Nonionic Surfactant OP-10 Research Articles

Wettability Characteristics of Low-Rank Coals Under the Coupling Effect of High Mineralization and Surfactants.

This paper investigates the unclear influence mechanism of the surfactant effect on improving coal seam wettability and CO2-enhanced coalbed methane technology to enhance the gas extraction efficiency in some coal mines under highly mineralized environments in China. Specifically, the microinfluence mechanism of the coupling effect of nonionic surfactant OP-10 and highly mineralized coal samples under special treatment on the wettability of coal seam is examined. By measuring the contact angle and surface tension of the samples, it is confirmed that high mineralization can limit the effect of surfactants on improving the wettability of coal seams to a certain point. Infrared spectroscopy and X-ray diffraction measurements were conducted on the samples under coupling conditions. It is found that high mineralization impedes the effectiveness of surfactants in enhancing the wettability of coal seams. The surfactants interact with coal samples at the functional group level, producing new hydrophilic functional groups and increasing the content of kaolin with strong hydrophilic properties, thereby increasing the wettability of coal seams. However, these hydrophilic functional groups disappear under coupling conditions and hydrophobic functional groups are produced. Additionally, high mineralization inhibits the effect of surfactants on the phase composition of coal samples. The findings of this research provide a theoretical basis for water injection of highly mineralized coal seams and methane replacement recovery by carbon dioxide technology, promoting the practical application of water injection and gas injection displacement of coal seams.

Experimental and molecular dynamics study of particles removal in the effect of heterogeneous condensation agglomeration enhanced by surfactants

Heterogeneous condensation agglomeration is a promising pretreatment technology for enlarging fine particles, which is helpful to enhance the particle removal capacity of conventional equipment. The interaction between water vapor and particles is a significant factor influencing the enhancement effect. In this study, two kinds of particles with different surface wettability and three types of surfactants were applied to study the effect and mechanism of particles removal in the surfactant enhanced heterogeneous condensation agglomeration. The experiment was carried out based on CAP system in which the cyclone was enhanced by heterogeneous condensation agglomeration. The results show that SiO2-OH particles with better wettability had better removal effect than SiO2-CH3 particles. Adding surfactant can promote the condensational growth and agglomeration of particles by promoting the wetting effect between water vapor and particles, thereby increasing the removal efficiency. The improvement effect is influenced by particle surface properties and surfactant types. Cationic surfactant CTAB is most effective for SiO2-OH particles, while nonionic surfactant OP-10 is most effective for SiO2-CH3 particles. Wettability modification was investigated by molecular dynamics simulations, and the results shows that as a result of the different polarity of the surface functional groups, the strong electrostatic interaction is dominated between SiO2-OH and water, while the weak van der Waals interaction between SiO2-CH3 and water is the dominant. The head group of CTAB can form strong electrostatic interaction with SiO2-OH surface, while the long tail chain of OP-10 is adsorbed on SiO2-CH3 particles through van der Waals interaction, leading to the reduce of solid-liquid interaction energy and improves the wetting effect of water on particle. This work is beneficial for selecting suitable surfactant for heterogeneous condensation agglomerations technology.

Interaction between Coomassie brilliant blue G250 and octylphenol polyoxyethylene ether (10) in aqueous solution

ABSTRACTThe characteristic absorption peak of Coomassie brilliant blue G250 (CBBG250) has obvious redshift phenomenon by the addition of octylphenol polyoxyethylene ether (10) (OP-10) in aqueous solution, which shows that there is interaction between CBBG250 and OP-10. Two physical models are described and applied to the study of the interactions of CBBG250 with OP-10. According to the microphase adsorption-spectral correction (MPASC) technique, CBBG250 can be adsorbed on a surfactant by electrostatic force, and the aggregation obeys the Langmuir isotherm. The adsorption constant and the maximum binding ratio of the aggregates are calculated to be B = 4.32 × 105 L/mol and N = 0.137, respectively. The surfactant-dye association interaction (SDAI) model believes that there is significant association interaction between the CBBG250 and nonionic surfactant OP-10 in aqueous solutions, and a series of thermodynamic parameters such as K, , and are also determined. The simulation results indicate that the two models can fit the experimental data very well.

Structures of nonionic surfactant modified montmorillonites and their enhanced adsorption capacities towards a cationic organic dye

This work aims to prepare and characterize novel organo-montmorillonites (OMts) using a nonionic surfactant - octylphenol polyoxyethylene ether (OP-10), and apply the materials for the removal of cationic organic dyes. The nonionic surfactant OP-10 can be successfully intercalated into the interlayer of montmorillonite and the obtained OMts still keep cation exchange capacity. The structural configuration of surfactant molecules between clay mineral layers varies from the surfactant loadings. Moreover, OMts with higher surfactant loadings have higher organic carbon content but lower specific surface area. The prepared OMts showed enhanced adsorption capacities towards cationic organic dye methylene blue (MB), and the adsorption amount increases with an increase of surfactant loading. The high adsorption capacity can be attributed to the fact that the novel OMts still keep cationic exchange capacity and OP-10 has plentiful polyoxyethylene ether chains in its molecule structure, which can capture MB molecules through hydrogen bonding. A probable mechanism for the removal of MB was proposed to be a synergistic effect of ion exchange, partition adsorption, hydrogen bonding and electrostatic interactions. Kinetic and isotherm data could be fitted with pseudo-second order model and Langmuir isotherm. The adsorption thermodynamics study has proved the spontaneous and endothermic nature of the adsorption process. The nonionic surfactant modified OMts could be promising candidate adsorbents for the removal of cationic organic dyes.

One‐pot synthesis of net‐like silica materials with double mesoporous structure

A novel net-like silica material with double mesoporous structure had been synthesised by one-pot hydrothermal synthesis method. In the synthesis process, pluronic copolymer P123 (EO20PO70EO20) and non-ionic surfactant OP-10 were used as templates and potassium fluoride (KF) was chosen as the additive. A study was carried out by small-angle X-ray scattering, scanning electron microscopy and transmission electron microscopy for the physical properties of the resultant products. It was found that the net-like silica materials exhibited a unique three-dimensional morphology with the addition of KF and preserved mesoporous structure. Moreover, the samples had double mesopores of 3.6 and 6.5 nm by the result of the nitrogen adsorption isotherm.

Электроосаждение никеля из растворов, содержащих жидкие кристаллы

The possibility of obtaining structured nickel coatings by chemical and electrochemical deposition was investigated. Deposition was performed from electrolytes containing liquid crystals. The electrolytes were prepared from a saturated (aqueous or ammoniac) solution of nickel chloride and nonionic surfactant OP-10 at a weight ratio of solutions 1:1. The chemical deposition of nickel was performed on aluminium substrate, and electrochemical deposition was performed on nickel, copper and titanium substrates. Deposition on aluminum and nickel was performed from electrolyte composed of a saturated aqueous solution of nickel chloride and OP-10. During the deposition on copper and titanium the aqueous solution of nickel chloride was replaced by ammoniac one. The purpose of the replacement was to increase the pH of the solution and, as a consequence, to decrease the hydrogen evolution and increase output of nickel. Studies of the coatings by scanning electron microscope showed that in the case of deposition of nickel from aqueous solution coating contains mainly nickel hydroxochloride. When replacing a water solution by ammoniac, the precipitated coating comprises nickel metal in the form of dendrites with a size from 50 to 1000 nm.

Study on Thermodynamics and Kinetics of Association Interactions between Malachite Green and OP-10 in Aqueous Solutions

The absorption spectrum of malachite green (MG) in a series of aqueous solutions with surfactant octylphenol polyoxyethylene ether (10) (OP-10) has been determined by the UV–Vis spectrophotometer. The association interaction between the MG and nonionic surfactant OP-10 in aqueous solutions resulted in obvious fading of MG. We established the thermodynamics model of association between MG and OP-10, and determined the association equilibrium constant in aqueous solutions. By measuring the absorbance of a series of aqueous solutions which have different molar concentrations of OP-10 but same concentration of MG at different time points, the order and rate constants of association reactions were determined and the reaction kinetics equation was set up.

Surfactant polycomplexes in displacement processes of non-polar liquids from porous systems and demulsification of reverse emulsions

The surface properties of the polycomplexes of the non-ionic surfactant OP-10 with synthetic polyelectrolytes (polyacrylic acid, polymethacrylic acid, and polyethylenimine) at the water | (toluene + cyclohexane + hexane) interface were studied. It was found that at the low relative concentrations of OP-10 in the mixture (n = 0.05–1) the decrease in the surface tension is maximal. The displacement rate of the oil from the capillaries of different nature with aqueous solutions of various polyelectrolytes and OP-10 depends weakly on the nature of the capillary. The coefficient of oil displacement from porous systems with aqueous solutions of polycomplexes is higher by 18–25% than that of oil recovery with water. The study of the demulsifying properties of the polycomplexes showed that the lifetime of the reverse emulsions, including oil emulsions, is sharply decreased for large n values (n = 5–20).

Stability of emulsion at the presence of polycomplexes based on polyacrilic and polymethacrilyc acids and nonionic surfactant OP-10

Stability of straight and reverse emulsions based on polyacrilic and polymethacrilyc acids and nonionic surfactant OP-10 was studied. Detergency of these polycomplexes on oil substrate covered on solid surfaces of different nature were considered. The results obtained allow explain the mechanism of exlusion of non-polar liquids from capillary-porous systems.

Facile preparation and formation mechanism of uniform silver nanoparticles ising OP-10 as emulsifier in reverse microemulsion

Using the polymerizable hydrophobic styrene monomer as the dispersion medium and the traditional nonionic surfactant OP-10 as emulsifier, stable silver nanoparticles of narrow size distribution were prepared by a reverse (w/o) microemulsion method. The powder X-ray diffraction (XRD) pattern indicated that the obtained silver nanoparticles were of face-centered cubic structure. The results of the transmission electron microscopy (TEM) show that the final silver nanoparticles are of spherical structure with an average diameter of 15.2 nm and of a Gaussian distribution. The internal high-ordered structure of silver nanoparticles was characterized by the field-emission high-resolution transmission electron microscopy (FEHRTEM), indicating that the silver is monocrystalline and it has only one nucleation site during the formation process of a nanoparticle. The time-resolved UV-visible absorption spectra was used to monitor the process of the reaction in situ. The results show that the concentration of silver nanoparticles increases but the size changes little and the morphology transforms from obvious ellipsoidal shape to nearly spherical shape during the process. The experimental results indicate that the droplets’ dynamic exchange which is closely related to the nature of surfactant film is the control factor of the kinetics. The dynamic exchange mechanism of silver nanoparticle formation is proposed to involve continual encounter of two separate droplets forming transient fused dimer in which the chemical reaction occurs followed by re-separation without combination. Attributed to the dual role of surfactant in the nanoparticle formation, tailored nanoparticles can be successfully synthesized in control in the premise of a certain stability of reverse microemulsion.

“One pot” synthesis of fluorinated block copolymers using a surface-active ATRP initiator under emulsion polymerization conditions

Three fluorinated block copolymers have been prepared successfully in emulsion system using a surface-active atom transfer radical polymerization (ATRP) initiator disodium 4-(10-(2-bromo-2-methylpropanoyloxy)decyloxy)-4-oxo-2-sulfonatobutanoate (1). The copolymerization can be conducted in “one pot” under activator generated by electron transfer (AGET) ATRP in emulsion conditions, thus greatly simplifying the operations and workup. The anionic surface-active ATRP initiator (1) and nonionic surfactant OP-10 may form synergistic stabilizers that effectively guarantee stability of the final latex. The ATRP follows first-order kinetics and has living/controlled characteristics based on the researching results of polymerization of trifluoroethyl methacrylate (TFEMA). Surface studies indicate that the fluorinated block copolymers reveal lower surface energy and stronger hydrophobic property compared with those non-fluorinated polymers. The decreasing order of surface energy of the polymers is: polystyrene (PS) > polytrifluoroethyl methacrylate-block-polystyrene (PTFEMA-b-PS) > polyhexafluorobutyl methacrylate-block-polystyrene (PHFBMA-b-PS) > polydodecafluoroheptyl methacrylate-block-polystyrene (PDFHMA-b-PS) > polydodecafluoroheptyl methacrylate (PDFHMA). Fluorinated homopolymer PDFHMA and copolymer PDFHMA-b-PS exhibits relatively low-surface energy, which is ascribed to the long and flexible DFHMA units containing in the polymers.

A novel one-step method to synthesize copper nitrate hydroxide nanorings

With the purpose of searching for a convenient process to synthesize nanoparticles with special structure, a simple solid-state reaction in the presence of nonionic surfactant OP-10 at room temperature was adopted to prepare copper nitrate hydroxide (Cu 2(OH) 3NO 3) nanorings with an average internal diameter of 250 nm and average wall thickness of 100 nm. The formation of Cu 2(OH) 3NO 3 nanorings has a close relation with OP-10. Transmission electron microscopy(TEM), field emission scanning electron microscopy(FESEM), thermogravimetric analysis(TGA) and X-ray diffractometry(XRD) were used to characterize the obtained nanorings. The UV-Vis spectrum shows that the optical property of Cu 2(OH) 3NO 3 nanorings is similar to that of CuO or CuS. The synthesis method used here proves both simplicity and high efficiency.

Study of the physicochemical properties of silica powder and the stability of organic–inorganic hybrid emulsion in the presence of ethanol

The physicochemical properties of silica powder and stability of organic–inorganic hybrid emulsion were investigated. Silica–polymer hybrid latex particles with petal-like morphology were synthesized by emulsion polymerization using a nonionic surfactant OP-10, an anionic surfactant Dowfax 2A1, copolymerization of mixture monomers (MMA–St–BA–AA monomers with molar ratios of 1:1:1.2:0.1), and modified silica powder in the presence of ethanol. The influence of several parameters such as pH values of the suspension, modified silica, ethanol, and monomer on the stability of organic–inorganic hybrid emulsion, latex particle size, and silica content in hybrid polymer was investigated. The experimental results indicate that the amount of surfactant adsorption only was reduced slightly in the presence of ethanol and the displacer effect of ethanol is limited, but ethanol leads to an increase of zeta potential of silica (i.e., a decrease of negative surface charge), and strongly attracts anionic oligomer formed in water onto the surface of silica, thereby promoting the uptake of polymer and monomer from the continuous phase. Silica particles modified by gamma-methacryloxy propyl trimethoxy silane (KH-570) had a proclivity for copolymerization with acrylate monomer due to surface-unsaturated double bond, good compatibility with the polymer due to a significant carbon content that originated from KH-570, low surface silanols group and relatively high zeta potential, thereby improving the SP percentages of hybrid emulsion. Also the weak acid environment leads to an increase of zeta potential of silica and improvement in the stability of hybrid emulsion. Particle formation was predominated by the interaction of the polymer with the silica particles in the earlier stage of polymerization. Optimal conditions were found to obtain a petal-like polymer layer around silica and to preserve the stability of hybrid particles.

The cloud point extraction of copper(II) with monocarboxylic acids into non-ionic surfactant phase

The possibility to use monocarboxylic acids and their mixtures with amines for copper concentrating by the way of micellar extraction at cloud point temperature, and later atomic absorption spectrometry (AAS) determination was investigated. Under the optimum conditions, preconcentration of 100 ml of water sample in the presence of 1% non-ionic surfactant OP-10, 0.005 M capric acid and 0.01 M octylamine permitted the detection of 0.01 μg ml −1 copper. The proposed method has been applied to the AAS determination of copper in water samples after cloud point extraction.

Porous structure and adsorption properties of natural porous coal

From the analysis of the adsorption of hexane vapour, the volumes of micro- and mesopores, half widths, and specific surface areas of mesopores of natural porous coal were calculated. The quantities of acidic and basic groups existing at the surface of the coal were determined. It was shown that a high concentration of hydrophilic sites initiates the adsorption of water molecule associates in micro- and mesopores of the coal already at the initial part of the isotherm. The role of micro- and mesopores and the chemistry of the coal surface in the adsorption of phenol, p-nitroaniline, crystalline violet and the commercial non-ionic surfactant OP-10 from aqueous solutions were discussed. A comparative analysis of the adsorptive properties of natural coal and CAD-iodine active carbon showed that natural coal is a promising material for the removal of various organic compounds from water.