| 摘要: |
| 探讨了丁苯橡胶乳液(SBR)及其掺量(0~20%，质量比)对碳纳米管(CNTs) 水泥砂浆导电性能和机敏性能的影响.采用扫描电子显微镜观察了SBR掺加前后CNTs 水泥砂浆的微观结构，进而探讨了SBR对CNTs 水泥砂浆导电性能和机敏性能的影响机理.结果表明：当SBR掺量为15%时，CNTs 水泥砂浆具有最强的导电性能和机敏性能.在CNTs 水泥砂浆中掺加SBR后，由于CNTs可以均匀分散在SBR中形成导电体系，而SBR能封闭水泥砂浆孔隙和形成三维网络结构，使得实际参与导电的CNTs数量增加，故CNTs 水泥砂浆导电性能、机敏性能随着SBR掺量的增加而增大.但当SBR掺量大于15%后，由于SBR本身具有成膜和引气作用，导致水泥砂浆孔隙率显著增加，且过多的SBR令SBR CNTs复合体系中CNTs的相对浓度降低，最终使得实际参与导电的CNTs数量降低，因此CNTs 水泥砂浆的导电性能和机敏性能反而降低. |
| 关键词: 碳纳米管 机敏性能 机理 丁苯橡胶乳液 |
| DOI：10.3969/j.issn.1007 9629.2013.01.012 |
| 分类号: |
| 基金项目:国家自然科学基金资助项目（50978041）；教育部高等学校博士点科研基金资助项目(20094402120002);广东省自然科学基金资助项目(S2011010005199) |
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| Piezoresistivity of Carbon Nanotubes Cement Mortars Modified byStyrene Butadiene Rubber Emulsion |
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LI Geng ying1, YANG Jing1, ZENG Ling bo1, ZHAO Xiao hua1, XU Shi lang2
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1.Department of Civil Engineering, Shantou University, Shantou 515063, China;2.College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310058, China
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| Abstract: |
| The electrical conductivity and piezoresistivity of carbon nanotubes(CNTs) cement mortars with 020%(by mass) styrene butadiene rubber emulsion(SBR) added were experimentally studied. The microstructure of CNTs cement mortars with or without SBR was investigated by using scanning electron microscopy(SEM)，and action mechanism of SBR on the electrical conductivity and piezoresistivity of CNTs cement mortars was discussed. The results show that both the electrical conductivity and piezoresistivity of CNTs cement mortars increase with increasing use level of SBR, and the optimal use level of SBR is 15%. It is found that CNTs are uniformly dispersed in SBR, and SBR could seal pores and form a three dimensional polymer network. As a result, there are more CNTs conductive units, and the electrical conductivity and piezoresistivity of CNTs cement mortars are improved with increasing use level of SBR. However, when the use level of SBR is higher than 15%, because of SBRs film forming and air entraining action the porosity of the mortar increases，and relative concentration of CNTs in SBR CNTs system reduces duo to higher content of SBR, so that the number of CNTs conductive units decreases causing lower electrical conductivity and piezoresistivity of CNTs cement mortars. |
| Key words: carbon nanotubes(CNTs) piezoresistivity mechanism styrene butadiene rubber emulsion(SBR) |
