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arXiv · 2401.09142

Improving physico-chemical properties and antifouling of nanofiltration membranes using coating DLC nanostructures

Zeynab Kiamehr·Mojtaba Shafiee·Babak Shokri
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Abstract

In this study for the first time, polymeric nanofiltration membranes based on polyethersulfone (PES) polymer were surface-modified by using a diamond-like carbon (DLC) nanostructure coating layer. The effect of this coating on the performance and anti-fouling properties of the membrane was investigated. The surface-modified membranes significantly improved the salt separation and their hydrophilicity was more than the control membrane after the reformation process. The amount of salt separation increased from 64% to 98% due to the decrease in the size of the holes on the surface. The absorption characteristic of DLC nanostructure in contact with feed solution was reported as another reason in this field. The contact angle (CA) of water also decreased due to the improvement of hydrophilicity, which means the increase of hydrophilicity in the above membranes. The amount of pure water flux passing through the membranes increases from one side of the membrane surface to both sides with the increase significantly of the coating level, so that its value reaches from about 8L/m2h for the M0 membrane to 65L/m2h in the membrane containing M3. The surface morphology of unmodified membranes changed from a rough state with an average of 16nm in PES membranes to a smoother state in modified membranes with an average of 9nm. The recovery rate of the flux and the total absorption rate were obtained in complete agreement with the results obtained from the CA of water and the amount of the calculated surface roughness parameter. The increase in the flux recovery rate and the decrease in the fouling rate indicated the successful improvement of the antifouling properties as a result of the coating process. Based on the washing test, the prepared sample has good stability against the number of washing cycles, which is a very important advantage for practical applications.

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Zeynab Kiamehr, Mojtaba Shafiee, Babak Shokri. 2024-01-17. Improving physico-chemical properties and antifouling of nanofiltration membranes using coating DLC nanostructures. https://arxiv.org/abs/2401.09142

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