152results about How to "Improve surface activity" patented technology

The invention relates to a novel preparing method of a material used for a silver tin oxide wire electric contact. The invention has a process that the material prepared by silver, tin and additives according to a certain proportion is put into an intermediate frequency smelter for melting; a high pressure water atomizing device is adopted for high pressure alloy atomization; atomized alloy powder is dried and oxidated for modification; an isostatic pressing ingot is formed after isostatic pressing treatment; the ingot is agglomerated in a heating furnace; the agglomerated ingot is delivered into an extruding machine to extrude wires; the extruded wire is pulled and annealed to get a finished wire. The material property and electric property of the silver tin oxide wire electric contact material manufactured by the method can satisfy the use condition with high requirement.

The invention provides positive electrode slurry of a lithium-ion secondary battery. The positive electrode slurry contains a positive electrode active material, a conductive agent, a binding agent, a surfactant and a solvent, wherein, the surfactant is the gemini surfactant. The invention also provides a positive electrode which is prepared by adopting the positive electrode slurry and the lithium-ion secondary battery containing the positive electrode. The positive electrode slurry of the lithium-ion secondary battery can greatly improve the performance of the battery, compared with the lithium-ion secondary battery which is obtained by adopting the traditional surfactant to carry out the pre-dispersion to the conductive agent, the performance of the invention is much higher, such as, the internal resistance of the battery is much lower, the capacity and the discharge rate of the battery are much higher.

The invention relates to a surfactant composition and a preparation method thereof, which mainly solve the problems that the oil displacement efficiency of the existing surfactant is low in the tertiary oil recovery process and damage to strata and oil wells, corrosion to equipment and pipelines and difficulty in demulsification occur because an oil displacement system contains inorganic alkali. According to the technical scheme of the invention, the surfactant composition comprises cationic surfactant and anionic-nonionic surfactant, wherein the cationic surfactant is at least one selected from quaternary ammonium salt or quaternary amine alkali, the anionic-nonionic surfactant is at least one selected from alkanolamide polyoxy ethylene/propylene ether carboxylate or alkanolamide polyoxy ethylene/propylene ether sulfonate, and the mol ratio of the cationic surfactant to the anionic-nonionic surfactant is (1:0.01)-(1:100). The invention also provides a preparation method of the surfactant composition. Thus, the problems are well solved; and the invention can be used for the forced oil recovery process of oil fields.

The present invention provides a preparation method for a novel dendritic oligomeric quaternary ammonium surfactant. The method comprises the following steps: (1) N, N-dimethyl-1,3 - propanediamine and an excess amount of methyl acrylate are subjected to a Michael addition reaction to generate a compound (I); (2) the compound (I) and an excess amount of N, N-dimethyl-1 ,3 - propanediamine are subjected to an amidation reaction to obtain a compound (II); and (3) the compound (II) and bromododecane are subjected to a quaternization reaction to obtain the final product of a compound (III). The surfactant prepared by using the method of the invention has excellent performances, and can be widely used in fields such as daily chemicals, water treatment, paper making and oilfield development.

The invention provides a preparation method of a quaternary ammonium salt Gemini surfactant containing alkyl amide ethyl, belonging to the technical field of synthesis of organic compounds. The preparation method of the quaternary ammonium salt Gemini surfactant containing alkyl amide ethyl comprises the following steps: preparing diamine containing alkyl amide ethyl, which is prepared from triethylenetetramine or N,N'-di(2-aminoethyl)-1,3-propane diamine and fatty acid methyl ester under the action of an alkaline catalyst, carrying out reaction on diamine, formaldehyde and formic acid to prepare ditertiary amine; and finally, carrying out reaction on ditertiary amine and dimethyl carbonate to generate the quaternary ammonium salt Gemini surfactant containing alkyl amide ethyl. The preparation method has the advantages that the surface activity of a product is excellent, the environment is not polluted and the like, a green chemical principle is met and the preparation method is a clean production process.

The invention relates to a combined surfactant and its preparation method, and mainly solves the problems of bad temperature resistance, low interface activity, and failing at reaching 10<-3>mN/m ultralow interface tension force especially at low concentration existing in surfactants used as the main composition of oil displacement agent systems in the prior art. The combined surfactant comprises, by mass, 1 part of a zwitterionic surfactant, 0.01-50 parts of an anionic-nonionic surfactant and 0.1-90 parts of water. The combined surfactant can well solve the problems, and can be used in the tertiary oil recovery production of oilfields. The molecular formula of each of the above surfactants is shown in the specification.

The invention discloses a method for preparing triiron tetraoxide nanometer particles. A hyperbranched polymer is hydrophobically modified by fatty acyl chloride to prepare an amphiphilic hyperbranched polymer; and the highly dispersed triiron tetraoxide nanometer particles are prepared via a water/organic one-step solvothermal method by virtue of the micelle self-assembly effect of the amphiphilic hyperbranched polymer as a protective agent in a solution, the average particle size of the triiron tetraoxide nanometer particles is 8nm-35nm; the surfaces of the triiron tetraoxide nanometer particles are amphiphilically modified by virtue of encapsulation and dispersion effects of the amphiphilic hyperbranched polymer on the triiron tetraoxide nanometer particles, so that triiron tetraoxide nanometer particles are dispersed and stably exist in solvents with different degrees of polarity, at the same time, a plurality of active groups are given on the surface of the particles, the active groups provide possible sites for the secondary functionalization of particles and the application range of the triiron tetraoxide nanometer particles is extended.

The invention relates to an oil displacement method implemented by the aid of aqueous solution of viscous-elastic surfactants. The oil displacement method mainly solves problems of difficulty in performing injection accumulation on low-permeability oil reservoirs and low oil displacement efficiency in the prior art. The technical scheme includes that that oil displacement method implemented by the aid of the viscous-elastic surfactants includes enabling rock cores containing crude oil to be in contact with oil displacement agents under the conditions that the oil displacement temperatures range from 40 DEG C to 100 DEG C and the total dissolved solid (TDS) in each liter of formation water is higher than 500 milligrams, and displacing the crude oil in the rock cores; the oil displacement agents contain the viscous-elastic surfactants and the formation water, and the concentration of the viscous-elastic surfactants in the oil displacement agents range from 0.01wt% to 1.5wt%; the viscous-elastic surfactants comprise zwitterionic surfactants and anionic-nonionic surfactants, and a mass ratio of the zwitterionic surfactants to the anionic-nonionic surfactants is 1:(100-1). The oil displacement method has the advantages that the problems can be effectively solved, and the oil displacement method is applicable to tertiary oil extraction production of low-permeability oil reservoirs.

The invention relates to a method for preparing submicron lamellar magnesium hydroxide by intensifying alkali, comprising the following steps of: mixing magnesium oxide, the alkali, a dispersing agent and water into slurry according to a certain proportion; carrying out mechanical and chemical treatment to prepare the slurry used for crystallization; carrying out hydrothermal crystallization; carrying out solid-liquid separation on a product, and washing and drying a solid to obtain submicron lamellar magnesium hydroxide powder. In the invention, filter liquor can be recycled; the hydrolysis of the magnesium oxide and the nucleation of the magnesium hydroxide are promoted by utilizing mechanical and chemical action and alkali intensifying action, the shape and the growth of a magnesium hydroxide crystal is regulated and controlled through the hydrothermal crystallization, and no alkali is consumed in the process; as the magnesium oxide is used as a raw material and an alkalizing mechanical and chemical treatment-hydrothermal crystallization process is adopted, the preparation process flow of the submicron high-dispersion lamellar magnesium hydroxide is shortened, the consumption of the alkali used for a process for preparing the magnesium hydroxide by precipitating soluble magnesium salt and the cost input are decreased, and the hydrothermal crystallization process does not generate any side product like chemical salt and is a clean production process; and in addition, the obtained submicron lamellar magnesium hydroxide is widely used in the fields of flame-retardant and catalytic carriers and other functional materials.

The invention relates to functionalized amino-titanium carbide and a preparation method thereof. The preparation method comprises the following steps: adding a two-dimensional layered nanometer material MXene-Ti3C2 into ultrapure water, and carrying out ultrasound so as to obtain a uniformly-dispersed Ti3C2 dispersion; adding p-phenylenediamine and isoamyl nitrite into the Ti3C2 dispersion, and carrying out a reaction under heating at 60 to 110 DEG C; and after the reaction is completed, cooling the reaction solution to room temperature, and carrying out separation and drying so as to obtain the functionalized amino-titanium carbide. According to the invention, by adopting two-dimensional layered Ti3C2 surface containing hydroxyl and fluorine functional groups, and through heating treatment of a solution of Ti3C2, p-phenylenediamine and isoamyl nitrite and functionalized modification of the hydroxyl and fluorine functional groups on the Ti3C2 surface, an amino group grows on the surface of the two-dimensional layered material MXene-Ti3C2, so the functionalized amino-Ti3C2 is obtained, and surface activity and specific surface area are improved.

The invention relates to a surfactant composition for intensifying oil extraction and a preparation method thereof, and is mainly used for solving the problems that the existing surfactant is poor in flushing efficiency in three oil extraction processes, and meanwhile, a drive system contains an inorganic base, resulting in damage to a stratum and an oil well, corrosion to equipment and pipeline, and demulsification difficulty. The problems are well solved by adopting the technical scheme of the surfactant composition and the preparation method thereof, wherein the surfactant composition comprises a cationic surfactant and an anion-nonionic surfactant; the cationic surfactant is selected from at least one of a quaternary ammonium salt or quaternary amine alkali; the anion-nonionic surfactant is any one of fatty alcohol-polyoxyethylene/polyoxypropylene ether carboxylate and sulfonate; the molar ratio of the cationic surfactant to the anion-nonionic surfactant is 1:0.01 to 1:100. The surfactant composition can be applied to the oilfield oil extraction intensifying process.

The invention relates to a preparation method of a nanometer cordierite-based ceramic dielectric material used for a high-frequency chip inductor, which comprises the following steps of: (1) preparing magnesia-alumina-silica sol; (2) preparing opposite-phase W/O (water-in-oil) microemulsion; (3) performing gelation technology; and (4) pressing amorphous cordierite powder obtained in the above steps by adopting a semi-dry method under the pressure of 100-120 MPa to form small wafers, sintering the small wafers at 850-1050 DEG C in a silicon-molybdenum rod resistor furnace, and maintaining the temperature for 3-6 hours to obtain the nanometer cordierite-based ceramic dielectric material used for the high-frequency chip inductor. The invention has the advantages of regular and uniform nanometer powder shape, high powder surface activity and low degree of aggregation, and is applicable to tape casting. The material can be cofired together with an Ag/Pd electrode at the temperature lower than 950 DEG C to be prepared into ceramics, and the dielectric requirements (epsilon<5, and tg delta<0.001; 1 GHz) and the thermal expansion requirements (3*10<-6>K<-1><=alpha<=6*10<-6>K<-1>, 25-300 DEG C) of the dielectric material used for the high-frequency chip inductor can be met.

The invention relates to a preparation method for on-thread and continuously growing carbon nanotubes on the surface of carbon fiber. The method specifically comprises the steps of performing surfaceelectrochemical anodic oxidation treatment on the carbon fiber, then immersing the treated carbon fiber in Co(NO3)2 solution, inletting hydrogen into a tube furnace to reduce metal salts on the surface of the carbon fiber into elementary metals, then placing the reduced carbon fiber into a chemical vapor deposition furnace, and under protection of hydrogen, performing acetylene pyrolysis at 500-800 DEG C and producing the carbon nanotubes on the surface of the carbon surface with the catalysis of the elementary metals to obtain a carbon fiber-reinforced polymer composite material with the surface loaded with the carbon nanotubes. The carbon nanotubes are multi-walled and the tube walls are basically parallel to the axes of the nanotubes, the multi-walled carbon nanotubes are composed of layered graphite structures, the spacing between the tube walls is small, and the carbon nanotubes of the carbon fiber are uniform in distribution and intertwined with one another to increase the layering resistance and the penetration thickness.

The invention discloses a preparation method of an O-hydroxypropyl-N-alkylated chitosan surfactant, which comprises the following steps: by using chitosan as the raw material, carrying out etherification with propylene oxide to obtain hydrophilic O-hydroxypropyl chitosan; and carrying out alkylation on 2-NH2 by respectively using alkylogens with different lengths of carbon chains to prepare serial O-hydroxypropyl-N-alkylated chitosan derivatives, so that the serial O-hydroxypropyl-N-alkylated chitosan derivatives have basic properties of a surfactant. The invention completes the original two chitosan modification methods by using a one-step method, omits the intermediate steps of neutralization, drying and the like, saves the reaction material and time, and synthesizes the required serial new products without introducing any unnecessary impurity. The product prepared by the method can be used as an emulsifier, wetting agent, washing agent or the like.

A method for preparing alkyl trimethyl quaternary ammonium salt belongs to the technical field of organic compound synthesis. In the preparation method, methyl carbonate is taken as a quaternizing reagent to synthesize monomethyl-carbonate quaternary ammonium salt, and the quaternary ammonium salt with other counter ions is synthesized by hydrolysis reaction or displacement reaction with various acids (alkalis). The preparation method has the advantages of no environmental pollution or toxin residue, and the product prepared by the method is widely applied to the field of daily chemicals and other industrial fields.

The invention discloses a hyperbranched polyamidoamine modified plant fiber reinforced polypropylene micro foaming composite material and a preparation method thereof. The hyperbranched polyamidoaminemodified plant fiber reinforced polypropylene micro foaming composite material consists of 97-98 wt% of polypropylene composite material and 2-3 wt% of chemical foaming agent, wherein the polypropylene composite material consists of polypropylene, hyperbranched polyamidoamine plant fiber, PP-g-GMA, antioxidant, lubricant and other additives. The hyperbranched polyamidoamine modified plant fiber reinforced polypropylene micro foaming composite material has the characteristics of low density, high strength, high rigidity, fine cell pores, uniform distribution, etc., can meet application requirements of automobile parts, adapts to development concepts of energy saving and environmental friendliness, and is in line with the development trend of automotive lightweight, therefore, the materialhas a broad development prospect in the field of automobiles.

The invention discloses a preparation and regeneration method of EDTA-Na2 modified active carbon. With the adoption of an EDTA-Na2 solution for carrying out modification treatment on coal-based active carbon, compared with unmodified active carbon, the prepared modified active carbon has obviously higher removal efficiency to heavy metal ions like Zn<2+> and Pb<2+> in waste water, and the EDTA-Na2 modified active carbon after absorption can be recycled through regeneration treatment.

The invention discloses a high-efficiency low-temperature oil sludge de-emulsifier, the de-emulsifier comprises the following components by weight part: 4-21 parts of rosin-polythylene oxide ester, 3-18 parts of disodium cocoyl monoethanolamide sulfosuccina, 0.1-1 part of acid catalyst and 60-92 parts of water. A preparation method of the de-emulsifier comprises the following steps: uniformly mixing rosin-polythylene oxide ester, disodium cocoyl monoethanolamide sulfosuccina, an acid catalyst and water, and then obtaining the low-temperature oil sludge de-emulsifier. The oil sludge de-emulsifier has the advantages of good demulsification effect under low temperature, wide usage temperature scope and high oil recovery rate, and the method has the advantages of low production cost, environmental protection, simple process and wide application scope. The oil sludge de-emulsifier can be used for harmlessness treatment of oil sludge at bottom of pot, scummings and activated sludge, and also can be used for treating various kinds of oil-containing sludge generated by petroleum exploitation, storage and transportation enterprises.

The invention discloses a preparation method of an aperture-adjustable cellulose and montmorillonite nano-composite carrier material. The method comprises the following steps: firstly, preparing nano cellulose suspension by an acid hydrolysis method; then, adding montmorillonite into a saturated solution of a surface active agent to obtain montmorillonite suspension; evenly mixing the nano cellulose suspension with the montmorillonite suspension, and then carrying out cyclic shearing and homogenizing to obtain cellulose/montmorillonite nano-suspension; carrying out ultrasonic dispersion, freeze drying and vacuum drying treatment on the cellulose/montmorillonite nano-suspension to obtain the aperture-adjustable cellulose and montmorillonite nano-composite carrier material. The preparation method is simple in operation, high in controllability and low in production cost; the prepared nano-composite carrier material has the aperture size of 0.1-0.5 micron and the specific surface area of 40-100m<2>/g; the material can be naturally degraded, is harmless to the environment and can be used as active material carriers with different sizes and shapes.

The invention discloses a treatment process for oily sludge. The treatment process comprises the following steps: putting the oily sludge in a raw material storage sludge basin into a sludge mixing tank, adding an emulsion breaker for emulsion breaking, putting the oily sludge subjected to emulsion breaking into a stacked type sludge dewatering machine for solid-liquid separation to obtain filtrate and mud cakes, putting the filtrate into a settling tank for settling separation, recycling waste oil discharged from the top of the settling tank, conveying the sludge at the bottom of the settling tank into the raw material storage sludge basin, feeding middle-layer mixed liquid into an air-liquid mixing tank for mixing with air to obtain a mixture, enabling the mixture to enter a separation basin for oil-water separation, recycling separated waste oil, putting sewage into a biochemical device for treatment, and discharging the sewage after the sewage meets the standard. According to the process, three-phase separation and treatment on oil, water and sludge of the oily sludge can be effectively realized, and most raw oil in the oily sludge can be further recycled; after being treated, the sewage meeting the standard can be discharged.

The invention relates to an oil displacement agent sulfated cellulose ether-acrylamide graft copolymer in tertiary oil recovery, a preparation method and an application thereof. In the preparation method, long-chain alkyl is introduced to a cellulose chain segment of sodium cellulose sulfate; the cellulose chain segment of sodium cellulose sulfate is subjected to hydrophobic modification to obtain sulfated cellulose ether; the sulfated cellulose ether is subjected to graft polymerization with acrylamide to obtain the sulfated cellulose ether-acrylamide graft copolymer with a structural formula in the specification. The prepared macromolecular surfactant sulfated cellulose ether-acrylamide graft copolymer has high surface activity and high viscosity increasing property, is used as an oil displacement agent in tertiary oil recovery, and has the effects of the polymer in enlarging waves and coefficients and the effect of the surfactant in reducing oil-water interfacial tension, so that the problem of chromatographic fractionation effect of current polymer-surfactant combination flooding can be solved, and the oil displacement efficiency is improved. The product can be either independently used as an oil displacement agent, or compounded with alkali or a polymer.

The invention discloses a polytetrafluoroethylene composite, a polytetrafluoroethylene composite holder for a bearing and a preparation method of the polytetrafluoroethylene composite holder for the bearing. The polytetrafluoroethylene composite is prepared from, by mass, 3%-8% of coupling agent modified nano aluminum oxide, 2%-5% of molybdenum disulfide and 90%-95% of polytetrafluoroethylene. The polytetrafluoroethylene composite is prepared by compounding polytetrafluoroethylene, coupling agent modified nano aluminum oxide and molybdenum disulfide. Nano aluminum oxide is large in heat conductivity and small in grain size, the crushing resistance, heat conductivity and wear resistance of the composite can be remarkably improved, the material surface activity can be improved after nano aluminum oxide is modified with a coupling agent, and surface binding force is increased. The friction and wear resistance of the composite can be enhanced through molybdenum disulfide; the composite has excellent self-lubricating performance and high tensile strength, crushing resistance, heat conductivity and friction and wear resistance are obviously improved, and the requirement of the ultralow-temperature high-speed bearing on the holder is met.

The invention belongs to the technical field of surfactants for fine chemistry and discloses a novel sugar-based surfactant, namely, alkoxyethyl-beta-D-xylopyranoside in order to solve the problem of limitation to application of traditional alkyl glycoside as the surfactant due to the fact water solubility of traditional alkyl glycoside is gradually reduced with increase of carbon chain length. Compared with traditional alkyl glycoside with the same carbon chain length, the surfactant has better water solubility and surface activity as well as selectable and controllable foaming capacity and emulsifying property. Besides, raw materials for synthesis comprisexylose obtained from waste crop leftovers and naturally-sourced fatty alcohol and have rich sources. The glycoside can be widely applied to application industries such as biochemical engineering, pharmacy, pesticides, food processing, cosmetics, scientific research and the like.

The invention relates to a noise-reducing polyethylene composite material for a drainage pipeline of a building and a preparation method thereof, belonging to the technical field of inorganic powder modified high-molecular polymers. The material comprises the following raw materials in parts by weight: 30-50 parts of polyethylene, 0.01-0.02 part of a peroxide initiator, 0.5-1 part of vinyl unsaturated silane, 50-60 parts of barium sulfate, 1-3 parts of a dispersant, 3-5 parts of titanium dioxide, 0.2-0.5 part of an antioxidant and 1-3 parts of carbon black. The material provided by the invention effectively solves the problem that existing drainage pipeline of the building is noisy and poor in high temperature resistance and chemical corrosion resistance. Raw materials are input to a high speed mixer to be mixed firstly, and then pelleted through a twin-screw extruder to obtain the composite material. The composite material provided by the invention has the advantages of mute-resistant effect, chemical corrosion resistance, heat resistance and shock resistance of a common tubular product, simple processing process, low cost and suitability of preparing the drainage pipeline of the building.

The invention discloses a sulphonate gemini surfactant and a preparing method thereof. The sulphonate gemini surfactant is named as diethylamine bi-(acyl-methyl alcohol ester-alpha-sodium solphonate), the sulphonate surfactant takes maleic anhydride as a raw material, and the specific synthesis method comprises three steps of ring cleavage reaction, addition reaction and esterification reaction of the maleic anhydride. The invention has the advantages that a disulphonate diester type surfactant has higher surface activity and better emulsibility, wettability and dispersion property, and the surfactant has better loam stripped property; target products have excellent surface activity, the critical micelle concentration of the target products is 0.42 mmol/L which is 1/23 of dodecyl sodium sulfate (9.8mmol/L), and the surface tension of the target products under the critical micelle concentration is 28.8mN/m which is 10.2mN/m lower than the dodecyl sodium sulfate (39.0mN/m); and the surfactant can be applied to daily chemicla such as washing agents, solubilizing agents, emulsifying agents, and the like and can also be used for water treatment of oil fields.

The invention discloses a composite flame retardant sizing agent for regenerated cellulose fiber, and the regenerated cellulose fiber produced by applying the composite flame retardant sizing agent. The composite flame retardant sizing agent is prepared by the following steps: mixing cellulose ether, chlorocyclotriphosphazene derivatives and alkyl polyglucoside according to the mass ratio of 1:(1-20):(0.1-5) and then dissolving in industrial soft water, wherein the cellulose ether is taken as an enhancer, chlorocyclotriphosphazene derivatives are taken as a flame retardant and alkyl polyglucoside is taken as an emulsifier. The regenerated cellulose fiber is prepared by the following steps: adding the 0.5-30wt% of the prepared composite flame retardant sizing agent into regenerated cellulose fiber spinning mother liquor, evenly stirring, defoaming for 30-180min and preparing by adopting a wet-process spinning method of the conventional regenerated cellulose fiber, and the regenerated cellulose fiber has excellent flame-retardant property and higher strength and wearability, the wet fracture strength is improved by more than 20% compared with the conventional flame-retardant viscose fiber, and the initial modulus is reduced by more than 35%.

SP-C peptoid compounds, lung surfactant compositions and related surfactant replacement therapies. Such SP-C peptoids can mimic lung surfactant protein C, and can be used in conjunction with biomimetic SP-B compounds over a range of lung surfactant compositions.

A vinyl acetate copolymer modified by silsesquioxane (tris sulfonic acid isobutyl polyhedral oligomeric silsesquioxane (POSS)) and a preparation method of the copolymer are disclosed, and a vinyl acetate copolymer is related. The invention provides the vinyl acetate copolymer modified by POSS and the preparation method of the copolymer. The vinyl acetate copolymer modified by POSS has the components in mass parts of: 35-45 parts of vinyl acetate; 10-15 parts of modified monomer, 0.5-1 parts of initiator; 2.5-5 parts of compound emulsifier; 4-6 parts of colloid protecting agent; and 40-60 parts of deionized water. Using an amphiphilic organic/inorganic hybrid enhanced material with surface activity as an emulsifier in the polymer synthesis process, enables the rigid cage structure of POSS to be effectively combined on the surface of the polymer. The modified vinyl acetate copolymer has an outer layer of the POSS nano reinforced material; and an inner layer of the vinyl acetate copolymer with a core-shell structure, thereby improving the usabilities of the polymer material such as water resistance, surface hardness and the like.

The invention relates to a preparation method and an application of alkali-free viscoelastic surfactant composition and mainly solves the problem of poor flooding effect of an existing flooding systemunder the condition of the high-temperature and low-permeability reservoir. According to the technical scheme, the alkali-free viscoelastic surfactant composition is prepared from a betaine surfactant, an anionic surfactant and water, wherein the betaine surfactant is represented as the formula (I) in the description; the anionic surfactant is selected from at least one of structures shown as theformula (II) in the description; in the formula (I), R1 is selected from any one of C8-C29 alkyl and alkenyl, and R2 and R3 are independently selected from C1-C5 alkylidene and hydroxyl substituted alkylidene; in the structural formula (II), X is selected from at least one of carboxylate radical and sulfonate radical. With the adoption of the technical scheme that the mole ratio of an ampholyticsurfactant to the anionic surfactant is 1:0.01-1:100, the technical problem is solved better, and the alkali-free viscoelastic surfactant composition can be applied to tertiary oil recovery of an oilfield.

The invention discloses a novel concrete defoaming agent, and a preparation method and application thereof. According to the novel concrete defoaming agent provided by the invention, a plurality of hydrophilic chain segments and hydrophobic chain segments are grafted on carboxyl groups of polyamino acid, wherein the hydrophilic chain segments are polyethylene glycol or polyethyleneimine containing4-10 repeat units, the hydrophobic chain segments are straight-chain alkyl groups containing 11-17 carbon atoms, and the polyamino acid is selected from polyaspartic acid or polyglutamic acid. The novel concrete defoaming agent disclosed by the invention has higher surface activity and better defoaming efficiency than a conventional single-chain type defoaming agent, and has good compatibility with additives. Generation of large bubbles in newly-mixed concrete can be inhibited in a short time, the gas content of the concrete is reduced, and therefore, hardening strength and durability of theconcrete are improved.