Tokyo University of Science, 2641 Yamazaki, Noda, Chiba, 278-8510, Japan.
Sci Rep. 2019 Sep 3;9(1):12677. doi: 10.1038/s41598-019-49131-y.
Graphene is expected to be used in separation applications such as desalination. However, it is difficult to predict the flow phenomena at the nanoscale using the conventional continuum law. Particularly at a Knudsen number (Kn) of >0.1, which is applied in filtration, it has been reported that not even slip boundary conditions can be applied. In this study, to identify the parameters that affect the applicability of the continuum law, we conducted a fluid permeation simulation using graphene. The deviation of the permeability from that of the continuum model was calculated by changing the channel width, fluid temperature, and fluid type. The result showed that the channel width has the largest influence among the three factors, and that the magnitude of the divergence is sorted out based on the Knudsen number. Therefore, the permeability can be predicted even at the nanoscale where the continuum law cannot be applied.
石墨烯有望应用于脱盐等分离应用。然而，使用传统的连续定律很难预测纳米尺度的流动现象。特别是在过滤中应用的 Knudsen 数（Kn）>0.1 时，据报道甚至不能应用滑移边界条件。在这项研究中，为了确定影响连续定律适用性的参数，我们使用石墨烯进行了流体渗透模拟。通过改变通道宽度、流体温度和流体类型来计算渗透率与连续模型的偏差。结果表明，在这三个因素中，通道宽度的影响最大，根据 Knudsen 数对发散的大小进行了排序。因此，即使在连续定律无法应用的纳米尺度，也可以预测渗透率。
