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A micro-crosslinked amphoteric hydrophobic association copolymer as high temperature-and salt-resistance fluid loss reducer for water-based drilling fluids
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作者 Jian Li Yu-Xi Ji +3 位作者 Xiao-Xiao Ni Kai-He Lv Xian-Bin Huang Jin-Sheng Sun 《Petroleum Science》 SCIE EI CAS CSCD 2024年第3期1980-1991,共12页
During ultradeep oil and gas drilling,fluid loss reducers are highly important for water-based drilling fluids,while preparing high temperature-and salt-resistance fluid loss reducers with excellent rheology and filtr... During ultradeep oil and gas drilling,fluid loss reducers are highly important for water-based drilling fluids,while preparing high temperature-and salt-resistance fluid loss reducers with excellent rheology and filtration performance remains a challenge.Herein,a micro-crosslinked amphoteric hydrophobic association copolymer(i.e.,DADC)was synthesized using N,N-dimethyl acrylamide,diallyl dimethyl ammonium chloride,2-acrylamido-2-methylpropane sulfonic acid,hydrophobic monomer,and pentaerythritol triallyl ether crosslinker.Due to the synergistic effects of hydrogen bonds,electrostatic interaction,hydrophobic association,and micro-crosslinking,the DADC copolymer exhibited outstanding temperature-and salt-resistance.The rheological experiments have shown that the DADC copolymer had excellent shear dilution performance and a certain degree of salt-responsive viscosity-increasing performance.The DADC copolymer could effectively adsorb on the surface of bentonite particles through electrostatic interaction and hydrogen bonds,which bring more negative charge to the bentonite,thus improving the hydration and dispersion of bentonite particles as well as the colloidal stability of the drilling fluids.Moreover,the drilling fluids constructed based on the DADC copolymer exhibited satisfactory rheological and filtration properties(FLHTHP=12 m L)after aging at high temperatures(up to200℃)and high salinity(saturated salt)environments.Therefore,this work provided new insights into designing and fabricating high-performance drilling fluid treatment agents,demonstrating good potential applications in deep and ultradeep drilling engineering. 展开更多
关键词 Fluid loss reducer Temperature-and salt-resistance Hydrophobic association AMPHOTERIC Micro-crosslinking
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A study of the properties of hydrophobically associating water-soluble polymers used in drilling fluids
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作者 舒福昌 史茂勇 +4 位作者 张岩 张峰 黄红玺 向兴金 王建华 《Petroleum Science》 SCIE CAS CSCD 2004年第4期57-61,共5页
Hydrophobically associating water-soluble polymers (HPAP) have been synthesized from acrylamide(AM), acrylate (AA), 2-acrylamido-2-methyl propane sulfonic acid (AMPS) and hydrophobic monomer (AP) in aqueous solution... Hydrophobically associating water-soluble polymers (HPAP) have been synthesized from acrylamide(AM), acrylate (AA), 2-acrylamido-2-methyl propane sulfonic acid (AMPS) and hydrophobic monomer (AP) in aqueous solution by radical polymerization. New polymer drilling fluids are made up of HPAP, which is used as viscosifiers and encapsulation agents. Properties of this system are reported in this paper. Results indicate that this system has a high value of yield point to plastic viscosity (YP/PV≥0.7), high viscosity at a low-shear rate (LSRV≥30000mPa·s), excellent shear thinning behavior, good solid-carrying behavior, resistance to shear, good thermal stability (as high as 140℃) and salt resistance. The system has excellent behavior in high-density solution of NaCl and in calcium and magnesium rich saline solutions. Hence, HPAP also can be used in saltwater polymer drilling fluids. 展开更多
关键词 hydrophobically associating water-soluble polymers drilling fluids VISCOSITY salt resistance
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Dissolution Characteristics of Hydrophobically Associating Polyacrylamide in Stirred Tanks 被引量:7
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作者 周国忠 谢明辉 +3 位作者 刘敏 吴华晓 龙湘犁 虞培清 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2010年第1期170-174,共5页
Enhanced oil recovery(EOR)by means of polymer flooding is an important technology for the strategic development of offshore oilfields in China.Hydrophobically associating polyacrylamide(HAPAM)has been recently propose... Enhanced oil recovery(EOR)by means of polymer flooding is an important technology for the strategic development of offshore oilfields in China.Hydrophobically associating polyacrylamide(HAPAM)has been recently proposed as a new flooding agent.The solubility of HAPAM is low,which is the bottleneck for further improving the oil recovery through polymer flooding in offshore oilfield.Stirred tanks have been used on offshore platforms to enhance HAPAM dissolving.But there is little literature on the study of HAPAM dissolving characteristics in stirred tanks.In this paper,effects of temperature,salinity,stirring speed,impeller type and stirring method on the dissolution of HAPAM are reported.The experimental results manifest that the dissolving rate of HAPAM increases with temperature and stirring speed,but the viscosity of the polymer solution decreases.There is an optimal range of salinity for polymer dissolving.Combining the operation mode of up-pumping with varying stirring speed,hydrofoil impeller can accelerate the dissolution of HAPAM and maintain a high solution viscosity. 展开更多
关键词 hydrophobically associating polyacrylamide VISCOSITY dissolution time impeller type stirring method
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Rheological Properties of Hydrophobically Associating Polyacrylamide Solution 被引量:5
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作者 Ren Kun Wang Jinlan +1 位作者 Lin Meiqin Xu Chunming 《Petroleum Science》 SCIE CAS CSCD 2006年第2期66-72,共7页
A temperature-resistant, salt-tolerant polyacrylamide, hydrophobically associating polymer (HAP), was synthesized in the State Key Laboratory of Heavy Oil Processing. The rheological behavior of HAP solution was inv... A temperature-resistant, salt-tolerant polyacrylamide, hydrophobically associating polymer (HAP), was synthesized in the State Key Laboratory of Heavy Oil Processing. The rheological behavior of HAP solution was investigated by means of flow experiments in porous media and by using a HAAKE RS600 rheometer. The results of Nuclepore membrane filtration showed that filtration time increased sharply when the critical association concentration was reached. Shear rate had a greater impact on viscosity and shear stress with increasing HAP concentration. The HAP solution with a concentration of 100 mg/L (salinity 32,868 mg/L) exhibited negative thixotropy. However, at the same salinity the HAP solution showed thixotropy and its viscosity became greater when the polymer concentration increased to 1,500 mg/L. The flow experiments in cemented core samples indicated that the resistance factor and residual resistance factor of the HAP solution were 31.8 and 12 when polymer concentration and salinity were 1,500 mg/L, 32,868 mg/L at 85℃ respectively, which is favorable for flooding application. Such factors of partially hydrolyzed polyaerylamide 3530S were merely 3.14 and 1.71, so it could not be applied to polymer flooding in the oilfield with high temperature and high salinity. 展开更多
关键词 Temperature-resistant salt-tolerant polyacrylamide hydrophobically associating polymer RHEOLOGY porous media VISCOSITY
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Double network self-healing hydrogel based on hydrophobic association and ionic bond for formation plugging 被引量:3
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作者 Ying-Rui Bai Qi-Tao Zhang +2 位作者 Jin-Sheng Sun Guan-Cheng Jiang Kai-He Lv 《Petroleum Science》 SCIE CAS CSCD 2022年第5期2150-2164,共15页
Self-healing hydrogels have attracted tremendous attention in the field of oil and gas drilling and production engineering because of their excellent self-healing performance after physical damage.In this study,a seri... Self-healing hydrogels have attracted tremendous attention in the field of oil and gas drilling and production engineering because of their excellent self-healing performance after physical damage.In this study,a series of double network self-healing(DN_(SA))hydrogels based on hydrophobic association and ionic bond were prepared for plugging pores and fractures in formations in oil and gas drilling and production engineering.The mechanical,rheological,and self-healing properties of the DN_(SA)hydrogels were investigated.Results revealed that the DN_(SA)hydrogels exhibited excellent mechanical properties with a tensile stress of 0.67 MPa and toughness of 7069 kJ/cm^(3) owing to the synergistic effect of the double network.In addition,the DN_(SA)hydrogels exhibited excellent compression resistance,notch insensitivity,and self-healing properties.The DN_(SA)-2 hydrogel was granulated and made into gel particles with different particle sizes and used as a plugging agent.The self-healing mechanism of DN_(SA)-2 hydrogel particles in fractures was explored,and it’s plugging effect on fractures of different widths and porous media of different permeabilities were investigated.Experimental results revealed that the plugging capacity of the DN_(SA)-2 hydrogel particles for a fracture with width of 5 mm and a porous medium with a permeability of 30μm^(2) was 3.45 and 4.21 MPa,respectively,which is significantly higher than those of commonly used plugging agents in the oilfield.The DN_(SA)hydrogels with excellent mechanical and self-healing properties prepared in this study will provide a new approach for applying hydrogels in oil and gas drilling and production engineering. 展开更多
关键词 Self-healing hydrogel Hydrophobic association Ionic bond Mechanical property Rheological property Formation plugging
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SYNTHESIS AND CHARACTERIZATION OF A NOVEL FLUORINE-CONTAINING HYDROPHOBICALLY ASSOCIATING POLYMER 被引量:3
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作者 Jin Yang Wei-yuan Huang Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1999年第3期281-288,共8页
In this article, the synthesis and characterization of a novel fluoromonomer and its copolymer with acrylamide is reported. 2-perfluoroamyl-4-hydroxylquinoline 2 was synthesized from ethyl 2, 2-dihydroperfluoroheptano... In this article, the synthesis and characterization of a novel fluoromonomer and its copolymer with acrylamide is reported. 2-perfluoroamyl-4-hydroxylquinoline 2 was synthesized from ethyl 2, 2-dihydroperfluoroheptanoate in high yields. The monomer 4 was then synthesized from 2 in two steps readily in high yields. Synthesis and characterization of copolymers of acrylamide (AM) and the fluoromonomer were investigated. The composition and intrinsic viscosity of these copolymers were studied. It was found that the rheological properties of aqueous solutions of polyacrylamide were modified significantly when a small proportion of the fluoromonomer 4 was incorporated on investigating the viscosity-concentration profiles, pseudoplasticity of these solutions and the effect of the presence of surfactant. These results could be explained by the hydrophobic association of the fluorocarbon segments in the aqueous solutions of these copolymers. 展开更多
关键词 hydrophobically associating polymer fluorine-containing acrylate perfluoroalkylation with RFI/Na2S2O4
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HYDROPHOBICALLY ASSOCIATING POLYACRYLAMIDES MODIFIED BY A NOVEL SELF-ASSOCIATIVE CATIONIC MONOMER 被引量:2
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作者 吴飞鹏 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2010年第2期137-145,共9页
A series of hydrophobically associating polyacrylamides modified by small amounts (〈 3 mol%) of a self- associative cationic monomer 4-(2-(acryloyloxy) ethoxy) benzyl tri-ethyl ammonium bromide (AEBA) as hydr... A series of hydrophobically associating polyacrylamides modified by small amounts (〈 3 mol%) of a self- associative cationic monomer 4-(2-(acryloyloxy) ethoxy) benzyl tri-ethyl ammonium bromide (AEBA) as hydrophobe were synthesized by radical copolymerization in aqueous solutions without external surfactants. The resulting eopolymers containing a multiblock structure exhibited a high tendency for hydrophobic association and a high thickening capacity. Solution properties and aggregation structures were investigated by viscometry and fluorescence technique. The high viscosity enhancement was found as the polymer concentration beyond a critical value c* and strongly depended on the copolymer microstructures. The number and length of hydrophobic microblocks within the copolymer backbones could be controlled by changing the AEBA concentration in copolymerization system. Addition of salt induced more hydrophobic association and viscosity enhancement. The synthesis method used was simple and environmentally friendly without any external surfactant contamination in comparison with the conventional micellar copolymerization. 展开更多
关键词 Self-associative monomer hydrophobically associating copolymer Aggregation behavior and structure Viscosity enhancement.
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Novel hydrophobically associative polyacrylamide with tunable viscosity 被引量:1
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作者 Xu Feng Zhang Wen Hui Wu 《Chinese Chemical Letters》 SCIE CAS CSCD 2009年第11期1361-1365,共5页
Hydrophobically associative polyacrylamide (HAPAM) were prepared in aqueous solution by radical copolymerization of novel cationic surface-active monomer, dimethylhexadecyl(3-acrylamidopropyl)ammonium bromide (DM... Hydrophobically associative polyacrylamide (HAPAM) were prepared in aqueous solution by radical copolymerization of novel cationic surface-active monomer, dimethylhexadecyl(3-acrylamidopropyl)ammonium bromide (DMHAB), with acrylamide (AM) in the presence of DMHAB/CTAB mixed micelles. The length of hydrophobic microblock (NH) in HAPAM is controlled by the molar fraction of DMHAB in mixed micelles, which can be mediated by the ratio of CTAB to DMHAB. The results of steady-state fluorescence probe and viscometry experiments showed the ability of HAPAM association was determined by the length of the hydrophobic microblock. HAPAM with tunable association ability are promising materials for thickening agent. 展开更多
关键词 hydrophobically associative polyacrylamide Surface-active monomer Mixed micelles Hydrophobic association
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Formation and Collapse of Cellulose Nanocrystals and Hydrophobic Association-induced Dual Cross-linked Nanocomposite Hydrogels: A Rheological Study
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作者 Xiaorui Jin Mingguo Ma Jun Yang 《Paper And Biomaterials》 CAS 2022年第3期19-29,共11页
The rheological characteristics of a physical gelation system,in which cellulose nanocrystals(CNC_(s))induced the entanglement of poly(acrylic acid)(PAA)chains and partial hydrophobic association of octylphenol polyox... The rheological characteristics of a physical gelation system,in which cellulose nanocrystals(CNC_(s))induced the entanglement of poly(acrylic acid)(PAA)chains and partial hydrophobic association of octylphenol polyoxyethylene acrylate(OP-10-AC)branches in a micellar solution of sodium dodecyl sulfate(SDS),were investigated.The gelation time of the physical gels decreased as the CNC content and number of hydrophobic branch units increased.At the gel point,the storage modulus(G')and loss modulus(G")followed the same frequency dependence(G'≈G"≈ωn),where the hydrophobic moieties attached to the side chains had a significant impact on the values of viscoelastic exponent(n).Beyond the gel point,the initial polymer solution was transformed to a solid-like gel,and the strength of the gel network was governed by associations between both the CNCs and hydrophobic groups.The evolution of the viscoelasticity during the gel-sol transition was monitored,demonstrating that due to a reversible arrangement of the hydrophobic units,a large proportion of physical cross-links dissociated under a thermal trigger and were reversibly reformed when the solution was cooled,while no such partial recovery was observed in the case of the single CNC-induced network systems(with no hydrophobic branches). 展开更多
关键词 HYDROGELS cellulose nanocrystals hydrophobic association RHEOLOGY
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Synthesis and Solution Properties of Hydrophobic Associating Polymers 被引量:2
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作者 任鲲 姜桂元 +1 位作者 徐春明 林梅钦 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2005年第2期266-270,共5页
Acrylamide/2-acrylamido alkane sulfonic acid hydrophobic associating copolymers were synthesized by micellar copolymerization. Effects of hydrophobe content, polymer concentration, salinity and surfactant on rheologic... Acrylamide/2-acrylamido alkane sulfonic acid hydrophobic associating copolymers were synthesized by micellar copolymerization. Effects of hydrophobe content, polymer concentration, salinity and surfactant on rheological behavior of copolymers were investigated and the conformation of polymers in solution was studied by means of environmental scanning electronic microscopy and dynamic light scattering. The experimental results showed that in the dilute regime the hydrophobic parts could interact intramolecularly, while in the regime where the polymer concentration was higher than the critical association concentration, intermolecular hydrophobic association became predominant. Within the limit of the solubility, the critical association concentration of the polymer decreased with the increase of the salinity. The experimental results of the solution conformation indicated the presence of the three-dimensional network structure in deionized water and the size of the mesh in the network varied with the polymer concentration. In NaCl solution, above the critical association concentration, an increase in polymer concentration enhanced the intermolecular association and also enlarged the hydrodynamic radius. It would result in the improvement of the thickening power of polymers. 展开更多
关键词 hydrophobic associating polymer salt tolerance VISCOSITY CONFORMATION
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SELF-ASSEMBLING AMPHIPHILIC POLYELECTROLYTES AND THEIR NANOSTRUCTURES
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作者 Yotaro Morishima 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2000年第4期323-336,共14页
The self-assembling behavior of random copolymers of sodium 2-(acrylamido)-2-methylpropanesulfonate (AMPS)and hydrophobic comonomers possessing dodecyl groups linked by various spacer bonds was discussed with a focus ... The self-assembling behavior of random copolymers of sodium 2-(acrylamido)-2-methylpropanesulfonate (AMPS)and hydrophobic comonomers possessing dodecyl groups linked by various spacer bonds was discussed with a focus on theeffect of the spacer. The characterization of association behavior of such polymers in water using quasielastic light scattering,capillary electrophoresis, NMR relaxation, various fluorescence, and viscoelastic methods was described. These copolymersform a variety of self-assembled nanostructures depending on the type of the spacer. Random copolymers of AMPS and N-dodecylmethacrylamide show a strong preference for intrapolymer self-association even in concentrated aqueous solutionsforming single-macromolecular self-assemblies (unimolecular micelles). In contrast, random copolymers of AMPS anddodecyl methacrylate are prone to undergo interpolymer associations yielding multipolymer micelles. In random copolymersof AMPS and a methacrylate substituted a nonionic surfactant (HO(CH_2CH_2O)_(25)C_(12)H_(25)) (C_(12)E_(25)), dodecyl groups are muchless restricted by the polymer backbone because they are linked via a long, flexible hydrophilic spacer. Thus, the polymer-bound C_(12)E_(25) surfactant moieties form micelles similar to those formed by discrete surfactants, but they are bridged bypolymer chains forming a network structure. 展开更多
关键词 SELF-ASSEMBLIES hydrophobically-modified polyelectrolytes NANOSTRUCTURES Hydrophobic association Unimolecular micelles Multipolymer micelles Transient network VISCOELASTICITY Shear thickening Shear thinning
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Template Effect of Hydrophobically Associating Polymers on the Construction of Cuprous Oxide Micro Structure 被引量:1
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作者 DONG Lei LIU Huan +3 位作者 LI Yanjuan ZHANG Hongtao YU Liangmin JIA Lanni 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2018年第1期138-144,共7页
To determine the template effect of hydrophobically associating copolymers(HACPs) on the morphology of nano/micro structures, six HACPs were synthesized and used as templates to biomimetically synthesize cuprous ox... To determine the template effect of hydrophobically associating copolymers(HACPs) on the morphology of nano/micro structures, six HACPs were synthesized and used as templates to biomimetically synthesize cuprous oxide(Cu2O), an important semiconductor. This experiment showed a clear relationship between the associating state of the HACP molecules and the morphology of the Cu2O particles. Cu2O hollow spheres were preferentially prepared when the HACP molecules were in an intramolecular associating state. Furthermore, a Cu2O hexapod was easily obtained when the HACP molecules were in an intermolecular associating state. The morphologies of the Cu2O crystals prepared in the presence of the HACPs also confirmed this result. 展开更多
关键词 TEMPLATE hydrophobically associating polymer Cuprous oxide MORPHOLOGY
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Mechanical Properties and Network Structure of Hydrophobic Association Hydrogels Prepared from Octylphenol Polyoxyethylene(7) Acrylate and Sodium Dodecyl Sulfate 被引量:1
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作者 LIANG Zi GAO Tingting XU Jianan LI Zhiying LIU Xiaoli LIU Fengqi 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2015年第4期633-639,共7页
Hydrophobic association hydrogels(HA-gels) with high mechanical strength were prepared by free radical micellar copolymerization in aqueous solutions of acrylamide(AM), anion surfactant sodium dodecyl sulfate(SDS... Hydrophobic association hydrogels(HA-gels) with high mechanical strength were prepared by free radical micellar copolymerization in aqueous solutions of acrylamide(AM), anion surfactant sodium dodecyl sulfate(SDS) and a small amount of hydrophobic monomer octylphenol polyoxyethylene(7) acrylate(OP-7-AC). We found that the molar ratio of SDS to OP-7-AC has a great effect on the tensile strength and other mechanical property parameters. The best ratio point R' was determined. On the basis of Mooney theory and statistical theory, the critical tensile ratios and critical tensile strengths of the hydrogels were obtained, elastic parameters C1 and C2 were calculated via uniaxial tensile equation and structural parameters, such as the effective network chain density and the averaged molecular weight of the chain between cross-linking points of all the hydrogels were evaluated. The results indicate that the variation of mechanical property parameters depends on the number of effective cross-linking points and the match degree of long and short chains. 展开更多
关键词 Hydrophobic association Cross-linking point Distribution of chain Surfactant
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Synthesis of Hydrophobically Modified Poly(acrylic acid) Gels and Interaction of the Gels with Cationic/Anionic Surfactants
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作者 田琴 唐小真 +1 位作者 庄东青 章云祥 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2002年第10期1088-1096,共9页
Poly(acrylic acid) (PAA) gel network with only chemical crosslinking and hydrophobically modified PAA (HM-PAA) gels with both chemical and physical crosslinking were synthesized by radical polymerization in tert-butan... Poly(acrylic acid) (PAA) gel network with only chemical crosslinking and hydrophobically modified PAA (HM-PAA) gels with both chemical and physical crosslinking were synthesized by radical polymerization in tert-butanol, using ethylene glycol dimethacrylate (EGDMA) as crosslinker, and 2-(N-ethylperfluorooctanesulfoamido)ethyl methacrylate (FMA), stearyl acrylate (SA) or lauryl acrylate (LA) as hydrophobic comonomer respectively. The effect of the fractions and the species of the hydrophobes on swelling properties of HM-PAA gels and the interaction of gels and surfactants were studied. The results showed that the swelling ratio of HM-PAA gels exhibited a sharp decrease with increasing hydrophobic comonomer concentration, which could be ascribed to the formation of strong hydrophobic association among hydrophobic groups. It was proved that two kinds of binding mechanisms of surfactant/gel and different kinds of hydrophobic clusters existed in gels containing both physical and chemical networks. 展开更多
关键词 hydrophobic association acrylic acid HYDROGEL SURFACTANT equilibrium swelling ratio
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Effects of Ethylene Oxide Spacer Length on Solution Properties of Water-Soluble Fluorocarbon-Containing Hydrophobically Associating Poly(Acrylic Acid-co-R_f-PEG Macromonomer)
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作者 杜立斌 庄东青 +1 位作者 刘寿平 章云祥 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2003年第6期698-705,共8页
Poly(acrylic acid)s (PAAs) modified with a series of fluorocarbon group (R f) end capped Poly(ethylene glycol) (PEG) macromonomers (number of ethylene oxide unit: 1, 9, 23, 45) and corresponding copolymers witho... Poly(acrylic acid)s (PAAs) modified with a series of fluorocarbon group (R f) end capped Poly(ethylene glycol) (PEG) macromonomers (number of ethylene oxide unit: 1, 9, 23, 45) and corresponding copolymers without fluorocarbon end groups were synthesized. It was found that the effect of the hydrophobic association of fluorocarbon groups on the solution viscosity prevailed over that of the hydrogen bond between grafted PEG and the backbone. Rheological measurement on the aqueous solutions of these poly(acrylic acid co R f PEG macromonomer)s demonstrated that the best thickening performance was shown when the number of ethylene oxide unit (EO number) was 23. 展开更多
关键词 fluorocarbon containing PEG macromonomer spacer rheological property hydrophobic association
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Preparation and properties of physically and chemically cross-linked hybrid hydrophobic association hydrogels with good mechanical strength
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作者 Guoqing Jiang Li Huang +2 位作者 Bo Li Quan Zhou Zhiying Li 《Science China Chemistry》 SCIE EI CAS CSCD 2016年第3期282-292,共11页
To correct the defects of hydrophobic association hydrogels (HA-gels), new physically and chemically cross-linked hybrid hy- drophobic association hydrogels (hybrid HA-gels) were prepared by radical copolymerizati... To correct the defects of hydrophobic association hydrogels (HA-gels), new physically and chemically cross-linked hybrid hy- drophobic association hydrogels (hybrid HA-gels) were prepared by radical copolymerization of acrylamide (AM), octylphe- nol polyoxyethylene (n) acrylate (OPnAC, n stands for the number of ethoxy group, and is 10 and 21) and N,N'-methylene- bisacrylamide (MBA). On the basis of the statistical molecular theory of rubber elastic, the Mooney-Rivlin model and using the tensile true stress (O'true) tested at room temperature, the number of network strands per unit volume (o~) and the num- ber-average molar mass of a network strand (Me) were evaluated for hybrid HA-gels. For the hydrogels, the effect of the con- tent of MBA and OP10AC on their tensile mechanical properties was studied by using o0 and Mc; also, the effect of the com- positions and temperature on their swelling behavior in distilled water was discussed in detail. In addition, hybrid HA-gels in- cluding a small quantity of MBA possessed the capabilities of secondary self-healing and remolding. In contrast with HA-gels prepared by the same compositions besides MBA, hybrid HA-gels showed good mechanical strength and long-term thermal stability in distilled water in the range of 25 to 80℃. Furthemore, hybrid HA-gels also avoided the self-deswelling behavior of HA-gels. The results show that the application fields of HA-gels will be greatly broadened after introducing a chemical cross-linking network. 展开更多
关键词 hydrophobic association hydrogels hybrid hydrogels mechanical properties swelling behavior reforming capability
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Fluorocarbon- containing hydrophobically modified poly(N-isopropylacrylamide)
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作者 章云祥 方勤 +1 位作者 府宇清 达爱华 《Chinese Journal of Chemistry》 SCIE CAS CSCD 1999年第3期244-257,202,共14页
A fluorocarbon-modified ply( N-isopropylacrylamide) has been synthesized by copolymerization of N-isopropyl acrylamide with a small amount of acrylate or methacrylate containing a perfluoroalkyl group. It was found th... A fluorocarbon-modified ply( N-isopropylacrylamide) has been synthesized by copolymerization of N-isopropyl acrylamide with a small amount of acrylate or methacrylate containing a perfluoroalkyl group. It was found that the hydrophilicity of macromolecular backbone is an important factor to the solution properties of the copolymers and that hydrophobic association between fluorocarbon group is stronger than that between the corresponding hydrocarbon analogies. The viscosity of some of the copolymer solutions was very sensitive to temperature. It was dilatant at higher fluorocarbon comonomer content ( 0. 20–1.0 mol%) and was Newtonian at very low fluorocarbon comonomer content (0.03–0.2 mol%). Evidence for hydrophobic association of the fluorocarbon groups was obtained from the effects of adding NaCl and surfactants on the solution viscosity. The LC-ST properties of these copolymers were studied by DSC method and this was also found to be consistent with hydrophobic association between the fluorocarbons. 展开更多
关键词 Green chemistry hydrophobic association poly( N-isopropylacrylamide) LCST fluorocarbon-containing hydrophobically associating polymers
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Bioinspired wet-resistant organogel for highly sensitive mechanical perception 被引量:3
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作者 Wen Zhao Dingli Gan +6 位作者 Xinyu Qu Jingying Liu Yunlong Liu Qian Wang Wenjun Wang Chencheng Sun Xiaochen Dong 《Science China Materials》 SCIE EI CAS CSCD 2022年第8期2262-2273,共12页
Smart flexible electronics with underwater motion detection have become a promising research aspect in intelligent perception.Inspired by the strong adaptability of marine creatures to complex underwater environments,... Smart flexible electronics with underwater motion detection have become a promising research aspect in intelligent perception.Inspired by the strong adaptability of marine creatures to complex underwater environments,conventional biocompatible hydrogels are worth developing into organogels with preferred underwater adhesive properties,hydrophobic and antiswelling performance,and motion perception ability.Herein,a highly sensitive organogel sensor exhibiting good hydrophobicity,electromechanical properties,and adhesion properties was prepared for underwater utilization by regulating the chemical components and internal interactions.The synergistic effect of massive reversible noncovalent bonds ensures the organogel’s excellent underwater adhesion to multifarious substrates.Meanwhile,the interactions of hydrophobic conductive fillers and the dynamic hydrophobic associations in the organogel endow it with satisfactory hydrophobic performance(contact angle of111.8°)and antiswelling property(equilibrium swelling ratio of-31%after 15-day immersion).The fabricated flexible organogel strain sensor exhibits high sensitivity(gauge factor of1.96),ultrafast response rate(79.1 ms),low limit of detection(0.45 Pa),and excellent cyclic stability(1044 tensile cycles followed by 3981 compressive cycles).Results demonstrate the proposed organogel’s precise perception of sophisticated human motions in air and underwater,which expands its application scenarios. 展开更多
关键词 flexible electronics ORGANOGEL hydrophobic association water-resistant underwater application
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