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

2021 ◽  
Vol 6 (4) ◽  
Author(s):  
Umi Fathanah ◽  
Hesti Meilina

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%.

2015 ◽  
Vol 1120-1121 ◽  
pp. 64-67
Author(s):  
Hong Shao ◽  
Chang Yu Tang ◽  
Mao Bing Shuai ◽  
Ke Qing Xu ◽  
Yuan Lin Zhou ◽  
...  

In this paper, we present a new approachcalled hyperthermal hydrogen induced cross-linking (HHIC) technology,which can successfully enhance the surface wettability of Parylene C (PC) film via cross-linking hydrophilic polyacrylic acid(PAA)on its surface. Water Contact Angle Meter and Fourier Transform Infrared Spectroscopy (FTIR) were used to characterize wetting property, surface chemical structureof PC film before or after HHIC treatment,respectively. The results show that PAA with polar functional groups can be successfully grafted onto the PC film. As a result, the water contact angle of the modified PC membrane surface decreased from 84° to 23°,PC membrane surface wettability is improved effectively.


2012 ◽  
Vol 627 ◽  
pp. 791-795
Author(s):  
Ru Li ◽  
Fen Fen Liu ◽  
Ji Fei Deng

The use of low-temperature plasmas to modify the surface of substrates and grafted acrylic acid is discussed. Their surface composition characterized by attenuated total reflectance fourier transform infrared (ATR-FTIR) spectra and water contact angle. The results of various techniques indicated that acrylic acid could be incorporated in the membrane surface. The plasma treatment time,plasma treatment power and grafting time effect on water contact angle. The water contact angle decreased from 67° for virgin PES to 11° for the plasma-induced and 0° for grafted AA.


Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 299 ◽  
Author(s):  
Gizelle C. Oehler ◽  
Fabiana Lisco ◽  
Farwah Bukhari ◽  
Soňa Uličná ◽  
Ben Strauss ◽  
...  

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.


2011 ◽  
Vol 418-420 ◽  
pp. 639-642
Author(s):  
Tao Yuan ◽  
Jian Qiang Meng ◽  
Guo Rong Cai ◽  
Yu Feng Zhang

An amphiphilic graft copolymer was obtained via atom transfer radical polymerization (ATRP) of methacrylate (MMA) initiated directly by polyvinylidene fluoride (PVDF). Hydrophilic PVDF membranes were prepared by immersion precipitation of PVDF-g-PMMA and PVDF blend solutions. The chemical structure and the molecular weight were characterized by 1H-NMR and GPC. The hydrophilicity of membrane surfaces were characterized by static water contact angle. Top surface and cross-section of membranes were observed by Field Emission Scanning Electron Microscope (FESEM). The results demonstrated the water contact angle of the membrane surface decreased from 89°to 67°, indicating enhanced hydrophilicity; the pure water flux water firstly decreased and then increased up to 1.7 times of the PVDF membrane. The retention of PEG (Mn=6000) could be maintained at 93%-95%.


2011 ◽  
Vol 64 (11) ◽  
pp. 2223-2229 ◽  
Author(s):  
J. L. Duan ◽  
H. M. Zhang ◽  
C. C. Wang ◽  
H. Y. Li ◽  
F. L. Yang

This paper introduces a versatile approach for surface modification of 621-terylene filtration fabric (FF) self-assembled by a dynamic layer-by-layer technique. The hexadecyl trimethyl ammonium bromide (HTAB) and cross-linked polyvinyl alcohol microspheres (PVA-MS) were alternatively deposited on support membrane under a pressure of 0.01 MPa to modify FF. Morphological changes and hydrophilicity of the modified FF were characterized in detail by scanning electron micrograph and water contact angle measurements. Results revealed that PVA-MS could be adsorbed mainly on the surface of FF and water contact angle decreased with the increase of HTAB/PVA-MS bilayer numbers indicating an enhanced hydrophilicity for the modified FF. Backwash experiments of the modified FF exhibited much higher stability of PVA-MS. Protein adsorption experiments were conducted to evaluate the antifouling property of the modified FF. Results indicated that protein adsorption of the membrane surface could be obviously improved by modification, which exhibited superior antifouling property of the modified FF.


2020 ◽  
Author(s):  
Muayad Al-shaeli ◽  
Stefan J. D. Smith ◽  
Shanxue Jiang ◽  
Huanting Wang ◽  
Kaisong Zhang ◽  
...  

<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>


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andrzej Sikora ◽  
Dariusz Czylkowski ◽  
Bartosz Hrycak ◽  
Magdalena Moczała-Dusanowska ◽  
Marcin Łapiński ◽  
...  

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.


Author(s):  
Wei Lee Lim ◽  
Shiplu Roy Chowdhury ◽  
Min Hwei Ng ◽  
Jia Xian Law

Tissue-engineered substitutes have shown great promise as a potential replacement for current tissue grafts to treat tendon/ligament injury. Herein, we have fabricated aligned polycaprolactone (PCL) and gelatin (GT) nanofibers and further evaluated their physicochemical properties and biocompatibility. PCL and GT were mixed at a ratio of 100:0, 70:30, 50:50, 30:70, 0:100, and electrospun to generate aligned nanofibers. The PCL/GT nanofibers were assessed to determine the diameter, alignment, water contact angle, degradation, and surface chemical analysis. The effects on cells were evaluated through Wharton’s jelly-derived mesenchymal stem cell (WJ-MSC) viability, alignment and tenogenic differentiation. The PCL/GT nanofibers were aligned and had a mean fiber diameter within 200–800 nm. Increasing the GT concentration reduced the water contact angle of the nanofibers. GT nanofibers alone degraded fastest, observed only within 2 days. Chemical composition analysis confirmed the presence of PCL and GT in the nanofibers. The WJ-MSCs were aligned and remained viable after 7 days with the PCL/GT nanofibers. Additionally, the PCL/GT nanofibers supported tenogenic differentiation of WJ-MSCs. The fabricated PCL/GT nanofibers have a diameter that closely resembles the native tissue’s collagen fibrils and have good biocompatibility. Thus, our study demonstrated the suitability of PCL/GT nanofibers for tendon/ligament tissue engineering applications.


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