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Effects of Fe_2O_3 Nanoparticles on water permeability and Strength Assessments of High Strength Self-Compacting Concrete

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Journal of Materials Science & Technology 2012年第1期28卷 73-82页

作者： Ali Khoshakhlagh Ali Nazari Gholamreza Khalaj Department of Materials Engineering Science and Research BranchIslamic Azad University Department of Materials Engineering Saveh BranchIslamic Azad University

In this work, compressive, flexural and split tensile strength together with coefficient of water absorption of high performance self-compacting concrete containing different amount of Fe2Os nanoparticles have been investigated. The strength and the water permeability of the specimens have been improved by adding Fe2Os nanoparticles in the cement paste up to 4.0 wt%. Fe203 nanoparticle as a foreign nucleation site could accelerate C-S-H gel formation as a result of increased crystalline Ca（OH）2 amount especially at the early age of hydration and hence increase the strength of the specimens. In addition, Fe203 nanoparticles are able to act as nanofillers and recover the pore structure of the specimens by decreasing harmful pores to improve the water permeability. Several empirical relations have been presented to predict the flexural and the split tensile strength of the specimens by means of the corresponding compressive strength at a certain age of curing. Accelerated peak appearance in conduction calorimetry tests, more weight loss in thermogravimetric analysis and more rapid appearance of peaks related to hydrated products in X-ray diffraction results indicate that Fe203 nanoparticles up to 4 wt% could improve the mechanical and the physical properties of the specimens.

关键词： water permeability Fe203 nanoparticles Compressive strength Split tensilestrength Flexural strength

water permeability in Fly Ash-Based Geopolymer Concrete

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Journal of Civil Engineering and Architecture 2010年第3期4卷 15-19页

作者： Charin Sanawong Wichian Chalee Department of Civil Engineering Faculty of Engineering Burapha University Chonburi Thailand

This research investigated the water permeability coefficient of fly ash-based geopolymer concrete. The effect of sodium hydroxide （Na（OH）） concentrations and Si/AI ratios on water permeability and compressive strength of geopolymer concretes were studied. The geopolymer concrete were prepared from Mae Moh fly ash with sodium silicate （Na2SiO3） and sodium hydroxide （Na（OH）） solutions. In the first group, concentration of Na（OH） was varied at 8, 10, 12, and 14 molar and the Si/AI ratio was kept constant at 1.98. In the second group, a concentration of Na（OH） was kept constant at 14 molar and the Si/AI ratio was varied at 2.2, 2.4, 2.6, and 2.8. The hardened concretes were air-cured in laboratory. The compressive strength and water permeability were tested at the age of 28 and 60 days. The results showed that compressive strengths of geopolymer concrete significantly increased with the increase of a concentration of Na（OH） and Si/AI ratio. The water permeability coefficients increase with the decrease of compressive strength. In addition, the high reduction of water permeability coefficients with time was found in geopolymer concrete with lower Na（OH） concentration than that higher Na（OH） concentration.

关键词： Fly ash-based geopolymer concrete water permeability Na(OH) concentration Si/AI ratio

New insights into the DPR mechanism of elastic energy released by polymer gel for enhanced oil recovery

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PETROLEUM 2024年第3期10卷 539-547页

作者： Jia, Hu Wu, Junyi Wu, Shaowei Liang, Yanbin Wang, Minghao Wan, Xiaojin Li, Pengwu Southwest Petr Univ State Key Lab Oil & Gas Reservoir Geol & Exploitat Chengdu Peoples R China CNOOC Zhanjiang Branch Zhanjiang Peoples R China PetroChina Dagang Oilfield Co Oil Prod Technol Inst Tianjin Peoples R China

Polymer gel was widely used as water shutoff agent in mature oil fields. And the results of single-phase plugging experiments show that the plugging rate of the polymer gel to the oil phase is lower than that of the water phase. However, the disproportionate permeability reduction (DPR) mechanism of polymer gels still remains controversial. In this paper, we used four gel formulations including polyethyleneimine (PEI) and phenol-formaldehyde crosslinked gel with and without adding laponite to investigate the effect of gel elastic property on the water shutoff mechanism. The result of sand pack flooding experiments shown that the gel with higher elastic modulus has better effects on decreasing water cut and increasing oil recovery. After adding laponite, the elastic modulus of phenol-formaldehyde crosslinked gel increased from 64.2 Pa to 192 Pa, and the elastic modulus of PEI crosslinked gel increased from 27.4 Pa to 36.5 Pa. Compared to the phenol-formaldehyde-HAPM gel, the oil recovery of laponite-phenol-formaldehyde-HPAM gel increased by 5.2% and the maximum water cut decreased by 8.3%. Besides, comparing with PEI-HPAM gel, the oil recovery of laponite-PEI-HPAM gel increased by 2.7% and the water cut dropped by 27.8%. In the meanwhile, the laponite-phenol-formaldehyde-HPAM gel with higher elastic modulus obviously swells in the formation water but almost remains constant in oil at 105 degrees C. The mass of gel soaked in the formation water increased from 42 g to 96 g and the gel volume increased by 300% within 48 hours. This study improves the understanding of the DPR mechanism of polymer gel for water shutoff. (c) 2022 Southwest Petroleum University. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd. This is an open access article under the CC BY-NC-ND license (http://***/licenses/by-nc-nd/4.0/).

关键词： Gel elasticity water shutoff DPR Laponite Oil recovery DISPROPORTIONATE permeability REDUCTION NONIONIC POLYACRYLAMIDE water permeability PHENOLIC RESIN

Self-healing polyamide reverse osmosis membranes with temperature-responsive intelligent nanocontainers for chlorine resistance

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化学科学与工程前沿:英文版 2023年第9期17卷 1183-1195页

作者： Qian Yang Lin Zhang Xiao Xie Qiong Sun Jianguang Feng Hongzhou Dong Na Song Liyan Yu Lifeng Dong College of Materials Science and Engineering Qingdao University of Science and TechnologyQingdao266042China Qingdao University of Science&Technology Analytical&Testing Center Qingdao266042China Department of Physics Hamline UniversitySt.Paul55104USA

Improving the performance of reverse osmosis membranes remains great challenge to ensure excellent NaCl rejection while maintaining high water permeability and chlorine resistance. Herein, temperature-responsive intelligent nanocontainers are designed and constructed to improve water permeability and chlorine resistance of polyamide membranes. The nanocontainer is synthesized by layer-by-layer self-assembly with silver nanoparticles as the core, sodium alginate and chitosan as the repair materials, and polyvinyl alcohol as the shell. When the polyamide layer is damaged by chlorine attack, the polyvinyl alcohol shell layer dissolves under temperature stimulation of 37 ℃, releasing inner sodium alginate and chitosan to repair broken amide bonds. The polyvinyl alcohol shell responds to temperature in line with actual operating environment, which can effectively synchronize the chlorination of membranes with temperature response and release inner materials to achieve self-healing properties. With adding temperature-responsive intelligent nanocontainers, the NaCl rejection of thin film composite membrane decreased by 15.64%, while that of thin film nanocomposite membrane decreased by only 8.35% after 9 chlorination cycles. Effective repair treatment and outstanding chlorine resistance as well as satisfactory stability suggest that temperature-responsive intelligent nanocontainer has great potential as membrane-doping material for the targeted repair of polyamide reverse osmosis membranes.

关键词： reverse osmosis nanocontainer self-healing chlorine resistance water permeability

Effects of nanoclay addition on the permeability and mechanical properties of ultra high toughness cementitious composites

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2020年第12期21卷 992-1007页

作者： Min-jia WANG He-dong LI Qiang ZENG Qing-fen CHANG Xiu-shan WANG School of Civil Engineering and Architecture Zhejiang Sci-Tech UniversityHangzhou 310018China College of Civil Engineering and Architecture Zhejiang UniversityHangzhou 310058China Department of Architectural Engineering Liaoyuan Vocational Technical CollegeLiaoyuan 136200China

Tuning microstructures by adding nanoparticles is a promising way of improving the performance of cementitious *** this study,nanoclay was introduced to polyvinyl alcohol(PVA)fiber reinforced ultra high toughness cementitious composites(UHTCCs).The mechanical properties,crack patterns,water permeation resistance,and microstructures of UHTCCs with different dosages of nanoclay were *** addition of a proper dosage of nanoclay shows few effects on the compressive strength of UHTCCs,however,the compressive strength is decreased when an excessive amount of nanoclay is *** flexural deformation capacity of UHTCCs is independent of nanoclay dosage,whereas the flexural strength generally decreases with an increasing dosage of *** cracking patterns were observed in the ultra high toughness cementitious composites containing nanoclay(NC-UHTCC)specimens subject to bending tests.A UHTCC with 1%(in weight)nanoclay shows the best water permeation resistance and the lowest water *** in the mechanical properties and the water permeation resistance of UHTCCs containing different dosages of nanoclay could be ascribed to the synthetic effects of filling and heterogeneous nucleation of nanoclay at low dosages and the agglomeration effect of nanoclay at high *** study is to optimize the water permeation resistance of UHTCCs,paving a path for the future application of UHTCCs in the fields of construction,decoration,and repair.

关键词： Nanoclay water permeability Pore structure Cementitious composites Strain hardening

Self-sealing of fractures in indurated claystones measured by water and gas flow

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第1期15卷 227-238页

作者： Chun-Liang Zhang Jean Talandier Gesellschaft für Anlagen-und Reaktorsicherheit(GRS) Braunschweig38122Germany Agence nationale pour la gestion des déchets radioactifs(ANDRA) Châtenay-Malabry cedex92298France

Self-sealing of fractures in the indurated Callovo-Oxfordian(COX)and Opalinus(OPA)claystones,which are considered as host rocks for disposal of radioactive waste,was investigated on artificially fractured *** samples were extracted from four lithological facies relatively rich in clay mineral,carbonate and quartz,*** self-sealing of fractures was measured by fracture closure,water permeability variation,gas penetration,and recovery of gas-induced *** of the fractured samples exhibited a dramatic reduction inwater permeability to low levels that is close to that of intact rock,depending on their mineralogical composition,fracture intensity,confining stress,and load *** self-sealing capacity of the clay-rich samples is higher than that of the carbonate-rich and sandy *** effects of sample size and fracture intensity were *** sealed fractures become gas-tight for certain in-jection ***,the measured gas breakthrough pressures are still lower than the confining *** gas-induced pathways can recover when contacting *** important findings imply that fractures in such indurated claystones can effectively recover to hinder water transport but allow gas release under relatively low pressures without compromising the rock integrity.

关键词： Claystone Self-sealing of fracture Fracture closure water permeability Gas breakthrough pressure Resealing of gas pathway

PTFE Electrospun Stent Graft—Preparation,Properties and Its Industrialization Prospect

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Chemical Research in Chinese Universities 2021年第3期37卷 589-597页

作者： LUO Yu GONG Xiaoyan Shawn XU Zhiwei MENG Kai ZHANG Ke-Qin ZHAO Huijing National Engineering Laboratory for Modern Silk College of Textile and Clothing EngineeringSoochow UniversitySuzhou215123China Suzhou Innomed Medical Device Co. Ltd.Suzhou215123China Nantong Textile&Silk Industrial Technology Research Institute Nantong226001China

Stent graft(SG),isolating the diseased vessels from the normal blood circulation and preventing the rupture of the aneurysm wall in minimally invasive surgery,is normally composed of a metallic stent and a cover with a textile *** this study,the electrospinning method was used to prepare a new type of cover,and the preparing conditions and the performance of the SG were *** polytetrafluoroethylene(PTFE)and polyethylene oxide(PEO)were blended at the ratios of 99:1,98:2,97:3 and electrospun to form precursor *** they were dried in a vacuum and sintered at different temperatures under different time periods to obtain PTFE membrane,which was compounded with a *** morphology,mechanical properties,water permeability and biological properties were *** results showed that when the membrane was sintered at 380℃ for 10 min,it had the best tensile *** integral water permeability of the PTFE electrospun SG was close to *** hemolysis rate of the SG was 2.84%,and human umbillical vein endothelial cells(HUVECs)can adhere and proliferate well on the surface of the PTFE *** PTFE electrospun SG had great potential for clinical application and industrialization.

关键词： Polytetrafluoroethylene(PTFE) Electrospinning Stent graft water permeability Biocompatibility

Various admixtures to mitigate the long-term strength retrogression of Portland cement cured under high pressure and high temperature conditions

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第1期15卷 191-203页

作者： Jiankun Qin Xueyu Pang Ashok Santra Guodong Cheng Hailong Li School of Petroleum Engineering China University of Petroleum(East China)Qingdao266580China Key Laboratory of Unconventional Oil&Gas Development(China University of Petroleum(East China)) Ministry of EducationQingdao266580China Drilling Technology Team Aramco Americas:Aramco Research Center16300 Park Row DriveHoustonTX77084USA

In order to investigate the problem of long-term strength retrogression in oil well cement systems exposed to high pressure and high temperature(HPHT)curing conditions,various influencing factors,including cement sources,particle sizes of silica flour,and additions of silica fume,alumina,colloidal iron oxide and nano-graphene,were *** simulate the environment of cementing geothermal wells and deep wells,cement slurries were directly cured at 50 MPa and 200?*** compositions(as determined by X-ray diffraction Rietveld refinement),water permeability,compressive strength and Young’s modulus were used to evaluate the qualities of the set ***-term curing(2e30 d)test results indicated that the adoption of 6 m m ultrafine crystalline silica played the most important role in stabilizing the mechanical properties of oil well cement systems,while the addition of silica fume had a detrimental effect on strength ***-term curing(2e180 d)test results indicated that nano-graphene could stabilize the Young’s modulus of oil well cement ***,none of the ad-mixtures studied here can completely prevent the strength retrogression phenomenon due to their inability to stop the conversion of amorphous to crystalline phases.

关键词： High pressure and high temperature(HPHT) Strength retrogression Young’s modulus water permeability Rietveld method

Effect of Aggregate Gradation with Fuller Distribution on Properties of Sulphoaluminate Cement Concrete

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Journal of Wuhan University of Technology(Materials Science) 2015年第5期30卷 1029-1035页

作者：宫晨琛 ZHANG Jie WANG Shoude LU Lingchao Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials University of Jinan

Experimental investigations on mechanical property and durability of sulphoaluminate cement concrete with aggregate gradations according to Fuller distribution are presented in this paper. Compressive strength, water impermeability and resistance capability to sulfate attack of SACC have the same trend of concrete with fine aggregates of Fuller distribution gradationwater penetration depth obeyed the second-order polynomial y=0.002x2-6.863 8x +5 862.3, and had a notable correlation R2=0.979 9. The sulphoaluminate cement concrete with total aggregate gradation with Fuller distribution for h=0.50 had the best resistance capability to sulfate attack. It was a second-order polynomial relationship between bulk density of aggregates and water penetration depth of y=0.002x2-6.863 8x+5 862.3 with R2=0.979 9, which indicated notable correlation. The fitting formula between bulk density of aggregates and sulfate resistance coefficient of SACC was y=0.000 5x+0.370 4 with R2=0.958 5.

关键词： concrete aggregate Fuller distribution bulk density compressive strength water permeability resistance to sulfate attack