Tunable Growth of ZnO Nanostructures on the Inner Wall of Capillary Tubes
Tunable Growth of ZnO Nanostructures on the Inner Wall of Capillary Tubes
复制标题
毛细管内壁氧化锌纳米结构的可调生长
DOI：
10.1021/acs.jpcc.8b11515
复制
发表时间：
2019
影响因子：
3.7
通讯作者：
Jing Guangyin
中科院分区：
文献类型：
--
作者：
Luo Hao;Leprince Wang Yamin;Jing Guangyin
结构化和功能性的微流控通道使微流控芯片和设备在各种应用中更加强大。在通道壁上原位修饰纳米结构是一种低成本、高效率的多功能微流控芯片的方法。然而，在大曲率衬底(即具有圆形截面的微管)上的纳米结构在剪切流中的良好控制生长仍然是缺乏的。在这项工作中，浸渍镀膜法是一种在工业上广泛使用的简单而有效的镀膜方法，它可以在毛细管内壁上沉积氧化锌种子层，将沉积种子层所需的时间从几个小时缩短到几分钟。然后，采用连续流化学处理方法动态生长了氧化锌纳米结构。在浸涂过程中，可以通过控制镀膜速度来控制纳米结构的形貌和数密度。此外，实验还证明了在一定的流量下纳米结构的最大生长速率，这可以从理论计算中定义。最优流速Qp很好地反映了Poiseuille流下反应-扩散过程的依赖性。本研究结果可为功能化纳米结构修饰在水和气体的动态超净化以及微流控设备中的医学检测等方面的应用提供一定的参考。
Structured and functional microfluidic channels make microfluidic chips and devices more powerful in a variety of applications. In situ decoration of nanostructures on the channel wall is a low-cost and high-efficiency method toward multifunctional microfluidic chips. However, well-controlled growth of nanostructures on a large curvature substrate (i.e., microtubes with a circular cross section) in a shear flow is still lacking. In this work, dip-coating, an easy and efficient coating method widely used in industry, has been developed to deposit the ZnO seed layers on the inner wall of the capillary tubes, which shortens the time needed for the deposition of seed layers from a few hours to minutes. Then, a continuous-flow chemical processing method was used for the growth of ZnO nanostructures in a dynamic way. The morphology and number density of nanostructures can be controlled by the coating speed during the dip-coating process. In addition, the experiments demonstrated a maximum growth rate of the nanostructures under a certain flow rate, which can be defined from the theoretical calculation. The optimum flow rateQopcaptures well the dependence on the reaction–diffusion process under the Poiseuille flow. The findings here could promote the functionalized nanostructure decorations for the applications including the dynamical ultrapurification of water and gas and medical detection in microfluidic devices.