Silicone-grafted carbonaceous nanotubes with enhanced dispersion stability and electrorheological efficiency
Silicone-grafted carbonaceous nanotubes with enhanced dispersion stability and electrorheological efficiency
复制标题
DOI：
10.1088/0957-4484/26/6/065704
复制
发表时间：
2015-02
期刊：
影响因子：
3.5
通讯作者：
Jianbo Yin;Xiaoxiao Wang;Xiaopeng Zhao
中科院分区：
文献类型：
--
作者：
Jianbo Yin;Xiaoxiao Wang;Xiaopeng Zhao
碳质颗粒是电响应电流变悬浮液的重要填料或分散相。但是碳质颗粒，特别是纳米级的碳质颗粒，在油中容易聚集。这一特性限制了基于碳质颗粒的电流变悬浮液的应用。为了提高碳纳米管的分散稳定性和电流变效率，本文通过将氧化碳纳米管与环氧基封端的有机硅接枝，制备了有机硅接枝碳纳米管。通过傅里叶变换红外光谱、X射线光电子能谱、热重分析和透射电子显微镜对样品进行了表征。通过润湿曲线和沉降实验研究了纳米管在硅油中的润湿性和分散稳定性。在电场作用下，用流变仪测量了CT分散在硅油中的电流变性能。结果表明，有机硅接枝改性可以明显改善CTs在硅油中的润湿性，减少CTs的再聚集。结果，硅氧烷接枝的CT在硅油中的悬浮液显示出高的分散稳定性。与裸CT的悬浮液相比，有机硅接枝CT的悬浮液具有更低的零场粘度，但具有更高的场致粘度，因此具有更高的电流变效率。这种增强的ER效率与硅酮接枝的CT在硅油中的改善的润湿性有关。
Carbonaceous particles are types of important fillers or dispersed phases of electro-responsive electrorheological (ER) suspensions. But carbonaceous particles, in particular with nano-order size, are easy to aggregate in oils. This characteristic limits the application of ER suspensions based on carbonaceous particles. In order to improve dispersion stability and ER efficiency, in this paper, we develop silicone-grafted carbonaceous nanotubes (CTs) by grafting oxidized carbonaceous nanotubes with epoxy-terminated silicone. The samples are characterized by Fourier transform infrared spectra, x-ray photoelectron spectroscopy, thermogravimetric analysis, and transmission electron microscopy. The wettability and dispersion stability of nanotubes in silicone oil are investigated by wetting curves and sedimentation tests. The ER properties of CTs when dispersed in silicone oil are measured by a rheometer under electric fields. It demonstrates that grafting with silicone can distinctly improve the wettability of CTs in silicone oil and decrease the re-aggregation of CTs. As a result, the suspension of silicone-grafted CTs in silicone oil shows high dispersion stability. Compared to the suspension of bare CTs, the suspension of silicone-grafted CTs exhibits lower zero-field viscosity but higher field-induced viscosity; thus it possesses higher ER efficiency. This enhanced ER efficiency is related to the improved wettability of silicone-grafted CTs in silicone oil.