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12. Surface modification of polyethylene by diffuse barrier discharge plasma

Author

Novak, Igor, Steviar, Marian, Popelka, Anton, Choclak, Ivan, Mosnaaek, Jaroslav, Spirkova, Milena, Janigova, Ivica, Kleinova, Angela, Sedliacik, Jan, and Slouf, Miroslav

Subjects
Topographical drawing -- Research, Adhesion -- Research, Plasma (Ionized gases) -- Usage, High temperature plasmas -- Usage, Engineering and manufacturing industries, Science and technology
Abstract

Low-density polyethylene (LDPE) modified by atmospheric dielectric surface barrier discharge plasma in oxygen was investigated to improve surface properties and adhesion of LDPE to more polar polymers. The process of plasma modification was investigated using several methods--surface energy measurements, Fourier Transform Infrared Spectroscopy with Attenuated Total Reflectance (FTIR-ATR), Scanning Electron Microscopy (SEM), and Atomic Force Microscopy (AFM). The surface energy of LDPE increased significantly after activation by oxygen barrier plasma even at very short time of modification. The FTIR-ATR spectra manifested the presence of carbonyl functional groups on the surface of polymer pretreated by oxygen barrier plasma. It was shown by SEM, and AFM, that the topography of modified LDPE was significantly changed and the surface of modified polymer exhibited higher roughness in comparison with unmodified polymer. The surface energy of treated LDPE diminished in the course of ageing especially during the first 10 days after modification by barrier plasma. Hydrophilicity of the modified LDPE surface was stabilized by photochemical post-functionalization with 2,2,6,6-tetramethyl-piperidin-4-yl-diazoacetate. POLYM. ENG. SCI., 53:516-523, 2013. © 2012 Society of Plastics Engineers, INTRODUCTION Polyethylene exhibits many valuable bulk properties, but it has low surface energy (1, 2) which causes its poor dyeability and bondability. The modification and/or activation is necessary for improving [...]

Published
2013
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22. Separation of Water/Oil Emulsions by an Electrospun Copolyamide Mat Covered with a 2D Ti3C2Tx MXene

Author

Moghaddasi, AbdolAli, Sobolčiak, Patrik, Popelka, Anton, and Krupa, Igor

Subjects
lcsh:QH201-278.5, lcsh:T, copolyamide, lcsh:Technology, vegetable oil, lcsh:TA1-2040, lcsh:Descriptive and experimental mechanics, lcsh:Electrical engineering. Electronics. Nuclear engineering, MXene, lcsh:Engineering (General). Civil engineering (General), lcsh:Microscopy, membrane, lcsh:TK1-9971, water purification, lcsh:QC120-168.85
Abstract

Purpose: Copolyamide 6,10 (coPA) electrospun mats were covered with multilayered (ML) and single-layered (SL) MXene (Ti3C2Tx) as a membrane for the separation of water/vegetable oil emulsions. Methods: Prepared membranes were characterized by atomic force microscopy (AFM), profilometry, the contact angle measurements of various liquids in air, and the underwater contact angle of vegetable oil. The separation efficiency was evaluated by measuring the UV transmittance of stock solutions compared to the UV transmittance of the filtrate. Results: The MXene coating onto coPA mats led to changes in the permeability, hydrophilicity, and roughness of the membranes and enhanced the separation efficiency of the water/vegetable oil emulsions containing 10, 100, and 1000 ppm of sunflower vegetable oil. It was found that membranes were highly oleophobic (&gt, 124&deg, ) under water, unlike in air, where the membranes showed high oleophobicity (&lt, 5&deg, ). The separation efficiency of water/oil emulsions for both types of covered membranes reached over 99%, with a surface coverage of 3.2 mg/cm2 Ti3C2Tx (for ML-Ti3C2Tx) and 2.9 mg/cm2 (for SL-Ti3C2Tx). Conclusions: The separation efficiency was greater than 98% for membranes covered with 2.65 mg/cm2 of ML-Ti3C2Tx, whereas the separation efficiency for membranes containing 1.89 and 0.77 mg/cm2 was less than 90% for all studied emulsion concentrations.

Published
2020

23. Antimicrobial modification of PLA scaffolds with ascorbic and fumaric acids via plasma treatment

Author

Popelka, Anton, Abdulkareem, Asma, Mahmoud, Abdelrahman A., Nassr, Mohammed G., Al-Ruweidi, Mahmoud Khatib A.A., Mohamoud, Khalid J., Hussein, Mohamned K., Lehocký, Marián, Veselá, Daniela, Humpolíček, Petr, and Kasak, Peter

Subjects
plasma treatment, technology, industry, and agriculture, PLA, ascorbic acid, fumaric acid, surface modification
Abstract

An optimal medical scaffold should be biocompatible and biodegradable and should have adequate mechanical properties and scaffold architecture porosity, a precise three-dimensional shape, and a reasonable manufacturing method. Polylactic acid (PLA) is a natural biodegradable thermoplastic aliphatic polyester that can be fabricated into nanofiber structures through many techniques, and electrospinning is one of the most widely used methods. Medical fiber mat scaffolds have been associated with inflammation and infection and, in some cases, have resulted in tissue degradation. Therefore, surface modification with antimicrobial agents represents a suitable solution if the mechanical properties of the fiber mats are not affected. In this study, the surfaces of electrospun PLA fiber mats were modified with naturally occurring L-ascorbic acid (ASA) or fumaric acid (FA) via a plasma treatment method. It was found that 30 s of radio-frequency (RF) plasma treatment was effective enough for the wettability enhancement and hydroperoxide formation needed for subsequent grafting reactions with antimicrobial agents upon their decomposition. This modification led to changes in the surface properties of the PLA fiber mats, which were analyzed by various spectroscopic and microscopic techniques. FTIR-ATR confirmed the chemical composition changes after the modification process and the surface morphology/topography changes were proven by SEM and AFM. Moreover, nanomechanical changes of prepared PLA fiber mats were investigated by AFM using amplitude modulation-frequency modulation (AM-FM) technique. A significant enhancement in antimicrobial activity of such modified PLA fiber mats against gram-positive Staphylococcus aureus and gram-negative Escherichia coli are demonstrated herein. © 2020 The Authors, Qatar National Research Fund (a member of The Qatar Foundation) [22-076-1-011]; Qatar University Collaborative Grant [QUCG-CAM-20/21-3]; Czech Science FoundationGrant Agency of the Czech Republic [19-16861S]

Published
2020

32. A comparative study on carbon neutral hydrogen carrier production: Formic acid from CO2vs. ammonia

Author

Mishra, Arti, Kim, Donghyun, Altahtamouni, Talal, Kasak, Peter, Popelka, Anton, Park, Hyunwoong, and Han, Dong Suk

Abstract

Hydrogen (H2) is increasingly recognized as a key player in the journey towards carbon neutrality, with ammonia (NH3) and formic acid (FA) emerging as significant hydrogen vectors. This review highlights advancements in catalyst efficiency for FA synthesis from CO2, particularly with bismuth (Bi) and tin (Sn) catalysts. It investigates diverse NH3and FA production methodologies, such as electrochemical, thermochemical, and photochemical processes, and underscores the integration of renewables to address their energy demands. The study also reviews novel materials like metal-organic frameworks (MOFs) and carbon-based catalysts that could enhance catalytic effectiveness. Transitioning from lab-scale models to industrial-scale applications requires addressing catalyst longevity and process enhancement, and it suggests investigating hybrid systems that might offer improved efficiency and yields. Concluding with a directive for future research, the study advocates for scalable, economically viable, and environmentally sustainable CO2conversion technologies, underscoring the essential roles of NH3and FA in a future with reduced carbon emissions.

Published
2024
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39. 2D Ti3C2Tx (MXene)-reinforced polyvinyl alcohol (PVA) nanofibers with enhanced mechanical and electrical properties

Author

Sobolčiak, Patrik, Ali, Adnan, Hassan, Mohammad K., Helal, Mohamed I., Tanvir, Aisha, Popelka, Anton, Al-Maadeed, Mariam A., Krupa, Igor, and Mahmoud, Khaled A.

Subjects
Ion Storage, Materials by Structure, Materials Science, Material Properties, Nanofibers, lcsh:Medicine, Research and Analysis Methods, Microscopy, Atomic Force, Nanocomposites, Electricity, X-Ray Diffraction, Specimen Storage, Nanotechnology, Mechanical Properties, Electron Microscopy, Cellulose, lcsh:Science, Electrodes, Materials by Attribute, Nanomaterials, Mechanical Phenomena, Sodium-ion Batteries, Microscopy, Physics, lcsh:R, Electric Conductivity, Temperature, Thermal Conductivity, Electrochemical Techniques, Insulators, Titanium Carbide, Storage and Handling, Polyvinyl Alcohol, Physical Sciences, Thermogravimetry, Microscopy, Electron, Scanning, Engineering and Technology, Composite Materials, Nanoparticles, Dielectrics, lcsh:Q, Scanning Electron Microscopy, Research Article
Abstract

Novel 2D Ti3C2Tx (MXene)-reinforced polyvinyl alcohol (PVA) nanofibers have been successfully fabricated by an electrospinning technique. The high aspect ratio, hydrophilic surfaces, and metallic conductivity of delaminated MXene nanosheet render it promising nanofiller for high performance nanocomposites. Cellulose nanocrystals (CNC) were used to improve the mechanical properties of the nanofibers. The obtained electrospun nanofibers had diameter from 174 to 194 nm depending on ratio between PVA, CNC and MXene. Dynamic mechanical analysis demonstrated an increase in the elastic modulus from 392 MPa for neat PVA fibers to 855 MPa for fibers containing CNC and MXene at 25C. Moreover, PVA nanofibers containing 0.14 wt. % Ti3C2Tx exhibited dc conductivity of 0.8 mS/cm conductivity which is superior compared to similar composites prepared using methods other than electrospinning. Improved mechanical and electrical characteristics of the Ti3C2Tx/CNC/PVA composites make them viable materials for high performance energy applications. 1 2017 Sobol?iak et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Scopus

Published
2017

44. [Acrylic acid plasma treatment of polypropylene nonwoven fabric] [Włókniny polipropylenowe poddane obróbce plazmowej z zastosowaniem kwasu akrylowego]

Author

Buček, Andrej, Popelka, Anton, Zahoranová, Anna, Kováčik, Dusˇan, Novák, Igor, and Černák, Mirko

Subjects
Hydrogel, Plasma grafting, Diaphragm discharge, technology, industry, and agriculture, Plasma treatment, Biocompatibility, Peel strength
Abstract

Nowadays hydrogel materials are being used in medical practice for wound dressing purposes. Hydrogel/textile composites can be formed to increase the mechanical strength and handling capability of hydrogel materials. Nonwoven textiles are optional for such applications, however, it is often necessary to improve their surface properties. Here plasma activation/grafting of polypropylene (PP) nonwoven fabric with an acrylate layer to improve its adhesive properties is reported. A diaphragm discharge was used for the plasma treatment of the PP fabric. The discharge was burnt in a solution of acrylic acid (AAc), which resulted in a single step process of plasma activation and plasma grafting of the fabric. Results of wettability testing and ATR-FTIR measurements showed the existence of a thin poly(acrylic acid) (PAAc) layer grafted on the fabric surface. Peel strength measurements showed a 4.7 fold increase in the peel strength when compared with untreated PP fabric. This publication is the result of the project: "Applied research and development of innovative drilling technology for ultra--deep geothermal wells", ITMS code 26240220042, supported by the Rese-arch & Development Operational Pro-gramme funded by the ERDF. This work was supported by the Slovak Research and Development Agency under contract No. APVV-14-0518. Scopus

Published
2016

48. Novel Electrodeposited Ni-B/Y2O3 Composite Coatings with Improved Properties.

Author

Shakoor, Rana Abdul, Waware, Umesh Somaji, Ali, Kamran, Kahraman, Ramazan, Popelka, Anton, Yusuf, Moinuddin Mohammed, and Hasan, Anwarul

Subjects
SURFACE coatings, ELECTROPLATING, COMPOSITE materials
Abstract

Ni-B/Y2O3 composite coatings were developed through an electrodeposition process to study the effect of addition of Y2O3 particles on structure, surface, thermal, mechanical, and anticorrosion properties of Ni-B coatings. It is revealed that parent crystal structure of Ni-B matrix is preserved by addition of Y2O3, however, a noticeable improvement in crystallinity is observed. The analysis of the surface exhibits formation of dense and nodular deposits in the two types of coatings, but incorporation of Y2O3 particles in Ni-B matrix has resulted in a noteworthy change in grain size and surface roughness. Thermal analysis of the surfaces indicates that Ni-B-Y2O3 composite coatings demonstrate superior thermal stability compared to Ni-B coatings. The nanoindentation analysis shows a significant enhancement in the mechanical characteristics of the Ni-B matrix by addition of Y2O3 particles. This may be contemplated as the result of grain refinement and dispersion hardening of the Ni-B matrix by the presence of hard Y2O3 particles. A decent improvement in the corrosion protection efficiency (73.6%) is also observed by addition of Y2O3 particles into Ni-B matrix. Simultaneous improvement of mechanical and anticorrosion properties suggests potential applications of Ni-B-Y2O3 coatings in oil and gas, automobile, and many other industries. [ABSTRACT FROM AUTHOR]

Published
2017
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49. 2D Ti3C2Tx (MXene)-reinforced polyvinyl alcohol (PVA) nanofibers with enhanced mechanical and electrical properties.

Author

Sobolčiak, Patrik, Ali, Adnan, Hassan, Mohammad K., Helal, Mohamed I., Tanvir, Aisha, Popelka, Anton, Al-Maadeed, Mariam A., Krupa, Igor, and Mahmoud, Khaled A.

Subjects
POLYVINYL alcohol, ELECTROSPINNING, VINYL polymers, CELLULOSE nanocrystals, BIODEGRADABLE nanoparticles
Abstract

Novel 2D Ti3C2Tx (MXene)-reinforced polyvinyl alcohol (PVA) nanofibers have been successfully fabricated by an electrospinning technique. The high aspect ratio, hydrophilic surfaces, and metallic conductivity of delaminated MXene nanosheet render it promising nanofiller for high performance nanocomposites. Cellulose nanocrystals (CNC) were used to improve the mechanical properties of the nanofibers. The obtained electrospun nanofibers had diameter from 174 to 194 nm depending on ratio between PVA, CNC and MXene. Dynamic mechanical analysis demonstrated an increase in the elastic modulus from 392 MPa for neat PVA fibers to 855 MPa for fibers containing CNC and MXene at 25°C. Moreover, PVA nanofibers containing 0.14 wt. % Ti3C2Tx exhibited dc conductivity of 0.8 mS/cm conductivity which is superior compared to similar composites prepared using methods other than electrospinning. Improved mechanical and electrical characteristics of the Ti3C2Tx /CNC/PVA composites make them viable materials for high performance energy applications. [ABSTRACT FROM AUTHOR]

Published
2017
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