氧化石墨烯涂覆砂增强水泥基材料抗氯离子侵蚀性能  

Graphene Oxide-coated Sand for Enhancing Chloride Resistance of Cement-based Materials

作　　者：冯甘霖 罗盛禹 罗启灵[1,2,3,4] 龙武剑 FENG Ganlin;LUO Shengyu;LUO Qiling;LONG Wujian(College of Civil and Transportation Engineering,Shenzhen University,Shenzhen 518060,Guangdong,China;Guangdong Provincial Key Laboratory of Durability for Marine Civil Engineering,Shenzhen 518060,Guangdong,China;Shenzhen Key Laboratory of Low Carbon Building Materials and Technology,Shenzhen 518060,Guangdong,China;State Key Laboratory for Geomechanics&Deep Underground Engineering,Shenzhen University,Shenzhen 518060,Guangdong,China)

机构地区：[1]深圳大学土木与交通工程学院,广东深圳518060 [2]广东省滨海土木工程耐久性重点实验室,广东深圳518060 [3]深圳市低碳建筑材料与技术重点实验室,广东深圳518060 [4]深圳大学,深地工程智能建造与健康运维全国重点实验室,广东深圳518060

出　　处：《硅酸盐学报》2025年第3期505-518,共14页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金资助项目(U2006223)。

摘　　要：氧化石墨烯(GO)的不均匀分散和团聚现象严重制约了其对水泥基复合材料孔隙结构及耐久性能的增强效果。通过将GO涂覆于氨基化砂粒表面,系统研究了其对GO水泥基复合材料抗氯离子侵蚀性能的影响规律及机理。结果显示:当GO掺量达到0.3%(质量分数)时,使用GO涂覆砂的方法,快速氯离子迁移测试氯离子渗透深度和扩散系数分别比对照组降低了24.8%和18.5%。压汞法测得有害孔级(>50 nm)孔径分布降低了36.8%。进一步的微观及物相分析测试结果表明,采用GO涂覆砂对水泥基复合材料性能提升的主要原因在于对界面过渡区的优化:一方面,氨丙基三乙氧基硅烷偶联剂通过与硅羧基的缩合反应紧密地连接到砂表面,另一方面,GO通过表面上的羰基或羧基和偶联剂氨基官能团之间的酰胺键共价键合,通过此“双键效应”GO可以稳定键合在砂表面从而改善其分散性,并同时促进界面过渡区水化,减少界面过渡区的缺陷和裂纹,从而大大提高水泥基复合材料对氯离子传输的抵抗能力。Introduction In coastal engineering,the durability of reinforced concrete structures is often compromised due to the corrosion of steel reinforcements caused by chloride ingress.This issue significantly affects the safety and longevity of these structures.In concrete materials,the interfacial transition zone(ITZ)between the cement matrix and aggregates is a critical point,affecting the pathways and rates of chloride ion diffusion.Although previous studies demonstrate that the incorporation of nanomaterials can enhance the durability of cement-based materials,the uneven dispersion and agglomeration of these nanomaterials restrict their effectiveness.In this paper,a modification method was proposed via coating graphene oxide(GO)onto aminated sand particles to improve the dispersion of GO within cement-based composites,thereby enhancing their durability.This approach could have a promising potential for extending the service life of coastal engineering structures.Methods In this study,a GO dispersion was firstly prepared and dispersed by ultrasound.Subsequently,a specific chemical treatment method was employed to coat GO onto standard sand surfaces,creating aminated functionalized sand(GO-MAs).The preparation process of GO-MAs included sand pretreatment,amination,and chemical bonding with GO.In the experiments,cement-based composites with different GO contents(i.e.,0.1%,0.3%,0.5%by mass)were prepared with high-performance polycarboxylate superplasticizers to enhance GO dispersion.The chloride ion resistance of these composites was evaluated by rapid chloride migration(RCM)tests and natural chloride diffusion tests.In addition,the mechanisms of GO-coated sand enhancing the microstructural properties of cement-based materials,particularly the ITZ,were analyzed by mercury intrusion porosimetry(MIP),scanning electron microscopy(SEM),energy-dispersive X-ray spectroscopy(EDS),X-ray diffraction(XRD),and thermogravimetric analysis(TG/DTG).Results and discussion The experimental results indicate that the incorporation of GO

关 键 词：氧化石墨烯涂覆砂 双重键合效应 抗氯离子侵蚀 界面过渡区 

分 类 号：TU528[建筑科学—建筑技术科学]