碳纳米管/液晶弹性体复合材料的力学性能

Mechanical property of carbon nanotube/liquid crystal elastomer composite materials

近年来,碳纳米管/液晶弹性体复合材料凭借其稳定高效的光热性能,成为目前刺激-响应液晶弹性体领域的一个重要研究方向,但目前研究者大多重点关注其光响应行为及使用场景,并未系统研究碳纳米管对液晶弹性体材料力学性能的影响。本文通过物理掺杂的方法制备了不同质量分数的碳纳米管/液晶弹性体复合材料,并利用傅里叶红外光谱、差示扫描量热仪、广角X射线衍射仪、动态热机械分析仪等对制备的复合材料进行热学、液晶性质和力学性能的表征及分析。实验结果表明,碳纳米管的掺杂量对复合材料的力学性能有明显影响,其中掺杂质量分数8%的单壁碳纳米管的液晶弹性体复合材料的力学性能最为优异。在30℃时,断裂强度为5.62 MPa,断裂伸长率为182%;在85℃(清亮点温度之上)时,其断裂强度为1.62 MPa,断裂伸长率为89%。相对于纯液晶弹性体薄膜材料而言,质量分数8%碳纳米管的液晶弹性体复合材料的断裂强度接近纯液晶弹性体薄膜的3倍,且可以实现最大收缩率为45%的可逆伸缩形变,在人造肌肉、软体机器人等智能材料领域表现出有良好的应用前景。

In recent years,carbon nanotube/liquid crystal elastomer(CNT-LCE)composite materials have received lots of scientific attention in the field of stimuli-responsive LCEs,due to the stable and efficient photothermal conversion properties.However,most researchers focused their attention on the stimuli-responsive behavior and application scenarios,but ignored the investigation of the effect of CNTs influencing on the mechanical properties of the LCE materials.Herein,a series of CNTs incorporated LCE composite films are prepared,and further characterized and analyzed by Fourier infrared spectroscopy,differential scanning calorimeter,wide-angle X-ray diffractometer and dynamic thermo-mechanical analyzer to explore the thermal,mesomorphic and mechanical properties of the composite films.The experimental results show that the doping amount of CNTs markedly influences the mechanical properties of these prepared CNT-LCE composite materials.Among them,the 8%(Mass fraction)CNTs incorporated LCE composite film exhibits the best mechanical properties.At 30℃,the breaking strength of the composite film is 5.62 MPa,and the breaking elongation is 182%.Beyond the clear point temperature,the breaking strength of the composite film is 1.62 MPa,and the elongation at break is 89%.Particularly,the breaking strength of this 8%CNTs incorporated LCE film is almost three times that of the pure LCE film.Besides,the CNT-LCE composite film can achieve a reversible shrinking deformation with a maximum contraction rate of 45%,which endows this material with a good application prospect in the field of intelligent materials,such as artificial muscle and soft robots,etc.