Papers by Keyword: Surfactant

Abstract: A fluid system consisting of polymer-based thickening agent (ACPAM) and a surfactant (Linear alkyl benzene sulfonate, LAS) is reported. The ACPAM polymer showed good thickening performance. At concentration 0.6 wt%, the viscosity of ACPAM solution reached 265 mPa∙s. ACPAM polymer solution was easily cross-linked by LAS at a wide pH range. The ACPAM gel system can be broken by ammonium persulfate under the temperature of 80~90°C. The residue content of the breaking fluid was low. Meanwhile, the ACPAM fluid system showed an excellent thermal stability & shearing resistance performance. It can be used in high temperature reservoir upto temperature 150°C.

Abstract: To improve the anti-corrosion properties of the aluminum, the electroless plating Ni-W-P on the aluminum is necessary. Investigation was made on the influences of additives (stabilizers and surfactants) on the deposition rate, weight loss corrosion rate, porosity, corrosion current, corrosion potential, electrochemical impedance spectroscopy (EIS) and webster hardness of electroless plating Ni-W-P alloy coating by electrochemical methods, etc. The results show that the deposition rate and anti-corrosion properties of electroless plating Ni-W-P are obviously improved when the stabilizer KIO₃ (1mg/L) is added into plating solution. In addition, the Ni-W-P coating become more dense, uniform and defect-free with the addition of stabilizer KIO₃ by comparison with no stabilizer. When the surfactant SDBS (50mg/L) added into bath, the corrosion resistance properties of electroless plating Ni-W-P alloy coating are also obtained.

Abstract: Using titanium trichloride (TiCl₃) as the precursor, cetyltrimethyl ammonium bromide (CTAB), polyvinyl pyrrolidone (PVP), sodium dodecyl sulfate (SDS) as the surfactants, sodium chloride (NaCl) as the mineralizer, titanium oxides (TiO₂) nanomicrospheres were synthesized at 170 °C for 24 h via hydrothermal method. Use x-ray diffraction (XRD) and scanning electron microscopy (SEM) to characterize the crystal structure and morphology of the microspheres. The results show that pure rutile phase TiO₂ microspheres can be prepared with the assist of surfactant by hydrothermal treatment. The spheres were composed of radial aligned nanorods. The diameters of the rods were about 40 nm and the lengths were about 500 nm. The diameters of the TiO₂ microspheres prepared using CTAB, PVP, SDS as the surfactant were among 1μm~2μm, 5μm~10μm, and 2μm~5μm, respectively.

Abstract: Dispersion of carbon nanotubes in water largely determines the excellent properties of carbon nanotubes can be fully exhibited in the composite material. Summarizes the characteristics of all kinds of surface active agent, select several can represent various types of surfactant reagents to test and comparing the several kinds of surfactants on the dispersion of carbon nanotubes, and focus on the effects of polyvinylpyrrolidone special molecular structure on the surface of the carbon nanotubes.

Abstract: The electrodeposition of zinc from acidic sulphate bath on steel substrate has been studied. The influence of sodium dodecylbenzenesulfonate (SDBS) as surfactant on the mechanism of the electrodeposition process has been investigated using potentiodynamic and cyclic voltammetry (CV) techniques. From the analysis of CV analysis, it is shown that in the surfactant free bath solution, hydrogen evolution occurs together with the zinc deposition. The presence of SDBS shifts the reduction potential of Zn²⁺ to more negative values, indicating that SDBS to some extent hinder the Zn electrodeposition.

Abstract: Integration of nanoparticles in enhanced oil recovery (EOR) has been intensively studied in recent years due to their unique properties owing to the nanoscale dimensions, rendering them to have different properties in comparison with its bulk material. Application of magnetic nanoparticles such as ferrites was able to exploit their rheological properties as a chain-like structure formed due to dipole-dipole alignment with the applied magnetic field. Ferromagnetic nanoparticles had shown an increment in the oil recovery under the irradiation of an EM wave. In this research, the influence of magnetic nanoparticles nickel-zinc-ferrite, Ni_1-xZn_xFe₂O₂ in the form of nanofluids on the recovery efficiency in EOR was studied. Nickel-zinc-ferrite magnetic nanoparticles with various values of x were synthesized to observe the effect of nickel to zinc ratio on recovery efficiency. The nanoparticles were characterized using X-ray Diffraction (XRD) and Vibrating Sample Magnetometer (VSM). Coreflooding experiments were conducted where the nanofluids were injected into the compacted sand saturated with crude oil under EM irradiation. The amount of oil recovered from the core was evaluated. VSM tests shows that the sample with x = 0.5 had the highest magnetization of 52.6 emu/g. The nanofluids prepared from the sample also achieved the highest crude oil recovery of 26.07% of the residual oil in place (ROIP).

Abstract: Microbial conversion is a key process in the biosynthetic routes of steroid medicine.The whole process of bioconversion includes two essential steps: (1) enzymatic reaction step where the enzyme-catalyzed substrate transformation takes place inside the cells, and (2) diffusion step that includes the diffusion of substrate molecules from the surface of solid substrate particles into bulk media (i.e., the solubilization of solid substrate), the diffusion of solubilized substrate molecules from bulk media into cells, and the diffusion of formed product molecules from inside cells into bulk media. In this review, the applications of three chemical factors (growth regulator,surfactant and cyclodextrin), and their effects on steroid microbial enzymatic conversion were extensively discussed, which provides insights into the development of novel approaches to cost-effectively improve biosynthesis efficiency in steroid medicine.

Abstract: The research of improving thermal properties of cool storage medium using nanocomposite technology is proposed in this paper. The nanocomposite cool storage material was prepared by the method of mixing directly. The effect of dispersant, ultrasonic time and concentration of dispersant were deeply researched. The optimizing concentration of dispersant and the optimizing dispersion process conditions are confirmed. The results show that thermal conductivity of TiO₂ /HS-6 nanofluids is noticeably enhanced to compare base fluid HS-6, the increasing extent is 21.5%. The results provide the basic data for the application research of TiO₂ nanoparticles in PCM for air-conditioning system.

Abstract: In this study, sawdust modified by cetyltimethyl ammonium bromide was applied to adsorb conge red in aqueous solutions. The characteristics of modified sawdust were characterized by Fourier transform infrared spectrum and scanning electron microscopy. The effect of factors, such as pH, contact time, temperature, dosage, and salt concentration, were investigated. The results revealed that the addition of modified sawdust can significantly increase the adsorption capacity of dye. The maximum adsorption capacity of dye on modified sawdust was 109 mg·g^-1 at 328K. The adsorption processes were rapid within the first 30 min and reached equilibrium in about 150 min. The adsorption kinetics fitted well with pseudo-second-order model. The pH value of the solution had significant impact on the amount of adsorption. Adsorption isotherm fitted better with the Langmuir model and the adsorption was an endothermic process

Abstract: In order to decide the formula of ASP system to be used in Henan oilfield, the weak base ternary composite system compounded with petroleum sulfonate(Ss), polymer and weak base; the alkali ASP system compounded with alkylbenzene sulfonates(Sy), polymer and alkali were studied, and the oil-water interface behaviour of Henan oilfield with weak base ASP system compounded with surfactant SHSA-HN6 and ZL-Ⅱ polymer was evaluated. The results showed that the interfacial tension reduction effect of Weak base ternary system is better than that of Alkali ternary system; the interfacial tension between oil and water can be reduced significantly by the weak base ternary system compounded with surfactant (Ss) and polymer (ZL-Ⅱand KYPAM). After adding 1.2% Na₂CO₃ to the mixture of surfactant (SHSA-HN6) and polymer, the interfacial tension of Henan oil-water was reduced to the ultra-low level(>10^-3mN/m).