Slip effect based bimodal nanofibrous membrane for high-efficiency and low-resistance air purification
Slip effect based bimodal nanofibrous membrane for high-efficiency and low-resistance air purification
复制标题
基于滑移效应的双峰纳米纤维膜用于高效低阻空气净化
DOI：
10.1016/j.seppur.2021.119258
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发表时间：
2021-07-15
影响因子：
8.6
通讯作者：
Yu, Jianyong
中科院分区：
文献类型：
--
作者：
Quan, Zhenzhen;Zu, Yao;Yu, Jianyong
纳米纤维材料在空气过滤方面具有很大的潜力，特别是在处理微/纳米颗粒物（PM）方面。然而，对于纤维膜过滤器，在保持超高过滤效率的同时降低压降仍然存在挑战。本文设计并制备了一种基于滑移效应的高效低阻双峰纳米纤维膜过滤器。通过对单根纤维周围空气流场的建模和数值模拟，发现直径为70 nm的纤维对滑移流降低空气阻力最有效。为了在纤维膜中引入滑移效应，设计了由支架纤维（200 nm）和最佳滑移效应功能纤维（70 nm）组成的双峰结构纤维膜过滤器，以增加纤维之间的差距。采用一步法自由表面静电纺丝制备了三明治结构的纤维膜过滤器，其中双峰纤维（70 + 200 nm）位于中间层，而上下层分别由110和70 nm的单峰纤维组成，形成梯度空气通道。三明治结构纤维膜对PM0.26的过滤效率高达99.984%，在低阻力（85.02 Pa）的前提下满足精密过滤的要求，品质因数（QF）高达0.1028 Pa-1。研究结果为纳米纤维膜的设计和制备提供了一种高效、低阻力的空气净化方法。
Nanofiber materials have great potential in air filtration, especially to deal with the micro-/nano-particulate matters (PM). However, there still remains a challenge to reduce pressure drop while maintaining ultra-high filtration efficiency for fibrous membrane filters. In the present article, the high-efficiency and low-resistance bimodal nanofibrous membrane filter based on slip effect was designed and fabricated. By modelling and numerically simulating the air flow field around single fiber, the fiber with diameter of 70 nm was found to be most effective for slip flow to reduce air resistance. To introduce the slip effect into fibrous membrane, bimodal structured fibrous membrane filters which consisted of scaffold fibers (200 nm) and the optimal slip effect functional fibers (70 nm) were designed to increase the gap between the fibers. Furthermore, a sandwich structured fibrous membrane filter was fabricated via one-step free surface electrospinning, in which the bimodal fibers (70 + 200 nm) was in the middle layer, while the upper and lower layers were consisted of unimodal fibers of 110 and 70 nm, separately, to form gradient air passageway. The sandwich structured fibrous membrane presented a filtration efficiency of 99.984% for PM0.26, meeting the requirements of precision filtration under the premise of low-resistance (85.02 Pa), with a QF (quality factor) as high as 0.1028 Pa-1. The results shown in the current work provide an efficient way for the design and fabrication of nanofibrous membrane for high-efficiency and low-resistance air purification against PM.