Plasma-Enhanced Surface Modification of Biopolymers

2005 ◽  
Author(s):  
K. Komvopoulos
Keyword(s):  
Surface Modification ◽  
Effective Means ◽  
Polymer Surface ◽  
Chemical Properties ◽  
Biochemical Properties ◽  
Polymer Surfaces ◽  
Polymer Materials ◽  
Rf Plasma ◽  
Main Process ◽  
Enhanced Surface

Recent advances in polymer surface science have been largely due to the well-recognized need to control the surface properties of polymer materials and the development of sophisticated surface-specific characterization techniques. While the majority of the research and development efforts have been mostly focused on bulk properties, demands for low surface energy polymers exhibiting low adhesion (friction) and good biocompatibility have generated significant interest on physical and chemical properties of polymer surfaces. For instance, ultra-high molecular weight polyethylene (UHMWPE) and low-density polyethylene (LDPE) are the principal materials used to replace damaged cartilage in total joint arthroplasty and to fabricate catheters for balloon angioplasty, respectively. Therefore, surface treatments to improve adhesion and biocompatibility of these polymer surfaces are of paramount importance in the medical field. Radio frequency (rf) plasma-enhanced surface modification (PESM) provides an effective means for altering the biochemical properties of polymer surfaces without affecting the bulk behavior. The main process steps of PESM are discussed here and its effectiveness is demonstrated by representative friction coefficient, contact angle, and biocompatibility results for LDPE and UHMWPE surfaces treated with various plasma chemistries.

Polymer Surface Modification

1992 ◽  
Vol 65 (3) ◽  
pp. 687-696 ◽  
Author(s):  
Walter H. Waddell ◽  
Larry R. Evans ◽  
James G. Gillick ◽  
Derek Shuttleworth
Keyword(s):  
Surface Modification ◽  
Scientific Literature ◽  
Ion Beam ◽  
Polymer Surface ◽  
Polymeric Materials ◽  
High Energy ◽  
Polymer Materials ◽  
Diverse Range ◽  
Rubber Industry ◽  
Wide Range

Abstract Surface modification as a technology has been employed in various ways for many years, however, the breadth and magnitude of its applications have grown significantly during the last decade. Much of this growth has been facilitated by the development and spread of rapid and reliable surface characterization techniques. And, as would be expected of a maturing field, the bulk of investigations are now turning to applications rather than a pure understanding. Publications in both the scientific literature and patents describe research on a diverse range of polymeric substrates and potential applications using a wide range of modification techniques. Methods include chemical, photochemical, and high-energy physical techniques to modify polymer surfaces. Searches were made of these methods as applied to the surface modification of polymeric materials of particular interest to the rubber industry. Chemical methods include reactions such as halogenation, addition, etching, and oxidation. Photochemical techniques include surface reactions such as oxidative and nonoxidative degradation, halogenation, and photografting. Physical methods include corona discharge, plasma, electron and ion beam treatments. The 1980's literature on these subjects is published in a variety of languages, including a number of informative review articles and books printed in English on various aspects of this subject. The subject of this review concentrates on the surface modification of polymeric materials of particular interest to the rubber industry by focussing largely on scientific literature published in English and patent literature published during this time period that describe interesting and useful surface chemistry on elastomer substrates and rubber articles containing polymers such as natural rubber, cis-polyisoprene, styrene-butadiene copolymer, nitrile rubber, silicone, etc, and fibers and fabric made from fiber-forming polymer materials such as aramid, nylon, polyester, and carbon fiber, and those techniques reported successful in altering their surfaces. For organizational simplicity, three basic categories are used: elastomers, fibers and others. The latter category refers to those substrates without specific, current application in the rubber industry, but which have interesting or novel scientific features. Restriction of interest to rubber-relevant materials greatly reduced the scope of this work, and the interested reader should be aware that a great deal of activity is to be found in the rigid plastic and, to a lesser extent, biopolymer industries.

The Impact of Surfactants on Separation of Mixed Polymer Wastes in Electrostatic Field

2020 ◽  
Vol 24 (4) ◽  
pp. 25-29
Author(s):  
A.M. Gonopolsky ◽  
E.A. Poluosmak
Keyword(s):  
Electrostatic Field ◽  
Polymer Surface ◽  
Chemical Properties ◽  
Polymer Materials ◽  
Technological Parameters ◽  
Polymer Waste ◽  
Maximum Charge ◽  
Pre Treatment ◽  
The Impact ◽  
Polymer Wastes

A quantitative analysis is carried out of such factors as electrostatic intensity, surface area of particles, dielectric permittivity, size polymer particles, and the type and concentration of surfactants, by the amount of electric charge of the polymer surface, obtained in the electrostatic field after their pre-treatment of surfactants. Dependencies of the maximum charge of polymer waste particles from the basic technological parameters of the drum electrostatic separator and physical-chemical properties of polymers and surfactants are shown. It has been found that degradation of polymeric waste in a surfactants aqueous solutions is an effective preliminary step of technology of electrostatic separation of a mixture of crushed polymer wastes that positive effect on their charging in an electrostatic field. The obtained data allows to develop the technological process precision selective separation of mixed polymer materials in an electrostatic field.

Effect of Plasma-Based Chemical Modification on Wettability of Polymer Materials for Cardiovascular Surgery

2015 ◽  
Vol 1085 ◽  
pp. 419-423 ◽  
Author(s):  
Yulia Khodyrevskaya ◽  
Yuliya Kudryavtseva ◽  
Gennady Remnev ◽  
Sergei Tverdokhlebov
Keyword(s):  
Chemical Modification ◽  
Polymer Surface ◽  
Polymer Surfaces ◽  
Polymer Materials ◽  
Pulsed Plasma ◽  
Plasma Exposure ◽  
Gas Discharges ◽  
Modified Polymers ◽  
Short Term Exposure ◽  
Modify Polymer

A method to modify polymer surface properties responsible for wettability and surface free energy has been proposed. Plasma-based chemical modification of polymer surfaces with gas discharges allows adjusting their functional properties. The main changes in polymer wettability occur within short-term exposure of polymer surfaces to pulsed plasma at atmospheric pressure (1-60 sec). The contact angle values for the modified polymers depend on the gaseous medium and the conditions of the plasma processing. Changing the power, the pulse repetition rate and plasma exposure time allow controlling the free surface energy, making the surface either hydrophobic or hydrophilic.

Ftir Investigations of Plasma Modified Polymer Surfaces and Their Interfaces with Plasma Deposited Tungsten

1989 ◽  
Vol 165 ◽  
Author(s):  
Jihperng Leu ◽  
Manoj Dalvie ◽  
Klavs F. Jensen
Keyword(s):  
Microwave Plasma ◽  
Polymer Surface ◽  
Chemical Vapor ◽  
Surface Modifications ◽  
Polymer Surfaces ◽  
Ex Situ ◽  
Rf Plasma ◽  
Polyimide Films ◽  
Modified Polymer ◽  
Surface Fluorination

AbstractSurface modifications of thin polyimide films (100–2000 A˚) in downstream microwave CF4/NF3/Ar plasmas and radio-frequency (RF) CF4 plasmas have been studied in situ by Fourier transform infrared (FTIR) reflection-absorption spectroscopy. The downstream microwave plasma treatment produced significant surface fluorination in terms of polyfluorinated alkyl and aryl compounds as well as acyl and benzoyl fluorides. The depth of fluorination was approximately 500 Å. Similar changes in polymer surface functionalities were observed for RF plasma surface modifications, but the depth of fluorination was reduced to 30Å because of ion-bombardment. The interface between the tungsten film and polyimide surfaces has been characterized by ex situ FTIR reflection-absorption technique through the silicon side of Si/polymer/W structures. The observed spectral changes relative to polyimide-gold interfaces were interpreted in terms of interactions of tungsten with functionalities of the polyimde backbone. Tungsten deposited by both sputtering and plasma enhanced chemical vapor deposition (PECVD) showed significant chemical interactions, strongest for PECVD tungsten.

Surface Modification of Poly (alkyl/Arylphosphazene) Thin Films

2000 ◽  
Vol 629 ◽  
Author(s):  
John V. St. John ◽  
Patty Wisian-Neilson
Keyword(s):  
Thin Films ◽  
Surface Modification ◽  
Chemical Resistance ◽  
Chemical Properties ◽  
Inorganic Polymers ◽  
Thin Polymer Films ◽  
Hydrophilic Interactions ◽  
Carboxylic Acid Groups ◽  
Polymer Interface ◽  
Thin Polymer

ABSTRACTPoly (methylphenylphosphazene) (PMPP) is an example of a unique class of inorganic polymers with alternating – (P=N)– backbones. Chemical modification of bulk PMPP can result in changes of physical properties such as chemical resistance, onset temperature of thermal degradation, elasticity, and flexibility. Surface modification of PMPP allows tailoring of the chemical properties at the polymer interface while maintaining the integrity of the bulk polymer. In this research, PMPP thin films were treated to form carboxylate or carboxylic acid groups at the surface. Surface modification was monitored by following changes in contact angle. The hydrophobic/hydrophilic interactions of carboxylated PMPP surfaces allow for mesoscale interactions of thin polymer films.

scholarly journals Size and surface modification of silica nanoparticles affect the severity of lung toxicity by modulating endosomal ROS generation in macrophages

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Masahide Inoue ◽  
Koji Sakamoto ◽  
Atsushi Suzuki ◽  
Shinya Nakai ◽  
Akira Ando ◽  
...  
Keyword(s):  
Immune Response ◽  
Surface Modification ◽  
Lung Injury ◽  
Cellular Uptake ◽  
Intratracheal Instillation ◽  
Chemical Properties ◽  
Raw264.7 Cells ◽  
Neutrophilic Infiltration ◽  
Silica Nanomaterials ◽  
Physico Chemical

Abstract Background As the application of silica nanomaterials continues to expand, increasing chances of its exposure to the human body and potential harm are anticipated. Although the toxicity of silica nanomaterials is assumed to be affected by their physio-chemical properties, including size and surface functionalization, its molecular mechanisms remain unclear. We hypothesized that analysis of intracellular localization of the particles and subsequent intracellular signaling could reveal a novel determinant of inflammatory response against silica particles with different physico-chemical properties. Results We employed a murine intratracheal instillation model of amorphous silica nanoparticles (NPs) exposure to compare their in vivo toxicities in the respiratory system. Pristine silica-NPs of 50 nm diameters (50 nm-plain) induced airway-centered lung injury with marked neutrophilic infiltration. By contrast, instillation of pristine silica particles of a larger diameter (3 μm; 3 μm-plain) significantly reduced the severity of lung injury and neutrophilic infiltration, possibly through attenuated induction of neutrophil chemotactic chemokines including MIP2. Ex vivo analysis of alveolar macrophages as well as in vitro assessment using RAW264.7 cells revealed a remarkably lower cellular uptake of 3 μm-plain particles compared with 50 nm-plain, which is assumed to be the underlying mechanism of attenuated immune response. The severity of lung injury and neutrophilic infiltration was also significantly reduced after intratracheal instillation of silica NPs with an amine surface modification (50 nm-NH2) when compared with 50 nm-plain. Despite unchanged efficacy in cellular uptake, treatment with 50 nm-NH2 induced a significantly attenuated immune response in RAW264.7 cells. Assessment of intracellular redox signaling revealed increased reactive oxygen species (ROS) in endosomal compartments of RAW264.7 cells treated with 50 nm-plain when compared with vehicle-treated control. In contrast, augmentation of endosomal ROS signals in cells treated with 50 nm-NH2 was significantly lower. Moreover, selective inhibition of NADPH oxidase 2 (NOX2) was sufficient to inhibit endosomal ROS bursts and induction of chemokine expressions in cells treated with silica NPs, suggesting the central role of endosomal ROS generated by NOX2 in the regulation of the inflammatory response in macrophages that endocytosed silica NPs. Conclusions Our murine model suggested that the pulmonary toxicity of silica NPs depended on their physico-chemical properties through distinct mechanisms. Cellular uptake of larger particles by macrophages decreased, while surface amine modification modulated endosomal ROS signaling via NOX2, both of which are assumed to be involved in mitigating immune response in macrophages and resulting lung injury.

A Novel Approach for Metal Surface Modification

2007 ◽  
Vol 280-283 ◽  
pp. 1805-1806
Author(s):  
Zhi Jun Cao ◽  
Jia Chen Liu ◽  
Li Bin Liu ◽  
Hao Ye ◽  
Yan Qiu Wei
Keyword(s):  
Surface Modification ◽  
Wear Rate ◽  
Charge State ◽  
Metal Surface ◽  
Surface Hardness ◽  
Metallic Surface ◽  
New Approach ◽  
Novel Approach ◽  
Complex Shapes ◽  
Enhanced Surface

A new approach was developed for surface modification of metallic surface. By treating nano-zirconia particles and metal surface in different charge state, nano-zirconia particles can be dispersedly inlaid in metal surface owing to electrostatic and nanometer effects. By using this method, metal components of complex shapes, especially those having inside surfaces, might be easily improved, i.e., enhanced surface hardness and wear rate.

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