A promising answer to enhance the floor hydrophobicity of hydrophobic membranes


Credit score: Jun Pan et al, Frontiers of Chemical Science and Engineering (2022)

As many chemists know, the membrane distillation (MD) course of has gained growing reputation and a focus for saline therapy, particularly due to its extraordinarily excessive salt rejection (the theoretical worth as much as 100%). In MD, the hydrophobic membrane serves as a core and important a part of realizing two-phase separation. Nevertheless, the present membrane wetting phenomenon all the time restricts the long-term steady operation and separation effectivity.

in article 1

Zhaoliang Cui, a professor from the Faculty of Chemical Engineering of Nanjing Tech College, and colleagues have discovered one promising answer to unravel this drawback by making ready hydrophobic poly(vinlidene fluoride-co-hexafluoro propylene) (PVDF-HFP) copolymer membrane to enhance floor hydrophobicity. Their research was printed on-line in Frontiers of Chemical Science and Engineering on March 28, 2022.

On this research, one hydrophobic fluorinated polymer material, PVDF-HFP, was chosen because the membrane materials to arrange porous membrane for membrane distillation utility. The thermally induced phase separation (TIPS) methodology was employed to arrange the membrane, which is a standard fabrication methodology. As a way to lower hurt from the volatilization of used solvent at a excessive temperature throughout the TIPS course of, the inexperienced and environmentally pleasant diluent acetyl tributyl citrate (ATBC) was used.

In accordance with the section diagram of PVDF-HFP/ATBC system, there was a large liquid-liquid section area among the many vary of ready polymer concentrations (25-40 wt%), indicating {that a} liquid-liquid section separation happens. Consequently, a ultimate bi-continuous construction could be obtained. The pore connectivity, permeability and mechanical properties of such a construction will profit the mass transfer throughout the separation course of. The floor contact angle, porosity, tensile strength and elongation at breaks of the ready membranes on this research have been as much as 123.87o, 60.43%, 5.89 MPa and 396.85%, respectively.

Then the ready PVDF-HFP membranes have been utilized within the membrane distillation course of treating 3.5 wt% NaCl saline. Firstly, the bottom desalination efficiency was examined at totally different feed temperatures, which confirmed that the permeate flux remained proportional to the feed temperature. That is in keeping with widespread data. Furthermore, for an extended testing interval, the ready membrane had a steady membrane distillation flux and was not wetted (the permeated conductivity was all the time round 2–3 mS·cm−1). These are all thrilling and satisfying outcomes.

Cui and his staff will proceed their research on the preparation of hydrophobic or super-hydrophobic membranes for membrane distillation purposes. They hope to arrange sufficient practical hydrophobic membranes to attain the ultimate purpose of zero liquid discharge of wasted saline to have the ability to recycle the commercial uncooked supplies and water assets.

Pervaporation membranes show promise for alkaline wastewater reclamation

Extra info:
Jun Pan et al, Poly(vinylidene fluoride-co-hexafluoro propylene) membranes ready by way of thermally induced section separation and utility in direct contact membrane distillation, Frontiers of Chemical Science and Engineering (2022). DOI: 10.1007/s11705-021-2098-y

Offered by
Larger Schooling Press

A promising answer to enhance the floor hydrophobicity of hydrophobic membranes (2022, Could 11)
retrieved 11 Could 2022
from https://phys.org/information/2022-05-solution-surface-hydrophobicity-hydrophobic-membranes.html

This doc is topic to copyright. Other than any honest dealing for the aim of personal research or analysis, no
half could also be reproduced with out the written permission. The content material is supplied for info functions solely.


Please enter your comment!
Please enter your name here