scholarly journals Highly Effective Anti-Organic Fouling Performance of a Modified PVDF Membrane Using a Triple-Component Copolymer of P(Stx-co-MAAy)-g-fPEGz as the Additive

Membranes ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 951
Author(s):  
Xiaoji Zhou ◽  
Yizhuo Sun ◽  
Shusu Shen ◽  
Yan Li ◽  
Renbi Bai
Keyword(s):  
Contact Angle ◽  
Polymeric Membranes ◽  
Water And Wastewater Treatment ◽  
Water Contact ◽  
Water Emulsion ◽  
Pvdf Membrane ◽  
Water Cleaning ◽  
Good Potential ◽  
And Performance ◽  
Lower Ratio

In this study, a triple-component copolymer of P(Stx-co-MAAy)-g-fPEGz containing hydrophobic (styrene, St), hydrophilic (methacrylic acid, MAA), and oleophobic (perfluoroalkyl polyethylene glycol, fPEG) segments was synthesized and used as an additive polymer to prepare modified PVDF membrane for enhanced anti-fouling performance. Two compositions of St:MAA at 4:1 and 1:1 for the additive and two blending ratios of the additive:PVDF at 1:9 and 3:7 for the modified membranes were specifically examined. The results showed that the presence of the copolymer additive greatly affected the morphology and performance of the modified PVDF membranes. Especially, in a lower ratio of St to MAA (e.g., St:MAA at 1:1 versus 4:1), the additive polymer and therefore the modified PVDF membrane exhibited both better hydrophilic as well as oleophobic surface property. The prepared membrane can achieve a water contact angle at as low as 48.80° and display an underwater oil contact angle at as high as 160°. Adsorption experiments showed that BSA adsorption (in the concentration range of 0.8 to 2 g/L) on the modified PVDF membrane can be reduced by as much as 93%. From the filtration of BSA solution, HA solution, and oil/water emulsion, it was confirmed that the obtained membrane showed excellent resistance to these organic foulants that are often considered challenging in membrane water treatment. The performance displayed slow flux decay during filtration and high flux recovery after simple water cleaning. The developed membrane can therefore have a good potential to be used in such applications as water and wastewater treatment where protein and other organic pollutants (including oils) may cause severe fouling problems to conventional polymeric membranes.

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.

scholarly journals Karakterisasi dan Kinerja Membran Polyethersulfone Termodifikasi Aditif Anorganik secara Blending Polimer

2021 ◽  
Vol 6 (4) ◽  
Author(s):  
Umi Fathanah ◽  
Hesti Meilina
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Membrane Surface ◽  
Scale Up ◽  
Hydroxyl Group ◽  
Water Contact ◽  
Dimethyl Acetamide ◽  
Phase Inversion Technique ◽  
And Performance ◽  
Pes Membrane

Recently, membrane technology has developed rapidly as a process for water treatment. The membrane process is in demand due to several advantages including being able to work at low temperatures, easier to operate and easy to scale up. Magnesium hydroxide (Mg(OH)2) is an inorganic compound that is inexpensive, non-toxic and hydrophilic, so it has the potential to be used as an additive in membrane fabrication. This study aims to determine the characteristics and performance (permeability and selectivity) of Polyethersulfone (PES) membrane modified with Mg(OH)2, using dimethyl Acetamide (DMAc) as solvent. The membrane was made by blending polymer with phase inversion technique and the characterization carried out included membrane morphological tests, functional group tests, water contact angle tests and evaluating membrane performance by measuring membrane selectivity and permeability. The results showed that the hydroxyl group contained in Mg(OH)2 was able to increase the hydrophilicity which was indicated by a decrease in the water contact angle on the modified membrane to 65o. The Mg(OH)2 additive acts as a pore-forming agent which can be seen in the changes in membrane morphology on the cross-section of the membrane surface. The performance of the membrane resulted in an increase in membrane permeability of 51 L/m2.hour.bar with humid acid rejection of 63%.

scholarly journals Imparting hydrophobic functionalities to copper surface using laser ablation and water emulsion of surfactants

2021 ◽  
Vol 289 ◽  
pp. 06004
Author(s):  
Sergey Grigoriev ◽  
Evgeniy Trushin ◽  
Alena Likhaeva ◽  
Alexander Volkov ◽  
Marat Dasaev
Keyword(s):  
Contact Angle ◽  
Laser Ablation ◽  
Water Contact Angle ◽  
Copper Surface ◽  
Water Contact ◽  
Water Emulsion ◽  
Laser Ablation Process ◽  
Exchange Processes ◽  
Intensify Heat Exchange ◽  
Lower Production

Wettability is one of the main characteristics of a surface and reflects the ability of a liquid to flow over a solid surface. Using hydrophobic functional surfaces in evaporator and condenser of heating plants to intensify heat exchange processes will increase efficiency and, consequently, reduce the metal consumption and weight-size parameters of this equipment. This will result in reduced energy consumption and lower production and operating costs. This paper presents an analysis of methods for creating hydrophobic surfaces. The fabrication of hydrophobic copper surface of experimental samples by creating multimodal relief in form of 50 µm grid by laser ablation process and subsequent reduction of surface energy of material using water emulsion of octadecylamine is grounded and described. The fluence was varied from 5 to 900 J/cm2 when modifying the surface using laser station. The dependence of the effect of laser fluence on water contact angle value is presented. Following the study, the optimum laser irradiation parameters for the surface of experimental samples were determined, at which the maximum value of water contact angle of 146.61° and the minimum value of roll-off angle of 13.5° were obtained.

scholarly journals Testing the Durability of Anti-Soiling Coatings for Solar Cover Glass by Outdoor Exposure in Denmark

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 299 ◽  
Author(s):  
Gizelle C. Oehler ◽  
Fabiana Lisco ◽  
Farwah Bukhari ◽  
Soňa Uličná ◽  
Ben Strauss ◽  
...  
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Light Transmission ◽  
High Water ◽  
Outdoor Exposure ◽  
Outdoor Environment ◽  
Cover Glass ◽  
Water Contact ◽  
Hydrophobic Coating ◽  
And Performance

The presence of soiling on photovoltaic modules reduces light transmission through the front cover glass to the active absorber, thereby reducing efficiency and performance. Current soiling mitigation techniques are expensive and/or ineffective. However, anti-soiling coatings applied to the solar cover glass have the potential to reduce soiling for long periods of time without continuous maintenance. This paper reports the performance of two transparent hydrophobic coatings (A and B) exposed to the outdoor environment of coastal Denmark for 24 weeks. A comparison was made between the performance of coated and uncoated glass coupons, periodically cleaned coupons, and accelerated laboratory tests. Although initial results were promising, water contact angle and transmittance values were found to decline continuously for all coated and uncoated coupons. Surface blisters, film thickness reduction, changes in surface chemistry (fluorine loss), and abrasion damage following cleaning were observed. Coupons cleaned every 4 weeks showed a restoration in transmittance. Cycles of light rainfall and evaporation combined with a humid and salty environment led to cementation occurring on all coupons. The development of an abrasion-resistant, super-hydrophobic coating with a low roll-off angle and high water contact angle is more likely to provide an anti-soiling solution by reducing the build-up of cementation.

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.

Long-Term Stable Metal Organic Framework (MOF) Based Mixed Matrix Membranes for Ultrafiltration

2020 ◽  
Author(s):  
Muayad Al-shaeli ◽  
Stefan J. D. Smith ◽  
Shanxue Jiang ◽  
Huanting Wang ◽  
Kaisong Zhang ◽  
...  
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Mixed Matrix Membranes ◽  
Recovery Ratio ◽  
Mixed Matrix ◽  
Water Contact ◽  
Membrane Performance ◽  
Metal Organic ◽  
Matrix Membranes

<p>In this study, novel <a>mixed matrix polyethersulfone (PES) membranes</a> were synthesized by using two different kinds of metal organic frameworks (MOFs), namely UiO-66 and UiO-66-NH<sub>2</sub>. The composite membranes were characterised by SEM, EDX, FTIR, PXRD, water contact angle, porosity, pore size, etc. Membrane performance was investigated by water permeation flux, flux recovery ratio, fouling resistance and anti-fouling performance. The stability test was also conducted for the prepared mixed matrix membranes. A higher reduction in the water contact angle was observed after adding both MOFs to the PES and sulfonated PES membranes compared to pristine PES membranes. An enhancement in membrane performance was observed by embedding the MOF into PES membrane matrix, which may be attributed to the super-hydrophilic porous structure of UiO-66-NH<sub>2</sub> nanoparticles and hydrophilic structure of UiO-66 nanoparticles that could accelerate the exchange rate between solvent and non-solvent during the phase inversion process. By adding the MOFs into PES matrix, the flux recovery ratio was increased greatly (more than 99% for most mixed matrix membranes). The mixed matrix membranes showed higher resistance to protein adsorption compared to pristine PES membranes. After immersing the membranes in water for 3 months, 6 months and 12 months, both MOFs were stable and retained their structure. This study indicates that UiO-66 and UiO-66-NH<sub>2</sub> are great candidates for designing long-term stable mixed matrix membranes with higher anti-fouling performance.</p>

scholarly journals Surface modification of PMMA polymer and its composites with PC61BM fullerene derivative using an atmospheric pressure microwave argon plasma sheet

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andrzej Sikora ◽  
Dariusz Czylkowski ◽  
Bartosz Hrycak ◽  
Magdalena Moczała-Dusanowska ◽  
Marcin Łapiński ◽  
...  
Keyword(s):  
Contact Angle ◽  
Surface Modification ◽  
Chemical Composition ◽  
Water Contact Angle ◽  
Plasma Sheet ◽  
Atmospheric Pressure ◽  
Argon Plasma ◽  
Fullerene Derivative ◽  
Water Contact ◽  
Pmma Polymer

AbstractThis paper presents the results of experimental investigations of the plasma surface modification of a poly(methyl methacrylate) (PMMA) polymer and PMMA composites with a [6,6]-phenyl-C61-butyric acid methyl ester fullerene derivative (PC61BM). An atmospheric pressure microwave (2.45 GHz) argon plasma sheet was used. The experimental parameters were: an argon (Ar) flow rate (up to 20 NL/min), microwave power (up to 530 W), number of plasma scans (up to 3) and, the kind of treated material. In order to assess the plasma effect, the possible changes in the wettability, roughness, chemical composition, and mechanical properties of the plasma-treated samples’ surfaces were evaluated by water contact angle goniometry (WCA), atomic force microscopy (AFM), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS). The best result concerning the water contact angle reduction was from 83° to 29.7° for the PMMA material. The ageing studies of the PMMA plasma-modified surface showed long term (100 h) improved wettability. As a result of plasma treating, changes in the samples surface roughness parameters were observed, however their dependence on the number of plasma scans is irregular. The ATR-FTIR spectra of the PMMA plasma-treated surfaces showed only slight changes in comparison with the spectra of an untreated sample. The more significant differences were demonstrated by XPS measurements indicating the surface chemical composition changes after plasma treatment and revealing the oxygen to carbon ratio increase from 0.1 to 0.4.

scholarly journals Self-Cleaning Polyester Fabric Prepared with TiOF2 and Hexadecyltrimethoxysilane

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 387
Author(s):  
Euigyung Jeong ◽  
Heeju Woo ◽  
Yejin Moon ◽  
Dong Yun Lee ◽  
Minjung Jung ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Contact Angle ◽  
Treatment Method ◽  
Polyester Fabric ◽  
Anatase Tio2 ◽  
The Self ◽  
Water Contact ◽  
Direct Fluorination ◽  
Tomato Ketchup ◽  
Self Cleaning

In this study, self-cleaning polyester (PET) fabrics were prepared using TiOF2 and hexadecyltrimethoxysilane(HDS) treatment. TiOF2 was synthesized via direct fluorination of a precursor TiO2 at various reaction temperatures. The prepared PET fabrics had superior photocatalytic self-cleaning properties compared with anatase TiO2/HDS-treated PET fabrics under UV and sunlight with 98% decomposition of methylene blue. TiOF2/HDS-treated PET fabrics also had superior superhydrophobic self-cleaning properties compared with anatase TiO2/HDS-treated PET fabrics with a 161° water contact angle and 6° roll-off angle. After the self-cleaning tests of the non-dyed TiOF2/HDS-treated PET fabrics, we prepared dyed TiOF2/HDS-treated PET fabrics to test practical aspects of the treatment method. These PET fabrics were barely stained by tomato ketchup; even when stained, they could be self-cleaned within 4 h. These results suggest that practical self-cleaning PET fabrics with superhydrophobicity and photocatalytic degradation could be prepared using TiOF2/HDS-treatment.

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