改性纳米二氧化硅对建筑砂浆力学性能的影响及机理  

Effect of KH560 Modified Nano-SiO_(2) on Macroscopic Properties of Cement-Based Materials and Microscopic Mechanism

作　　者：白利婷 柴奇 BAI Liting;CAI Qi(School of Architecture and Engineering,Jiaxing Nanhu University,Jiaxing Zhejiang 314001,China;Jiaxing Xingke Technology Development Investment Co.,Ltd.,Jiaxing Zhejiang 314001,China)

机构地区：[1]嘉兴南湖学院建筑工程学院,浙江嘉兴314001 [2]嘉兴兴科科技发展投资有限公司,浙江嘉兴314001

出　　处：《当代化工》2025年第2期347-352,共6页Contemporary Chemical Industry

基　　金：嘉兴市青年科技人才专项项目(项目编号:2024AY40020);重庆市研究生科研创新项目(项目编号:CYS19375);重庆市教委科学技术研究项目(项目编号:KJQN201912910)。

摘　　要：使用硅烷偶联剂KH560对纳米SiO_(2)进行表面改性,系统研究了改性前后纳米SiO_(2)对水泥砂浆流动性、7 d及28 d抗折抗压强度的影响,采用FT-IR分析、粒径分布测试及SEM观测分析了KH560对纳米SiO_(2)团聚状态的实际改善效果,并通过XRD物相分析及微观形貌观测阐述了改性纳米SiO_(2)对水泥基材料宏观力学性能的作用机理。结果表明:使用KH560对纳米Si O_(2)改性后,纳米SiO_(2)颗粒空间位阻增大,平均粒径由295.3 nm显著降低至93.2 nm,化学反应活性增强,可以促进水泥的水化进程,生成更多对水泥基材料力学性能发展有利的水化硅酸钙凝胶。当改性纳米SiO_(2)掺入质量分数为3%时,水泥砂浆力学性能达到最优,此时7、28 d抗折强度分别为10.7、14.2 MPa,7、28 d抗压强度分别为40.1、58.2 MPa,同时具有较好的施工性能和密实性。Silane coupling agent KH560 was used to modify the surface of nano-SiO_(2),and the effects of nano-SiO_(2) before and after modification on the fluidity,7 d and 28 d bending and compressive strength of cement mortar were systematically studied.The actual improvement effect of KH560 on the agglomeration state of nano-SiO_(2) was analyzed by FT-IR analysis,particle size distribution test and SEM observation.The effect mechanism of modified nano-SiO_(2) on the macroscopic mechanical properties of cement-based materials was described by XRD phase analysis and microscopic morphology observation.The results showed that after the modification of nano-SiO_(2) with KH560,the steric hindrances of nano-SiO_(2) particles increased,the average particle size decreased significantly from 295.3 nm to93.2 nm,and the chemical reactivity was enhanced,which could promote the hydration process of cement and generate more hydrated calcium silicate gels that were beneficial to the development of mechanical properties of cement-based materials.When the mass fraction of modified nano SiO_(2) was 3%,the mechanical properties of cement mortar reached the best,and the 7 d and 28 d flexural strengths were 10.7 MPa and 14.2 MPa,respectively,and the 7 d and 28 d compressive strengths were 40.1 MPa and 58.2 MPa,respectively.At the same time,it had good construction performance and compactness.

关 键 词：硅烷偶联剂 纳米SiO_(2) 水泥基复合材料 力学性能 微观结构 

分 类 号：TU528[建筑科学—建筑技术科学] TQ127.2[化学工程—无机化工]