Effect of Hydrogen Concentration on the Growth of Carbon Nanotube Arrays for Gecko-Inspired Adhesive Applications
Effect of Hydrogen Concentration on the Growth of Carbon Nanotube Arrays for Gecko-Inspired Adhesive Applications
复制标题
氢浓度对壁虎粘合剂应用中碳纳米管阵列生长的影响
DOI：
10.3390/coatings7120221
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发表时间：
2017-12-01
期刊：
影响因子：
3.4
通讯作者：
Dai, Zhendong
中科院分区：
文献类型：
--
作者：
Li, Yang;Ji, Keju;Dai, Zhendong
垂直排列的碳纳米管(VACNTs)具有优异的结构和力学性能，受到自然界中胶粘剂结构的启发，被认为是制造干胶粘剂的潜在候选者。催化化学气相沉积广泛用于VACNTs的生长，但VACNT的制备参数(如氢气浓度)对其粘接性能的影响机理尚不清楚，这使得对VACNTs粘结剂结构的精确控制成为一个持续不断的挑战。本文以电子束沉积的SiO_2/Al_2O_3为支撑层，Fe为催化剂，C2H4/H_2混合气体为原料，在还原气氛(H_2)为0%~35%的条件下制备了VACNT。在氢气浓度为15%(5 mm×5 mm)时合成的VACNTs的最大负载量为856g，宏观剪切粘结强度为34N/cm2。我们提出了一个与氢浓度相关的VACNTs剪切粘接性能模型。通过调节反应过程中存在的氢气量，可以精确控制制备的VACNTs的形貌和质量，这对其剪切粘接性能有很大影响。这些结果有利于碳纳米管作为干胶粘结剂的应用。
Vertically-aligned carbon nanotubes (VACNTs) have extraordinary structural and mechanical properties, and have been considered as potential candidates for creating dry adhesives inspired by adhesive structures in nature. Catalytic chemical vapor deposition is widely used to grow VACNTs; however, the influential mechanism of VACNT preparation parameters (such as H2 concentration) on its adhesion property is not clear, making accurate control over the structure of VACNTs adhesive an ongoing challenge. In this article, we use electron beam-deposited SiO2/Al2O3 as a support layer, Fe as catalyst, and C2H4/H2 gas mixtures as a feed gas to prepare VACNTs, while varying the ratio of the reducing atmosphere (H2) from 0% to 35%. VACNTs synthesized at a 15% H2 concentration (5 mm × 5 mm in size) can support a maximal weight of 856 g, which indicates a macroscopic shear adhesive strength of 34 N/cm2. We propose a hydrogen-concentration-dependent model for the shear adhesive performance of VACNTs. By adjusting the amount of hydrogen present during the reaction, the morphology and quality of the prepared VACNTs can be precisely controlled, which significantly influences its shear adhesive performance. These results are advantageous for the application of carbon nanotubes as dry adhesives.