scholarly journals Fabrication of ZnO-Al2O3-PTFE Multilayer Nano-Structured Functional Film on Cellulose Insulation Polymer Surface and Its Effect on Moisture Inhibition and Dielectric Properties

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1367 ◽  
Author(s):  
Cong Liu ◽  
Jian Hao ◽  
Yanqing Li ◽  
Ruijin Liao
Keyword(s):  
Contact Angle ◽  
Power Transformer ◽  
Polymer Surface ◽  
Rf Magnetron Sputtering ◽  
Hydroxyl Group ◽  
Breakdown Field ◽  
Water Contact ◽  
Insulating Paper ◽  
Cellulose Insulation ◽  
Insulation Performance

After a century of practice, cellulose insulating polymer (insulating paper/pressboard) has been shown to be one of the best and most widely used insulating materials in power transformers. However, with the increased voltage level of the transformer, research has focused on improving the insulation performance of the transformer’s cellulose insulation polymer. Considering the complex environment of the transformer, it is not enough to improve the single performance of the insulating polymer. In this study, a nano-structured ZnO-Al2O3-PTFE (polytetrafluoroethylene) multifunctional film was deposited on the surface of insulating pressboard by radio frequency (RF) magnetron sputtering. The effect of the multilayered ZnO-Al2O3-PTFE functional film on the dielectric and water contact angle of the cellulose insulating polymer was investigated. The scanning electron microscopy/energy dispersive spectrometry (SEM/EDS) showed that the nano-structured ZnO-Al2O3-PTFE functional film was successfully deposited on the cellulose insulation pressboard surface. The functional film presented an obvious stratification phenomenon. By analyzing the result of the contact angle, it was found that the functional film shields the hydroxyl group of the inner cellulose and improves hydrophobicity. The AC breakdown field strength of the treated samples was obviously increased (by 12 to ~17%), which means that the modified samples had a better dielectric insulation performance. This study provides a surface modification method to comprehensively improve electrical properties and the ability to inhibit the moisture of the cellulose insulating polymer, used in a power transformer.

Surface Modification of Polycarbonateurethane by Grafting Phosphorylcholine Glyceraldehydes for Improving Hemocompatibility

2012 ◽  
Vol 1403 ◽  
Author(s):  
Wei Gao ◽  
Yakai Feng ◽  
Jian Lu ◽  
Jintang Guo
Keyword(s):  
Contact Angle ◽  
Photoelectron Spectroscopy ◽  
Polymer Surface ◽  
Xps Analysis ◽  
Poly Ethylene Glycol ◽  
Water Contact ◽  
X Ray ◽  
Poly Ethylene ◽  
Covalently Linked ◽  
Scanning Electron

ABSTRACTPhosphorylcholine glyceraldehyde (PCGA) was used as a phosphorylcholine (PC) group containing compound to graft onto the surface of polycarbonateurethane (PCU) film using 1,6-hexanediamine (HDA) or α,ω-diamino-poly(ethylene glycol) (APEG, Mn = 200) as a spacer, in order to introduce biomimetic structure onto the polymer surface. X-ray photoelectron spectroscopy (XPS) analysis shows that PCGA has been covalently linked to the PCU surface. Water contact angle test suggests that the surface hydrophilicity has been improved after PCGA is grafted onto the surface of PCU film. Scanning electron microscope (SEM) observation of the modified PCU films after contacting with plasma-rich plasma demonstrates that platelets rarely adhere but a large number of platelets adhere to the original PCU surface. The hemocompatibility of the PC modified PCU film has been improved obviously after grafting with PCGA with PEG spacer.

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 Plasma Surface Modification of Epoxy Polymer in Air DBD and Gliding Arc

Processes ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 104
Author(s):  
Panagiotis Dimitrakellis ◽  
François Faubert ◽  
Maxime Wartel ◽  
Evangelos Gogolides ◽  
Stéphane Pellerin
Keyword(s):  
Contact Angle ◽  
Surface Modification ◽  
Plasma Treatment ◽  
Water Contact Angle ◽  
Epoxy Polymer ◽  
Plasma Reactor ◽  
Polymer Surface ◽  
Water Contact ◽  
Plasma Sources ◽  
Gliding Arc

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.

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.

scholarly journals Superhydrophobic functionalized cellulosic paper by copper hydroxide nanorods for oils purification

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ahmed S. Belal ◽  
Jehan El Nady ◽  
Azza Shokry ◽  
Shaker Ebrahim ◽  
Moataz Soliman ◽  
...  
Keyword(s):  
Contact Angle ◽  
Filter Paper ◽  
Separation Efficiency ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Absorption Capacity ◽  
Morphological Properties ◽  
Copper Hydroxide ◽  
Immersion Method ◽  
Water Contact

AbstractOily water contamination has been sighted as one of the most global environmental pollution. Herein, copper hydroxide nanorods layer was constructed onto cellulosic filter paper surface cured with polydopamine, Ag nanoparticles, and Cu NPs through immersion method. This work has been aimed to produce a superhydrophobic and superoleophilic cellulosic filter paper. The structure, crystalline, and morphological properties of these modified cellulosic filter paper were investigated. Scanning electron microscope images confirmed that the modified surface was rougher compared with the pristine surface. The contact angle measurement confirmed the hydrophobic nature of these modified surfaces with a water contact angle of 169.7°. The absorption capacity was 8.2 g/g for diesel oil and the separation efficiency was higher than 99%. It was noted that the flux in the case of low viscosity solvent as n-hexane was 9663.5 Lm−2 h−1, while for the viscous oil as diesel was 1452.7 Lm−2 h−1.

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