Surface Modification of PS Super-Filtration Membranes with Low Temperature Plasma

2013 ◽  
Vol 800 ◽  
pp. 606-609 ◽  
Author(s):  
Ru Li ◽  
Fen Fen Liu ◽  
Ji Fei Deng

The polysulfone membranes surface modification by the low temperature air plasma for the study. The PS membranes surface composition, filtration, antifouling characteristics with the modification was characterized by water contact angle, water fluxes, interception rate. Polysulfone membranes hydrophilic has been greatly improved, by water contact angle decreased significantly with low temperature air plasma treatment .Optimal conditions for plasma processing are power 60W, 1.5min, vacuum 60Pa.The water fluxes for the modified PS were increased 2.3 times than the nascent one, the interception rate was little changed. Membrane pollution gradually increased as the wastewater permeation flux decreased with time.

2020 ◽  
Vol 2 (2) ◽  
pp. 48-49

Ivory nuts, produced by palms from the genus Phytelephas, possess a hard and microporous endosperm with a strong resemblance to elephant ivory. The nuts sustainable appeal made them popular as eco-friendly substitutes to ivory since they promote the development of forest communities without contributing to deforestation and animal poaching. In addition, they have been commercialized as microbeads to replace microplastics in cosmetic applications. However, this material is vulnerable to deterioration by micro-organisms and insects, as they are predominantly constituted by β-1,4-mannan, a hydrophilic polysaccharide similar to cellulose. In this context, seed endosperm was treated for 80 s by an atmospheric air plasma jet so as to modify its wettability, as plasma has been widely studied recently for seed disinfection and surface modification. Plasma treated samples were characterized by the water contact angle, AFM, and Raman imaging. Water contact angle results showed an increase from (31.5 ± 8.7)º to (78.9 ± 5.4)º, indicating incorporation of hydrophobic moieties to the sample surface. In turn, AFM images demonstrate the formation of a rough and heterogeneous coating that resembles epicuticular wax layers. Furthermore, principal component analysis of Raman imaging results evidenced contributions from wax (1156, 1170 and 1410 cm-1), carbohydrates (1020, 1080 and 1106 cm-1), and lignin (1573, 1635 and 1662 cm-1). These results indicate that plasma treatment promoted the migration of hydrophobic waxes to the surface and their crosslinking with fragmented cell wall material such as mannan, xylan, and lignin, promoting seed hydrophobization with no need for additional precursors or generation of side products.


2021 ◽  
Vol 11 (4) ◽  
pp. 12227-12237
Author(s):  
Yuri Ferreira da Silva ◽  
Renata Nunes Oliveira ◽  
Renata Antoun Simao

Ivory nuts, bioproducts from South American palms, possess a hard, water-insoluble, and microporous endosperm with a strong resemblance to elephant ivory. The nuts sustainable appeal made them popular as eco-friendly substitutes to ivory and, more recently, microbeads. However, their hygroscopicity and mannan composition impart susceptibility to deterioration by microbes and insects. Cold plasma treatment has been widely investigated as a clean and cost-effective procedure for seed disinfection and surface modification. Hence, in this work, ivory nut endosperm was treated by an air plasma jet to modify wettability. Plasma treated samples were characterized by the water contact angle, AFM, and Raman imaging. Water contact angle results presented an increase from (31.5 ± 8.7)º to (78.9 ± 5.4)º, demonstrating surface hydrophobization. This result was attributed to the modification of surface chemistry by migration and repolymerization of extractives promoted by plasma treatment. AFM results evidenced the formation of a heterogeneous layer containing lamellar features similar to plant epicuticular waxes. Besides, principal component analysis of Raman imaging results highlighted spectral contributions from wax, xylan, mannan, and lignin. These results demonstrate that atmospheric air plasma jets can be employed for ivory nut hydrophobization with no need for additional precursors, altering surface chemistry by crosslinking endosperm native substances.


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.


2013 ◽  
Vol 423-426 ◽  
pp. 443-447 ◽  
Author(s):  
Wen Wen Dou ◽  
Yu Chao Niu ◽  
Xiang Ju Liu ◽  
Xiao Li Wang ◽  
Yong Xu

Antireflective coatings with stable hydrophobicity for solar tube were prepared via sol-gel method and hexamethyldisilazane (HMDS) treatment. The coatings have a high porosity, groove-like surface morphology and a big static water contact angle. As a result, the coatings exhibit high transmittance even in high humidity environments. The transmittance peak can reach up to 99.02% which increased by 7% compared with the substrate and the wavelength band increased by more than 5% is from 438nm to 1000nm. After prolonged exposure to strong ultraviolet (UV) irradiation, the static water contact angle of the HMDS treated antireflective coatings decreased very small from 102o to 98o. In addition, the low-temperature tests showed the contact angle did not decline even at-50°C. The results suggest that the coatings prepared in present paper have stable hydrophobic and antireflective performance in the environment of strong UV radiation and low temperature.


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.


2001 ◽  
Vol 188 (1) ◽  
pp. 97-114 ◽  
Author(s):  
Michelle L. Steen ◽  
Lynley Hymas ◽  
Elizabeth D. Havey ◽  
Nathan E. Capps ◽  
David G. Castner ◽  
...  

Processes ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 104
Author(s):  
Panagiotis Dimitrakellis ◽  
François Faubert ◽  
Maxime Wartel ◽  
Evangelos Gogolides ◽  
Stéphane Pellerin

We studied the epoxy polymer surface modification using air plasma treatment in a Gliding Arc (GA) plasma reactor and a pulsed Dielectric Barrier Discharge (DBD). We employed optical emission spectroscopy (OES) measurements to approximate the vibrational and rotational temperatures for both plasma sources, as well as surface temperature measurements with fiber optics and IR thermography to corelate with the corresponding hydrophilization of the epoxy material. Water contact angle measurements revealed a rapid hydrophilization for both plasma sources, with a slightly more pronounced effect for the air DBD treatment. Ageing studies revealed stable hydrophilicity, with water contact angle saturating at values lower than 50°, corresponding to a >50% decrease compared to the untreated epoxy polymer. ATR-FTIR spectroscopy studies showed an additional absorption band assigned to carbonyl group, with its peak intensity being higher for the DBD treated surfaces. The spectra were also correlated with the surface functionalization via the relative peak area ratio of carbonyl to oxirane and benzene related bands. According to SEM imaging, GA plasma treatment led to no apparent morphological change, contrary to DBD treatment, which resulted in nano-roughness formation. The enhanced surface oxidation as well as the nano-roughness formation on epoxy surface with the air DBD treatment were found to be responsible for the stable hydrophilization.


2009 ◽  
Vol 103 (5) ◽  
pp. 845-856 ◽  
Author(s):  
Ilaria Donelli ◽  
Paola Taddei ◽  
Philippe F. Smet ◽  
Dirk Poelman ◽  
Vincent A. Nierstrasz ◽  
...  

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>


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