Single wall carbon nanotube/polyethylene nanocomposites: Nucleating and templating polyethylene crystallites
Single wall carbon nanotube/polyethylene nanocomposites: Nucleating and templating polyethylene crystallites
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DOI：
10.1021/ma0527698
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发表时间：
2006-04-18
期刊：
影响因子：
5.5
通讯作者：
Winey, KI
中科院分区：
文献类型：
--
作者：
Haggenmueller, R;Fischer, JE;Winey, KI
研究了单壁碳纳米管（SWNT）存在下聚乙烯（PE）在各向同性和定向复合材料中的结晶动力学和结晶形态。开发了一种热凝固方法，以将单壁碳纳米管负载量高达30重量%，均匀分布。热分析解释使用Avrami方程表明，纳米管提供成核位点的PE和加速的PE晶体生长速率，同时减少从球晶到盘形的晶体尺寸。在熔融纺丝过程中，单壁碳纳米管束上的成核作用显著增加了纤维的密度，从而使1 wt % SWNT-HDPE复合纤维中的PE微观结构为具有直片（而非扭曲）的串晶。通过比较由各种加工条件产生的单壁碳纳米管和PE的取向，我们表明，单壁碳纳米管束模板通过施加垂直于单壁碳纳米管的生长方向的PE晶体的生长。这为控制SWNT-聚合物界面提供了一条新的途径，从而控制纳米复合材料的物理性能。
The crystallization kinetics and resulting morphology of polyethylene (PE) in the presence of single wall carbon nanotubes (SWNT) are investigated in isotropic and aligned composites. A hot coagulation method was developed to incorporate SWNT loadings as high as 30 wt % with uniform distribution. Thermal analysis interpreted using the Avrami equation showed that the nanotubes provide nucleation sites to PE and accelerate the PE crystal growth rate while reducing the crystal dimensionality from spherulitic to disk-shaped. Nucleating on SWNT bundles significantly increases the shish density during melt fiber spinning, so that the PE microstructure is shish kebab with straight (not twisted) lamellae in I wt % SWNT-HDPE composite fibers. By comparing the orientations of SWNT and PE produced by various processing conditions, we show that SWNT bundles template the growth of PE crystals by imposing a growth direction perpendicular to the SWNT. This provides a new route toward controlling the SWNT-polymer inter-face and thereby the physical properties of nanocomposites.