Vapor-grown carbon nanofiber/poly(ethylene-co-vinyl acetate) composites with electrical-active two-way shape memory behavior
Vapor-grown carbon nanofiber/poly(ethylene-co-vinyl acetate) composites with electrical-active two-way shape memory behavior
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DOI：
10.1177/1045389x17698246
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发表时间：
2017-03
影响因子：
2.7
通讯作者：
C. Qian;Yaofeng Zhu;Yubing Dong;Yaqin Fu
中科院分区：
文献类型：
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作者：
C. Qian;Yaofeng Zhu;Yubing Dong;Yaqin Fu
采用溶液共混法将气相生长的碳纳米纤维填充到聚(乙烯-乙酸乙烯酯共聚物)中，实现电激活的双向形状记忆。通过组合分析技术对气相生长碳纳米纤维/聚(乙烯-乙酸乙烯酯共聚物)纳米复合材料进行了系统而明确的研究。实验结果表明，随着纳米复合材料中碳纳米纤维含量的增加，其结晶温度(T_C)升高，熔融温度(T_M)降低。这一结果表明，碳纳米纤维在结晶过程中可以起到成核剂的作用，但可能会阻碍热力学稳定晶体的形成。与纯聚(乙烯-乙酸乙烯酯)共混物相比，纳米复合材料具有较高的弹性模量，但强度较低。在双向形状记忆测试中，纳米复合材料的可逆应变和形状恢复率均有所下降。然而，在循环加热和循环冷却过程中，所有样品都观察到明显的双向形状转变。由于气相生长的碳纳米纤维具有较高的导电性，且在基体中分布均匀，因此添加15%的气相生长碳纳米纤维的纳米复合材料可以快速、均匀地进行电加热。最终实现了电激活的双向形状记忆效应。这项工作有助于在先进功能的设备应用中设计电激活的双向形状记忆聚合物。
Vapor-grown carbon nanofibers were filled into poly(ethylene-co-vinyl acetate) through solution mixing to achieve electrical-active two-way shape memory. The vapor-grown carbon nanofiber/poly(ethylene-co-vinyl acetate) nanocomposites were systematically and explicitly investigated through combined analytical techniques. Experimental results showed an increase in crystallization temperature (Tc) and a decrease in melting temperature (Tm) as the vapor-grown carbon nanofiber concentration in the nanocomposites increased. This result indicates that carbon nanofibers can act as nucleating agents during crystallization but may hinder the formation of thermodynamically stable crystals. The nanocomposites had a higher modulus but a lower strength than pure poly(ethylene-co-vinyl acetate). In two-way shape memory testing, a decrease in reversible strain and shape recovery occurred in the nanocomposites. Nevertheless, obvious two-way shape switching was observed in all samples during cyclic heating and cooling. The nanocomposite with 15% vapor-grown carbon nanofibers could be electrically heated rapidly and uniformly because of the high conductivity of vapor-grown carbon nanofibers and their uniform distribution in the matrix. Finally, the electrical-active two-way shape memory effect was achieved. This work contributes to the design of electrical-active two-way shape memory polymers in device applications for advanced functions.