中文摘要：

采用3-硅羟基-1-丙基磺酸（SIT8378.3）和聚氧乙烯十八烷基胺（Ethomeen18/25）在酸化多壁纳米碳管表面上生成长链壳层，相当于“溶剂”，使碳纳米管在没有溶剂时，损耗模量G″高于储能模量G′，具有流体特性。结果表明，长链分子接枝于碳纳米管表面使碳纳米管的直径增大，碳纳米管质量分数为16.03%。碳纳米管在去离子水中稳定分散，渗流阈值为5 mg/g。

英文摘要：

Carboxylic-acid functionalized multiwall carbon nanotubes （ MWCNT-COOH ） were first modified by （ CH3 O ） 3 Si （ CH2 ） 3 SO3 H by an esterification reaction of the carboxylic-acid group with a methoxy group, then by hydrolyzing N, N-di （ 2-hydroxyethoxy） ethyl octadecylamine by an ion exchange reaction to form a quaternary ammonium salt as a soft shell of the MWC-NTs. The modified MWCNTs had a larger diameter than the original MWCNTs and their MWCNT content was up to 16. 03 wt%. The loss modulus of the modified MWCNTs is bigger than the storage modulus, which is a characteristic of a solvent-free nanofluid. The modified MWNTs can be well dispersed in deionized water and the resulting dispersion is stable. Their seepage threshold value in water is about 5 mg/g.