State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai, People's Republic of China.
Nanotechnology. 2011 Jun 3;22(22):225603. doi: 10.1088/0957-4484/22/22/225603. Epub 2011 Apr 1.
We report an approach of flake powder metallurgy to the uniform, two-dimensional (2D) distribution of carbon nanotubes (CNTs) in Cu flake powders. It consists of the preparation of Cu flakes by ball milling in an imidazoline derivative (IMD) aqueous solution, surface modification of Cu flakes with polyvinyl alcohol (PVA) hydrosol and adsorption of CNTs from a CNT aqueous suspension. During ball milling, a hydrophobic monolayer of IMD is adsorbed on the surface of the Cu flakes, on top of which a hydrophilic PVA film is adsorbed subsequently. This PVA film could further interact with the carboxyl-group functionalized CNTs and act to lock the CNTs onto the surfaces of the Cu flakes. The CNT volume fraction is controlled easily by adjusting the concentration/volume of CNT aqueous suspension and Cu flake thickness. The as-prepared CNT/Cu composite flakes will serve as suitable building blocks for the self-assembly of CNT/Cu laminated composites that enable the full potential of 2D distributed CNTs to achieve high thermal conductivity.
我们提出了一种通过片状粉末冶金法使碳纳米管（CNT）在铜片状粉末中均匀二维（2D）分布的方法。该方法包括在咪唑啉衍生物（IMD）水溶液中通过球磨制备铜片、用聚乙烯醇（PVA）水溶胶对铜片进行表面改性以及从 CNT 水悬浮液中吸附 CNT。在球磨过程中，IMD 的疏水性单层被吸附在铜片表面上，随后在其表面上吸附亲水性 PVA 膜。这种 PVA 膜可以进一步与羧基功能化的 CNT 相互作用，并将 CNT 锁定在铜片表面上。通过调整 CNT 水悬浮液的浓度/体积和铜片的厚度可以轻松控制 CNT 的体积分数。所制备的 CNT/Cu 复合片将作为自组装 CNT/Cu 层状复合材料的合适构建块，从而充分发挥 2D 分布 CNT 的潜力，实现高导热性。
