School of Engineering, Monash University Malaysia, 47500 Bandar Sunway, Selangor, Malaysia.
Nanoscale. 2017 May 18;9(19):6497-6508. doi: 10.1039/c7nr01690e.
We exploit the possibility of enhancing the molecular transport of liquids through graphene films using amplitude modulated surface acoustic waves (SAWs) to demonstrate effective and efficient nanoparticle filtration. The use of the SAW, which is an extremely efficient means for driving microfluidic transport, overcomes the need for the large mechanical pumps required to circumvent the large pressure drops encountered in conventional membranes for nanoparticle filtration. 100% filtration efficiency was obtained for micron-dimension particulates, decreasing to only 95% for the filtration of particles of tens of nanometers in dimension, which is comparable to that achieved with other methods. To circumvent clogging of the film, which is typical with all membrane filters, a backwash operation to flush the nanoparticles is incorporated simply by reversing the SAW-induced flow such that 98% recovery of the initial filtration rate is recovered. Given these efficiencies, together with the low cost and compact size of the chipscale SAW devices, we envisage the possibility of scaling out the process by operating a large number of devices in parallel to achieve typical industrial-scale throughputs with potential benefits in terms of substantially lower capital, operating and maintenance costs.
我们利用振幅调制表面声波（SAW）增强液体在石墨烯薄膜中的分子传输的可能性，展示了有效的纳米颗粒过滤效果。表面声波是一种非常有效的微流道驱动方式，它克服了传统纳米颗粒过滤膜中需要使用大型机械泵来克服大压降的问题。对于微米级的颗粒，我们实现了 100%的过滤效率，而对于几十纳米尺寸的颗粒，过滤效率仅下降到 95%，这与其他方法相当。为了避免像所有膜过滤器一样出现膜堵塞的问题，我们通过简单地反转表面声波诱导的流来进行反冲洗操作，从而使初始过滤速率恢复到 98%。鉴于这些效率，以及芯片级表面声波器件的低成本和紧凑尺寸，我们设想可以通过并行操作大量设备来扩展该过程，从而实现典型的工业规模通量，在资本、运营和维护成本方面具有显著优势。
