complicated if we consider the nonaqueous oil-oil interface, i.e, the stabilization of nonaqueous oil-in-oil (o/o) emulsions by solid particles and reactive surfactants which, to our knowledge, has not been studied before. We have prepared Pickering nonaqueous simple (o/o) emulsions stabilized by a combination of kaolinite particles and a nonionic polymerizable surfactant Noigen RN10 (polyoxyethylene alkylphenyl ether). Different pairs of immiscible oils were used which gave different emulsion stabilities. Using kaolinite with equal volumes of paraffin oil/formamide system gave no stable emulsions at all concentrations while the addition of Noigen RN10 enhanced the emulsion stability. In contrast, addition of Noigen RN10 surfactant to silicon oil-in-glycerin emulsions stabilized by kaolinite resulted in destabilization of the system at all concentrations. For all systems studied here, no phase inversion in simple emulsion was observed by altering the volume fraction of the dispersed phase as compared to the known water-based simple Pickering emulsions.

General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Etat colloïdal et états dispersés, Colloidal state and disperse state, Agent surface, Surfactant, Agente superficie, Carbone, Carbon, Carbono, Couche bimoléculaire, Bilayer, Capa bimolecular, Gonflement, Swelling, Inflamiento, Mélange, Mixture, Mezcla, Bilayer swelling, glycerin, and refractive index matching

Bilayer swelling behavior of cationic and anionic surfactant mixtures in solution induced by adding glycerin was investigated. The measurements were performed a system, cationic tetradecyl-trimetylammonium bromide (TTABr), and anionic sodium perfluorodecanoate (C9F19CO2Na) surfactant mixtures with their stoichiometric mole ratio being exactly 1 in aqueous solution. The non-precipitated phase of cationic and anionic hydro- and perfluoro-carbon surfactant mixtures being the mole ratio of 1:1 could be identified to be lamellar gel phase, which was characterized by freeze-fracture transmission electron microscopy (FF-TEM) and x-ray diffraction (XRD) measurements. Deuterium nuclear magnetic resonance (2H NMR) and rheology were used to characterize the phase transition from the lamellar gel to smaller vesicles. Phase transition from lamellar gel to smaller vesicles can be induced by adding glycerin to replace water. The addition of glycerin lowers the turbidity of the dispersion and swells the interlamellar distance between bilayers, which could be explained by matching of refractive index between solvent and bilayers.

General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Etat colloïdal et états dispersés, Colloidal state and disperse state, Acide, Acids, Acido, Acier, Steel, Acero, Carbone, Carbon, Carbono, Corrosion, Corrosión, Diffraction RX, X ray diffraction, Difracción RX, Inhibition, Inhibición, Microscopie électronique balayage, Scanning electron microscopy, Microscopía electrónica barrido, Polarisation, Polarization, Polarización, Acid corrosion, EIS, SEM, XRD, carbon steel, and polarization

Corrosion inhibition and adsorption behavior of two triazole derivatives on API 5L-B carbon steel in CO2-saturated 3.5% NaCl solutions was investigated using potentiodynamic polarization, EIS and EFM techniques. Specimen surfaces were characterized using SEM, EDX and XRD. Results show that the two compounds are mixed-type inhibitors and inhibition efficiency increases with increasing concentrations. Adsorption of the two compounds is a mixed between chemisorptions and physisorption and obeys Langmuir adsorption isotherm. Activation energy and thermodynamic parameters were calculated. Surface analyses confirm the formation of iron nitrides on the metal surface, which supports results obtained from previous techniques.

General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Physicochimie de surface, Surface physical chemistry, Etat colloïdal et états dispersés, Colloidal state and disperse state, Etudes physiques et chimiques. Granulométrie. Phénomènes électrocinétiques, Physical and chemical studies. Granulometry. Electrokinetic phenomena, Métal transition, Transition metal, Metal transición, Intérieur, Inner, Interior, Nanoparticule, Nanoparticle, Nanopartícula, Or, Gold, Oro, Point isoélectrique, Isoelectric point, Punto isoeléctrico, Propriété surface, Surface properties, Propiedad superficie, Solution aqueuse, Aqueous solution, Solución acuosa, Solution électrolyte, Electrolyte solution, Solución electrólito, Structure, Estructura, Gold nanoparticles, inner structure, isoelectric point, and surface properties

Gold nanoparticles reduced by sodium citrate (d∼ 10nm) and purchased gold colloid particles (d~ 500 nm) were examined and compared. The properties of both gold particles and their biofunctionalized derivatives with L-cysteine and L-glutathione were studied in the presence of sodium nitrate. The structural investigations indicated an aggregated inner structure. The isoelectric points of pure gold, citrate reduced gold, and functionalized gold were measured and compared. The low isoelectric point of pure gold/water interface was explained by considering the distribution and accumulation of H+ and OH- ions within the interfacial water layer, being more pronounced for OH- ions.

General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Etat colloïdal et états dispersés, Colloidal state and disperse state, Biopolymère, Biopolymer, Biopolímero, Dynamique, Dynamics, Dinámica, Eau, Water, Agua, Glucide, Carbohydrate, Glúcido, Gomme xanthane, Xanthan gum, Goma xantan, Huile, Oil, Aceite, Matière grasse, Fat, Materia grasa, Modèle, Models, Modelo, Rhéologie, Rheology, Reología, Carbohydrate biopolymers, dynamic rheology, locust bean gum, power-law model, structural characteristics, and water-in-oil spread

Effects of xanthan gum (XG) (0.1 wt%) and pectin (PE) (0.5 wt%) alone and in combination with different concentrations (0.2 and 0.4 wt%) of locust bean gum (LBG), modified starch (MS), and Na-alginate (ALG) on some of the rheological characteristics of low-fat spreads, including flow behavior curves, rheological modeling, apparent viscosity, rheological modules (storage modulus (G) and loss modulus (G')), and delta degree (G/G') were studied. Results showed the power-law model was better than the Herschel-Bulkley model to describe the flow curve of dispersions. The k-value in the power-law model increased with increase in biopolymers concentration in solution. All samples exhibited shear-thinning flow behavior with a low yield stress. Dynamic oscillatory shear test showed that the spreads had a viscoelastic solid behavior with a gel-like structure. The G value was increased by increasing frequency from 0.03 to 15 Hz, while the G' and G'/G values decreased. Also, MS in combination with XG and PE led to increase the G values of spreads in comparison with ALG and LBG. Moreover, microstructural and stability observations revealed that the spreads prepared with 0.1% XG-0.2% LBG significantly had the highest oiling out.

General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Etat colloïdal et états dispersés, Colloidal state and disperse state, Biomasse, Biomass, Biomasa, Biosorption, Biosorción, Chimie physique, Physical chemistry, Fisicoquímica, Cinétique, Kinetics, Cinética, Equilibre, Equilibrium, Equilibrio, Mécanisme, Mechanism, Mecanismo, Spectrométrie IR, Infrared spectrometry, Espectrometría IR, Azure A, FTIR, Zea mays, and biosorption

The mechanism of Azure A (AA) biosorption by Zea mays biomass (ZMB) was studied. Surface chemistry and morphology were characterized by potentiometric titration, pH of zero charge, FTIR, and microscope analysis. The equilibrium data was modeled by Langmuir, Freundlich, Redlich-Peterson, Temkin, and multilayer models. AA biosorption was mainly limited by chemisorption, but the role of intraparticle diffusion could not be neglected. The integrative analysis of surface chemistry/biosorption studies showed that chemisorption, ion exchange, complexation, and/or electrostatic attraction were involved during AA biosorption. The maximum biosorption capacity of ZMB (q 5.84 mg/g) was registered at pH7.6.

General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Etat colloïdal et états dispersés, Colloidal state and disperse state, Analyse corrélation, Correlation analysis, Análisis correlación, Cristallisation, Crystallization, Cristalización, Modification, Modificación, Mécanisme, Mechanism, Mecanismo, Pétrole brut, Crude oil, Petróleo bruto, Co-crystallization, EVA pour point depressant, gray correlation analysis, and modification effect

The Ar-Sai waxy crude oils were taken as the research objects, and the viscosity reduction rates and the condensation point reduction rates were regarded as the evaluation indexes, the impacts of components content of the crude oils and carbon number distribution of waxes on the modification effect of EVA-type pour point depressant (PPD) were analyzed by using gray correlation analysis method. The oil wax was acquired by applying the extraction and separation techniques initially, then the structures and the lattice parameters of wax crystals before and after adding the PPD were studied by polarized light microscopy observation and x-ray diffraction techniques, the mechanism of pour point depression was discussed at last. The results indicate that wax content and the low carbon number wax have significant influences on the modification effect of PPD, while the impact of high carbon number wax is relatively small. Co-crystallization is the main mechanism of pour point depression, nevertheless, the impacts of the asphaltenes, resins, solid particles, and light components of the crude oils on the modification effect of the PPD cannot be ignored.

General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Physicochimie de surface, Surface physical chemistry, Etat colloïdal et états dispersés, Colloidal state and disperse state, Micelles. Lames minces, Micelles. Thin films, Propriété physicochimique, Physicochemical properties, Propiedad fisicoquímica, Agent surface, Surfactant, Agente superficie, Ion antagoniste, Counter ion, Ion antagonista, Liaison, Binding, Enlace, Médicament, Drug, Medicamento, Solution micellaire, Micellar solution, Solución micelar, Tension superficielle, Surface tension, Tensión superficial, Binding constant, counterion binding parameter, drug-surfactant interaction, surface tension, and trimethoprim

Binding and distribution properties of trimethoprim (TMP) in the presence of various anionic surfactants; sodium octyl sulfate (C8SC4Na), sodium decyl sulfate (C10SO4Na), sodium lauryl sulfate (C12SO4Na), and sodium tetradecyl sulfate (C14SO4Na) has been studied by conductivity, spectrophotometry and surface tension measurements. The surface properties of anionic surfactants, that is, maximum surface excess concentration (Γmax) and minimum area per surfactant molecule (Amin) at the air/water interface have been evaluated in the absence and presence of TMP using Gibbs adsorption isotherm. From conductivity data the ionization degree and counterion binding parameter have been obtained. Spectrophotometric experiments were used to determine binding constants of TMP to anionic micelles. With the increasing alkyl chain of surfactants, the interaction becomes stronger, which shows the importance of hydrophobic forces and incorporation of TMP molecules to the pure micelles of anionic surfactants increased. The results obtained from the surface tension and conductometric studies have been correlated with those obtained from the spectroscopic studies and binding tendency of TMP to anionic micelles followed the order as: C14SO4Na > C12SO4Na > C10SO4Na > C8SO4Na. From these results, the study of the interaction TMP in different anionic micellar solutions provided information about the characteristics of binding properties of poorly soluble drugs.

General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Etat colloïdal et états dispersés, Colloidal state and disperse state, Emulsions. Microémulsions. Mousses, Emulsions. Microemulsions. Foams, Agent surface anionique, Anionic surfactant, Agente superficie aniónico, Agent surface ionique, Ionic surfactant, Agente superficie iónica, Constante association, Association constant, Constante asociación, Microémulsion, Microemulsion, Microemulsión, Thermodynamique, Thermodynamics, Termodinámica, SDS, Sodium sulfate(dodécyl), Sudan red (III), and microemulsions

The absorption spectrum of Sudan red III (SR) in oil solutions and a series of O/W microemulsion with surfactant sodium dodecyl sulfate (SDS) has been determined by the UV-Vis spectrophotometer. We found that an association interaction existed between the stain SR and anionic surfactant SDS in water/mixed oil/SDS microemulsions. By measuring the absorbance of Sudan red in a series of microemulsions which has different R values and using the appropriate association models to analyze the experimental data, we obtain the association constants of SR and SDS, and the values of thermodynamics functions of association ΔrGm has also been calculated from the association constants.

General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Etat colloïdal et états dispersés, Colloidal state and disperse state, Emulsions. Microémulsions. Mousses, Emulsions. Microemulsions. Foams, Diamètre, Diameter, Diámetro, Emulsion, Emulsión, Goutte, Drop, Gota, Modèle, Models, Modelo, Probabilité, Probability, Probabilidad, Bimodal distribution, Sauter mean diameter, drop breakage, predication model, and probability distribution

In order to increase the present understanding of bimodal emulsion drop size distributions, systematic series of experiments have been carried out to investigate the effects of formulation variables on bimodal drop size distributions, and probability distribution functions were proposed to analyze the distribution. The results show that, the span of the drop size and Sauter mean diameter become larger when the dispersed phase volume fraction becomes higher and rotor speed becomes lower; the Frechet function represents the experimental data satisfactorily. The prediction model of Sauter mean diameter established by combining the prediction theory of the maximum stable drop diameter and experimental analysis results can fit the experimental data well.

General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Physicochimie de surface, Surface physical chemistry, Etat colloïdal et états dispersés, Colloidal state and disperse state, Acide gras, Fatty acids, Acido graso, Aminoacide, Aminoacid, Aminoácido, Cystine, Cistina, Propriété surface, Surface properties, Propiedad superficie, Agent de surface gemini, Gemini surfactant, Amino acid, L-cystine, fatty acids, gemini surfactants, and surface active properties

The present work reports the synthesis and evaluation of surface active properties of amino acid-based gemini surfactants, namely, sodium dilauraminocystine (SDLC) and sodium dimyristaminocystine (SDMC) derived from L-cystine and fatty acids. The effect of reaction variables like molar ratio of raw materials and temperature has been studied for the synthesis of these gemini surfactants. In preparation of these gemini surfactants, fatty acids (lauric/myristic) were reacted with thionyl chloride to obtain respective acid chlorides (lauroyl/myristoyl). These acid chlorides were further reacted with L-cystine at different reaction conditions to get amino acid based-gemini surfactants. The study revealed that 1:2.5 molar ratio of reactants, namely, L-cystine and lauroyl/ myristoyl chloride and 10-15° reaction temperature resulted in maximum yield of amino acid-based gemini surfactants (SDLC and SDMC). Surface active properties of synthesized gemini surfactants (SDLC and SDMC) were also compared with their corresponding monomeric units, namely, sodium lauroyl cysteine (SLC) and sodium myristoyl cysteine (SMC), respectively. The results demonstrated that gemini surfactants (SDLC and SDMC) had better surface active properties than their corresponding monomeric units. The structures of synthesized amino acid-based gemini surfactants were also confirmed by FTIR, 1H NMR, 13C NMR, and ESI-MS spectral data.

General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Physicochimie de surface, Surface physical chemistry, Etat colloïdal et états dispersés, Colloidal state and disperse state, Propriété physicochimique, Physicochemical properties, Propiedad fisicoquímica, Eau, Water, Agua, Huile, Oil, Aceite, Hydrophilie, Hydrophily, Hidrofilia, Interface, Interfase, Mélange binaire, Binary mixture, Mezcla binaria, Sulfonate, Sulfonato, Synergie, Synergism, Sinergia, Tension interfaciale, Interface tension, Tensión interfacial, Alkylbenzene sulfonate, hydrophilic-lipophilic ability, synergism, and ultralow interfacial tension

In order to study the synergism between alkybenzene sulfonate and alkybenzene sulfonate, five di-n-alkylbenzene sulfonates were used and the interfacial tensions of single sulfonates and their binary mixtures against a series of alkane homologues were measured. The effects of hydrophilic-lipophilic abilities of sulfonates and mixing ratio on synergism were discussed. It is revealed that the synergistic mechanism derives from the amelioration of the hydrophilic-lipophilic ability of the surfactant system, and the method to achieve synergism is adding the hydrophilic alkybenzene sulfonate to the lipophilic alkylbenzene sulfonate, and ultralow interfacial tensions can be obtained in proper mixing ratios. The results are useful for enhanced oil recovery.

General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Physicochimie de surface, Surface physical chemistry, Etat colloïdal et états dispersés, Colloidal state and disperse state, Acide, Acids, Acido, Calcium, Calcio, Dynamique moléculaire, Molecular dynamics, Dinámica molecular, Eau, Water, Agua, Huile, Oil, Aceite, Interface, Interfase, Orientation, Orientación, Pétrole brut, Crude oil, Petróleo bruto, Structure, Estructura, ARN tetraacid, Acidic crude oil, calcium naphthenate scale, molecular dynamics, naphthenic acids, and oil-water interface

Fouling caused by tetracarboxylic acids in transport and separation process chains involving petroemulsions occurs when the interfacial concentration of tetraacids becomes large enough for calcium ions in the water phase to crosslink the adsorbed tetraacid molecules and form a precipitate. At present, the structure and orientation of tetraacid molecules at oil-water interfaces, which influences the precipitation behavior, has not been studied in detail. In this work, molecular dynamics simulations of indigenous and synthetic tetracarboxylic acid compounds are presented to describe the structure and spatial orientation of tetraacid molecules at oil-water interfaces. Molecular distributions relative to the oil-water dividing surface along with the length and orientation angle distributions of the acidic arm groups are presented. The probability distributions determined here that describe the tetraacids at an oil-water interface can be employed to reconstruct the density of carboxylic acid groups at the oil-water interface. The interfacial carboxylic acid density can be employed to determine the fraction of adsorbed tetraacid molecules that are crosslinked with calcium ions based on the distances between carboxylic acid groups. The simulations presented also form a basis to calculate interfacial molecular areas and virial coefficients to employ in molecular mixed monolayer adsorption isotherms.