Designing an All-Carbon Membrane for Water Desalination

Abstract

We design an all-carbon membrane for the filtration and desalination of water. A unique layered assembly of carbon nanostructures including graphite oxide (GO), buckypaper consisting of carbon nanotubes, and a strong carbon fabric provides high mechanical strength and thermal stability, resilience to harsh chemical cleaning agents and electrical conductivity, thus addressing major shortcomings of commercial reverse osmosis membranes. We use ab initio density functional theory calculations to obtain atomic-level insight into the permeation of water molecules in-between GO layers and across in-layer vacancy defects. Our calculations elucidate the reason for selective rejection of solvated Na + ions in an optimized GO membrane that is structurally stabilized in a sandwich arrangement in-between layers of buckypaper, which are protected on both sides by strong carbon fabric layers. arXiv:1908.02225v2 [cond-mat.mtrl-sci]

Swelling properties of graphite oxides and graphene oxide multilayered materials

“…Enveloping of GO membranes using CNTs was also recently proposed. 315 We note also that Al 3+ ions suggested as a reason for water stability of GO membranes prepared on alumina filters 304 are likely to originate from small Al 2 O 3 particles which are commonly found on the surface of membranes peeled off from the alumina filters. 224…”

Advantages, limitations, and future suggestions in studying graphene-based desalination membranes

“…The performance of different nanoporous graphene or stacked GO membranes has been described. Some new hybrid graphenebased membrane designs, such as using MXenes, [113][114][115][116] GO quantum dots, 113 carbon nanotubes 105,107 have also been presented. The use of graphene nanomaterials in membranes for other desalination processes, such as membrane distillation and forward osmosis, was also examined.…”

Recent Advances in Applications of Carbon Nanotubes for Desalination: A Review

“…Their representative images are displayed in Figure 1 [ 24 ]. The two main types of freestanding CNT membranes commonly used for desalination are vertically aligned CNT (VACNT) membranes ( Figure 1 a) and buckypaper CNT membranes ( Figure 1 b) [ 25 , 26 ]. Composited CNT membranes mainly include three categories: mixed-matrix CNT membranes ( Figure 1 c), CNTs as the intermediate layer ( Figure 1 d), CNTs coated on the membrane surface or support ( Figure 1 e) [ 24 ].…”