Idarraga-Mora Jaime A, Childress Anthony S, Friedel Parker S, Ladner David A, Rao Apparao M, Husson Scott M
Department of Chemical and Biomolecular Engineering, Clemson University, 127 Earle Hall, Clemson, SC 29634, USA.
Department of Physics and Astronomy, and Clemson Nanomaterials Institute, Clemson University, Clemson, SC 29634, USA.
Membranes (Basel). 2018 Nov 18;8(4):111. doi: 10.3390/membranes8040111.
This paper discusses the role played by the mechanical stiffness of porous nanocomposite supports on thin-film composite (TFC) membrane water permeance. Helically coiled and multiwall carbon nanotubes (CNTs) were studied as additives in the nanocomposite supports. Mechanical stiffness was evaluated using tensile tests and penetration tests. While a low loading of CNTs caused macrovoids that decreased the structural integrity, adding higher loads of CNTs compensated for this effect, and this resulted in a net increase in structural stiffness. It was found that the Young's modulus of the nanocomposite supports increased by 30% upon addition of CNTs at 2 wt %. Results were similar for both types of CNTs. An empirical model for porous composite materials described the Young's modulus results. The nanocomposite supports were subsequently used to create TFC membranes. TFC membranes with stiffer supports were more effective at preventing declines in water permeance during compression. These findings support the idea that increasing the mechanical stiffness of TFC membrane nanocomposite supports is an effective strategy for enhancing water production in desalination operations.
本文讨论了多孔纳米复合支撑体的机械刚度对薄膜复合（TFC）膜透水率的影响。研究了螺旋缠绕的多壁碳纳米管（CNT）作为纳米复合支撑体中的添加剂。通过拉伸试验和穿透试验评估机械刚度。虽然低负载的碳纳米管会导致大孔隙，从而降低结构完整性，但添加更高负载的碳纳米管可弥补这种影响，从而导致结构刚度净增加。研究发现，添加2 wt%的碳纳米管后，纳米复合支撑体的杨氏模量增加了30%。两种类型的碳纳米管结果相似。一种多孔复合材料的经验模型描述了杨氏模量的结果。随后，纳米复合支撑体被用于制备TFC膜。支撑体更硬的TFC膜在压缩过程中更有效地防止透水率下降。这些发现支持了这样一种观点，即提高TFC膜纳米复合支撑体的机械刚度是提高海水淡化操作产水量的有效策略。
