scholarly journals Carnauba Wax/Halloysite Nanotube with Improved Anti-Wetting and Permeability of Hydrophobic PVDF Membrane via DCMD

Membranes ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 228
Author(s):  
Wan Aisyah Fadilah Wae AbdulKadir ◽  
Abdul Latif Ahmad ◽  
Ooi Boon Seng
Keyword(s):  
Vinylidene Fluoride ◽  
Metal Oxide Nanoparticles ◽  
Membrane Distillation ◽  
Attenuated Total Reflection ◽  
Hydrophobic Membrane ◽  
Water Contact ◽  
Halloysite Nanotube ◽  
Pvdf Membrane ◽  
Carnauba Wax ◽  
Wetting Properties

The hydrophobic membranes have been widely explored to meet the membrane characteristics for the membrane distillation (MD) process. Inorganic metal oxide nanoparticles have been used to improve the membrane hydrophobicity, but limited studies have used nano clay particles. This study introduces halloysite nanotube (HNT) as an alternative material to synthesis a hydrophobic poly(vinylidene fluoride) (PVDF)-HNT membrane. The PVDF membranes were fabricated using functionalized HNTs (e.g., carnauba wax and 1H,1H,2H,2H-perfluorooctyl-trichlorosilane (FOTS)). The results were determined by Fourier transform infrared-attenuated total reflection, scanning electron microscope, goniometer and porometer to determine the desired hydrophobic membrane for direct contact membrane distillation (DCMD). The addition of FOTS-HNT (fs-HNT) and carnauba wax-HNT (fw-HNT) in the PVDF membrane enhanced the water contact angle (CA) to 127° and 137°, respectively. The presence of fw-HNT in the PVDF membrane exhibited higher liquid entry pressure (LEP) (2.64 bar) compared to fs-HNT in the membrane matrix (1.44 bar). The PVDF/fw-HNT membrane (Pfw-HNT) obtained the highest flux of 7.24 L/m2h with 99.9% salt removal. A stable permeability in the Pfw-HNT membrane was obtained throughout 16 h of DCMD. The incorporation of fw-HNT in the PVDF membrane had improved the anti-wetting properties and the membrane performance with the anti-fouling effect.

scholarly journals Effect of temperature and salt on PVDF membrane wetting properties

2021 ◽  
Author(s):  
Kefan Jiang ◽  
◽  
Hooman Chamani ◽  
Takeshi Matsuura ◽  
Dipak Rana ◽  
...  
Keyword(s):  
Contact Angle ◽  
Polyvinylidene Fluoride ◽  
Membrane Separation ◽  
Feed Solution ◽  
Membrane Distillation ◽  
Effect Of Temperature ◽  
Separation Processes ◽  
Water Contact ◽  
Pvdf Membrane ◽  
Wetting Properties

Membrane distillation (MD) is a thermally driven separation process. Despite many advantages over other membrane separation processes, pore wetting hampers the wide commercial applications of the MD process. In this paper, the effect of temperature and presence (or absence) of salt in the feed solution on the wetting properties of commercial polyvinylidene fluoride (PVDF) membrane during a period of eight weeks was investigated. Liquid entry pressure (LEP) and water contact angle (WCA) were employed to characterize the wetting properties of the PVDF membrane. The result shows that the temperature has a significant impact on the decrease of the contact angle of the PVDF membrane.

Surface Modification of Poly(Vinylidene Fluoride) Microporous Membrane by Ferric Hydroxide Sol-Gel

2011 ◽  
Vol 343-344 ◽  
pp. 637-642 ◽  
Author(s):  
Ya Jie Xie ◽  
Wan Peng Hu ◽  
Zhuan Wang ◽  
Song Xu
Keyword(s):  
Surface Modification ◽  
Vinylidene Fluoride ◽  
Ferric Hydroxide ◽  
Contact Angles ◽  
Attenuated Total Reflection ◽  
Water Contact ◽  
Pvdf Membrane ◽  
Water Cleaning ◽  
Poly Vinylidene Fluoride ◽  
Adsorption Amount

Surface modification of poly(vinylidene fluoride) (PVDF) membrane was accomplished by the adsorption of ferric hydroxide sol to impove its hydrophilicity. The adsorption curves of the membranes were analyzed by weight measurements, and the typical results showed a two-platform character in low concentration. The effects of the adsorption time, the ferric hydroxide sol concentration, the test temperature, as well as the water cleaning time on the adsorption amount were observed. Attenuated total reflection-Fourier transform infrared spectroscopy (ATR/ FTIR) analysis showed that the adsorption of ferric hydroxide sol on poly(vinylidene fluoride) microporous membranes (PVDFMM) is effective. The membranes hydrophilic performance was represented by water contact angle measurements. The water contact angles changes from the virgin 128°to the lowest value 81.90° in the range of 0~0.10 mol/L ferric hydroxide aqueous solution. The results indicated that ferric hydroxide sol can be immobilized on the PVDF films by adsorption, and the membrane hydrophilic performence increases with the increase of the adsorption amount of the ferric hydroxide sol onto the PVDF membrane surface.

scholarly journals Hydrophilic modification of poly(vinylidene fluoride) ultrafiltration membranes by surface UV photo-grafting with N,N′-methylene-bisacrylamide as monomer and Ce(IV) as initiator

2015 ◽  
Vol 6 (2) ◽  
pp. 280-289
Author(s):  
Baoli Shi ◽  
Zheng Li ◽  
Xing Su
Keyword(s):  
Vinylidene Fluoride ◽  
Membrane Surface ◽  
Ultrafiltration Membranes ◽  
Water Contact ◽  
Pvdf Membrane ◽  
Hydrophilic Modification ◽  
Poly Vinylidene Fluoride ◽  
Modified Membrane ◽  
Porosity Measurements ◽  
Pure Pvdf

A UV photo-grafting method was utilised to enhance the hydrophilicity and anti-fouling property of self-made poly(vinylidene fluoride) (PVDF) ultrafiltration membranes. N,N′-methylene-bisacrylamide (MBAA) was used as monomer and Ce(IV) was used as initiator to obtain balance between grafting treatment consumption and enhanced performance. MBAA could be grafted onto the surface of pure PVDF membranes through a water-phase grafting method under UV photoradiation. When the MBAA concentration was 0.07 mol/L, the Ce(IV) concentration was 0.04 mol/L, and the irradiation duration was 3 min, the membrane surface was grafted with a sufficient amount of monomer under a UV photoradiation intensity of 5.0 mW/cm2. The water contact angle on the surface of the modified membrane decreased by approximately 16°, and flux recovery increased by approximately 40% compared with the pure PVDF membrane when treating river water. For bovine serum albumin rejection and porosity measurements no significant changes were observed between pure PVDF and graft-treated membranes. The enhanced performance of the modified membrane in this work was moderate, but the UV irradiation duration (3 min) was short. The integrative effects of UV modification in this work were satisfactory when both irradiation duration and enhanced performance were considered.

Novel Membrane Suitable for Membrane Distillation: Effect of Mixed Nanofillers on the Membrane Performance

2019 ◽  
Vol 801 ◽  
pp. 325-330 ◽  
Author(s):  
Mohamed R. El-Marghany ◽  
Ahmed H. El-Shazly ◽  
Mohamed Sameh Abdalghany Salem ◽  
Mohamed Nabil Sabry ◽  
Norhan Nady
Keyword(s):  
Sodium Chloride ◽  
Vinylidene Fluoride ◽  
Chloride Concentration ◽  
Membrane Distillation ◽  
Polymeric Membrane ◽  
Sodium Chloride Concentration ◽  
Electrospinning Technique ◽  
Average Pore ◽  
Water Contact ◽  
Membrane Performance

The aim of the present work is to investigate the performance of a newly fabricated membrane used for the membrane distillation process. Both titanium dioxide nanorods and multi-walled carbon nanotubes together were dispersed inside Poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) membrane. Both pure PVDF-HFP and its composite membrane with the two fillers together PVDF-HFP/TiO2-CNTs were fabricated using electrospinning technique and were imaged by using SEM. Both the fiber diameter and the average pore diameter were calculated by using ImageJ software. Static water contact angle, membrane porosity, liquid enter pressure were determined. Moreover, the membrane performance was determined by using membrane distillation (MD) system for desalination. The effect of the feed conditions such as feed temperature, flow rate, and salt concentration, were studied. The obtained results confirm the improvement in the membrane productivity up to 46% at 9000 ppm sodium chloride concentration and by about 13.7% than the pure polymeric membrane at the highest used feed sodium chloride concentration (36000 ppm).

Hydrophilic Modification of PVDF Membrane by Using PHEMA-PDMS-PHEMA Amphiphilic Copolymer as Addictive

2015 ◽  
Vol 799-800 ◽  
pp. 16-20
Author(s):  
Dan Li ◽  
Chun Ju He
Keyword(s):  
Vinylidene Fluoride ◽  
Pure Water ◽  
Water Flux ◽  
Amphiphilic Copolymer ◽  
Water Recovery ◽  
Hydroxyethyl Methacrylate ◽  
Water Contact ◽  
Pvdf Membrane ◽  
Hydrophilic Modification ◽  
Copolymer Poly

The hydrophilic modification of poly (vinylidene fluoride) (PVDF) membrane is achieved by using amphiphilic copolymer poly (2-hydroxyethyl methacrylate)-b-polydimethylsiloxane-b-poly (2-hydroxyethyl methacrylate) (PHEMA-b-PDMS-b-PHEMA) as addictive. The copolymer is synthesized via atom transfer radical polymerization (ATRP) and the membranes are prepared by non-solvent induced phase separation. The addition of amphiphlic copolymer has significant influence on membrane hydrophilicity and anti-fouling property. As the addictive content increasing, the water contact angle is decreased from 92° to 65°, water flux and pure water recovery rate are increased from 52.9L/m2h to 263.3 L/m2h and 71 to 95%, respectively.

scholarly journals Facile Fabrication of Multi-Hydrogen Bond Self-Assembly Poly(MAAc-co-MAAm) Hydrogel Modified PVDF Ultrafiltration Membrane to Enhance Anti-Fouling Property

Membranes ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 761
Author(s):  
Weigui Fu ◽  
Guoxia Li ◽  
Gaowei Zhai ◽  
Yunji Xie ◽  
Meixiu Sun ◽  
...  
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Self Assembly ◽  
Vinylidene Fluoride ◽  
Pure Water ◽  
Polymer Gel ◽  
Hydrophobic Membrane ◽  
Water Contact ◽  
Monomer Ratio ◽  
Gel Layer

In this work, a facile preparation method was proposed to reduce natural organics fouling of hydrophobic membrane via UV grafting polymerization with methacrylic acid (MAAc) and methyl acrylamide (MAAm) as hydrophilic monomers, followed by multihydrogen bond self-assembly. The resulting poly(vinylidene fluoride)-membranes were characterized with respect to monomer ratio, chemical structure and morphology, surface potential, and water contact angle, as well as water flux and organic foulants ultrafiltration property. The results indicated that the optimal membrane modified with a poly(MAAc-co-MAAm) polymer gel layer derived from a 1:1 monomer ratio exhibited superior hydrophilicity and excellent gel layer stability, even after ultrasonic treatment or soaking in acid or alkaline aqueous solution. The initial water contact angle of modified membranes was only 36.6° ± 2.9, and dropped to 0° within 13 s. Moreover, flux recovery rates (FRR) of modified membranes tested by bovine serum albumin (BSA), humic acid (HA), and sodium alginate (SA) solution, respectively, were all above 90% after one-cycle filtration (2 h), significantly higher than that of the pure membrane (70–76%). The total fouling rates (Rt) of the pure membrane for three foulants were as high as 47.8–56.2%, while the Rt values for modified membranes were less than 30.8%. Where Rt of BSA dynamic filtration was merely 10.7%. The membrane designed through grafting a thin-layer hydrophilic hydrogel possessed a robust antifouling property and stability, which offers new insights for applications in pure water treatment or protein purification.

scholarly journals Membrane distillation of saline and oily water using nearly superhydrophobic PVDF membrane incorporated with SiO2 nanoparticles

2018 ◽  
Vol 78 (12) ◽  
pp. 2532-2541 ◽  
Author(s):  
N. Hamzah ◽  
M. Nagarajah ◽  
C. P. Leo
Keyword(s):  
Polyvinylidene Fluoride ◽  
Volume Ratio ◽  
Sio2 Nanoparticles ◽  
Membrane Distillation ◽  
Permeate Flux ◽  
Oil And Grease ◽  
Sem Images ◽  
Water Contact ◽  
Pvdf Membrane ◽  
Oily Water

Abstract Fat, oil and grease in wastewater generated from household kitchens, restaurants and food processing plants affect sewer systems, water resources and environment adversely. Hence, membrane distillation of saline and oily water was studied using a nearly superhydrophobic membrane developed in this work. Polyvinylidene fluoride (PVDF) membrane incorporated SiO2 nanoparticles was synthesized via phase inversion with dual baths and modified using hexadecyltrimethoxy silane. The volume ratio of silane to ethanol was varied between 1:200 to 1:25. The membrane characteristics were examined using a goniometer, a porometer, scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The PVDF-SiO2 membrane modified using the volume ratio of 1:50 achieved the highest water contact angle of 141.6° and LEP of 2.642 bar. This membrane was further tested in membrane distillation to observe the permeate flux of distilled water, saline solution (1 M NaCl) as well as saline and oily solution (1 M NaCl; 1,000 ppm of palm oil). The modified PVDF/SiO2 showed high permeate flux which is nearly four times of the permeate flux of neat PVDF membrane, but still susceptible of salt and oil fouling as shown in SEM images.

scholarly journals Surface Oxidation of Ethylenechlorotrifluoroethylene (ECTFE) Membrane for the Treatment of Real Produced Water by Membrane Distillation

2018 ◽  
Vol 15 (8) ◽  
pp. 1561 ◽  
Author(s):  
Zahra Anari ◽  
Arijit Sengupta ◽  
Sumith Wickramasinghe
Keyword(s):  
Produced Water ◽  
Membrane Surface ◽  
Surface Oxidation ◽  
Membrane Distillation ◽  
Hydrophobic Membrane ◽  
Water Contact ◽  
Potential Measurement ◽  
Salt Deposition ◽  
Organic Fouling ◽  
Simple Surface

Modification of ethyleneechlorotrifluoroethylene (ECTFE) membranes by simple surface oxidation was reported in the present investigation in order to induce thin hydrophilic layer on hydrophobic membrane surface for the treatment of real produced water (PW). FTIR spectra indicates the appearance of hydrophilic functional groups (–OH and –COOH) on the membrane surface due to modification, while water contact angle, zeta potential measurement, EDX, XPS analysis confirmed the presence of O functionalized hydrophilic groups on the surface. The effect of modification temperature and the time of surface oxidation on the performance of the resulting membranes were studied systematically, which revealed that induction of optimized hydrophilicity can successfully reduce the organic fouling. However, too much hydrophilic surface induces polar/electrostatic interaction resulting salt deposition on membrane surface. A simple on site cleaning procedure was demonstrated to be successful for the treatment PW for at least three consecutive cycles of membrane distillation (MD).

scholarly journals Recent Progress on Tailoring and Modification of Membranes for Membrane Distillation: A Review

2021 ◽  
Vol 25 (3) ◽  
pp. 93-117
Author(s):  
Nur Hashimah Alias ◽  
Nur Fazira Sufianasuri
Keyword(s):  
High Efficiency ◽  
Saline Water ◽  
Morphological Structure ◽  
Membrane Distillation ◽  
Future Research ◽  
Separation And Purification ◽  
Hydrophobic Membrane ◽  
Comprehensive Overview ◽  
Water Contact ◽  
Hydrophobic Membranes

Membrane distillation (MD) has gained the interest of many researchers since it is a promising method for the separation and purification process. Membrane distillation (MD) is a non-isothermal separation process in which differential vapor pressure between porous hydrophobic membrane surfaces acts as a driving factor. A hydrophobic membrane is used in the application of MD, which permits only the passage of vapor produced on the feed side through its pores to the permeate side. One of the most significant obstacles to the commercialisation of the MD method is a lack of appropriate membranes for the process. On the other hand, conventional hydrophobic membranes are subjected to rapid wetting and severe fouling, mainly when low surface tension compounds are present in saline water, resulting in decreased MD performance. In recent decades, MD membranes have received exceptional scientific interest, with substantial progress being made in the design and production of MD membranes appropriate for use in many applications. This review gives a comprehensive overview of recent research developments in the tailoring morphological structure of hydrophobic membranes, emphasising advancements in the fabrication and modification of membranes towards exhibiting high efficiency in the MD process. In addition, the critical morphology characteristics, mainly surface roughness, wettability, and water contact angle, are analysed. Finally, the challenges faced and future research direction is highlighted.  

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