One-step nanotopography construction by polyaniline polymerization for a superhydrophobic nanofibrous membrane towards direct contact membrane distillation

2019 ◽  
Vol 6 (8) ◽  
pp. 2553-2564 ◽  
Author(s):  
Lingling Zhong ◽  
Zhigao Zhu ◽  
Yu Han ◽  
Qiao Wang ◽  
Dongmei Liu ◽  
...  
Keyword(s):  
Direct Contact ◽  
Water Flux ◽  
High Water ◽  
Membrane Distillation ◽  
Nanofibrous Membrane ◽  
Direct Contact Membrane Distillation ◽  
One Step ◽  
Nanofibrous Membranes

In situ polymerization of aniline is used to prepare superhydrophobic PVDF nanofibrous membranes for direct contact membrane distillation with high water flux and long wetting times.

scholarly journals Triple-Layer Nanofiber Membranes for Treating High Salinity Brines Using Direct Contact Membrane Distillation

Membranes ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 60 ◽  
Author(s):  
Mustafa Al-Furaiji ◽  
Jason T. Arena ◽  
Jian Ren ◽  
Nieck Benes ◽  
Arian Nijmeijer ◽  
...  
Keyword(s):  
Direct Contact ◽  
Polyvinylidene Fluoride ◽  
Water Flux ◽  
Feed Solution ◽  
High Water ◽  
Membrane Distillation ◽  
Pvdf Membrane ◽  
Direct Contact Membrane Distillation ◽  
Triple Layer ◽  
Layer Membrane

A composite, three-layered membrane for membrane distillation was prepared from electrospun polyvinylidene fluoride (PVDF) nanofibers supported by commercial polyethersulfone (PES) nanofiber based nonwoven from E.I. duPont de Nemours company (DuPont). The membranes were tested in direct contact membrane distillation (DCMD) using a 5.0 M sodium chloride brine as a feed solution. The triple layer membrane combines the hydrophobicity of PVDF and the robustness of the PES. The triple layer membrane demonstrated excellent performance in DCMD (i.e., relatively high water flux compared to the commercial PVDF membrane and a complete salt rejection of the brine) with mechanical properties imparted by the PES layer. This work is the first to demonstrate the use of a commercially produced nanofiber nonwoven for membrane distillation.

One-step fabrication of isotropic poly(vinylidene fluoride) membranes for direct contact membrane distillation (DCMD)

Desalination ◽  
2020 ◽  
Vol 477 ◽  
pp. 114265 ◽  
Author(s):  
Miaomiao Tian ◽  
Shushan Yuan ◽  
Florian Decaesstecker ◽  
Junyong Zhu ◽  
Alexander Volodine ◽  
...  
Keyword(s):  
Direct Contact ◽  
Vinylidene Fluoride ◽  
Membrane Distillation ◽  
Direct Contact Membrane Distillation ◽  
Poly Vinylidene Fluoride ◽  
One Step

scholarly journals Porous Hydrophobic–Hydrophilic Composite Hollow Fiber and Flat Membranes Prepared by Plasma Polymerization for Direct Contact Membrane Distillation

Membranes ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 120 ◽  
Author(s):  
Ashok K. Sharma ◽  
Adam Juelfs ◽  
Connor Colling ◽  
Saket Sharma ◽  
Stephen P. Conover ◽  
...  
Keyword(s):  
Hollow Fiber ◽  
Direct Contact ◽  
Plasma Polymerization ◽  
Polyvinylidene Fluoride ◽  
Hydrophobic Surface ◽  
Diffusion Path ◽  
High Water ◽  
Membrane Distillation ◽  
Vapor Flux ◽  
Direct Contact Membrane Distillation

High water vapor flux at low brine temperatures without surface fouling is needed in membrane distillation-based desalination. Brine crossflow over surface-modified hydrophobic hollow fiber membranes (HFMs) yielded fouling-free operation with supersaturated solutions of scaling salts and their precipitates. Surface modification involved an ultrathin porous polyfluorosiloxane or polysiloxane coating deposited on the outside of porous polypropylene (PP) HFMs by plasma polymerization. The outside of hydrophilic MicroPES HFMs of polyethersulfone was also coated by an ultrathin coating of porous plasma-polymerized polyfluorosiloxane or polysiloxane rendering the surface hydrophobic. Direct contact membrane distillation-based desalination performances of these HFMs were determined and compared with porous PP-based HFMs. Salt concentrations of 1, 10, and 20 wt% were used. Leak rates were determined at low pressures. Surface and cross-sections of two kinds of coated HFMs were investigated by scanning electron microscopy. The HFMs based on water-wetted MicroPES substrate offered a very thin gas gap in the hydrophobic surface coating yielding a high flux of 26.4–27.6 kg/m2-h with 1 wt% feed brine at 70 °C. The fluxes of HFMs on porous PP substrates having a long vapor diffusion path were significantly lower. Coated HFM performances have been compared with flat hydrophilic membranes of polyvinylidene fluoride having a similar plasma-polymerized hydrophobic polyfluorosiloxane coating.

scholarly journals HYDROPHOBIZATION OF PET TRACK-ETCHED MEMBRANES FOR DIRECT CONTACT MEMBRANE DISTILLATION OF LIQUID RADIOACTIVE WASTES

2020 ◽  
Vol 17 (2) ◽  
pp. 45-54
Author(s):  
A.B. Yeszhanov ◽  
Keyword(s):  
Direct Contact ◽  
Gamma Ray ◽  
Water Flux ◽  
Atomic Emission ◽  
Membrane Distillation ◽  
Radioactive Wastes ◽  
Low Level ◽  
Direct Contact Membrane Distillation ◽  
Hydrophobic Membranes ◽  
Entry Pressure

This article provides the results of liquid low-level radioactive wastes treatment by direct contact membrane distillation using polyethylene terephthalate hydrophobic track-etched membranes. The hydrophobization of track-etched membranes was carried out by UV-induced graft polymerization of triethoxyvinylsilane with styrene and coating with fluorine-containing silanes. Hydrophobic membranes were investigated by scanning electron microscope, Fourier-transform infrared spectroscopy, contact anglemeasurements, and liquid entry pressure analysis. Prepared membranes were tested in treatment of liquid low-level radioactive wastes by membrane distillation. The influence of pore sizes on water flux and rejection degree was studied. Rejection degree was evaluated by conductometry and atomic emission method. Decontamination factors evaluated by gamma-ray spectroscopy for 60Co, 137Cs, and 241Am are 85.4, 1900 and 5.4 for membranes modified with polystyrene and triethoxyvinylsilanewith pore diameters of 142 nm; 85.0, 1462 and 4 for membranes modified with perfluorododecyltrichlorosilanewith pore diameters of 150 nm respectively.

scholarly journals Simulation of direct contact membrane distillation regeneration of liquid desiccant solutions used in air-conditioning

2020 ◽  
Vol 58 (6) ◽  
pp. 747
Author(s):  
Hung Cong Duong ◽  
Lan Thi Thu Tran
Keyword(s):  
Direct Contact ◽  
Air Conditioning ◽  
Water Flux ◽  
Experimental Tests ◽  
Membrane Distillation ◽  
Operating Conditions ◽  
Membrane Properties ◽  
Experimental Investigations ◽  
Liquid Desiccant ◽  
Direct Contact Membrane Distillation

Membrane distillation (MD) has great potential for the treatment of hyper saline waters, including liquid desiccant solutions used in air-conditioning systems. Previous experimental investigations have demonstrated the technical feasibility of MD for regeneration of liquid desiccant solutions. In this study, a direct contact membrane distillation (DCMD) process of the LiCl liquid desiccant solution was simulated using MATLAB software. The simulation was first validated using data obtained from experimental tests. Then, it was used to elucidate the water temperatures, LiCl concentration, and water flux profiles along the membrane leaf inside the DCMD membrane module. Finally, with the help of the simulation, the effects of membrane properties and process operating conditions on the DCMD process performance were systematically examined. The results obtained from this simulation enrich the knowledge and hence facilitate the realization of MD for the liquid desiccant solution regeneration application.

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