The influence of the plasma modification on properties of PCL films as corneal implants

2020 ◽  
Author(s):  
Ekaterina O. Filippova ◽  
Nina M. Ivanova
Keyword(s):  
Plasma Modification

scholarly journals Antibacterial Properties of Plasma-Activated Perfluorinated Substrates with Silver Nanoclusters Deposition

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 182
Author(s):  
Petr Slepička ◽  
Silvie Rimpelová ◽  
Nikola Slepičková Kasálková ◽  
Dominik Fajstavr ◽  
Petr Sajdl ◽  
...  
Keyword(s):  
Surface Properties ◽  
Antibacterial Properties ◽  
Argon Plasma ◽  
Antimicrobial Effect ◽  
Silver Nanoclusters ◽  
Plasma Modification ◽  
Material Surface ◽  
Silver Deposition ◽  
Force Microscopy ◽  
Atomic Force

This article is focused on the evaluation of surface properties of polytetrafluoroethylene (PTFE) nanotextile and a tetrafluoroethylene-perfluoro(alkoxy vinyl ether) (PFA) film and their surface activation with argon plasma treatment followed with silver nanoclusters deposition. Samples were subjected to plasma modification for a different time exposure, silver deposition for different time periods, or their combination. As an alternative approach, the foils were coated with poly-L-lactic acid (PLLA) and silver. The following methods were used to study the surface properties of the polymers: goniometry, atomic force microscopy, and X-ray photoelectron microscopy. By combining the aforementioned methods for material surface modification, substrates with antibacterial properties eliminating the growth of Gram-positive and Gram-negative bacteria were prepared. Studies of antimicrobial activity showed that PTFE plasma-modified samples coated with PLLA and deposited with a thin layer of Ag had a strong antimicrobial effect, which was also observed for the PFA material against the bacterial strain of S. aureus. Significant antibacterial effect against S. aureus, Proteus sp. and E. coli has been demonstrated on PTFE nanotextile plasma-treated for 240 s, coated with PLLA, and subsequently sputtered with thin Ag layer.

scholarly journals Rapid Surface Modification of Ultrafiltration Membranes for Enhanced Antifouling Properties

Membranes ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 401
Author(s):  
Noresah Said ◽  
Ying Siew Khoo ◽  
Woei Jye Lau ◽  
Mehmet Gürsoy ◽  
Mustafa Karaman ◽  
...  
Keyword(s):  
Surface Modification ◽  
Deposition Time ◽  
Plasma Deposition ◽  
Membrane Surface ◽  
Pure Water ◽  
Plasma Modification ◽  
Surface Hydrophilicity ◽  
Water Cleaning ◽  
Modification Method ◽  
Modified Membrane

In this work, several ultrafiltration (UF) membranes with enhanced antifouling properties were fabricated using a rapid and green surface modification method that was based on the plasma-enhanced chemical vapor deposition (PECVD). Two types of hydrophilic monomers—acrylic acid (AA) and 2-hydroxyethyl methacrylate (HEMA) were, respectively, deposited on the surface of a commercial UF membrane and the effects of plasma deposition time (i.e., 15 s, 30 s, 60 s, and 90 s) on the surface properties of the membrane were investigated. The modified membranes were then subjected to filtration using 2000 mg/L pepsin and bovine serum albumin (BSA) solutions as feed. Microscopic and spectroscopic analyses confirmed the successful deposition of AA and HEMA on the membrane surface and the decrease in water contact angle with increasing plasma deposition time strongly indicated the increase in surface hydrophilicity due to the considerable enrichment of the hydrophilic segment of AA and HEMA on the membrane surface. However, a prolonged plasma deposition time (>15 s) should be avoided as it led to the formation of a thicker coating layer that significantly reduced the membrane pure water flux with no significant change in the solute rejection rate. Upon 15-s plasma deposition, the AA-modified membrane recorded the pepsin and BSA rejections of 83.9% and 97.5%, respectively, while the HEMA-modified membrane rejected at least 98.5% for both pepsin and BSA. Compared to the control membrane, the AA-modified and HEMA-modified membranes also showed a lower degree of flux decline and better flux recovery rate (>90%), suggesting that the membrane antifouling properties were improved and most of the fouling was reversible and could be removed via simple water cleaning process. We demonstrated in this work that the PECVD technique is a promising surface modification method that could be employed to rapidly improve membrane surface hydrophilicity (15 s) for the enhanced protein purification process without using any organic solvent during the plasma modification process.

Cold Plasma Modification Effects on the Water Flow through Sintered UHMWPE Membranes

2009 ◽  
Vol 48 (2) ◽  
pp. 136-140 ◽  
Author(s):  
T. L. Leal ◽  
K. M. Souto ◽  
L. H. Carvalho ◽  
L. H. Lira ◽  
C. A. Júnior ◽  
...  
Keyword(s):  
Water Flow ◽  
Cold Plasma ◽  
Plasma Modification ◽  
Flow Through

Influence of Oxygen Plasma Modification Carbon Fiber on Flexural Strength and Hydrothermal Properties of CF/PES Composite

2014 ◽  
Vol 926-930 ◽  
pp. 141-144
Author(s):  
Xu Cui ◽  
Yan Jiao Huang ◽  
Yu Gao ◽  
Shuo Wang
Keyword(s):  
Composite Material ◽  
Carbon Fiber ◽  
Flexural Strength ◽  
Plasma Treatment ◽  
Oxygen Plasma ◽  
Retention Rate ◽  
Test Method ◽  
Plasma Modification ◽  
Resin Matrix ◽  
Strength Retention

In this paper, low temperature oxygen plasma treatment method was adopted to process the carbon fiber surface. Flexural Strength test method was utilized to represent f composite material flexural strength. This paper observed flexural failure morphology of composite material by aid of SEM, then it compared the mechanical property, hygroscopicitiy and flexural strength retention rate of composite material before and after the plasma treatment. Results showed that the optimum treatment conditions of carbon fiber were 300W treatment power and 15-minute treatment time. Under the condition, the highest flexural strength value be increased by 19.55%.Saturated bibulous is low and bibulous rate is slow, flexural strength retention rate is 94.9%. And at the same time PES-C resin matrix can be strengthened, which will further improve the mechanical properties of composite materials.

Oxygen-plasma-assisted formaldehyde adsorption mechanism of SnO2 electrospun fibers

2021 ◽  
Author(s):  
Haiying Du ◽  
Yuxia Wu ◽  
Zhaorui Zhang ◽  
Wanmin He ◽  
Yanhui Sun ◽  
...  
Keyword(s):  
Oxygen Plasma ◽  
Adsorption Mechanism ◽  
Gas Sensing ◽  
High Energy ◽  
Plasma Modification ◽  
Electrospun Fibers ◽  
Chemisorbed Oxygen ◽  
Formaldehyde Sensing ◽  
Formaldehyde Adsorption ◽  
Sensing Performance

Abstract Abstract: Chemisorbed oxygen acts a crucial role in the redox reaction of semiconductor gas sensors, and which is of great significance for improving gas sensing performance. In this study, an oxygen-plasma-assisted technology is presented to enhance the chemisorbed oxygen for improving the formaldehyde sensing performance of SnO2 electropun fiber. An inductively coupled plasma device was used for oxygen plasma treatment of SnO2 electrospun fibers. The surface of SnO2 electrospun fibers was bombarded with high-energy oxygen plasma for facilitating the chemisorption of electronegative oxygen molecules on the SnO2 (110) surface to obtain an oxygen-rich structure. Oxygen-plasma-assisted SnO2 electrospun fibers exhibited excellent formaldehyde sensing performance. The formaldehyde adsorption mechanism of oxygen-rich SnO2 was investigated using density functional theory. After oxygen plasma modification, the adsorption energy and the charge transfer number of formaldehyde to SnO2 were increased significantly. And an unoccupied electronic state appeared in the SnO2 band structure, which could enhance the formaldehyde adsorption ability of SnO2. The gas sensing test revealed that plasma-treated SnO2 electrospun fibers exhibited excellent gas sensing properties to formaldehyde, low operating temperature, high response sensitivity, and considerable cross-selectivity. Thus, plasma modification is a simple and effective method to improve the gas sensing performance of sensors.

Structural-Mechanical Properties of Polyurethane Surface after Carbon Ion Subplantation

2021 ◽  
Vol 887 ◽  
pp. 370-375
Author(s):  
I.A. Morozov ◽  
A.S. Kamenetskikh
Keyword(s):  
Mechanical Properties ◽  
Surface Relief ◽  
Low Energy ◽  
Plasma Modification ◽  
Carbon Ions ◽  
Uniaxial Deformation ◽  
Treatment Regimes ◽  
Subsequent Investigation ◽  
Ion Plasma ◽  
Potential Applications

Ion-plasma modification of polymers has many potential applications, in particular, in the development of biomedical products. Treatment of soft polymers can easily damage the surface; low-energy plasma and subsequent investigation of the structural and mechanical properties of the surface are required. Polyurethane is a widely used block copolymer. Subplantation of carbon ions heterogeneously changes the structural and mechanical properties of the surface (relief, stiffness, thickness of the modified coating), forming a graphene-like nanolayer. Uniaxial deformation of the treated materials in some cases leads to the damage of the surface (local nanocracks, folds). Materials have increased hydrophobicity, good deformability (valid for certain treatment regimes) and can find application in design of products with improved biomedical properties.

Interlaminar Fracture in Carbon Fiber/Thermoplastic Composites

1989 ◽  
Vol 170 ◽  
Author(s):  
J. A. Hinkley ◽  
W. D. Bascom ◽  
R. E. Allred
Keyword(s):  
Fracture Toughness ◽  
Carbon Fiber ◽  
Carbon Fibers ◽  
High Strain ◽  
Thermoplastic Composites ◽  
Plasma Modification ◽  
Interlaminar Fracture Toughness ◽  
Interlaminar Fracture ◽  
Polyphenylene Oxide ◽  
Commercial Carbon

AbstractThe surfaces of commercial carbon fibers are generally chemically cleaned or oxidized and then coated with an oligomeric sizing to optimize their adhesion to epoxy matrix resins. Evidence from fractography, from embedded fiber testing and from fracture energies suggests that these standard treatments are relatively ineffective for thermoplastic matrices. This evidence is reviewed and model thermoplastic composites (polyphenylene oxide/high strain carbon fibers) are used to demonstrate how differences in adhesion can lead to a two-fold change in interlaminar fracture toughness.The potential for improved adhesion via plasma modification of fiber surfaces is discussed. Finally, a surprising case of fiber-catalyzed resin degradation is described.

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