Review of some research work on surface modification and polymerizations by non-equilibrium plasma in Turkey

International Nuclear Information System (INIS)

Akovali, Guneri

2004-01-01

Non equilibrium plasma studies in Turkey can be considered as organized on two different lines: surface modification studies and plasma polymerization studies. Plasma surface modification studies: In different laboratories in Turkey the modification of materials' surfaces by plasma covers a wide spectra, for example: fibers (Carbon (CF) and polyacrylonitrile (PAN)), fabrics (PET/Cotton and PET/PA), biomaterials-food oriented (PU), denture Acrylic matrix, plasmochemical modification of a (PE and PP) film surface by several selected silicon and tin containing monomers, polymer blends and composites, recycled rubber and epoxy systems, etc. Plasma polymerization studies: This topic is accomplished by a great number of projects, for instance: plasma initiation polymerization and copolymerization of Styrene and MMA, Plasma-initiated polymerizations of Acrylamide (AA), kinetics of polymer deposition of several selected saturated hydrocarbons, silanization treatments by hexamethyldisilazane (HDMS), Plasma initiated polymerization (PIP) of allyl alcohol and 1-propano, (PSP) and (PIP) studies related to activated charcoal are done to explore their applications in haemoperfusion, an amperometric alcohol single-layer electrode is prepared by (EDA) plasma polymerization, preparation of mass sensitive immuno sensors and single layer multi enzyme electrodes by plasma polymerisation technique, etc

Surface modification of polylactic acid films by atmospheric pressure plasma treatment

Science.gov (United States)

Kudryavtseva, V. L.; Zhuravlev, M. V.; Tverdokhlebov, S. I.

2017-09-01

A new approach for the modification of polylactic acid (PLA) materials using atmospheric pressure plasma (APP) is described. PLA films plasma exposure time was 20, 60, 120 s. The surface morphology and wettability of the obtained PLA films were investigated by atomic force microscopy (AFM) and the sitting drop method. The atmospheric pressure plasma increased the roughness and surface energy of PLA film. The wettability of PLA has been improved with the application of an atmospheric plasma surface treatment. It was shown that it is possible to obtain PLA films with various surface relief and tunable wettability. Additionally, we demonstrated that the use of cold atmospheric pressure plasma for surface activation allows for the immobilization of bioactive compounds like hyaluronic acid (HA) on the surface of obtained films. It was shown that composite PLA-HA films have an increased long-term hydrophilicity of the films surface.

Work function modifications of graphite surface via oxygen plasma treatment

Science.gov (United States)

Duch, J.; Kubisiak, P.; Adolfsson, K. H.; Hakkarainen, M.; Golda-Cepa, M.; Kotarba, A.

2017-10-01

The surface modification of graphite by oxygen plasma was investigated experimentally (X-ray diffraction, nanoparticle tracking analysis, laser desorption ionization mass spectrometry, thermogravimetry, water contact angle) and by molecular modelling (Density Functional Theory). Generation of surface functional groups (mainly sbnd OHsurf) leads to substantial changes in electrodonor properties and wettability gauged by work function and water contact angle, respectively. The invoked modifications were analyzed in terms of Helmholtz model taking into account the theoretically determined surface dipole moment of graphite-OHsurf system (μ = 2.71 D) and experimentally measured work function increase (from 0.75 to 1.02 eV) to determine the sbnd OH surface coverage (from 0.70 to 1.03 × 1014 groups cm-2). Since the plasma treatment was confined to the surface, the high thermal stability of the graphite material was preserved as revealed by the thermogravimetric analysis. The obtained results provide a suitable quantitative background for tuning the key operating parameters of carbon electrodes: electronic properties, interaction with water and thermal stability.

Surface modification of polyethylene by diffuse barrier discharge plasma

Czech Academy of Sciences Publication Activity Database

Novák, I.; Števiar, M.; Popelka, A.; Chodák, I.; Mosnáček, J.; Špírková, Milena; Janigová, I.; Kleinová, A.; Sedliačik, J.; Šlouf, Miroslav

2013-01-01

Roč. 53, č. 3 (2013), s. 516-523 ISSN 0032-3888 R&D Projects: GA AV ČR(CZ) IAAX08240901 Institutional research plan: CEZ:AV0Z40500505 Keywords : low-density polyethylene * plasma discharge * surface modification Subject RIV: JI - Composite Materials Impact factor: 1.441, year: 2013

Surface modification and stability of detonation nanodiamonds in microwave gas discharge plasma

International Nuclear Information System (INIS)

Stanishevsky, Andrei V.; Walock, Michael J.; Catledge, Shane A.

2015-01-01

Graphical abstract: - Highlights: • Single and binary gas plasma modification of nanodiamond powders studied. • Temperature-dependent effect of N 2 and N 2 /H 2 plasma reported for the first time. • Role of H 2 in H 2 /N 2 and H 2 /O 2 plasma modification of nanodiamond discussed. - Abstract: Detonation nanodiamonds (DND), with low hydrogen content, were exposed to microwave plasma generated in pure H 2 , N 2 , and O 2 gases and their mixtures, and investigated using X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), Raman, and X-ray photoelectron spectroscopies. Considerable alteration of the DND surface was observed under the plasma conditions for all used gases, but the diamond structure of the DND particle core was preserved in most cases. The stabilizing effect of H 2 in H 2 /N 2 and H 2 /O 2 binary gas plasmas on the DND structure and the temperature-dependent formation of various CNH x surface groups in N 2 and H 2 /N 2 plasmas were observed and discussed for the first time. DND surface oxidation and etching were the main effects of O 2 plasma, whereas the N 2 plasma led to DND surfaces rich in amide groups below 1073 K and nitrile groups at higher temperatures. Noticeable graphitization of the DND core structure was detected only in N 2 plasma when the substrate temperature was above 1103 K.

Plasma based Ar+ beam assisted poly(dimethylsiloxane) surface modification

International Nuclear Information System (INIS)

Vladkova, T.G.; Keranov, I.L.; Dineff, P.D.; Youroukov, S.Y.; Avramova, I.A.; Krasteva, N.; Altankov, G.P.

2005-01-01

Plasma based Ar + beam performed in RF (13.56 MHz) low-pressure (200 mTorr) glow discharge (at 100 W, 1200 W and 2500 W) with a serial capacitance was employed for surface modification of poly(dimethylsiloxane) (PDMS) aimed at improvement of its interactions with living cells. The presence of a serial capacitance ensures arise of an ion-flow inside the plasma volume directed toward the treated sample and the vary of the discharge power ensures varied density of the ion-flow. XPS analysis was performed to study the changes in the surface chemical composition of the modified samples and the corresponding changes in the surface energy were monitored by contact angle measurements. We found that plasma based Ar + beam transforms the initially hydrophobic PDMS surface into a hydrophilic one mainly due to a raising of the polar component of the surface tension, this effect being most probably due to an enrichment of the modified surface layer with permanent dipoles of a [SiO x ]-based network and elimination of the original methyl groups. The initial adhesion of human fibroblast cells was studied on the described above plasma based Ar + beam modified and acrylic acid (AA) grafted or not fibronectin (FN) pre-coated or bare surfaces. The cell response seems to be related with the peculiar structure and wettability of the modified PDMS surface layer after plasma based Ar + beam treatment followed or not by AA grafting

Surface modification and stability of detonation nanodiamonds in microwave gas discharge plasma

Energy Technology Data Exchange (ETDEWEB)

Stanishevsky, Andrei V., E-mail: astan@uab.edu; Walock, Michael J.; Catledge, Shane A.

2015-12-01

Graphical abstract: - Highlights: • Single and binary gas plasma modification of nanodiamond powders studied. • Temperature-dependent effect of N{sub 2} and N{sub 2}/H{sub 2} plasma reported for the first time. • Role of H{sub 2} in H{sub 2}/N{sub 2} and H{sub 2}/O{sub 2} plasma modification of nanodiamond discussed. - Abstract: Detonation nanodiamonds (DND), with low hydrogen content, were exposed to microwave plasma generated in pure H{sub 2}, N{sub 2}, and O{sub 2} gases and their mixtures, and investigated using X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), Raman, and X-ray photoelectron spectroscopies. Considerable alteration of the DND surface was observed under the plasma conditions for all used gases, but the diamond structure of the DND particle core was preserved in most cases. The stabilizing effect of H{sub 2} in H{sub 2}/N{sub 2} and H{sub 2}/O{sub 2} binary gas plasmas on the DND structure and the temperature-dependent formation of various CNH{sub x} surface groups in N{sub 2} and H{sub 2}/N{sub 2} plasmas were observed and discussed for the first time. DND surface oxidation and etching were the main effects of O{sub 2} plasma, whereas the N{sub 2} plasma led to DND surfaces rich in amide groups below 1073 K and nitrile groups at higher temperatures. Noticeable graphitization of the DND core structure was detected only in N{sub 2} plasma when the substrate temperature was above 1103 K.

Plasma-Assisted Synthesis and Surface Modification of Electrode Materials for Renewable Energy.

Science.gov (United States)

Dou, Shuo; Tao, Li; Wang, Ruilun; El Hankari, Samir; Chen, Ru; Wang, Shuangyin

2018-02-14

Renewable energy technology has been considered as a "MUST" option to lower the use of fossil fuels for industry and daily life. Designing critical and sophisticated materials is of great importance in order to realize high-performance energy technology. Typically, efficient synthesis and soft surface modification of nanomaterials are important for energy technology. Therefore, there are increasing demands on the rational design of efficient electrocatalysts or electrode materials, which are the key for scalable and practical electrochemical energy devices. Nevertheless, the development of versatile and cheap strategies is one of the main challenges to achieve the aforementioned goals. Accordingly, plasma technology has recently appeared as an extremely promising alternative for the synthesis and surface modification of nanomaterials for electrochemical devices. Here, the recent progress on the development of nonthermal plasma technology is highlighted for the synthesis and surface modification of advanced electrode materials for renewable energy technology including electrocatalysts for fuel cells, water splitting, metal-air batteries, and electrode materials for batteries and supercapacitors, etc. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Plasma processing of large curved surfaces for superconducting rf cavity modification

Directory of Open Access Journals (Sweden)

J. Upadhyay

2014-12-01

Full Text Available Plasma-based surface modification of niobium is a promising alternative to wet etching of superconducting radio frequency (SRF cavities. We have demonstrated surface layer removal in an asymmetric nonplanar geometry, using a simple cylindrical cavity. The etching rate is highly correlated with the shape of the inner electrode, radio-frequency (rf circuit elements, gas pressure, rf power, chlorine concentration in the Cl_{2}/Ar gas mixtures, residence time of reactive species, and temperature of the cavity. Using variable radius cylindrical electrodes, large-surface ring-shaped samples, and dc bias in the external circuit, we have measured substantial average etching rates and outlined the possibility of optimizing plasma properties with respect to maximum surface processing effect.

Plasma modification of polypropylene surfaces and its alloying with styrene in situ

Energy Technology Data Exchange (ETDEWEB)

Ma Guiqiu, E-mail: magq@tju.edu.cn [School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin, 300072 (China); Liu Ben; Li Chen; Huang Dinghai; Sheng Jing [School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin, 300072 (China)

2012-01-15

The treatment of polypropylene surfaces has been studied by dielectric barrier discharges plasma of Ar. The structure and morphology of polypropylene surfaces of Ar plasma modification are characterized by X-ray photoelectron spectroscopy, Fourier transform infrared spectrometers and scanning electron microscope. The modified by plasma treatment of iPP (isotactic polypropylene) surface properties have been examined in a determination of free radicals. The modified active surfaces of polypropylene can induce grafting copolymerization of styrene onto polypropylene. The structure of grafting copolymer is characterized and the grafting percent of styrene onto polypropylene is calculated. The homopolymer of styrene can be formed under grafting copolymerization of styrene onto polypropylene, which follows that the alloying of polypropylene with styrene is achieved in situ.

Preparation of poly(2-chloroaniline) membrane and plasma surface modification

International Nuclear Information System (INIS)

Kir, E.; Oksuz, L.; Helhel, S.

2006-01-01

P2ClAn membranes were obtained from chemically synthesized poly(2-chloroaniline) (P2ClAn) by casting method. These membranes were cast from dimethyl formamide (DMF) and were in the undoped state. P2ClAn membranes were characterized by Fourier infrared spectroscopy and scanning electron microscopy. Measurements of water content capacity, membrane thickness and ion-exchange capacity of the cast membranes were carried out. P2ClAn membranes were treated by electron cylotron resonance (ECR) plasma for surface modification. Plasma treatment has been successfully utilized for improving the surface properties of P2ClAn membranes such as increasing pore diameters and number of pores for better anion or molecule transportation

Study on surface modification of polymer films by using atmospheric plasma jet source

International Nuclear Information System (INIS)

Takemura, Yuichiro; Hara, Tamio; Yamaguchi, Naohiro

2008-01-01

Reactive gas plasma treatments of poly(ethylene terephthalate) (PET) and polyimide (Kapton) have been performed using an atmospheric plasmas jet source. Characteristics of surface modification have been examined by changing the distance between the plasma jet source and the treated sample, and by changing the working gas spaces. Simultaneously, each plasma jet source has been investigated by space-resolving spectroscopy in the UV/visible region. Polymer surfaces have been analyzed by X-ray photoelectron spectroscopy (XPS). A marked improvement in the hydrophilicity of the polymer surfaces has been made by using N 2 or O 2 plasma jet source with a very short exposure time of about 0.01 s, whereas the less improvement has been obtained using on air plasma jet source because of NO x compound production. Changes in the chemical states of C of the polymer surfaces have been observed in XPS spectra after N 2 plasma jet spraying. (author)

Influence of DC plasma modification on the selected properties and the geometrical surface structure of polylactide prior to autocatalytic metallization

Energy Technology Data Exchange (ETDEWEB)

Moraczewski, Krzysztof, E-mail: kmm@ukw.edu.pl [Kazimierz Wielki University, Chodkiewicza 30, 85-064 Bydgoszcz (Poland); Rytlewski, Piotr [Kazimierz Wielki University, Chodkiewicza 30, 85-064 Bydgoszcz (Poland); Malinowski, Rafał [Institute for Engineering of Polymer Materials and Dyes, Marii Skłodowskiej-Curie 55, 87-100 Toruń (Poland); Tracz, Adam [Centre for Molecular and Macromolecular Studies of the Polish Academy of Sciences, Sienkiewicza 112, 90-363 Łódź (Poland); Żenkiewicz, Marian [Institute for Engineering of Polymer Materials and Dyes, Marii Skłodowskiej-Curie 55, 87-100 Toruń (Poland)

2015-03-01

The paper presents the results of studies to determine the applicability of plasma modification in the process of polylactide (PLA) surface preparation prior to the autocatalytic metallization. The polylactide plasma modification was carried out in an oxygen or nitrogen chemistry. The samples were tested with the following methods: scanning electron microscopy (SEM), atomic force microscopy (AFM), goniometry and electron spectrophotometry (XPS). Scanning electron microscopy and atomic force microscopy images were demonstrated. The results of surface free energy calculations, performed based on the results of the contact angle measurements have been presented. The results of the qualitative (degree of oxidation or nitridation) and quantitative analysis of the chemical composition of the polylactide surface layer have also been described. The results of the studies show that the DC plasma modification performed in the proposed condition is a suitable as a method of surface preparation for the polylactide metallization. - Highlights: • We modified polylactide surface layer with plasma generated in oxygen or nitrogen. • We tested selected properties and surface structure of modified samples. • DC plasma modification can be used to prepare the PLA surface for metallization. • For better results metallization should be preceded by sonication process.

Materials surface modification by plasma bombardment under simultaneous erosion and redeposition conditions

International Nuclear Information System (INIS)

Hirooka, Y.; Goebel, D.M.; Conn, R.W.

1986-07-01

The first in-depth investigation of surface modification of materials by continuous, high-flux argon plasma bombardment under simultaneous erosion and redeposition conditions have been carried out for copper and 304 stainless steel using the PISCES facility. The plasma bombardment conditions are: incident ion flux range from 10 17 to 10 19 ions sec -1 cm -2 , total ion fluence is controlled between 10 19 and 10 22 ions cm -2 , electron temperature range from 5 to 15 eV, and plasma density range from 10 11 to 10 13 cm -3 . The incident ion energy is 100 eV. The sample temperature is between 300 and 700K. Under redeposition dominated conditions, the material erosion rate due to the plasma bombardment is significantly smaller (by a factor up to 10) than that can be expected from the classical ion beam sputtering yield data. It is found that surface morphologies of redeposited materials strongly depend on the plasma bombardment condition. The effect of impurities on surface morphology is elucidated in detail. First-order modelings are implemented to interpret the reduced erosion rate and the surface evolution. Also, fusion related surface properties of redeposited materials such as hydrogen reemission and plasma driven permeation have been characterized

Surface modification of chitosan/PEO nanofibers by air dielectric barrier discharge plasma for acetylcholinesterase immobilization

Energy Technology Data Exchange (ETDEWEB)

Dorraki, Naghme, E-mail: n.dorraki@web.sbu.ac.ir [Laser and Plasma Research Institute, Shahid Beheshti University, Evin 1983963113, Tehran (Iran, Islamic Republic of); Safa, Nasrin Navab [Laser and Plasma Research Institute, Shahid Beheshti University, Evin 1983963113, Tehran (Iran, Islamic Republic of); Jahanfar, Mehdi [Protein Research Center, Shahid Beheshti University, Evin 1983963113, Tehran (Iran, Islamic Republic of); Ghomi, Hamid [Laser and Plasma Research Institute, Shahid Beheshti University, Evin 1983963113, Tehran (Iran, Islamic Republic of); Ranaei-Siadat, Seyed-Omid [Protein Research Center, Shahid Beheshti University, Evin 1983963113, Tehran (Iran, Islamic Republic of)

2015-09-15

Highlights: • We used an economical and effective method for surface modification. • Chitosan/PEO nanofibrous membranes were modified by air-DBD plasma. • The most NH{sub 3}{sup +} group was generated on the 6 min plasma modified membrane. • We immobilized acetylcholinesterase on the plasma modified and unmodified membranes. • More enzyme activity was detected on the modified membrane by plasma. - Abstract: There are different methods to modify polymer surfaces for biological applications. In this work we have introduced air-dielectric barrier discharge (DBD) plasma at atmospheric pressure as an economical and safe method for modifying the surface of electrospun chitosan/PEO (90/10) nanofibers for acetylcholinesterase (AChE) immobilization. According to the contact angle measurement results, the nanofibers become highly hydrophilic when they are exposed to the DBD plasma for 6 min in compared to unmodified membrane. Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) results reveal hydroxyl, C=O and NH{sub 3}{sup +} polar groups increment after 6 min plasma treatment. Contact angle measurements and ATR-FTIR results are confirmed by X-ray photoelectron spectroscopy (XPS). AChE at pH 7.4 carries a negative charge and after immobilization on the surface of plasma-treated nanofibrous membrane attracts the NH{sub 3}{sup +} group and more enzyme activity is detected on the plasma-modified nanofibers for 6 min in compared to unmodified nanofibers. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) are used for the surface topography and morphology characterization. The results have proved that air-DBD plasma is a suitable method for chitosan/PEO nanofibrous membrane modification as a biodegradable and functionalized substrate for enzyme immobilization.

The third generation multi-purpose plasma immersion ion implanter for surface modification of materials

CERN Document Server

Tang Bao Yin; Wang Xiao Feng; Gan Kong Yin; Wang Song Yan; Chu, P K; Huang Nian Ning; Sun Hong

2002-01-01

The third generation multi-purpose plasma immersion ion implantation (PIII) equipment has been successfully used for research and development of surface modification of biomedical materials, metals and their alloys in the Southwest Jiaotong University. The implanter equipped with intense current, pulsed cathodic arc metal plasma sources which have both strong coating function and gas and metal ion implantation function. Its pulse high voltage power supply can provide big output current. It can acquire very good implantation dose uniformity. The equipment can both perform ion implantation and combine ion implantation with sputtering deposition and coating to form many kinds of synthetic surface modification techniques. The main design principles, features of important components and achievement of research works in recent time have been described

Surface modification of carbon/epoxy prepreg using oxygen plasma and its effect on the delamination resistance behavior of carbon/epoxy composites

International Nuclear Information System (INIS)

Kim, M.H.; Rhee, K.Y.; Kim, H.J.; Jung, D.H.

2007-01-01

It was shown in previous study that the fracture toughness of carbon/epoxy laminated composites could be significantly improved by modifying the surface of the prepreg using Ar + irradiation in an oxygen environment. In this study, the surface of carbon/epoxy prepreg was modified using an oxygen plasma to improve the delamination resistance behavior of carbon/epoxy laminated composites. The variation of the contact angle on the prepreg surface was determined as a function of the modification time, in order to determine the optimal modification time. An XPS analysis was conducted to investigate the chemical changes on the surface of the prepreg caused by the plasma modification. Mode I delamination resistance curves of the composites with and without surface modification were plotted as a function of the delamination increment. The results showed that the contact angle varied from ∼64 o to ∼47 o depending on the modification time and reached a minimum for a modification time of 30 min. The XPS analysis showed that the hydrophilic carbonyl C=O group was formed by the oxygen plasma modification. The results also showed that the delamination resistance behavior was significantly improved by the plasma modification of the prepreg. This improvement was caused by the better layer-to-layer adhesion as well as increased interfacial strength between the fibers and matrix

Modification of surfaces and surface layers by non equilibrium processes

International Nuclear Information System (INIS)

Beamson, G.; Brennan, W.J.; Clark, D.T.; Howard, J.

1988-01-01

Plasmas are examples of non-equilibrium phenomena which are being used increasingly for the synthesis and modification of materials impossible by conventional routes. This paper introduces methods available by describing the construction and characteristics of some equipment used for the production of different types of plasmas and other non-equilibrium phenomena. This includes high energy ion beams. The special features, advantages and disadvantages of the techniques will be described. There are a multitude of potential application relevant to electronic, metallic, ceramic, and polymeric materials. However, scale-up from the laboratory to production equipment depends on establishing a better understanding of both the physics and chemistry of plasma as well as plasma-solid interactions. Examples are given of how such an understanding can be gained. The chemical analysis of polymer surfaces undergoing modification by inert gas, hydrogen or oxygen plasmas is shown to give physical information regarding the relative roles of diffusion of active species, and direct and radiative energy transfer from the plasma. Surface modification by plasma depositing a new material onto an existing substrate is discussed with particular reference to the deposition of amorphous carbon films. Applications of the unique properties of these films are outlined together with our current understanding of these properties based on chemical and physical methods of analysis of both the films and the plasmas producing them. Finally, surface modification by ion beams is briefly illustrated using examples from the electronics and metals industries where the modification has had a largely physical rather than chemical effect on the starting material. (orig.)

Surface modifications on toughened, fine-grained, recrystallized tungsten with repetitive ELM-like pulsed plasma irradiation

Energy Technology Data Exchange (ETDEWEB)

Kikuchi, Y., E-mail: ykikuchi@eng.u-hyogo.ac.jp [Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, 671-2280 Hyogo (Japan); Sakuma, I.; Kitagawa, Y.; Asai, Y.; Onishi, K.; Fukumoto, N.; Nagata, M. [Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, 671-2280 Hyogo (Japan); Ueda, Y. [Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Kurishita, H. [Institute for Materials Research, Tohoku University, Ibaraki 311-1313 (Japan)

2015-08-15

Surface modifications of toughened, fine-grained, recrystallized tungsten (TFGR W) materials with 1.1 wt.% TiC and 3.3 wt.% TaC dispersoids due to repetitive ELM-like pulsed (∼0.15 ms) helium plasma irradiation have been investigated by using a magnetized coaxial plasma gun. No surface cracking at the center part of the TFGR W samples exposed to 20 plasma pulses of ∼0.3 MJ m{sup −2} was observed. The suppression of surface crack formation due to the increase of the grain boundary strength by addition of TiC and TaC dispersoids was confirmed in comparison with a pure W material. On the other hand, surface cracks and small pits appeared at the edge part of the TFGR W sample after the pulsed plasma irradiation. Erosion of the TiC and TaC dispersoids due to the pulsed plasma irradiation could cause the small pits on the surface, resulting in the surface crack formation.

Surface modifications on toughened, fine-grained, recrystallized tungsten with repetitive ELM-like pulsed plasma irradiation

Science.gov (United States)

Kikuchi, Y.; Sakuma, I.; Kitagawa, Y.; Asai, Y.; Onishi, K.; Fukumoto, N.; Nagata, M.; Ueda, Y.; Kurishita, H.

2015-08-01

Surface modifications of toughened, fine-grained, recrystallized tungsten (TFGR W) materials with 1.1 wt.% TiC and 3.3 wt.% TaC dispersoids due to repetitive ELM-like pulsed (∼0.15 ms) helium plasma irradiation have been investigated by using a magnetized coaxial plasma gun. No surface cracking at the center part of the TFGR W samples exposed to 20 plasma pulses of ∼0.3 MJ m-2 was observed. The suppression of surface crack formation due to the increase of the grain boundary strength by addition of TiC and TaC dispersoids was confirmed in comparison with a pure W material. On the other hand, surface cracks and small pits appeared at the edge part of the TFGR W sample after the pulsed plasma irradiation. Erosion of the TiC and TaC dispersoids due to the pulsed plasma irradiation could cause the small pits on the surface, resulting in the surface crack formation.

Surface modification of polyacrylonitrile co-polymer membranes using pulsed direct current nitrogen plasma

Energy Technology Data Exchange (ETDEWEB)

Pal, Dipankar; Neogi, Sudarsan; De, Sirshendu, E-mail: sde@che.iitkgp.ernet.in

2015-12-31

Low temperature plasma treatment using pulsed direct current discharge of nitrogen gas was employed to enhance hydrophilicity of the polyacrylonitrile co-polymer membranes. The membranes were characterized in terms of morphology, structure, hydrophilicity, and membrane performance. Properties and functional groups on the surface of polyacrylonitrile co-polymer membranes were investigated by contact angle, scanning electron microscopy, Fourier transform infrared and X-ray photoelectron spectroscopy. Effects of plasma conditions, namely, pulsed voltage, duty cycle and treatment time on increase in membrane hydrophilicity were studied. Permeability of treated membrane was increased by 47% and it was retained up to 70 days. Surface etching due to plasma treatment was confirmed by weight loss of the treated membranes. Due to surface etching, average pore size increased and rejection of 200 kDa polyethylene glycol decreased to about 70% for the treated membrane. Oxygen and nitrogen functional groups were responsible for surface hydrophilicity. - Highlights: • Surface modification of polyacrylonitrile co-polymer membranes by pulsed direct current nitrogen plasma • Hydrophilic functional groups incorporated on the membrane surface • Significant enhancement of the permeability and wettability of the membranes • Water contact angle increased with storage time and finally stabilized.

Surface modification of polyacrylonitrile co-polymer membranes using pulsed direct current nitrogen plasma

International Nuclear Information System (INIS)

Pal, Dipankar; Neogi, Sudarsan; De, Sirshendu

2015-01-01

Low temperature plasma treatment using pulsed direct current discharge of nitrogen gas was employed to enhance hydrophilicity of the polyacrylonitrile co-polymer membranes. The membranes were characterized in terms of morphology, structure, hydrophilicity, and membrane performance. Properties and functional groups on the surface of polyacrylonitrile co-polymer membranes were investigated by contact angle, scanning electron microscopy, Fourier transform infrared and X-ray photoelectron spectroscopy. Effects of plasma conditions, namely, pulsed voltage, duty cycle and treatment time on increase in membrane hydrophilicity were studied. Permeability of treated membrane was increased by 47% and it was retained up to 70 days. Surface etching due to plasma treatment was confirmed by weight loss of the treated membranes. Due to surface etching, average pore size increased and rejection of 200 kDa polyethylene glycol decreased to about 70% for the treated membrane. Oxygen and nitrogen functional groups were responsible for surface hydrophilicity. - Highlights: • Surface modification of polyacrylonitrile co-polymer membranes by pulsed direct current nitrogen plasma • Hydrophilic functional groups incorporated on the membrane surface • Significant enhancement of the permeability and wettability of the membranes • Water contact angle increased with storage time and finally stabilized.

Modification of structural materials by pulsed plasma flows

International Nuclear Information System (INIS)

Bandura, A.N.; Garkusha, I.E.; Byrka, O.V.; Makhlaj, V.A.

2011-01-01

Features of surface modification and materials alloying from gas and metallic plasma as a result of the plasma ions mixing with the steel substrate in liquid phase are investigated in this paper.The experiments have been carried out with pulsed plasma gun, which generates plasma streams with ion energy up to 2 keV, plasma density 2x10 14 cm -3 , average specific power of 10 MW/cm 2 and plasma energy density in the range of (5-40) J/cm 2 . The nitrogen, helium, other gases and their mixtures can be used as working gases. The regime of plasma treatment was chosen with variation of both the discharge voltage and the distance of the material surface from the gun output. Modification of thin (0.5-2 µm) PVD coatings of MoN, C+W, TiN, TiC, Cr, Cr+CrN and others by the pulsed plasma streams are analyzed also. It is shown that pulsed plasma treatment results in essential improvement of physical and mechanical properties of exposed materials. For example, microhardness of samples with Cr coating, after plasma treatment, increased in 2,5 times. Mechanisms of surface modification of a different alloys and coating irradiated with pulsed plasma streams of different ions are discussed. (authors)

New electron-ion-plasma equipment for modification of materials and products surface

International Nuclear Information System (INIS)

Koval', N.N.

2013-01-01

Electron-ion-plasma treatment of materials and products, including surface clearing and activation, formation surface layers with changed chemical and phase structure, increased hardness and corrosion resistance; deposition of various functional coatings, has received a wide distribution in a science and industry. Widespread methods of ion-plasma modification of material and product surfaces are ion etching and activation, ion-plasma nitriding, arc or magnetron deposition of functional coatings, including nanostructured. The combination of above methods of surface modification allows essentially to improve exploitation properties of treated products and to optimize the characteristics of modified surfaces for concrete final requirements. For the purpose of a combination of various methods of ion-plasma treatment in a single work cycle at Institute of High Current Electronics of SB RAS (IHCE SB RAS) specialized technological equipment 'DUET', 'TRIO' and 'QUADRO' and 'KVINTA' have been developed. This equipment allow generating uniform low-temperature gas plasma at pressures of (0.1-1) Pa with concentration of (10 9 -10 11 ) cm -3 in volume of (0.1-1) m 3 . In the installations consistent realization of several various operations of materials and products treatment in a single work cycle is possible. The operations are preliminary heating and degassing, ion clearing, etching and activation of materials and products surface by plasma of arc discharges; chemicothermal treatment (nitriding) for formation of diffusion layer on a surface of treated sample using plasma of nonself-sustained low-pressure arc discharge; deposition of single- or multilayered superhard (≥40 GPa) nanocrystalline coatings on the basis of pure metals or their compounds (nitrides, carbides, carbonitrides) by the arc plasma-assisted method. For realization of the modes all installations are equipped by original sources of gas and metal plasma. Besides, in

Comparison of some effects of modification of a polylactide surface layer by chemical, plasma, and laser methods

Energy Technology Data Exchange (ETDEWEB)

Moraczewski, Krzysztof, E-mail: kmm@ukw.edu.pl [Department of Materials Engineering, Kazimierz Wielki University, Department of Materials Engineering, ul. Chodkiewicza 30, 85-064 Bydgoszcz (Poland); Rytlewski, Piotr [Department of Materials Engineering, Kazimierz Wielki University, Department of Materials Engineering, ul. Chodkiewicza 30, 85-064 Bydgoszcz (Poland); Malinowski, Rafał [Institute for Engineering of Polymer Materials and Dyes, ul. M. Skłodowskiej–Curie 55, 87-100 Toruń (Poland); Żenkiewicz, Marian [Department of Materials Engineering, Kazimierz Wielki University, Department of Materials Engineering, ul. Chodkiewicza 30, 85-064 Bydgoszcz (Poland)

2015-08-15

Highlights: • We modified polylactide surface layer with chemical, plasma or laser methods. • We tested selected properties and surface structure of modified samples. • We stated that the plasma treatment appears to be the most beneficial. - Abstract: The article presents the results of studies and comparison of selected properties of the modified PLA surface layer. The modification was carried out with three methods. In the chemical method, a 0.25 M solution of sodium hydroxide in water and ethanol was utilized. In the plasma method, a 50 W generator was used, which produced plasma in the air atmosphere under reduced pressure. In the laser method, a pulsed ArF excimer laser with fluency of 60 mJ/cm{sup 2} was applied. Polylactide samples were examined by using the following techniques: scanning electron microscopy (SEM), atomic force microscopy (AFM), goniometry and X-ray photoelectron spectroscopy (XPS). Images of surfaces of the modified samples were recorded, contact angles were measured, and surface free energy was calculated. Qualitative and quantitative analyses of chemical composition of the PLA surface layer were performed as well. Based on the survey it was found that the best modification results are obtained using the plasma method.

Influence of gas and treatment time on the surface modification of EPDM rubber treated at afterglow microwave plasmas

Science.gov (United States)

da Maia, J. V.; Pereira, F. P.; Dutra, J. C. N.; Mello, S. A. C.; Becerra, E. A. O.; Massi, M.; Sobrinho, A. S. da Silva

2013-11-01

The ethylene propylene diene monomer (EPDM) rubber possesses excellent physical/chemical bulk properties, is cost-effective, and has been used in the mechanical and aerospace industry. However, it has an inert surface and needs a surface treatment in order to improve its adhesion properties. Plasma modification is the most accepted technique for surface modification of polymers without affecting the properties of the bulk. In this study, an afterglow microwave plasma reactor was used to generate the plasma species responsible for the EPDM surface modification. The plasma modified surfaces were analyzed by means of contact angle measurement, adhesion tests, attenuated total reflection-infrared spectroscopy, X-ray photoelectron spectroscopy and scanning electron microscopy. Two experimental variables were analyzed: type of the plasma gases and exposure time were considered. The predominant failure mode was adhesive, for long treatment times a mixture of adhesive and cohesive failure can be observed and the best conditions tested there was an increase of the rupture strength of about 27%, that can be associated mainly with the creation of oxygen containing functional groups on the rubber surface (CO, COC and CO) identified by spectroscopic methods. The predominant failure mode was adhesive, for long treatment times a mixture of adhesive and cohesive failure can be observed. In various conditions tested the contact angles easily decreased more than 500%. What can be concluded that high wettability is a necessary condition to obtain good adhesion, but this is not a sufficient condition.

Influence of gas and treatment time on the surface modification of EPDM rubber treated at afterglow microwave plasmas

International Nuclear Information System (INIS)

Maia, J.V. da; Pereira, F.P.; Dutra, J.C.N.; Mello, S.A.C.; Becerra, E.A.O.; Massi, M.; Sobrinho, A.S. da Silva

2013-01-01

The ethylene propylene diene monomer (EPDM) rubber possesses excellent physical/chemical bulk properties, is cost-effective, and has been used in the mechanical and aerospace industry. However, it has an inert surface and needs a surface treatment in order to improve its adhesion properties. Plasma modification is the most accepted technique for surface modification of polymers without affecting the properties of the bulk. In this study, an afterglow microwave plasma reactor was used to generate the plasma species responsible for the EPDM surface modification. The plasma modified surfaces were analyzed by means of contact angle measurement, adhesion tests, attenuated total reflection-infrared spectroscopy, X-ray photoelectron spectroscopy and scanning electron microscopy. Two experimental variables were analyzed: type of the plasma gases and exposure time were considered. The predominant failure mode was adhesive, for long treatment times a mixture of adhesive and cohesive failure can be observed and the best conditions tested there was an increase of the rupture strength of about 27%, that can be associated mainly with the creation of oxygen containing functional groups on the rubber surface (C-O, C-O-C and C=O) identified by spectroscopic methods. The predominant failure mode was adhesive, for long treatment times a mixture of adhesive and cohesive failure can be observed. In various conditions tested the contact angles easily decreased more than 500%. What can be concluded that high wettability is a necessary condition to obtain good adhesion, but this is not a sufficient condition.

Influence of gas and treatment time on the surface modification of EPDM rubber treated at afterglow microwave plasmas

Energy Technology Data Exchange (ETDEWEB)

Maia, J.V. da, E-mail: jaisondamaia@hotmail.com [Plasmas and Processes Laboratory, Department of Physics, Technological Institute of Aeronautics, 12228-900 S. J. dos Campos, SP (Brazil); Department of Physics, Federal Institute of Santa Catarina, 89251-000 Jaraguá do Sul, SC (Brazil); Pereira, F.P. [Plasmas and Processes Laboratory, Department of Physics, Technological Institute of Aeronautics, 12228-900 S. J. dos Campos, SP (Brazil); Dutra, J.C.N.; Mello, S.A.C. [EBO, Chemistry Division, IAE, CTA, 12228-900 S. J. dos Campos, SP (Brazil); Becerra, E.A.O. [Department of Physics, Pontifical Catholic University of Rio de Janeiro, Rio de Janeiro, RJ (Brazil); Massi, M.; Sobrinho, A.S. da Silva [Plasmas and Processes Laboratory, Department of Physics, Technological Institute of Aeronautics, 12228-900 S. J. dos Campos, SP (Brazil)

2013-11-15

The ethylene propylene diene monomer (EPDM) rubber possesses excellent physical/chemical bulk properties, is cost-effective, and has been used in the mechanical and aerospace industry. However, it has an inert surface and needs a surface treatment in order to improve its adhesion properties. Plasma modification is the most accepted technique for surface modification of polymers without affecting the properties of the bulk. In this study, an afterglow microwave plasma reactor was used to generate the plasma species responsible for the EPDM surface modification. The plasma modified surfaces were analyzed by means of contact angle measurement, adhesion tests, attenuated total reflection-infrared spectroscopy, X-ray photoelectron spectroscopy and scanning electron microscopy. Two experimental variables were analyzed: type of the plasma gases and exposure time were considered. The predominant failure mode was adhesive, for long treatment times a mixture of adhesive and cohesive failure can be observed and the best conditions tested there was an increase of the rupture strength of about 27%, that can be associated mainly with the creation of oxygen containing functional groups on the rubber surface (C-O, C-O-C and C=O) identified by spectroscopic methods. The predominant failure mode was adhesive, for long treatment times a mixture of adhesive and cohesive failure can be observed. In various conditions tested the contact angles easily decreased more than 500%. What can be concluded that high wettability is a necessary condition to obtain good adhesion, but this is not a sufficient condition.

Deposition of thin films and surface modification by pulsed high energy density plasma

International Nuclear Information System (INIS)

Yan Pengxun; Yang Size

2002-01-01

The use of pulsed high energy density plasma is a new low temperature plasma technology for material surface treatment and thin film deposition. The authors present detailed theoretical and experimental studies of the production mechanism and physical properties of the pulsed plasma. The basic physics of the pulsed plasma-material interaction has been investigated. Diagnostic measurements show that the pulsed plasma has a high electron temperature of 10-100 eV, density of 10 14 -10 16 cm -3 , translation velocity of ∼10 -7 cm/s and power density of ∼10 4 W/cm 2 . Its use in material surface treatment combines the effects of laser surface treatment, electron beam treatment, shock wave bombardment, ion implantation, sputtering deposition and chemical vapor deposition. The metastable phase and other kinds of compounds can be produced on low temperature substrates. For thin film deposition, a high deposition ratio and strong film to substrate adhesion can be achieved. The thin film deposition and material surface modification by the pulsed plasma and related physical mechanism have been investigated. Thin film c-BN, Ti(CN), TiN, DLC and AlN materials have been produced successfully on various substrates at room temperature. A wide interface layer exists between film and substrate, resulting in strong adhesion. Metal surface properties can be improved greatly by using this kind of treatment

Influence of tungsten microstructure and ion flux on deuterium plasma-induced surface modifications and deuterium retention

Energy Technology Data Exchange (ETDEWEB)

Buzi, Luxherta [IEK - Plasmaphysik, Forschungszentrum Juelich GmbH, Association EURATOM-FZJ, Juelich (Germany); FOM Institute DIFFER-Dutch Institute for Fundamental Energy Research (Netherlands); Ghent University (Belgium); Temmerman, Greg de [FOM Institute DIFFER-Dutch Institute for Fundamental Energy Research (Netherlands); Reinhart, Michael; Matveev, Dmitry; Unterberg, Bernhard; Wienhold, Peter; Breuer, Uwe; Kreter, Arkadi [IEK - Plasmaphysik, Forschungszentrum Juelich GmbH, Association EURATOM-FZJ, Juelich (Germany); Oost, Guido van [Ghent University (Belgium)

2014-07-01

Tungsten is to be used as plasma-facing material for the ITER divertor due to its favourable thermal properties, low erosion and fuel retention. Bombardment of tungsten by low energy ions of hydrogen isotopes, at different surface temperature, can lead to surface modifications and influence the fuel accumulation in the material. This contribution will assess the impact of material microstructure and the correlation between the particle flux, surface modifications and deuterium retention in tungsten. Tungsten samples were exposed to deuterium plasma at a surface temperature of 510 K, 670 K and 870 K, ion energy of 40 eV and ion fluence of 10{sup 26} m{sup -2}. The high and low ion flux ranges were in the order 10{sup 24} m{sup -2}s{sup -1} and 10{sup 22} m{sup -2}s{sup -1}. Depth profiling of deuterium in all the samples was done by secondary ion mass spectroscopy technique and a scanning electron microscope was used to investigate the surface modifications. Modelling of the D desorption spectra with the coupled reaction diffusion system model will be also presented.

Comparison of some effects of modification of a polylactide surface layer by chemical, plasma, and laser methods

Science.gov (United States)

Moraczewski, Krzysztof; Rytlewski, Piotr; Malinowski, Rafał; Żenkiewicz, Marian

2015-08-01

The article presents the results of studies and comparison of selected properties of the modified PLA surface layer. The modification was carried out with three methods. In the chemical method, a 0.25 M solution of sodium hydroxide in water and ethanol was utilized. In the plasma method, a 50 W generator was used, which produced plasma in the air atmosphere under reduced pressure. In the laser method, a pulsed ArF excimer laser with fluency of 60 mJ/cm2 was applied. Polylactide samples were examined by using the following techniques: scanning electron microscopy (SEM), atomic force microscopy (AFM), goniometry and X-ray photoelectron spectroscopy (XPS). Images of surfaces of the modified samples were recorded, contact angles were measured, and surface free energy was calculated. Qualitative and quantitative analyses of chemical composition of the PLA surface layer were performed as well. Based on the survey it was found that the best modification results are obtained using the plasma method.

Plasma treatment induces internal surface modifications of electrospun poly(L-lactic) acid scaffold to enhance protein coating

International Nuclear Information System (INIS)

Jin Seo, Hyok; Hee Lee, Mi; Kwon, Byeong-Ju; Kim, Hye-Lee; Park, Jong-Chul; Jin Lee, Seung; Kim, Bong-Jin; Wang, Kang-Kyun; Kim, Yong-Rok

2013-01-01

Advanced biomaterials should also be bioactive with regard to desirable cellular responses, such as selective protein adsorption and cell attachment, proliferation, and differentiation. To enhance cell-material interactions, surface modifications have commonly been performed. Among the various surface modification approaches, atmospheric pressure glow discharge plasma has been used to change a hydrophobic polymer surface to a hydrophilic surface. Poly(L-lactic acid) (PLLA)-derived scaffolds lack cell recognition signals and the hydrophobic nature of PLLA hinders cell seeding. To make PLLA surfaces more conducive to cell attachment and spreading, surface modifications may be used to create cell-biomaterial interfaces that elicit controlled cell adhesion and maintain differentiated phenotypes. In this study, (He) gaseous atmospheric plasma glow discharge was used to change the characteristics of a 3D-type polymeric scaffold from hydrophobic to hydrophilic on both the outer and inner surfaces of the scaffold and the penetration efficiency with fibronectin was investigated. Field-emission scanning electron microscope images showed that some grooves were formed on the PLLA fibers after plasma treatment. X-ray photoelectron spectroscopy data also showed chemical changes in the PLLA structure. After plasma treatment, -CN (285.76 eV) was increased in C1s and -NH 2 (399.70 eV) was increased significantly and –N=CH (400.80 eV) and –NH 3 + (402.05 eV) were newly appeared in N1s. These changes allowed fibronectin to penetrate into the PLLA scaffold; this could be observed by confocal microscopy. In conclusion, helium atmospheric pressure plasma treatment was effective in modifying the polymeric scaffold, making it hydrophilic, and this treatment can also be used in tissue engineering research as needed to make polymers hydrophilic

Plasma Surface Modification for Immobilization of Bone Morphogenic Protein-2 on Polycaprolactone Scaffolds

Science.gov (United States)

Kim, Byung Hoon; Myung, Sung Woon; Jung, Sang Chul; Ko, Yeong Mu

2013-11-01

The immobilization of recombinant human bone formation protein-2 (rhBMP-2) on polycaprolactone (PCL) scaffolds was performed by plasma polymerization. RhBMP-2, which induces osteoblast differentiation in various cell types, is a growth factor that plays an important role in bone formation and repair. The surface of the PCL scaffold was functionalized with the carboxyl groups of plasma-polymerized acrylic acid (PPAA) thin films. Plasma polymerization was carried out at a discharge power of 60 W at an acrylic acid flow rate of 7 sccm for 5 min. The PPAA thin film exhibited moderate hydrophilic properties and possessed a high density of carboxyl groups. Carboxyl groups and rhBMP-2 on the PCL scaffolds surface were identified by attenuated total reflection Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy, respectively. The alkaline phosphatase activity assay showed that the rhBMP-2 immobilized PCL scaffold increased the level of MG-63 cell differentiation. Plasma surface modification for the preparation of biomaterials, such as biofunctionalized polymer scaffolds, can be used for the binding of bioactive molecules in tissue engineering.

Surface monofunctionalized polymethyl pentene hollow fiber membranes by plasma treatment and hemocompatibility modification for membrane oxygenators

Science.gov (United States)

Huang, Xin; Wang, Weiping; Zheng, Zhi; Fan, Wenling; Mao, Chun; Shi, Jialiang; Li, Lei

2016-01-01

The hemocompatibility of polymethyl pentene (PMP) hollow fiber membranes (HFMs) was improved through surface modification for membrane oxygenator applications. The modification was performed stepwise with the following: (1) oxygen plasma treatment, (2) functionalization of monosort hydroxyl groups through NaBH4 reduction, and (3) grafting 2-methacryloyloxyethyl phosphorylcholine (MPC) or heparin. SEM, ATR-FTIR, and XPS analyses were conducted to confirm successful grafting during the modification. The hemocompatibility of PMP HFMs was analyzed and compared through protein adsorption, platelet adhesion, and coagulation tests. Pure CO2 and O2 permeation rates, as well as in vitro gas exchange rates, were determined to evaluate the mass transfer properties of PMP HFMs. SEM results showed that different nanofibril topographies were introduced on the HFM surface. ATR-FTIR and XPS spectra indicated the presence of functionalization of monosort hydroxyl group and the grafting of MPC and heparin. Hemocompatibility evaluation results showed that the modified PMP HFMs presented optimal hemocompatibility compared with pristine HFMs. Gas permeation results revealed that gas permeation flux increased in the modified HFMs because of dense surface etching during the plasma treatment. The results of in vitro gas exchange rates showed that all modified PMP HFMs presented decreased gas exchange rates because of potential surface fluid wetting. The proposed strategy exhibits a potential for fabricating membrane oxygenators for biomedical applications to prevent coagulation formation and alter plasma-induced surface topology and composition.

Nanocapillary Atmospheric Pressure Plasma Jet: A Tool for Ultrafine Maskless Surface Modification at Atmospheric Pressure.

Science.gov (United States)

Motrescu, Iuliana; Nagatsu, Masaaki

2016-05-18

With respect to microsized surface functionalization techniques we proposed the use of a maskless, versatile, simple tool, represented by a nano- or microcapillary atmospheric pressure plasma jet for producing microsized controlled etching, chemical vapor deposition, and chemical modification patterns on polymeric surfaces. In this work we show the possibility of size-controlled surface amination, and we discuss it as a function of different processing parameters. Moreover, we prove the successful connection of labeled sugar chains on the functionalized microscale patterns, indicating the possibility to use ultrafine capillary atmospheric pressure plasma jets as versatile tools for biosensing, tissue engineering, and related biomedical applications.

Atmospheric plasma surface modifications of electrospun PCL/chitosan/PCL hybrid scaffolds by nozzle type plasma jets for usage of cell cultivation

Energy Technology Data Exchange (ETDEWEB)

Surucu, Seda [Department of Metallurgical and Materials Engineering, Atilim University, Incek, Golbasi, 06836, Ankara (Turkey); Masur, Kai [Leibniz Institute for Plasma Science and Technology (Germany); Turkoglu Sasmazel, Hilal, E-mail: hilal.sasmazel@atilim.edu.tr [Department of Metallurgical and Materials Engineering, Atilim University, Incek, Golbasi, 06836, Ankara (Turkey); Von Woedtke, Thomas; Weltmann, Klaus Dieter [Leibniz Institute for Plasma Science and Technology (Germany)

2016-11-01

Highlights: • Electrospun PCL/chitosan/PCL scaffolds introduced to the literature by us were modified with atmospheric pressure plasma jets. • Plasma was fed into the system with different gas flow rates, time and distances. • Topographical and functional changes were examined by various characterization methods. • Optimum plasma treatment parameters for enhanced topography and functionality were determined. • Electrospun hybrid plasma surface modified samples showed the increased biocompatibility performance of L929 fibroblast cells. - Abstract: This paper reports Ar gas, Ar + O{sub 2}, Ar + O{sub 2} + N{sub 2} gas mixtures and dry air plasma modifications by atmospheric pressure argon driven kINPen and air driven Diener (PlasmaBeam) plasma jets to alter surface properties of three dimensional (3D), electrospun PCL/Chitosan/PCL layer by layer hybrid scaffolds to improve human fibroblast (MRC5) cell attachment and growth. The characterizations of the samples were done by contact angle (CA) measurements, scanning electron microscopy (SEM), X-Ray Photoelectron spectroscopy (XPS) analysis. The results showed that the plasma modification carried out under dry air and Ar + O{sub 2} + N{sub 2} gas mixtures were altered effectively the nanotopography and the functionality of the material surfaces. It was found that the samples treated with Ar + O{sub 2} + N{sub 2} gas mixtures for 1 min and dry air for 9 min have better hydrophilicity 78.9° ± 1.0 and 75.6° ± 0.1, respectively compared to the untreated samples (126.5°). Biocompatibility performance of the scaffolds was determined with alamarBlue (aB) assay and MTT assay methods, Giemsa staining, fluorescence microscope, confocal laser scanning microscope (CLSM) and scanning electron microscope (SEM) analyses. The results showed that plasma treated samples increased the hydrophilicity and oxygen functionality and topography of the surfaces significantly, thus affecting the cell viability and proliferation on

Atmospheric plasma surface modifications of electrospun PCL/chitosan/PCL hybrid scaffolds by nozzle type plasma jets for usage of cell cultivation

International Nuclear Information System (INIS)

Surucu, Seda; Masur, Kai; Turkoglu Sasmazel, Hilal; Von Woedtke, Thomas; Weltmann, Klaus Dieter

2016-01-01

Highlights: • Electrospun PCL/chitosan/PCL scaffolds introduced to the literature by us were modified with atmospheric pressure plasma jets. • Plasma was fed into the system with different gas flow rates, time and distances. • Topographical and functional changes were examined by various characterization methods. • Optimum plasma treatment parameters for enhanced topography and functionality were determined. • Electrospun hybrid plasma surface modified samples showed the increased biocompatibility performance of L929 fibroblast cells. - Abstract: This paper reports Ar gas, Ar + O_2, Ar + O_2 + N_2 gas mixtures and dry air plasma modifications by atmospheric pressure argon driven kINPen and air driven Diener (PlasmaBeam) plasma jets to alter surface properties of three dimensional (3D), electrospun PCL/Chitosan/PCL layer by layer hybrid scaffolds to improve human fibroblast (MRC5) cell attachment and growth. The characterizations of the samples were done by contact angle (CA) measurements, scanning electron microscopy (SEM), X-Ray Photoelectron spectroscopy (XPS) analysis. The results showed that the plasma modification carried out under dry air and Ar + O_2 + N_2 gas mixtures were altered effectively the nanotopography and the functionality of the material surfaces. It was found that the samples treated with Ar + O_2 + N_2 gas mixtures for 1 min and dry air for 9 min have better hydrophilicity 78.9° ± 1.0 and 75.6° ± 0.1, respectively compared to the untreated samples (126.5°). Biocompatibility performance of the scaffolds was determined with alamarBlue (aB) assay and MTT assay methods, Giemsa staining, fluorescence microscope, confocal laser scanning microscope (CLSM) and scanning electron microscope (SEM) analyses. The results showed that plasma treated samples increased the hydrophilicity and oxygen functionality and topography of the surfaces significantly, thus affecting the cell viability and proliferation on/within scaffolds.

Microwave plasma initiated graft copolymerization modification of monomers onto PTFE surface

International Nuclear Information System (INIS)

Guan Weishu; Wen Yunjian; Fang Yan; Yin Yongxiang

1996-02-01

A graft copolymerization modification technique of monomers onto polytetrafluoroethylene (PTFE) surface initiated by a 2.45 GHz non-equilibrium microwave plasma has been investigated. Standard X-Ray Photoelectron Spectroscopy (XPS), Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR), Scanning Electron Microscopy (sEM) and wetting techniques were used for examination and analysis of samples. Considerable changes in chemical structure, composition and in morphology of grafted surface of PTFE were found. Results showed the occurrence of noticeable defluorination and cross-linked structure on grafted surface, and indicated that different kinds and contents of oxygen-containing functional groups were introduced into the surface of PTFE. Wetting and adhesion experiment of the sample proved that significant improvements in hydrophilicity and adhesion of surface were exhibited. These results confirmed the success of grafting. (8 refs., 7 figs., 1 tab.)

Diagnostics of microwave assisted electron cyclotron resonance plasma source for surface modification of nylon 6

Science.gov (United States)

More, Supriya E.; Das, Partha Sarathi; Bansode, Avinash; Dhamale, Gayatri; Ghorui, S.; Bhoraskar, S. V.; Sahasrabudhe, S. N.; Mathe, Vikas L.

2018-01-01

Looking at the increasing scope of plasma processing of materials surface, here we present the development and diagnostics of a microwave assisted Electron Cyclotron Resonance (ECR) plasma system suitable for surface modification of polymers. Prior to the surface-treatment, a detailed diagnostic mapping of the plasma parameters throughout the reactor chamber was carried out by using single and double Langmuir probe measurements in Ar plasma. Conventional analysis of I-V curves as well as the elucidation form of the Electron Energy Distribution Function (EEDF) has become the source of calibration of plasma parameters in the reaction chamber. The high energy tail in the EEDF of electron temperature is seen to extend beyond 60 eV, at much larger distances from the ECR zone. This proves the suitability of the rector for plasma processing, since the electron energy is much beyond the threshold energy of bond breaking in most of the polymers. Nylon 6 is used as a representative candidate for surface processing in the presence of Ar, H2 + N2, and O2 plasma, treated at different locations inside the plasma chamber. In a typical case, the work of adhesion is seen to almost get doubled when treated with oxygen plasma. Morphology of the plasma treated surface and its hydrophilicity are discussed in view of the variation in electron density and electron temperature at these locations. Nano-protrusions arising from plasma treatment are set to be responsible for the hydrophobicity. Chemical sputtering and physical sputtering are seen to influence the surface morphology on account of sufficient electron energies and increased plasma potential.

Atmospheric plasma surface modifications of electrospun PCL/chitosan/PCL hybrid scaffolds by nozzle type plasma jets for usage of cell cultivation

Science.gov (United States)

Surucu, Seda; Masur, Kai; Turkoglu Sasmazel, Hilal; Von Woedtke, Thomas; Weltmann, Klaus Dieter

2016-11-01

This paper reports Ar gas, Ar + O2, Ar + O2 + N2 gas mixtures and dry air plasma modifications by atmospheric pressure argon driven kINPen and air driven Diener (PlasmaBeam) plasma jets to alter surface properties of three dimensional (3D), electrospun PCL/Chitosan/PCL layer by layer hybrid scaffolds to improve human fibroblast (MRC5) cell attachment and growth. The characterizations of the samples were done by contact angle (CA) measurements, scanning electron microscopy (SEM), X-Ray Photoelectron spectroscopy (XPS) analysis. The results showed that the plasma modification carried out under dry air and Ar + O2 + N2 gas mixtures were altered effectively the nanotopography and the functionality of the material surfaces. It was found that the samples treated with Ar + O2 + N2 gas mixtures for 1 min and dry air for 9 min have better hydrophilicity 78.9° ± 1.0 and 75.6° ± 0.1, respectively compared to the untreated samples (126.5°). Biocompatibility performance of the scaffolds was determined with alamarBlue (aB) assay and MTT assay methods, Giemsa staining, fluorescence microscope, confocal laser scanning microscope (CLSM) and scanning electron microscope (SEM) analyses. The results showed that plasma treated samples increased the hydrophilicity and oxygen functionality and topography of the surfaces significantly, thus affecting the cell viability and proliferation on/within scaffolds.

Modeling polyvinyl chloride Plasma Modification by Neural Networks

Science.gov (United States)

Wang, Changquan

2018-03-01

Neural networks model were constructed to analyze the connection between dielectric barrier discharge parameters and surface properties of material. The experiment data were generated from polyvinyl chloride plasma modification by using uniform design. Discharge voltage, discharge gas gap and treatment time were as neural network input layer parameters. The measured values of contact angle were as the output layer parameters. A nonlinear mathematical model of the surface modification for polyvinyl chloride was developed based upon the neural networks. The optimum model parameters were obtained by the simulation evaluation and error analysis. The results of the optimal model show that the predicted value is very close to the actual test value. The prediction model obtained here are useful for discharge plasma surface modification analysis.

Surface Modification of Electrospun PVDF/PAN Nanofibrous Layers by Low Vacuum Plasma Treatment

Directory of Open Access Journals (Sweden)

Fatma Yalcinkaya

2016-01-01

Full Text Available Nanofibres are very promising for water remediation due to their high porosity and small pore size. Mechanical properties of nanofibres restrict the application of pressure needed water treatments. Various PAN, PVDF, and PVDF/PAN nanofibre layers were produced, and mechanical properties were improved via a lamination process. Low vacuum plasma treatment was applied for the surface modification of nanofibres. Atmospheric air was used to improve hydrophilicity while sulphur hexafluoride gas was used to improve hydrophobicity of membranes. Hydrophilic membranes showed higher affinity to attach plasma particles compared to hydrophobic membranes.

Modification of polycarbonate surface in oxidizing plasma

Science.gov (United States)

Ovtsyn, A. A.; Smirnov, S. A.; Shikova, T. G.; Kholodkov, I. V.

2017-11-01

The properties of the surface of the film polycarbonate Lexan 8010 were experimentally studied after treatment in a DC discharge plasma in oxygen and air at pressures of 50-300 Pa and a discharge current of 80 mA. The contact angles of wetting and surface energies are measured. The topography of the surface was investigated by atomic force microscopy. The chemical composition of the surface was determined from the FT-IR spectroscopy data in the variant of total internal reflection, as well as X-ray photoelectron spectroscopy. Treatment in the oxidizing plasma leads to a change in morphology (average roughness increases), an increase in the surface energy, and the concentration of oxygen-containing groups (hydroxyl groups, carbonyl groups in ketones or aldehydes and in oxyketones) on the surface of the polymer. Possible reasons for the difference in surface properties of polymer under the action of oxygen and air plasma on it are discussed.

Inner surface modification of a tube by magnetic glow-arc plasma source ion implantation

International Nuclear Information System (INIS)

Zhang Guling; Chinese Academy of Sciences, Beijing; Wang Jiuli; Feng Wenran; Chen Guangliang; Gu Weichao; Niu Erwu; Fan Songhua; Liu Chizi; Yang Size; Wu Xingfang

2006-01-01

A new method named the magnetic glow-arc plasma source ion implantation (MGA-PSII) is proposed for inner surface modification of tubes. In MGA-PSII, under the control of an axial magnetic field, which is generated by an electric coil around the tube sample, glow arc plasma moves spirally into the tube from its two ends. A negative voltage applied on the tube realized its inner surface implantation. Titanium nitride (TiN) films are prepared on the inner surface of a stainless steel tube in diameter 90 mm and length 600 mm. Hardness tests show that the hardness at the tube centre is up to 20 GPa. XRD, XPS and AES analyses demonstrate that good quality of TiN films can be achieved. (authors)

Inner Surface Modification of a Tube by Magnetic Glow-Arc Plasma Source Ion Implantation

Science.gov (United States)

Zhang, Gu-Ling; Wang, Jiu-Li; Wu, Xing-Fang; Feng, Wen-Ran; Chen, Guang-Liang; Gu, Wei-Chao; Niu, Er-Wu; Fan, Song-Hua; Liu, Chi-Zi; Yang, Si-Ze

2006-05-01

A new method named the magnetic glow-arc plasma source ion implantation (MGA-PSII) is proposed for inner surface modification of tubes. In MGA-PSII, under the control of an axial magnetic field, which is generated by an electric coil around the tube sample, glow arc plasma moves spirally into the tube from its two ends. A negative voltage applied on the tube realized its inner surface implantation. Titanium nitride (TiN) films are prepared on the inner surface of a stainless steel tube in diameter 90 mm and length 600 mm. Hardness tests show that the hardness at the tube centre is up to 20 GPa. XRD, XPS and AES analyses demonstrate that good quality of TiN films can be achieved.

Surface modification of biomaterials by pulsed laser ablation deposition and plasma/gamma polymerization

Science.gov (United States)

Rau, Kaustubh R.

Surface modification of stainless-steel was carried out by two different methods: pulsed laser ablation deposition (PLAD) and a combined plasma/gamma process. A potential application was the surface modification of endovascular stents, to enhance biocompatibility. The pulsed laser ablation deposition process, had not been previously reported for modifying stents and represented a unique and potentially important method for surface modification of biomaterials. Polydimethylsiloxane (PDMS) elatomer was studied using the PLAD technique. Cross- linked PDMS was deemed important because of its general use for biomedical implants and devices as well as in other fields. Furthermore, PDMS deposition using PLAD had not been previously studied and any information gained on its ablation characteristics could be important scientifically and technologically. The studies reported here showed that the deposited silicone film properties had a dependence on the laser energy density incident on the target. Smooth, hydrophobic, silicone-like films were deposited at low energy densities (100-150 mJ/cm2). At high energy densities (>200 mJ/cm2), the films had an higher oxygen content than PDMS, were hydrophilic and tended to show a more particulate morphology. It was also determined that (1)the deposited films were stable and extremely adherent to the substrate, (2)silicone deposition exhibited an `incubation effect' which led to the film properties changing with laser pulse number and (3)films deposited under high vacuum were similar to films deposited at low vacuum levels. The mechanical properties of the PLAD films were determined by nanomechanical measurements which are based on the Atomic Force Microscope (AFM). From these measurements, it was possible to determine the modulus of the films and also study their scratch resistance. Such measurement techniques represent a significant advance over current state-of-the-art thin film characterization methods. An empirical model for

Investigation of graft copolymerization modification of PTFE surface using microwave plasma

International Nuclear Information System (INIS)

Wen Yunjian; Guan Weishu; Fang Yan; Ying Yongxiang

1995-03-01

Investigation of graft copolymerization modification of PTFE surface with kind of one or another reactive monomers was performed by using non-equilibrium microwave plasma at 2.45 GHz under various operating conditions. Untreated clean samples and grafted samples were examined and analyzed with different surface analytical techniques such as X-Ray Photoelectron Spectroscopy (XPS), Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Scanning Electron Microscopy (SEM). The results showed that the occurrence of noticeable de-fluorination and cross linking on grafted surface, and different polar groups and content of oxygen-containing were introduced into the grafted surface of PTFE. Fibriform hetero-structure layer was also formed. These results confirmed the success of graft and indicated that the hydrophilicity of the grafted surface is excellent and a significant improvement in adhesion characteristics has been achieved. The experiments revealed that the changes in surface properties are correlated closely to the changes in chemical structure, composition and morphology. (8 figs., 1 refs.)

The magnetic field application for the gas discharge plasma control in processes of surface coating and modification

International Nuclear Information System (INIS)

Asadullin, T Ya; Galeev, I G

2017-01-01

In this paper the method of magnetic field application to control the gas discharge plasma effect on the various surfaces in processes of surface coating and modification is considered. The magnetic field directed perpendicular to the direction of electric current in the gas discharge plasma channel is capable to reject this plasma channel due to action of Lorentz force on the moving electrically charged particles [1,2]. The three-dimensional spatial structure of magnetic field is created by system of necessary quantity of the magnets located perpendicular to the direction of course of electric current in the gas-discharge plasma channel. The formation of necessary spatial distribution of magnetic field makes possible to obtain a required distribution of plasma parameters near the processed surfaces. This way of the plasma channel parameters spatial distribution management is the most suitable for application in processes of plasma impact on a surface of irregular shape and in cases when the selective impact of plasma on a part of a surface of a product is required. It is necessary to apply automated computer management of the process parameters [3] to the most effective plasma impact. (paper)

Surface modification of ceramics and metals by ion implantation combined with plasma irradiation

International Nuclear Information System (INIS)

Miyagawa, Soji; Miyagawa, Yoshiko; Nakao, Setsuo; Ikeyama, Masami; Saitoh, Kazuo

2000-01-01

To develop a new surface modification technique using ion implantation combined with plasma irradiation, thin film formation by IBAD (Ion Beam Assisted Deposition) and atom relocation processes such as radiation enhanced diffusion and ion beam mixing under high dose implantation have been studied. It was confirmed that the computer simulation code, dynamic-SASAMAL (IBAD version) developed in this research, is quite useful to evaluate ballistic components in film formation by high dose implantation on ceramics and metals, by ion beam mixing of metal-ceramics bi-layer and by the IBAD method including hydrocarbon deposition. Surface modification process of SiC by simultaneous irradiation of ions with a radical beam has also been studied. A composite of SiC and β-Si 3 N 4 was found to be formed on a SiC surface by hot implantation of nitrogen. The amount of β- Si 3 N 4 crystallites increased with increasing the dosage of the hydrogen radical beam during nitrogen implantation. (author)

Surface modification of polymeric substrates by plasma-based ion implantation

Science.gov (United States)

Okuji, S.; Sekiya, M.; Nakabayashi, M.; Endo, H.; Sakudo, N.; Nagai, K.

2006-01-01

Plasma-based ion implantation (PBII) as a tool for polymer modification is studied. Polymeric films have good performances for flexible use, such as food packaging or electronic devices. Compared with inorganic rigid materials, polymers generally have large permeability for gases and moisture, which causes packaged contents and devices to degrade. In order to add a barrier function, surface of polymeric films are modified by PBII. One of the advantageous features of this method over deposition is that the modified surface does not have peeling problem. Besides, micro-cracks due to mechanical stress in the modified layer can be decreased. From the standpoint of mass production, conventional ion implantation that needs low-pressure environment of less than 10-3 Pa is not suitable for continuous large-area processing, while PBII works at rather higher pressure of several Pa. In terms of issues mentioned above, PBII is one of the most expected techniques for modification on flexible substrates. However, the mechanism how the barrier function appears by ion implantation is not well explained so far. In this study, various kinds of polymeric films, including polyethyleneterephthalate (PET), are modified by PBII and their barrier characteristics that depend on the ion dose are evaluated. In order to investigate correlations of the barrier function with implanted ions, modified surface is analyzed with X-ray photoelectron spectroscopy (XPS). It is assumed that the diffusion and sorption coefficients are changed by ion implantation, resulting in higher barrier function.

Surface modification of polymeric substrates by plasma-based ion implantation

International Nuclear Information System (INIS)

Okuji, S.; Sekiya, M.; Nakabayashi, M.; Endo, H.; Sakudo, N.; Nagai, K.

2006-01-01

Plasma-based ion implantation (PBII) as a tool for polymer modification is studied. Polymeric films have good performances for flexible use, such as food packaging or electronic devices. Compared with inorganic rigid materials, polymers generally have large permeability for gases and moisture, which causes packaged contents and devices to degrade. In order to add a barrier function, surface of polymeric films are modified by PBII. One of the advantageous features of this method over deposition is that the modified surface does not have peeling problem. Besides, micro-cracks due to mechanical stress in the modified layer can be decreased. From the standpoint of mass production, conventional ion implantation that needs low-pressure environment of less than 10 -3 Pa is not suitable for continuous large-area processing, while PBII works at rather higher pressure of several Pa. In terms of issues mentioned above, PBII is one of the most expected techniques for modification on flexible substrates. However, the mechanism how the barrier function appears by ion implantation is not well explained so far. In this study, various kinds of polymeric films, including polyethyleneterephthalate (PET), are modified by PBII and their barrier characteristics that depend on the ion dose are evaluated. In order to investigate correlations of the barrier function with implanted ions, modified surface is analyzed with X-ray photoelectron spectroscopy (XPS). It is assumed that the diffusion and sorption coefficients are changed by ion implantation, resulting in higher barrier function

Strategies to improve the adhesion of rubbers to adhesives by means of plasma surface modification

Science.gov (United States)

Martín-Martínez, J. M.; Romero-Sánchez, M. D.

2006-05-01

The surface modifications produced by treatment of a synthetic sulfur vulcanized styrene-butadiene rubber with oxidizing (oxygen, air, carbon dioxide) and non oxidizing (nitrogen, argon) RF low pressure plasmas, and by treatment with atmospheric plasma torch have been assessed by ATR-IR and XPS spectroscopy, SEM, and contact angle measurements. The effectiveness of the low pressure plasma treatment depended on the gas atmosphere used to generate the plasma. A lack of relationship between surface polarity and wettability, and peel strength values was obtained, likely due to the cohesive failure in the rubber obtained in the adhesive joints. In general, acceptable adhesion values of plasma treated rubber were obtained for all plasmas, except for nitrogen plasma treatment during 15 minutes due to the creation of low molecular weight moieties on the outermost rubber layer. A toluene wiping of the N{2 } plasma treated rubber surface for 15 min removed those moieties and increased adhesion was obtained. On the other hand, the treatment of the rubber with atmospheric pressure by means of a plasma torch was proposed. The wettability of the rubber was improved by decreasing the rubber-plasma torch distance and by increasing the duration because a partial removal of paraffin wax from the rubber surface was produced. The rubber surface was oxidized by the plasma torch treatment, and the longer the duration of the plasma torch treatment, the higher the degree of surface oxidation (mainly creation of C O moieties). However, although the rubber surface was effectively modified by the plasma torch treatment, the adhesion was not greatly improved, due to the migration of paraffin wax to the treated rubber-polyurethane adhesive interface once the adhesive joint was produced. On the other hand, the extended treatment with plasma torch facilitated the migration of zinc stearate to the rubber-adhesive interface, also contributing to deteriorate the adhesion in greater extent. Finally

Surface modification of polymer nanofibres by plasma treatment

International Nuclear Information System (INIS)

Wei, Q.F.; Gao, W.D.; Hou, D.Y.; Wang, X.Q.

2005-01-01

Polymer nanofibres have great potential for technical applications in biomaterials, filtration, composites and electronics. The surface properties of nanofibres are of importance in these applications. In this study, cold gas plasma treatment was used to modify the surface of polyamide 6 nanofibres prepared by electrospinning. The chemical nature of the nanofibre surfaces was examined by X-ray photoelectron spectroscopy (XPS). Atomic force microscopy (AFM) was employed to study the surface characteristics of the fibres. The AFM results indicate a significant change in the morphology of the fibre surface before and after plasma treatment. A Philips Environmental Scanning Electron Microscopy (ESEM) was also used to study the wetting behaviour of the fibres. In the ESEM, relative humidity was raised to 100% to facilitate the water condensation onto fibre surfaces for wetting observation. The ESEM observation revealed that the plasma treatment significantly altered the surface wettability of the polyamide 6 nanofibres

Surface modification effects of fluorine-doped tin dioxide by oxygen plasma ion implantation

Science.gov (United States)

Tang, Peng; Liu, Cai; Zhang, Jingquan; Wu, Lili; Li, Wei; Feng, Lianghuan; Zeng, Guanggen; Wang, Wenwu

2018-04-01

SnO2:F (FTO), as a kind of transparent conductive oxide (TCO), exhibits excellent transmittance and conductivity and is widely used as transparency electrodes in solar cells. It's very important to modifying the surface of FTO for it plays a critical role in CdTe solar cells. In this study, modifying effects of oxygen plasma on FTO was investigated systematically. Oxygen plasma treatment on FTO surface with ion accelerating voltage ranged from 0.4 kV to 1.6 kV has been processed. The O proportion of surface was increased after ion implantation. The Fermi level of surface measurement by XPS valance band spectra was lowered as the ion accelerating voltage increased to 1.2 kV and then raised as accelerating voltage was elevated to 1.6 kV. The work function measured by Kelvin probe force microscopy increased after ion implanting, and it was consistent with the variation of Fermi level. The change of energy band structure of FTO surface mainly originated from the surface composition variation. As FTO conduction was primarily due to oxyanion hole, the carrier was electron and its concentration was reduced while O proportion was elevated at the surface of FTO, as a result, the Fermi level lowered and the work function was enlarged. It was proved that oxygen plasma treatment is an effective method to modulate the energy band structure of the surface as well as other properties of FTO, which provides much more space for interface and surface modification and then photoelectric device performance promotion.

Surface modification of polyester fabrics by atmospheric-pressure air/He plasma for color strength and adhesion enhancement

Energy Technology Data Exchange (ETDEWEB)

Zhang, Chunming, E-mail: zcm1229@126.com [College of Textiles and Clothing, Qingdao University, Qingdao 266071 (China); Sunvim Grp Co Ltd, Gaomi 261500 (China); Zhao, Meihua; Wang, Libing; Qu, Lijun [College of Textiles and Clothing, Qingdao University, Qingdao 266071 (China); Men, Yajing [Sunvim Grp Co Ltd, Gaomi 261500 (China)

2017-04-01

Highlights: • Air/He plasma gave hydrophilicity on polyester surface and decreased contact angle to 18°. • The roughness of polyester increased and pit-like structures appeared on the surface after plasma treatment. • XPS confirmed the generation of new functional groups on polyester fabric. • The improved pigment color yield and anti-bleeding performance were contributed by the alteration of pigment adhesion. • The air/He plasma was more effective than air plasma at the same treatment time. - Abstract: Surface properties of water-based pigmented inks for ink-jet printed polyester fabrics were modified with atmospheric-pressure air/He plasma to improve the color strength and pigment adhesion of the treated surfaces. The influence of various parameters, including the surface morphology, chemical compositions, surface energy and dynamic contact angles of the control and plasma treated samples was studied. Color strength and edge definition were used to evaluate the ink-jet printing performance of fabrics. The change in pigment adhesion to polyester fibers was analyzed by SEM (scanning electron microscopy). AFM (Atomic force microscope) and XPS (X-ray photoelectron spectroscopy) analyses indicated the increase in surface roughness and the oxygen-containing polar groups(C=O, C−OH and COOH) reinforced the fixation of pigments on the fiber surface. The result from this study suggested that the improved pigment color yield was clearly affected by alteration of pigment adhesion enhanced by plasma surface modification. Polyester fabrics exhibited better surface property and ink-jet printing performance after the air/He mixture plasma treatment comparing with those after air plasma treatment.

Surface modification of polyester fabrics by atmospheric-pressure air/He plasma for color strength and adhesion enhancement

International Nuclear Information System (INIS)

Zhang, Chunming; Zhao, Meihua; Wang, Libing; Qu, Lijun; Men, Yajing

2017-01-01

Highlights: • Air/He plasma gave hydrophilicity on polyester surface and decreased contact angle to 18°. • The roughness of polyester increased and pit-like structures appeared on the surface after plasma treatment. • XPS confirmed the generation of new functional groups on polyester fabric. • The improved pigment color yield and anti-bleeding performance were contributed by the alteration of pigment adhesion. • The air/He plasma was more effective than air plasma at the same treatment time. - Abstract: Surface properties of water-based pigmented inks for ink-jet printed polyester fabrics were modified with atmospheric-pressure air/He plasma to improve the color strength and pigment adhesion of the treated surfaces. The influence of various parameters, including the surface morphology, chemical compositions, surface energy and dynamic contact angles of the control and plasma treated samples was studied. Color strength and edge definition were used to evaluate the ink-jet printing performance of fabrics. The change in pigment adhesion to polyester fibers was analyzed by SEM (scanning electron microscopy). AFM (Atomic force microscope) and XPS (X-ray photoelectron spectroscopy) analyses indicated the increase in surface roughness and the oxygen-containing polar groups(C=O, C−OH and COOH) reinforced the fixation of pigments on the fiber surface. The result from this study suggested that the improved pigment color yield was clearly affected by alteration of pigment adhesion enhanced by plasma surface modification. Polyester fabrics exhibited better surface property and ink-jet printing performance after the air/He mixture plasma treatment comparing with those after air plasma treatment.

Surface modification of gutta-percha cones by non-thermal plasma

Energy Technology Data Exchange (ETDEWEB)

Prado, Maíra, E-mail: maira@metalmat.ufrj.br [Department of Metallurgic and Materials Engineering, Federal University of Rio de Janeiro – UFRJ, Rio de Janeiro, RJ (Brazil); Menezes, Marilia Santana de Oliveira [Department of Metallurgic and Materials Engineering, Federal University of Rio de Janeiro – UFRJ, Rio de Janeiro, RJ (Brazil); Gomes, Brenda Paula Figueiredo de Almeida [Department of Restorative Dentistry, Endodontics Division, Piracicaba Dental School, State University of Campinas - UNICAMP, Piracicaba, SP (Brazil); Barbosa, Carlos Augusto de Melo [Department of Clinical Dentistry, Endodontic Division, Federal University of Rio de Janeiro – UFRJ, Rio de Janeiro, RJ (Brazil); Athias, Leonardo [Social Indicators Division, Brazilian Institute of Geography and Statistics, Rio de Janeiro, RJ (Brazil); Simão, Renata Antoun [Department of Metallurgic and Materials Engineering, Federal University of Rio de Janeiro – UFRJ, Rio de Janeiro, RJ (Brazil)

2016-11-01

This study was designed to evaluate the effects of Oxygen and Argon plasma on gutta-percha surfaces. A total of 185 flat smooth gutta-percha surfaces were used. Samples were divided into groups: control: no plasma treatment; Oxygen: treatment with Oxygen plasma for 1 min; Argon: treatment with Argon plasma for 1 min. Samples were evaluated topographically by scanning electron microscopy and atomic force microscopy; and chemically by Fourier Transform-infrared Spectroscopy. A goniometer was used to determine the surface free energy and the wettability of the endodontic sealers. Additionally 60 bovine teeth were filled using pellets of gutta-percha (control, oxygen and argon plasma) and the sealers. Teeth were evaluated by push-out and microleakage tests. Data were statistically analyzed using specific tests. Argon plasma did not change the surface topography, while Oxygen plasma led to changes. Both treatments chemically modified the gutta-percha surface. Argon and Oxygen plasma increased the surface free energy and favored the wettability of AH Plus and Pulp Canal Sealer EWT. Regarding bond strength analysis, for AH Plus sealer, both plasma treatments on gutta-percha favored the bond strength to dentin. However, for Pulp Canal Sealer, there is no statistically significant influence. For leakage test, dye penetration occurred between sealer and dentin in all groups. In conclusion, Oxygen plasma led to both topographic and chemical changes in the gutta-percha surface, while Argon plasma caused only chemical changes. Both treatments increased the surface free energy, favoring the wettability of AH Plus and Pulp Canal Sealer EWT sealers and influenced positively in the adhesion and leakage. - Highlights: • Argon plasma did not change the gutta-percha surface. • Oxygen plasma led to topographic changes. • Both treatments chemically modified the gutta-percha surface. • Treatments increased the surface free energy and favored the wettability of sealers. • Plasma

Surface modification of gutta-percha cones by non-thermal plasma

International Nuclear Information System (INIS)

Prado, Maíra; Menezes, Marilia Santana de Oliveira; Gomes, Brenda Paula Figueiredo de Almeida; Barbosa, Carlos Augusto de Melo; Athias, Leonardo; Simão, Renata Antoun

2016-01-01

This study was designed to evaluate the effects of Oxygen and Argon plasma on gutta-percha surfaces. A total of 185 flat smooth gutta-percha surfaces were used. Samples were divided into groups: control: no plasma treatment; Oxygen: treatment with Oxygen plasma for 1 min; Argon: treatment with Argon plasma for 1 min. Samples were evaluated topographically by scanning electron microscopy and atomic force microscopy; and chemically by Fourier Transform-infrared Spectroscopy. A goniometer was used to determine the surface free energy and the wettability of the endodontic sealers. Additionally 60 bovine teeth were filled using pellets of gutta-percha (control, oxygen and argon plasma) and the sealers. Teeth were evaluated by push-out and microleakage tests. Data were statistically analyzed using specific tests. Argon plasma did not change the surface topography, while Oxygen plasma led to changes. Both treatments chemically modified the gutta-percha surface. Argon and Oxygen plasma increased the surface free energy and favored the wettability of AH Plus and Pulp Canal Sealer EWT. Regarding bond strength analysis, for AH Plus sealer, both plasma treatments on gutta-percha favored the bond strength to dentin. However, for Pulp Canal Sealer, there is no statistically significant influence. For leakage test, dye penetration occurred between sealer and dentin in all groups. In conclusion, Oxygen plasma led to both topographic and chemical changes in the gutta-percha surface, while Argon plasma caused only chemical changes. Both treatments increased the surface free energy, favoring the wettability of AH Plus and Pulp Canal Sealer EWT sealers and influenced positively in the adhesion and leakage. - Highlights: • Argon plasma did not change the gutta-percha surface. • Oxygen plasma led to topographic changes. • Both treatments chemically modified the gutta-percha surface. • Treatments increased the surface free energy and favored the wettability of sealers. • Plasma

The hidden radiation chemistry in plasma modification and XPS analysis of polymer surfaces

International Nuclear Information System (INIS)

George, G.A.; Le, T.T.; Elms, F.M.; Wood, B.J.

1996-01-01

Full text: The surface modification of polymers using plasma treatments is being widely researched to achieve changes in the surface energetics and consequent wetting and reactivity for a range of applications. These include i) adhesion for polymer bonding and composite material fabrication and ii) biocompatibility of polymers when used as orthopedic implants, catheters and prosthetics. A low pressure rf plasma produces a variety of species from the introduced gas which may react with the surface of a hydrocarbon polymer, such as polyethylene. In the case of 0 2 and H 2 0, these species include oxygen atoms, singlet molecular oxygen and hydroxyl radicals, all of which may oxidise and, depending on their energy, ablate the polymer surface. In order to better understand the reactive species formed both in and downstream from a plasma and the relative contributions of oxidation and ablation, self-assembled monolayers of n-alkane thiols on gold are being used as well characterised substrates for quantitative X-ray photoelectron spectroscopy (XPS). The identification and quantification of oxidised carbon species on plasma treated polymers from broad, asymmetric XPS signals is difficult, so derivatisation is often used to enhance sensitivity and specificity. For example, trifluoroacetic anhydride (TFAA) selectively labels hydroxyl functionality. The surface analysis of a modified polymer surface may be confounded by high energy radiation chemistry which may occur during XPS analysis. Examples include scission of carbon-halogen bonds (as in TFM adducts), decarboxylation and main-chain polyene formation. The extent of free-radical chemistry occurring in polyethylene while undergoing XPS analysis may be seen by both ESR and FT-IR analysis

Low-temperature oxidizing plasma surface modification and composite polymer thin-film fabrication techniques for tailoring the composition and behavior of polymer surfaces

Science.gov (United States)

Tompkins, Brendan D.

This dissertation examines methods for modifying the composition and behavior of polymer material surfaces. This is accomplished using (1) low-temperature low-density oxidizing plasmas to etch and implant new functionality on polymers, and (2) plasma enhanced chemical vapor deposition (PECVD) techniques to fabricate composite polymer materials. Emphases are placed on the structure of modified polymer surfaces, the evolution of polymer surfaces after treatment, and the species responsible for modifying polymers during plasma processing. H2O vapor plasma modification of high-density polyethylene (HDPE), low-density polyethylene (LDPE), polypropylene (PP), polystyrene (PS), polycarbonate (PC), and 75A polyurethane (PU) was examined to further our understanding of polymer surface reorganization leading to hydrophobic recovery. Water contact angles (wCA) measurements showed that PP and PS were the most susceptible to hydrophobic recovery, while PC and HDPE were the most stable. X-ray photoelectron spectroscopy (XPS) revealed a significant quantity of polar functional groups on the surface of all treated polymer samples. Shifts in the C1s binding energies (BE) with sample age were measured on PP and PS, revealing that surface reorganization was responsible for hydrophobic recovery on these materials. Differential scanning calorimetry (DSC) was used to rule out the intrinsic thermal properties as the cause of reorganization and hydrophobic recovery on HDPE, LDPE, and PP. The different contributions that polymer cross-linking and chain scission mechanisms make to polymer aging effects are considered. The H2O plasma treatment technique was extended to the modification of 0.2 microm and 3.0 microm track-etched polycarbonate (PC-TE) and track-etched polyethylene terephthalate (PET-TE) membranes with the goal of permanently increasing the hydrophilicity of the membrane surfaces. Contact angle measurements on freshly treated and aged samples confirmed the wettability of the

Experimental investigation of the material surface modification in microsecond plasma opening switch

Energy Technology Data Exchange (ETDEWEB)

Bystritskij, V; Grigor` ev, S; Kharlov, A; Sinebryukhov, A [Russian Academy of Sciences, Tomsk (Russian Federation). Institute of Electrophysics; Burkov, P [Russian Academy of Scinces, Tomsk (Russian Federation). Institute of Strength Physics and Materials Control; Grigorev, V; Koval, T [Institute of Nuclear Physics, Tomsk (Russian Federation)

1997-12-31

The paper is devoted to the investigations of the material surface modification by high power ion beam generated in microsecond plasma opening switch (MPOS). Various types of steels were investigated: stainless steel 17-4PH, carbon steel C1020, pure iron. For all these materials, the optimal regimes for irradiation were defined. A significant increase in microhardness (1.5 to 2-fold) was obtained for these materials. Numerical calculations and theoretical estimations of the ion beam-matter interaction were also performed. The advantages and problems of this approach are discussed. (author). 8 figs., 3 refs.

Application of Atmospheric Dielectric Barrier Discharge Plasma for Polyethylene Powder Modification

International Nuclear Information System (INIS)

Pichal, J.; Aubrecht, L.; Pichal, J.; Hladik, J.; Spatenka, P.; Spatenka, P.

2006-01-01

Paper refers about a novel plasma reactor exploiting the dielectric barrier discharge (DBD) burning in air at atmospheric pressure by ambient temperature and its usability tests. Test modifications were performed with the high density polyethylene powder Borealis CB 9155-01. Modification effect was evaluated by means of dynamic capillarity rising measurements. Tests proved significant powder capillarity changes. The existence of powder surface changes was also confirmed by ESCA tests. Modification aging effect was remarkably small, hence modification effect is very time stable. In comparison with other in literature described apparatus used for this purpose the plasma reactor is of a simple construction and needs no vacuum equipment. Its operation costs are low. Described plasma modification method seems to be an appropriate method for plasma modification of polyethylene powder on the industrial scale

The surface modification of polystyrene

International Nuclear Information System (INIS)

Tremlett, C.

2000-03-01

Polymers have ideal bulk properties for many applications. However, adhesion to many polymers is poor without surface pretreatment. This can result, for example, in peeling paint and printing, adhesive joint failure and bio-incompatibility. In applications such as painting, printing, adhesive bonding and biocompatibility, various cleaning or surface chemical modifications may be employed. A commodity polymer where pretreatment is sometimes needed is polystyrene. This project investigated, in detail, the effects of a novel method of modification namely mediated electrochemical oxidation (MEO), as a mode of surface modification on polystyrene and a comparison was made with other polymers. The resulting modification was investigated using a range of surface analysis techniques to obtain complementary information. These included, X-ray photoelectron spectroscopy, contact angles, static secondary ion mass spectrometry, atomic force microscopy, chemical derivatization, scanning electron microscopy, attenuated total reflection Fourier Transform infrared spectroscopy and composite lap shear joint testing. It has been shown that MEO modifies the surface of polystyrene introduced oxygen mainly as hydroxyl groups, and a small number of carbonyl groups, that are positioned only on the backbone hydrocarbon chain. This modification improved adhesion, was stable and samples could be stored in aqueous media. The resulting hydroxylation was further derivatized using an amino acid to provide a specialised surface. This was very different from the multiple oxygen functionalities introduced in the comparison studies by UV/ozone and plasma treatments. (author)

RF plasma based selective modification of hydrophilic regions on super hydrophobic surface

Energy Technology Data Exchange (ETDEWEB)

Lee, Jaehyun; Hwang, Sangyeon; Cho, Dae-Hyun [Department of Mechanical Engineering, Sungkyunkwan University, Suwon 16419 (Korea, Republic of); Hong, Jungwoo [Department of Mechanical Engineering, Graduate of Medical Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141 (Korea, Republic of); Shin, Jennifer H., E-mail: j_shin@kaist.ac.kr [Department of Mechanical Engineering, Graduate of Medical Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141 (Korea, Republic of); Byun, Doyoung, E-mail: dybyun@skku.edu [Department of Mechanical Engineering, Sungkyunkwan University, Suwon 16419 (Korea, Republic of)

2017-02-01

Highlights: • Simple and amenable reforming method for a substrate with disparate patterns of hydrophilic dots on super-hydrophobic surfaces is proposed. • Wettability characteristics and modification mechanism for the surfaces are conducted and revealed through SEM, AFM, WSI, and SIMS. • Several representative materials for various applications are successfully deposited. - Abstract: Selective modification and regional alterations of the surface property have gained a great deal of attention to many engineers. In this paper, we present a simple, a cost-effective, and amendable reforming method for disparate patterns of hydrophilic regions on super-hydrophobic surfaces. Uniform super-hydrophobic layer (Contact angle; CA > 150°, root mean square (RMS) roughness ∼0.28 nm) can be formed using the atmospheric radio frequency (RF) plasma on top of the selective hydrophilic (CA ∼ 70°, RMS roughness ∼0.34 nm) patterns imprinted by electrohydrodynamic (EHD) jet printing technology with polar alcohols (butyl carbitol or ethanol). The wettability of the modified surface was investigated qualitatively utilizing scanning electron microscopy (SEM), atomic force microscopy (AFM), and wavelength scanning interferometer (WSI). Secondary ion mass spectroscopy (SIMS) analysis showed that the alcohol addiction reaction changed the types of radicals on the super-hydrophobic surface. The wettability was found to depend sensitively on chemical radicals on the surface, not on surface morphology (particle size and surface roughness). Furthermore, three different kinds of representative hydrophilic samples (polystyrene nano-particle aqueous solution, Salmonella bacteria medium, and poly(3,4-ethylenediocythiophene) ink) were tested for uniform deposition onto the desired hydrophilic regions. This simple strategy would have broad applications in various research fields that require selective deposition of target materials.

RF plasma based selective modification of hydrophilic regions on super hydrophobic surface

International Nuclear Information System (INIS)

Lee, Jaehyun; Hwang, Sangyeon; Cho, Dae-Hyun; Hong, Jungwoo; Shin, Jennifer H.; Byun, Doyoung

2017-01-01

Highlights: • Simple and amenable reforming method for a substrate with disparate patterns of hydrophilic dots on super-hydrophobic surfaces is proposed. • Wettability characteristics and modification mechanism for the surfaces are conducted and revealed through SEM, AFM, WSI, and SIMS. • Several representative materials for various applications are successfully deposited. - Abstract: Selective modification and regional alterations of the surface property have gained a great deal of attention to many engineers. In this paper, we present a simple, a cost-effective, and amendable reforming method for disparate patterns of hydrophilic regions on super-hydrophobic surfaces. Uniform super-hydrophobic layer (Contact angle; CA > 150°, root mean square (RMS) roughness ∼0.28 nm) can be formed using the atmospheric radio frequency (RF) plasma on top of the selective hydrophilic (CA ∼ 70°, RMS roughness ∼0.34 nm) patterns imprinted by electrohydrodynamic (EHD) jet printing technology with polar alcohols (butyl carbitol or ethanol). The wettability of the modified surface was investigated qualitatively utilizing scanning electron microscopy (SEM), atomic force microscopy (AFM), and wavelength scanning interferometer (WSI). Secondary ion mass spectroscopy (SIMS) analysis showed that the alcohol addiction reaction changed the types of radicals on the super-hydrophobic surface. The wettability was found to depend sensitively on chemical radicals on the surface, not on surface morphology (particle size and surface roughness). Furthermore, three different kinds of representative hydrophilic samples (polystyrene nano-particle aqueous solution, Salmonella bacteria medium, and poly(3,4-ethylenediocythiophene) ink) were tested for uniform deposition onto the desired hydrophilic regions. This simple strategy would have broad applications in various research fields that require selective deposition of target materials.

Surface modification by electrolytic plasma processing for high Nb-TiAl alloys

Science.gov (United States)

Gui, Wanyuan; Hao, Guojian; Liang, Yongfeng; Li, Feng; Liu, Xiao; Lin, Junpin

2016-12-01

Metal surface modification by electrolytic plasma processing (EPP) is an innovative treatment widely commonly applied to material processing and pretreatment process of coating and galvanization. EPP involves complex processes and a great deal of parameters, such as preset voltage, current, solution temperature and processing time. Several characterization methods are presented in this paper for evaluating the micro-structure surfaces of Ti45Al8Nb alloys: SEM, EDS, XRD and 3D topography. The results showed that the oxide scale and other contaminants on the surface of Ti45Al8Nb alloys can be effectively removed via EPP. The typical micro-crater structure of the surface of Ti45Al8Nb alloys were observed by 3D topography after EPP to find that the mean diameter of the surface structure and roughness value can be effectively controlled by altering the processing parameters. The mechanical properties of the surface according to nanomechanical probe testing exhibited slight decrease in microhardness and elastic modulus after EPP, but a dramatic increase in surface roughness, which is beneficial for further processing or coating.

Surface Modification of Metals using Plasma Torch

International Nuclear Information System (INIS)

Hassan, A.

2009-01-01

Low temperature plasma nitriding of 304L stainless steel is performed using a home made low power direct-current plasma torch. Plasma nitriding is carried out in temperature range of 300-550 degree C for 1 to 4 hours, in various N 2 H 2 gas mixture ratios at about 5 Torr pressure and torch power 300 Watts. The effect of treatment time, temperature and working gas composition on the microstructure and mechanical properties of plasma nitrided surface layers is investigated. The microstructure, phase composition and micro hardness profile of the nitrided surface layers are characterized by optical microscopy, scanning electron microscope (SEM), X-ray diffraction (XRD) and Vickers micro hardness tester. The results show that plasma treatment for 14 h over a temperature range of 300 - 550 degree C yields nitride case depth of 20 - 50 μm and the hardness of the nitrided layer is in the range of 700-1250 HV. Plasma nitriding of stainless steel samples at about 475 degree C in 70 % of nitrogen admixed with hydrogen at 5 torr shows the maximum increase of hardness 1220 HV which is about four times that of untreated layers. The XRD pattern confirmed the formation of an expanded austenite .N phase, due to the nitrogen incorporation into original lattice and forms supersaturated face center cubic phase. In addition preliminary results for aluminum nitriding is also shown

Modification of Material Surface Using Plasma-Enhanced Ion Beams

National Research Council Canada - National Science Library

Bystritskii, V

1998-01-01

...) Technology for Materials Surface Modification. Following second year programmatic plan, formulated in the conclusion of the 1-st year report we focused our effort on study of aluminum alloys modification (Al2024, 6061, 7075...

Ion bombardment modification of surfaces

International Nuclear Information System (INIS)

Auciello, O.

1984-01-01

An historical overview of the main advances in the understanding of bombardment-induced surface topography is presented. The implantation and sputtering mechanisms which are relevant to ion bombardment modification of surfaces and consequent structural, electronic and compositional changes are described. Descriptions of plasma and ion-beam sputtering-induced film formation, primary ion-beam deposition, dual beam techniques, cluster of molecule ion-beam deposition, and modification of thin film properties by ion bombardment during deposition are presented. A detailed account is given of the analytical and computational modelling of topography from the viewpoint of first erosion theory. Finally, an account of the possible application and/or importance of textured surfaces in technologies and/or experimental techniques not considered in previous chapters is presented. refs.; figs.; tabs

Modification of surface properties of LLDPE by water plasma discharge

International Nuclear Information System (INIS)

Chantara Thevy Ratnam; Hill, D.J.T.; Firas Rasoul; Whittaker, A.K.; Imelda Keen

2007-01-01

Linear low density polyethylene (LLDPE) surface was modified by water plasma treatment. The LLDPE surface was treated at 10 and 20 W discharge power at various exposure times. A laboratory scale Megatherm radio frequency (RF) plasma apparatus that operates at 27 MHz was used to generate the water plasmas. The changes in chemical structure of the LLDPE polymeric chain upon plasma treatment were characterized by FTIR and XPS techniques. The selectivity of trifluoroacetic anhydride (TFAA) toward hydroxyl groups is used to quantify the hydroxyl groups formed on the polymer surface upon plasma treatment. After exposition to the plasma discharge a decline in water contact angle were observed. FTIR and XPS measurements indicate an oxidation of degraded polymeric chains and creation of hydroxyl, carbonyl, ether, ester and carboxyl groups. Chemical derivatization with TFAA of water plasma treated polymer surfaces has shown that under the conditions employed, a very small (less than 5%) of the oxygen introduced by the water plasma treatment was present as hydroxyl group. (Author)

O2 Plasma Etching and Antistatic Gun Surface Modifications for CNT Yarn Microelectrode Improve Sensitivity and Antifouling Properties.

Science.gov (United States)

Yang, Cheng; Wang, Ying; Jacobs, Christopher B; Ivanov, Ilia N; Venton, B Jill

2017-05-16

Carbon nanotube (CNT) based microelectrodes exhibit rapid and selective detection of neurotransmitters. While different fabrication strategies and geometries of CNT microelectrodes have been characterized, relatively little research has investigated ways to selectively enhance their electrochemical properties. In this work, we introduce two simple, reproducible, low-cost, and efficient surface modification methods for carbon nanotube yarn microelectrodes (CNTYMEs): O 2 plasma etching and antistatic gun treatment. O 2 plasma etching was performed by a microwave plasma system with oxygen gas flow and the optimized time for treatment was 1 min. The antistatic gun treatment flows ions by the electrode surface; two triggers of the antistatic gun was the optimized number on the CNTYME surface. Current for dopamine at CNTYMEs increased 3-fold after O 2 plasma etching and 4-fold after antistatic gun treatment. When the two treatments were combined, the current increased 12-fold, showing the two effects are due to independent mechanisms that tune the surface properties. O 2 plasma etching increased the sensitivity due to increased surface oxygen content but did not affect surface roughness while the antistatic gun treatment increased surface roughness but not oxygen content. The effect of tissue fouling on CNT yarns was studied for the first time, and the relatively hydrophilic surface after O 2 plasma etching provided better resistance to fouling than unmodified or antistatic gun treated CNTYMEs. Overall, O 2 plasma etching and antistatic gun treatment improve the sensitivity of CNTYMEs by different mechanisms, providing the possibility to tune the CNTYME surface and enhance sensitivity.

Plasma Surface Modification of Polyaramid Fibers for Protective Clothing

Science.gov (United States)

Widodo, Mohamad

2011-12-01

The purpose of this research was to develop a novel process that would achieve biocidal properties on Kevlar fabric via atmospheric pressure plasma jet (APPJ) induced-graft polymerization of monomers. In the course of the study, experiments were carried out to understand plasma-monomer-substrate interactions, particularly, how each of the main parameters in the plasma processing affects the formation of surface radicals and eventually the degree of graft polymerization of monomers. The study also served to explore the possibility of developing plasma-initiated and plasma-controlled graft polymerization for continuous operation. In this regards, three methods of processing were studied, which included two-step plasma graft-polymerization with immersion, two-step and one-step plasma graft-polymerization with pad-dry. In general, plasma treatment did not cause visible damage to the surface of Kevlar fibers, except for the appearance of tiny globules distributed almost uniformly indicating a minor effect of plasma treatment to the surface morphology of the polymer. From the examination of SEM images, however, it was found that a very localized surface etching seemed to have taken place, especially at high RF power (800 W) and long time of exposure (60 s), even in plasma downstream mode of operation. It was suggested that a small amount of charged particles might have escaped and reached the substrate surface. High density of surface radicals, which is the prerequisite for high graft density and high antimicrobial activity, was achieved by the combination of high RF power and short exposure time or low RF power and long time of exposure. This was a clear indication that the formation of surface radicals is a function of amount of the dissipated energy, which also explained the two-factor interaction between the two process parameters. XPS results showed that hydrolysis of the anilide bond of PPTA chains took place to some extent on the surface of Kevlar, leading to the

Surface modification of titanium by plasma nitriding

Directory of Open Access Journals (Sweden)

Kapczinski Myriam Pereira

2003-01-01

Full Text Available A systematic investigation was undertaken on commercially pure titanium submitted to plasma nitriding. Thirteen different sets of operational parameters (nitriding time, sample temperature and plasma atmosphere were used. Surface analyses were performed using X-ray diffraction, nuclear reaction and scanning electron microscopy. Wear tests were done with stainless steel Gracey scaler, sonic apparatus and pin-on-disc machine. The obtained results indicate that the tribological performance can be improved for samples treated with the following conditions: nitriding time of 3 h; plasma atmosphere consisting of 80%N2+20%H2 or 20%N2+80%H2; sample temperature during nitriding of 600 or 800 degreesC.

Transience of plasma surface modification as an adhesion promoter for polychlorotrifluorethylene

International Nuclear Information System (INIS)

Subrahmanyan, S.; Dillard, J.G.; Love, B.J.; Romand, M.; Charbonnier, M.

2002-01-01

Poly(chlorotrifluoroethylene) (PCTFE) and other fluoropolymers are increasingly used as inner layer dielectrics. However, these polymers have low surface energies and correspondingly poor adhesive properties. Results are presented on the use of a low-pressure ammonia plasma to enhance the surface bondability of PCTFE. The plasma modified PCTFE film surfaces were characterized by x-ray photoelectron spectroscopy and contact angle measurements. Surface modified films exhibited improved adhesion to electroless copper deposits (180 deg. peel test) compared to coated PCTFE controls and that underwent no plasma exposure. Annealing studies were conducted between 30 and 100 deg. C to examine the stability of the plasma-modified surfaces. For samples annealed below T g , contact angle measurements indicated that the plasma-introduced groups remained bound on the surface for four weeks. For specimens annealed above T g , the surface functionalities were absorbed within the bulk and surface rearrangement occurred within 10 h of annealing time. As a result of rearrangement, the benefit of adhesion enhancement by plasma is lost and the adhesion to copper is reduced

Transience of plasma surface modification as an adhesion promoter for polychlorotrifluorethylene

CERN Document Server

Subramanian, S; Love, B J; Romand, M; Charbonnier, M

2002-01-01

Poly(chlorotrifluoroethylene) (PCTFE) and other fluoropolymers are increasingly used as inner layer dielectrics. However, these polymers have low surface energies and correspondingly poor adhesive properties. Results are presented on the use of a low-pressure ammonia plasma to enhance the surface bondability of PCTFE. The plasma modified PCTFE film surfaces were characterized by x-ray photoelectron spectroscopy and contact angle measurements. Surface modified films exhibited improved adhesion to electroless copper deposits (180 deg. peel test) compared to coated PCTFE controls and that underwent no plasma exposure. Annealing studies were conducted between 30 and 100 deg. C to examine the stability of the plasma-modified surfaces. For samples annealed below T sub g , contact angle measurements indicated that the plasma-introduced groups remained bound on the surface for four weeks. For specimens annealed above T sub g , the surface functionalities were absorbed within the bulk and surface rearrangement occurre...

Microscale surface modifications for heat transfer enhancement.

Science.gov (United States)

Bostanci, Huseyin; Singh, Virendra; Kizito, John P; Rini, Daniel P; Seal, Sudipta; Chow, Louis C

2013-10-09

In this experimental study, two surface modification techniques were investigated for their effect on heat transfer enhancement. One of the methods employed the particle (grit) blasting to create microscale indentations, while the other used plasma spray coating to create microscale protrusions on Al 6061 (aluminum alloy 6061) samples. The test surfaces were characterized using scanning electron microscopy (SEM) and confocal scanning laser microscopy. Because of the surface modifications, the actual surface area was increased up to 2.8× compared to the projected base area, and the arithmetic mean roughness value (Ra) was determined to vary from 0.3 μm for the reference smooth surface to 19.5 μm for the modified surfaces. Selected samples with modified surfaces along with the reference smooth surface were then evaluated for their heat transfer performance in spray cooling tests. The cooling system had vapor-atomizing nozzles and used anhydrous ammonia as the coolant in order to achieve heat fluxes up to 500 W/cm(2) representing a thermal management setting for high power systems. Experimental results showed that the microscale surface modifications enhanced heat transfer coefficients up to 76% at 500 W/cm(2) compared to the smooth surface and demonstrated the benefits of these practical surface modification techniques to enhance two-phase heat transfer process.

Surface modification of polyester fabric with plasma pretreatment and carbon nanotube coating for antistatic property improvement

Energy Technology Data Exchange (ETDEWEB)

Wang, C.X., E-mail: cxwang@mail.dhu.edu.cn [College of Textiles and Clothing, Yancheng Institute of Technology, Jiangsu 224051 (China); Collaborative Innovation Center for Ecological Building Materials and Environmental Protection Equipments, Jiangsu 224051 (China); Key Laboratory for Advanced Technology in Environmental Protection, Jiangsu 224051 (China); Lv, J.C. [College of Textiles and Clothing, Yancheng Institute of Technology, Jiangsu 224051 (China); Ren, Y. [School of Textile and Clothing, Nantong University, Jiangsu 226019 (China); Zhi, T.; Chen, J.Y.; Zhou, Q.Q. [College of Textiles and Clothing, Yancheng Institute of Technology, Jiangsu 224051 (China); Lu, Z.Q.; Gao, D.W. [College of Textiles and Clothing, Yancheng Institute of Technology, Jiangsu 224051 (China); Collaborative Innovation Center for Ecological Building Materials and Environmental Protection Equipments, Jiangsu 224051 (China); Key Laboratory for Advanced Technology in Environmental Protection, Jiangsu 224051 (China); Jin, L.M. [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204 (China)

2015-12-30

Graphical abstract: - Highlights: • PET was finished by plasma treatment and SWCNT coating to improve antistatic property. • Plasma modification had a positive effect on SWCNT coating on PET fiber surface. • O{sub 2} plasma was more effective in SWCNT coating than Ar plasma in the shorter time. • Antistatic enhanced and then declined with enhancing treatment time and output power. • Antistatic increased with increasing concentration, curing time, curing temperature. - Abstract: This study introduced a green method to prepare antistatic polyester (PET) fabrics by plasma pretreatment and single-walled carbon nanotube (SWCNT) coating. The influences of plasma conditions and SWCNT coating parameters on antistatic property of PET fabrics were investigated. PET fabrics were pretreated under various plasma conditions such as different treatment times, output powers and working gases, and then SWCNT coating on the plasma treated PET fabrics was carried out by coating-dry-cure using various coating parameters including different SWCNT concentrations, curing times and curing temperatures. PET fabrics were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and volume resistivity. SEM and XPS analysis of the plasma treated PET fabrics revealed the increase in surface roughness and oxygen/nitrogen containing groups on the PET fiber surface. SEM and XPS analysis of the plasma treated and SWCNT coated PET fabrics indicated the SWCNT coating on PET fiber surface. The plasma treated and SWCNT coated PET fabrics exhibited a good antistatic property, which increased and then decreased with the increasing plasma treatment time and output power. The antistatic property of the O{sub 2} plasma treated and SWCNT coated PET fabric was better and worse than that of N{sub 2} or Ar plasma treated and SWCNT coated PET fabric in the shorter treatment time and the longer treatment time, respectively. In addition, the antistatic property of the

Surface modification of polyester fabric with plasma pretreatment and carbon nanotube coating for antistatic property improvement

International Nuclear Information System (INIS)

Wang, C.X.; Lv, J.C.; Ren, Y.; Zhi, T.; Chen, J.Y.; Zhou, Q.Q.; Lu, Z.Q.; Gao, D.W.; Jin, L.M.

2015-01-01

Graphical abstract: - Highlights: • PET was finished by plasma treatment and SWCNT coating to improve antistatic property. • Plasma modification had a positive effect on SWCNT coating on PET fiber surface. • O 2 plasma was more effective in SWCNT coating than Ar plasma in the shorter time. • Antistatic enhanced and then declined with enhancing treatment time and output power. • Antistatic increased with increasing concentration, curing time, curing temperature. - Abstract: This study introduced a green method to prepare antistatic polyester (PET) fabrics by plasma pretreatment and single-walled carbon nanotube (SWCNT) coating. The influences of plasma conditions and SWCNT coating parameters on antistatic property of PET fabrics were investigated. PET fabrics were pretreated under various plasma conditions such as different treatment times, output powers and working gases, and then SWCNT coating on the plasma treated PET fabrics was carried out by coating-dry-cure using various coating parameters including different SWCNT concentrations, curing times and curing temperatures. PET fabrics were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and volume resistivity. SEM and XPS analysis of the plasma treated PET fabrics revealed the increase in surface roughness and oxygen/nitrogen containing groups on the PET fiber surface. SEM and XPS analysis of the plasma treated and SWCNT coated PET fabrics indicated the SWCNT coating on PET fiber surface. The plasma treated and SWCNT coated PET fabrics exhibited a good antistatic property, which increased and then decreased with the increasing plasma treatment time and output power. The antistatic property of the O 2 plasma treated and SWCNT coated PET fabric was better and worse than that of N 2 or Ar plasma treated and SWCNT coated PET fabric in the shorter treatment time and the longer treatment time, respectively. In addition, the antistatic property of the plasma treated

Surface modification of nanoporous alumina membranes by plasma polymerization

Energy Technology Data Exchange (ETDEWEB)

Losic, Dusan; Cole, Martin A; Dollmann, Bjoern; Vasilev, Krasimir; Griesser, Hans J [Ian Wark Research Institute, University of South Australia, Mawson Lakes, Adelaide, SA 5095 (Australia)], E-mail: dusan.losic@unisa.edu.au

2008-06-18

The deposition of plasma polymer coatings onto porous alumina (PA) membranes was investigated with the aim of adjusting the surface chemistry and the pore size of the membranes. PA membranes from commercial sources with a range of pore diameters (20, 100 and 200 nm) were used and modified by plasma polymerization using n-heptylamine (HA) monomer, which resulted in a chemically reactive polymer surface with amino groups. Heptylamine plasma polymer (HAPP) layers with a thickness less than the pore diameter do not span the pores but reduce their diameter. Accordingly, by adjusting the deposition time and thus the thickness of the plasma polymer coating, it is feasible to produce any desired pore diameter. The structural and chemical properties of modified membranes were studied by scanning electron microscopy (SEM), atomic force microscopy (AFM) and x-ray electron spectroscopy (XPS). The resultant PA membranes with specific surface chemistry and controlled pore size are applicable for molecular separation, cell culture, bioreactors, biosensing, drug delivery, and engineering complex composite membranes.

Surface modification of nanoporous alumina membranes by plasma polymerization

International Nuclear Information System (INIS)

Losic, Dusan; Cole, Martin A; Dollmann, Bjoern; Vasilev, Krasimir; Griesser, Hans J

2008-01-01

The deposition of plasma polymer coatings onto porous alumina (PA) membranes was investigated with the aim of adjusting the surface chemistry and the pore size of the membranes. PA membranes from commercial sources with a range of pore diameters (20, 100 and 200 nm) were used and modified by plasma polymerization using n-heptylamine (HA) monomer, which resulted in a chemically reactive polymer surface with amino groups. Heptylamine plasma polymer (HAPP) layers with a thickness less than the pore diameter do not span the pores but reduce their diameter. Accordingly, by adjusting the deposition time and thus the thickness of the plasma polymer coating, it is feasible to produce any desired pore diameter. The structural and chemical properties of modified membranes were studied by scanning electron microscopy (SEM), atomic force microscopy (AFM) and x-ray electron spectroscopy (XPS). The resultant PA membranes with specific surface chemistry and controlled pore size are applicable for molecular separation, cell culture, bioreactors, biosensing, drug delivery, and engineering complex composite membranes

Long-lasting antifog plasma modification of transparent plastics.

Science.gov (United States)

Di Mundo, Rosa; d'Agostino, Riccardo; Palumbo, Fabio

2014-10-08

Antifog surfaces are necessary for any application requiring optical efficiency of transparent materials. Surface modification methods aimed toward increasing solid surface energy, even when supposed to be permanent, in fact result in a nondurable effect due to the instability in air of highly hydrophilic surfaces. We propose the strategy of combining a hydrophilic chemistry with a nanotextured topography, to tailor a long-lasting antifog modification on commercial transparent plastics. In particular, we investigated a two-step process consisting of self-masked plasma etching followed by plasma deposition of a silicon-based film. We show that the deposition of the silicon-based coatings on the flat (pristine) substrates allows a continuous variation of wettability from hydrophobic to superhydrophilic, due to a continuous reduction of carbon-containing groups, as assessed by Fourier transform infrared and X-ray photoelectron spectroscopies. By depositing these different coatings on previously nanotextured substrates, the surface wettability behavior is changed consistently, as well as the condensation phenomenon in terms of microdroplets/liquid film appearance. This variation is correlated with advancing and receding water contact angle features of the surfaces. More importantly, in the case of the superhydrophilic coating, though its surface energy decreases with time, when a nanotextured surface underlies it, the wetting behavior is maintained durably superhydrophilic, thus durably antifog.

Plasma assisted surface treatments of biomaterials.

Science.gov (United States)

Minati, L; Migliaresi, C; Lunelli, L; Viero, G; Dalla Serra, M; Speranza, G

2017-10-01

The biocompatibility of an implant depends upon the material it is composed of, in addition to the prosthetic device's morphology, mechanical and surface properties. Properties as porosity and pore size should allow, when required, cells penetration and proliferation. Stiffness and strength, that depend on the bulk characteristics of the material, should match the mechanical requirements of the prosthetic applications. Surface properties should allow integration in the surrounding tissues by activating proper communication pathways with the surrounding cells. Bulk and surface properties are not interconnected, and for instance a bone prosthesis could possess the necessary stiffness and strength for the application omitting out prerequisite surface properties essential for the osteointegration. In this case, surface treatment is mandatory and can be accomplished using various techniques such as applying coatings to the prosthesis, ion beams, chemical grafting or modification, low temperature plasma, or a combination of the aforementioned. Low temperature plasma-based techniques have gained increasing consensus for the surface modification of biomaterials for being effective and competitive compared to other ways to introduce surface functionalities. In this paper we review plasma processing techniques and describe potentialities and applications of plasma to tailor the interface of biomaterials. Copyright © 2017 Elsevier B.V. All rights reserved.

Surface modification of blood-contacting biomaterials by plasma-polymerized superhydrophobic films using hexamethyldisiloxane and tetrafluoromethane as precursors

Energy Technology Data Exchange (ETDEWEB)

Hsiao, Chaio-Ru [Department of Materials Science and Engineering, Feng Chia University, No. 100, Wenhwa Rd., Seatwen District, Taichung City 40724, Taiwan (China); Lin, Cheng-Wei [Department of Dental Technology and Materials Science, Central Taiwan University of Science and Technology, No. 666, Buzih Rd., Beitun District, Taichung City 40601, Taiwan (China); Chou, Chia-Man, E-mail: cmchou@vghtc.gov.tw [Department of Surgery, Taichung Veterans General Hospital, No. 1650, Sec. 4, Taiwan Boulevard, Seatwen District, Taichung City 40705, Taiwan (China); Department of Medicine, National Yang-Ming University, No. 155, Sec. 2, Linong Street, Beitou District, Taipei City 11221, Taiwan (China); Chung, Chi-Jen, E-mail: cjchung@seed.net.tw [Department of Dental Technology and Materials Science, Central Taiwan University of Science and Technology, No. 666, Buzih Rd., Beitun District, Taichung City 40601, Taiwan (China); He, Ju-Liang [Department of Materials Science and Engineering, Feng Chia University, No. 100, Wenhwa Rd., Seatwen District, Taichung City 40724, Taiwan (China)

2015-08-15

Highlights: • Biomaterials modified by nanoparticle-containing plasma polymerized films. • A superhydrophoic film was obtained, and the properties of the coating were examined. • In vitro blood compatibility tests revealed neither platelet adhesion nor fibrinogen adsorption. • Surface modification technology of medical devices: non-cytotoxic and no blood clot formation. - Abstract: This paper proposes a plasma polymerization system that can be used to modify the surface of the widely used biomaterial, polyurethane (PU), by employing low-cost hexamethyldisiloxane (HMDSO) and tetrafluoromethane (CF{sub 4}) as precursors; this system features a pulsed-dc power supply. Plasma-polymerized HMDSO/CF{sub 4} (pp-HC) with coexisting micro- and nanoscale morphology was obtained as a superhydrophobic coating material by controlling the HMDSO/CF{sub 4} (f{sub H}) monomer flow ratio. The developed surface modification technology can be applied to medical devices, because it is non-cytotoxic and has favorable hemocompatibility, and no blood clots form when the device surface direct contacts. Experimental results reveal that the obtained pp-HC films contained SiO{sub x} nanoparticles randomly dispersed on the micron-scale three-dimensional network film surface. The −CF functional group, −CF{sub 2} bonding, and SiO{sub x} were detected on the film surface. The maximal water contact angle of the pp-HC coating was 161.2°, apparently attributable to the synergistic effect of the coexisting micro- and nanoscale surface morphology featuring a low surface-energy layer. The superhydrophobic and antifouling characteristics of the coating were retained even after it was rubbed 20 times with a steel wool tester. Results of in vitro cytotoxicity, fibrinogen adsorption, and platelet adhesion tests revealed favorable myoblast cell proliferation and the virtual absence of fibrinogen adsorption and platelet adhesion on the pp-HC coated specimens. These quantitative findings imply

Method for atmospheric pressure reactive atom plasma processing for surface modification

Science.gov (United States)

Carr, Jeffrey W [Livermore, CA

2009-09-22

Reactive atom plasma processing can be used to shape, polish, planarize and clean the surfaces of difficult materials with minimal subsurface damage. The apparatus and methods use a plasma torch, such as a conventional ICP torch. The workpiece and plasma torch are moved with respect to each other, whether by translating and/or rotating the workpiece, the plasma, or both. The plasma discharge from the torch can be used to shape, planarize, polish, and/or clean the surface of the workpiece, as well as to thin the workpiece. The processing may cause minimal or no damage to the workpiece underneath the surface, and may involve removing material from the surface of the workpiece.

Bioactive surface modifications on inner walls of poly-tetra-fluoro-ethylene tubes using dielectric barrier discharge

Energy Technology Data Exchange (ETDEWEB)

Cho, Yong Ki [Department of Physics, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Heat Treatment and Surface Engineering R and D Group, Korea Institute of Industrial Technology, Incheon 406-840 (Korea, Republic of); Park, Daewon; Kim, Hoonbae [Department of Physics, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Lee, Hyerim; Park, Heonyong [Department of Molecular Biology, Dankook University, Yongin 448-701 (Korea, Republic of); Kim, Hong Ja [Department of Internal Medicine, Dankook University, Cheonan 330-714 (Korea, Republic of); Jung, Donggeun, E-mail: djung@skku.ac.kr [Department of Physics, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

2014-03-01

Graphical abstract: - Highlights: • The surface modification of the inner walls of poly-tetra-fluoro-ethylene (PTFE) tubing was carried out to improve vascular grafts. • Focus was centered on the cell attachment of the inner wall of the PTFE by sequential processes of hydrogen plasma treatment, hydrocarbon deposition, and reactive plasma treatment using micro plasma discharge. - Abstract: Bioactive surface modification can be used in a variety of medical polymeric materials in the fields of biochips and biosensors, artificial membranes, and vascular grafts. In this study, the surface modification of the inner walls of poly-tetra-fluoro-ethylene (PTFE) tubing was carried out to improve vascular grafts, which are made of biocompatible material for the human body in the medical field. Focus was centered on the cell attachment of the inner wall of the PTFE by sequential processes of hydrogen plasma treatment, hydrocarbon deposition, and reactive plasma treatment on the PFTE surface using micro plasma discharge. Micro plasma was generated by a medium-frequency alternating current high-voltage generator. The preliminary modification of PTFE was conducted by a plasma of hydrogen and argon gases. The hydrocarbon thin film was deposited on modified PTFE with a mixture of acetylene and argon gases. The reactive plasma treatment using oxygen plasma was done to give biocompatible functionality to the inner wall surface. The hydrophobic surface of bare PTFE is made hydrophilic by the reactive plasma treatment due to the formation of carbonyl groups on the surface. The reactive treatment could lead to improved attachment of smooth muscle cells (SMCs) on the modified PTFE tubing. Fourier transform infrared absorption spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and water contact angle measurement were used for the analysis of the surface modification. The SMC-attached PTFE tube developed will be applicable to in vitro human vasculature

Bioactive surface modifications on inner walls of poly-tetra-fluoro-ethylene tubes using dielectric barrier discharge

International Nuclear Information System (INIS)

Cho, Yong Ki; Park, Daewon; Kim, Hoonbae; Lee, Hyerim; Park, Heonyong; Kim, Hong Ja; Jung, Donggeun

2014-01-01

Graphical abstract: - Highlights: • The surface modification of the inner walls of poly-tetra-fluoro-ethylene (PTFE) tubing was carried out to improve vascular grafts. • Focus was centered on the cell attachment of the inner wall of the PTFE by sequential processes of hydrogen plasma treatment, hydrocarbon deposition, and reactive plasma treatment using micro plasma discharge. - Abstract: Bioactive surface modification can be used in a variety of medical polymeric materials in the fields of biochips and biosensors, artificial membranes, and vascular grafts. In this study, the surface modification of the inner walls of poly-tetra-fluoro-ethylene (PTFE) tubing was carried out to improve vascular grafts, which are made of biocompatible material for the human body in the medical field. Focus was centered on the cell attachment of the inner wall of the PTFE by sequential processes of hydrogen plasma treatment, hydrocarbon deposition, and reactive plasma treatment on the PFTE surface using micro plasma discharge. Micro plasma was generated by a medium-frequency alternating current high-voltage generator. The preliminary modification of PTFE was conducted by a plasma of hydrogen and argon gases. The hydrocarbon thin film was deposited on modified PTFE with a mixture of acetylene and argon gases. The reactive plasma treatment using oxygen plasma was done to give biocompatible functionality to the inner wall surface. The hydrophobic surface of bare PTFE is made hydrophilic by the reactive plasma treatment due to the formation of carbonyl groups on the surface. The reactive treatment could lead to improved attachment of smooth muscle cells (SMCs) on the modified PTFE tubing. Fourier transform infrared absorption spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and water contact angle measurement were used for the analysis of the surface modification. The SMC-attached PTFE tube developed will be applicable to in vitro human vasculature

Maskless Surface Modification of Polyurethane Films by an Atmospheric Pressure He/O2 Plasma Microjet for Gelatin Immobilization

Directory of Open Access Journals (Sweden)

Man Zhang

2018-04-01

Full Text Available A localized maskless modification method of polyurethane (PU films through an atmospheric pressure He/O2 plasma microjet (APPμJ was proposed. The APPμJ system combines an atmospheric pressure plasma jet (APPJ with a microfabricated silicon micronozzle with dimension of 30 μm, which has advantages of simple structure and low cost. The possibility of APPμJ in functionalizing PU films with hydroxyl (–OH groups and covalent grafting of gelatin for improving its biocompatibility was demonstrated. The morphologies and chemical compositions of the modified surface were analyzed by scanning electronic microscopy (SEM, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS. The fluorescent images show the modified surface can be divided into four areas with different fluorescence intensity from the center to the outside domain. The distribution of the rings could be controlled by plasma process parameters, such as the treatment time and the flow rate of O2. When the treatment time is 4 to 5 min with the oxygen percentage of 0.6%, the PU film can be effectively local functionalized with the diameter of 170 μm. In addition, the modification mechanism of PU films by the APPμJ is investigated. The localized polymer modified by APPμJ has potential applications in the field of tissue engineering.

Ultrasound enhanced plasma surface modification at atmospheric pressure

DEFF Research Database (Denmark)

Kusano, Yukihiro; Singh, Shailendra Vikram; Norrman, Kion

2012-01-01

Efficiency of atmospheric pressure plasma treatment can be highly enhanced by simultaneous high power ultrasonic irradiation onto the treating surface. It is because ultrasonic waves with a sound pressure level (SPL) above ∼140 dB can reduce the thickness of a boundary gas layer between the plasma...... arc at atmospheric pressure to study adhesion improvement. The effect of ultrasonic irradiation with the frequency diapason between 20 and 40 kHz at the SPL of ∼150 dB was investigated. After the plasma treatment without ultrasonic irradiation, the wettability was significantly improved...

Surface bioactivity modification of titanium by CO 2 plasma treatment and induction of hydroxyapatite: In vitro and in vivo studies

Science.gov (United States)

Hu, Xixue; Shen, Hong; Shuai, Kegang; Zhang, Enwei; Bai, Yanjie; Cheng, Yan; Xiong, Xiaoling; Wang, Shenguo; Fang, Jing; Wei, Shicheng

2011-01-01

Since metallic biomaterials used for orthopedic and dental implants possess a paucity of reactive functional groups, bioactivity modification of these materials is challenging. In the present work, the titanium discs and rods were treated with carbon dioxide plasma and then incubated in a modified simulated body fluid 1.5SBF to obtain a hydroxyapatite layer. Surface hydrophilicity of samples, changes of surface chemistry, surface morphologies of samples, and structural analysis of formed hydroxyapatite were investigated by contact angle to water, X-ray photoelectron spectrometer (XPS), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) and X-ray diffraction (XRD). The results demonstrated that hydrophilicity of titanium surface was improved and hydroxyl groups increased after modification with carbon dioxide plasma treatment. The hydroxyl groups on the surface of titanium were the richest after carbon dioxide plasma treatment under the condition of 20 W for less than 30 s. The hydroxyapatite formability of titanium surface was enhanced by carbon dioxide plasma pretreatment, which was attributed to the surface chemistry. MC3T3-E1 cell as a model cell was cultured on the Ti, CPT-Ti and CPT/SBF-Ti discs in vitro, and the results of the morphology and differentiation of the cell showed that CPT/SBF-Ti was the highest bioactive. The relative parameters of the new bone around the Ti and CPT/SBF-Ti rods including bone mineral density (BMD), a ratio of bone volume to total volume (BV/TV), trabecular thickness (Tb.Th.) and trabecular number (Tb.N.) were analyzed by a micro-computed tomography (micro-CT) after 4-, 8- and 12-week implantation periods in vivo. The results indicated that the CPT/SBF-Ti was more advantageous for new bone formation.

Application of plasma technology for the modification of polymer and textile materials

Directory of Open Access Journals (Sweden)

Radetić Maja M.

2004-01-01

Full Text Available Plasma treatment is based on the physico-chemical changes of the material surface and as an ecologically and economically acceptable process it can be an attractive alternative to conventional modifications. The possibilities of plasma technology application to the modification of polymer and textile materials are discussed. Different specific properties of the material can be achieved by plasma cleaning, etching, functionalization or polymerization. The final effects are strongly influenced by the treatment parameters (treatment time, pressure, power, gas flow, the applied gas and nature of the material. The plasma treatment of polymers is predominantly focused on cleaning and activation of the surfaces to increase adhesion, binding, wettability, dye ability and printability. Current studies deal more with plasma polymerization where an ultra thin film of plasma polymer is deposited on the material surface and, depending on the applied monomer, different specific properties can be obtained (i.e. chemical and thermal resistance, abrasion resistance, antireflexion, water repellence, etc.. Plasma application to textiles is mostly oriented toward wool and synthetic fibres, though some studies also consider cotton, hemp, flax and silk. The main goal of plasma treatment is to impart a more hydrophilic fibre surface and accordingly increase wettability, dye ability, printability and particularly, shrink resistance in the case of wool. Recent studies have favored technical textiles, where plasma polymerization can offer a wide range of opportunities.

Model polymer etching and surface modification by a time modulated RF plasma jet: role of atomic oxygen and water vapor

Science.gov (United States)

Luan, P.; Knoll, A. J.; Wang, H.; Kondeti, V. S. S. K.; Bruggeman, P. J.; Oehrlein, G. S.

2017-01-01

The surface interaction of a well-characterized time modulated radio frequency (RF) plasma jet with polystyrene, poly(methyl methacrylate) and poly(vinyl alcohol) as model polymers is investigated. The RF plasma jet shows fast polymer etching but mild chemical modification with a characteristic carbonate ester and NO formation on the etched surface. By varying the plasma treatment conditions including feed gas composition, environment gaseous composition, and treatment distance, we find that short lived species, especially atomic O for Ar/1% O2 and 1% air plasma and OH for Ar/1% H2O plasma, play an essential role for polymer etching. For O2 containing plasma, we find that atomic O initiates polymer etching and the etching depth mirrors the measured decay of O atoms in the gas phase as the nozzle-surface distance increases. The etching reaction probability of an O atom ranging from 10-4 to 10-3 is consistent with low pressure plasma research. We also find that adding O2 and H2O simultaneously into Ar feed gas quenches polymer etching compared to adding them separately which suggests the reduction of O and OH density in Ar/O2/H2O plasma.

Surface damage of W exposed to combined stationary D plasma and ELMs-like pulsed plasma

Energy Technology Data Exchange (ETDEWEB)

Jia, Y.Z., E-mail: jaja880816@aliyun.com [Science and Technology on Reactor Fuel and Materials Laboratory, Nuclear Power Institute of China, Chengdu, Sichuan 610213 (China); Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Liu, W., E-mail: liuw@mail.tsinghua.edu.cn [Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Xu, B.; Qu, S.L. [Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Morgan, T.W. [FOM Institute DIFFER-Dutch Institute for Fundamental Energy Research, 5612AJ Eindhoven (Netherlands)

2017-04-15

The surface damage of W under D plasma and ELMs-like transient heat loads was studied by combined stationary and pulsed D plasma. Low-flux transient heat loads will promote blister formation due to the gas expansion inside the blisters. On the contrary, high-flux transient heat loads will mitigate blistering due to the high surface temperature. Therefore, blistering on W surface first increased and then decreased with the increasing transient heat loads. The promotion effect of pulsed plasma on blistering is more obvious on [001] and [110] surfaces than on [111] surface, and the orientation dependence of blisters was mitigated by the transient heat loads. Surface modification induced by transient heat loads only formed on [001] and [110] surfaces, but did not form on [111] surface. The orientation dependence of surface modification was mainly due to the slipping system of dislocations.

Plasma etching treatment for surface modification of boron-doped diamond electrodes

Energy Technology Data Exchange (ETDEWEB)

Kondo, Takeshi [Department of Industrial Chemistry, Faculty of Engineering, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601 (Japan); Ito, Hiroyuki [Department of Industrial Chemistry, Faculty of Engineering, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601 (Japan); Kusakabe, Kazuhide [Department of Applied Physics, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601 (Japan); Ohkawa, Kazuhiro [Department of Applied Physics, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601 (Japan); Einaga, Yasuaki [Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Yokohama 223-8522 (Japan); Fujishima, Akira [Kanagawa Academy of Science and Technology (KAST), 3-2-1 Sakado, Takatsu-ku, Kawasaki, Kanagawa 213-0012 (Japan); Kawai, Takeshi [Department of Industrial Chemistry, Faculty of Engineering, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601 (Japan)]. E-mail: kawai@ci.kagu.tus.ac.jp

2007-03-01

Boron-doped diamond (BDD) thin film surfaces were modified by brief plasma treatment using various source gases such as Cl{sub 2}, CF{sub 4}, Ar and CH{sub 4}, and the electrochemical properties of the surfaces were subsequently investigated. From X-ray photoelectron spectroscopy analysis, Cl and F atoms were detected on the BDD surfaces after 3 min of Cl{sub 2} and CF{sub 4} plasma treatments, respectively. From the results of cyclic voltammetry and electrochemical AC impedance measurements, the electron-transfer rate for Fe(CN){sub 6} {sup 3-/4-} and Fe{sup 2+/3+} at the BDD electrodes was found to decrease after Cl{sub 2} and CF{sub 4} plasma treatments. However, the electron-transfer rate for Ru(NH{sub 3}){sub 6} {sup 2+/3+} showed almost no change after these treatments. This may have been related to the specific interactions of surface halogen (C-Cl and C-F) moieties with the redox species because no electrical passivation was observed after the treatments. In addition, Raman spectroscopy showed that CH{sub 4} plasma treatment of diamond surfaces formed an insulating diamond-like carbon thin layer on the surfaces. Thus, by an appropriate choice of plasma source, short-duration plasma treatments can be an effective way to functionalize diamond surfaces in various ways while maintaining a wide potential window and a low background current.

Long-Time Plasma Membrane Imaging Based on a Two-Step Synergistic Cell Surface Modification Strategy.

Science.gov (United States)

Jia, Hao-Ran; Wang, Hong-Yin; Yu, Zhi-Wu; Chen, Zhan; Wu, Fu-Gen

2016-03-16

Long-time stable plasma membrane imaging is difficult due to the fast cellular internalization of fluorescent dyes and the quick detachment of the dyes from the membrane. In this study, we developed a two-step synergistic cell surface modification and labeling strategy to realize long-time plasma membrane imaging. Initially, a multisite plasma membrane anchoring reagent, glycol chitosan-10% PEG2000 cholesterol-10% biotin (abbreviated as "GC-Chol-Biotin"), was incubated with cells to modify the plasma membranes with biotin groups with the assistance of the membrane anchoring ability of cholesterol moieties. Fluorescein isothiocyanate (FITC)-conjugated avidin was then introduced to achieve the fluorescence-labeled plasma membranes based on the supramolecular recognition between biotin and avidin. This strategy achieved stable plasma membrane imaging for up to 8 h without substantial internalization of the dyes, and avoided the quick fluorescence loss caused by the detachment of dyes from plasma membranes. We have also demonstrated that the imaging performance of our staining strategy far surpassed that of current commercial plasma membrane imaging reagents such as DiD and CellMask. Furthermore, the photodynamic damage of plasma membranes caused by a photosensitizer, Chlorin e6 (Ce6), was tracked in real time for 5 h during continuous laser irradiation. Plasma membrane behaviors including cell shrinkage, membrane blebbing, and plasma membrane vesiculation could be dynamically recorded. Therefore, the imaging strategy developed in this work may provide a novel platform to investigate plasma membrane behaviors over a relatively long time period.

A combination of CO2 laser and plasma surface modification of poly(etheretherketone) to enhance osteoblast response

International Nuclear Information System (INIS)

Zheng, Yanyan; Xiong, Chengdong; Wang, Zhecun; Li, Xiaoyu; Zhang, Lifang

2015-01-01

Highlights: • COOH and microgrooves containing micropores or microcraters structure were constructed on PEEK surface by a combination of CO 2 laser and plasma treatment. • The mechanical properties of PEEK are maintained after single or dual surface treatment. • Pre-osteoblast cells (MC3T3-E1) adhesion, spreading and proliferation were improved remarkably on dual treated PEEK surface. • Cell pseudopodia protrude into the micropores or microcraters, in favor of forming firmer bone-implant integration. - Abstract: Poly(etheretherketone) (PEEK) is a rigid semicrystalline polymer that combines excellent mechanical properties, broad chemical resistance and bone-like stiffness and is widely used in biomedical fields. However, the bio-inert surface of PEEK tends to hinder its biomedical applications when direct osteointegration between the implants and the host tissue is desired. In this work, we demonstrate a dual modification method, which combines the laser and plasma surface treatment to combine advantages of both chemical states and microstructures for osteoblasts responses. While the plasma treatment introduces surface carboxyl groups (−COOH) onto PEEK surface, the laser treatment constructs microstructures over the PEEK surface. Our results indicated that −COOH as well as microgrooves containing micropores or microcraters structure are constructed on PEEK surface and plasma treatment has no apparent effect on the morphology of microstructures produced by laser micromachining. Unexpectedly, the superior mechanical properties of PEEK were maintained irrespective of the treatment used. Compared to native PEEK and single treated PEEK, dual modified PEEK is more favorable for pre-osteoblasts (MC3T3-E1) adhesion, spreading and proliferation. Moreover, cell pseudopodia protrude into the micropores or microcraters, in favor of forming firmer bone-implant integration. Our study illustrates enhanced osteoblasts responses to dual treated PEEK surface, which gives

Surface Modification of Polypropylene Microporous Membrane by Atmospheric-Pressure Plasma Immobilization of N,N-dimethylamino Ethyl Methacrylate

International Nuclear Information System (INIS)

Zhong Shaofeng

2010-01-01

Surface modification of polypropylene microporous membrane (PPMM) was performed by atmospheric pressure dielectric barrier discharge plasma immobilization of N,N-dimethylamino ethyl methacrylate (DMAEMA). Structural and morphological changes on the membrane surface were characterized by attenuated total reflection-Fourier transform infrared spectroscopy (FT-IR/ATR), X-ray photoelectron spectroscope (XPS) and field emission scanning electron microscopy (FE-SEM). Water contact angles of the membrane surfaces were also measured by the sessile drop method. Results reveal that both the plasma-treating conditions and the adsorbed DMAEMA amount have remarkable effects on the immobilization degree of DMAEMA. Peroxide determination by 1,1-diphenyl-2-picrvlhydrazyl (DPPH) method verifies the exsistence of radicals induced by plasma, which activize the immobilization reaction. Pure water contact angle on the membrane surface decreased with the increase of DMAEMA immobilization degree, which indicates an enhanced hydrophilicity for the modified membranes. The effects of immobilization degrees on pure water fluxes were also measured. It is shown that pure water fluxes first increased with immobilization degree and then decreased. Finally, permeation of bovine serum albumin (BSA) and lysozyme solution were measured to evaluate the antifouling property of the DMAEMA-modified membranes, from which it is shown that both hydrophilicity and electrostatic repulsion are beneficial for membrane antifouling.

Surface modification of a natural zeolite by treatment with cold oxygen plasma: Characterization and application in water treatment

Science.gov (United States)

De Velasco-Maldonado, Paola S.; Hernández-Montoya, Virginia; Montes-Morán, Miguel A.; Vázquez, Norma Aurea-Rangel; Pérez-Cruz, Ma. Ana

2018-03-01

In the present work the possible surface modification of natural zeolite using cold oxygen plasma was studied. The sample with and without treatment was characterized using nitrogen adsorption isotherms at -196 °C, FT-IR spectroscopy, SEM/EDX analysis and X-Ray Diffraction. Additionally, the two samples were used for the removal of lead and acid, basic, reactive and food dyes in batch systems. The natural zeolite was found to be a mesoporous material with a low specific surface area (23 m2/g). X-ray patterns confirmed that clinoptilolite was the main crystal structure present in the natural zeolite. The molecular properties of dyes and the zeolitic structure were studied using molecular simulation, with the purpose to understand the adsorption mechanism. The results pointed out that only the roughness of the clinoptilolite was affected by the plasma treatment, whereas the specific surface area, chemical functionality and crystal structure remained constant. Finally, adsorption results confirmed that the plasma treatment had no significant effects on the dyes and lead retention capacities of the natural zeolite.

Model polymer etching and surface modification by a time modulated RF plasma jet: role of atomic oxygen and water vapor

International Nuclear Information System (INIS)

Luan, P; Knoll, A J; Wang, H; Oehrlein, G S; Kondeti, V S S K; Bruggeman, P J

2017-01-01

The surface interaction of a well-characterized time modulated radio frequency (RF) plasma jet with polystyrene, poly(methyl methacrylate) and poly(vinyl alcohol) as model polymers is investigated. The RF plasma jet shows fast polymer etching but mild chemical modification with a characteristic carbonate ester and NO formation on the etched surface. By varying the plasma treatment conditions including feed gas composition, environment gaseous composition, and treatment distance, we find that short lived species, especially atomic O for Ar/1% O 2 and 1% air plasma and OH for Ar/1% H 2 O plasma, play an essential role for polymer etching. For O 2 containing plasma, we find that atomic O initiates polymer etching and the etching depth mirrors the measured decay of O atoms in the gas phase as the nozzle-surface distance increases. The etching reaction probability of an O atom ranging from 10 −4 to 10 −3 is consistent with low pressure plasma research. We also find that adding O 2 and H 2 O simultaneously into Ar feed gas quenches polymer etching compared to adding them separately which suggests the reduction of O and OH density in Ar/O 2 /H 2 O plasma. (letter)

Bioactive surface modifications on inner walls of poly-tetra-fluoro-ethylene tubes using dielectric barrier discharge

Science.gov (United States)

Cho, Yong Ki; Park, Daewon; Kim, Hoonbae; Lee, Hyerim; Park, Heonyong; Kim, Hong Ja; Jung, Donggeun

2014-03-01

Bioactive surface modification can be used in a variety of medical polymeric materials in the fields of biochips and biosensors, artificial membranes, and vascular grafts. In this study, the surface modification of the inner walls of poly-tetra-fluoro-ethylene (PTFE) tubing was carried out to improve vascular grafts, which are made of biocompatible material for the human body in the medical field. Focus was centered on the cell attachment of the inner wall of the PTFE by sequential processes of hydrogen plasma treatment, hydrocarbon deposition, and reactive plasma treatment on the PFTE surface using micro plasma discharge. Micro plasma was generated by a medium-frequency alternating current high-voltage generator. The preliminary modification of PTFE was conducted by a plasma of hydrogen and argon gases. The hydrocarbon thin film was deposited on modified PTFE with a mixture of acetylene and argon gases. The reactive plasma treatment using oxygen plasma was done to give biocompatible functionality to the inner wall surface. The hydrophobic surface of bare PTFE is made hydrophilic by the reactive plasma treatment due to the formation of carbonyl groups on the surface. The reactive treatment could lead to improved attachment of smooth muscle cells (SMCs) on the modified PTFE tubing. Fourier transform infrared absorption spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and water contact angle measurement were used for the analysis of the surface modification. The SMC-attached PTFE tube developed will be applicable to in vitro human vasculature-mimetic model systems, and to medical vascular grafts.

Plasma surface functionalization and dyeing kinetics of Pan-Pmma copolymers

Science.gov (United States)

Labay, C.; Canal, C.; Rodríguez, C.; Caballero, G.; Canal, J. M.

2013-10-01

Fiber surface modification with air corona plasma has been studied through dyeing kinetics under isothermal conditions at 30 °C on an acrylic-fiber fabric with a cationic dye (CI Basic Blue 3) analyzing the absorption, desorption and fixing on the surface of molecules having defined cationic character. The initial dyeing rate in the first 60 s indicates an increase of 58.3% in the dyeing rate due to the effect of corona plasma on the acrylic fiber surface. At the end of the dyeing process, the plasma-treated fabrics absorb 24.7% more dye, and the K/S value of the acrylic fabric increases by 8.8%. With selected dyestuff molecules, new techniques can be designed to amplify the knowledge about plasma-treated surface modifications of macromolecules.

Surface modification of PTMSP membranes by plasma treatment: Asymmetry of transport in organic solvent nanofiltration.

Science.gov (United States)

Volkov, A V; Tsarkov, S E; Gilman, A B; Khotimsky, V S; Roldughin, V I; Volkov, V V

2015-08-01

For the first time, the effect of asymmetry of the membrane transport was studied for organic solvents and solutes upon their nanofiltration through the plasma-modified membranes based on poly(1-trimethylsilyl-1-propyne) (PTMSP). Plasma treatment is shown to provide a marked hydrophilization of the hydrophobic PTMSP surface (the contact angle of water decreases from 88 down to 20°) and leads to the development of a negative charge of -5.2 nC/cm(2). The XPS measurements prove the formation of the oxygen-containing groups (Si-O and C-O) due to the surface modification. The AFM images show that the small-scale surface roughness of the plasma-treated PTMSP sample is reduced but the large-scale surface heterogeneities become more pronounced. The modified membranes retain their hydrophilic surface properties even after the nanofiltration tests and 30-day storage under ambient conditions. The results of the filtration tests show that when the membrane is oriented so that its modified layer contacts the feed solution, the membrane permeability for linear alcohols (methanol-propanol) and acetone decreases nearly two times. When the modified membrane surface faces the permeate, the membrane is seen to regain its transport characteristics: the flux becomes equal to that of the unmodified PTMSP. The well-pronounced effect of the transport asymmetry is observed for the solution of the neutral dye Solvent Blue 35 in methanol, ethanol, and acetone. For example, the initial membrane shows the negative retention for the Solvent Blue 35 dye (-16%) upon its filtration from the ethanol solution whereas, for the modified PTMSP membrane, the retention increases up to 17%. Various effects contributing to the asymmetry of the membrane transport characteristics are discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

Surface Modification of Polymer Substrates for Biomedical Applications

Directory of Open Access Journals (Sweden)

Oldřich Neděla

2017-09-01

Full Text Available While polymers are widely utilized materials in the biomedical industry, they are rarely used in an unmodified state. Some kind of a surface treatment is often necessary to achieve properties suitable for specific applications. There are multiple methods of surface treatment, each with their own pros and cons, such as plasma and laser treatment, UV lamp modification, etching, grafting, metallization, ion sputtering and others. An appropriate treatment can change the physico-chemical properties of the surface of a polymer in a way that makes it attractive for a variety of biological compounds, or, on the contrary, makes the polymer exhibit antibacterial or cytotoxic properties, thus making the polymer usable in a variety of biomedical applications. This review examines four popular methods of polymer surface modification: laser treatment, ion implantation, plasma treatment and nanoparticle grafting. Surface treatment-induced changes of the physico-chemical properties, morphology, chemical composition and biocompatibility of a variety of polymer substrates are studied. Relevant biological methods are used to determine the influence of various surface treatments and grafting processes on the biocompatibility of the new surfaces—mammalian cell adhesion and proliferation is studied as well as other potential applications of the surface-treated polymer substrates in the biomedical industry.

Controlled modification of octadecyltrichlorosilane self-assembled monolayer by CO2 plasma

International Nuclear Information System (INIS)

Delorme, Nicolas; Bardeau, Jean-Francois; Bulou, Alain; Poncin-Epaillard, Fabienne

2006-01-01

CO 2 -plasma is used to introduce functional groups on the uppermost surface of an alkoxy silane self-assembled monolayer (Sam). The structural and chemical modifications of the material surface were monitored by X-ray reflectometry, atomic force microscopy, X-ray photoelectrons spectroscopy and water contact angle measurements. Optimization of the plasma parameters is performed in order to achieve a maximum functionalization and to prevent degradation of the SAM. Finally, the ability of grafting organic compounds onto the plasma modified SAMS was demonstrated by the formation of an alkoxysilane bilayer

Surface Modification of Asymmetric Polysulfone/Polyethylene Glycol Membranes by DC Ar-Glow Discharge Plasma

Directory of Open Access Journals (Sweden)

Chalad Yuenyao

2016-01-01

Full Text Available Polysulfone/polyethylene glycol (PSF/PEG membranes were prepared by dry/wet phase inversion method. Effects of direct current glow discharge plasma using argon as working gas on morphological structures and gas separation properties of membranes were studied. Alteration of membrane characteristics were analyzed by various techniques like contact angle, scanning electron microscope, Fourier transform infrared spectroscopy, and dynamic mechanical thermal analysis. Gas separation properties were measured in terms of permeation and ideal O2/N2 selectivity. Results showed that hydrophilic and gas separation properties of PSF/PEG membranes increased by plasma surface modification. It was also shown that the dosage of PEG and plasma treatment affected the morphological structures and mechanical and gas separation properties. The macro voids and transmembrane structure disappeared with a little amount of PEG dosage. Pore size and mechanical strength tend to decrease with increasing PEG dosage up to 10 wt%. Glass transition temperature (Tg receded from 201.8 to 143.7°C for pure PSF and PSF/PEG with PEG dosage of 10 wt%. O2 and N2 gases permeation through the 10-minute plasma treated membranes tend to increase. However, the permeation strongly dispersed when treatment time was more extended.

Surface modification of polyvinyl alcohol/malonic acid nanofibers by gaseous dielectric barrier discharge plasma for glucose oxidase immobilization

International Nuclear Information System (INIS)

Afshari, Esmail; Mazinani, Saeedeh; Ranaei-Siadat, Seyed-Omid; Ghomi, Hamid

2016-01-01

Highlights: • We fabricated polyvinyl alcohol/malonic acid nanofibers using electrospinning. • The surface nanofibers were modified by gaseous (air, nitrogen, CO_2 and argon) dielectric barrier discharge. • Among them, air plasma had the most significant effect on glucose oxidase immobilization. • Chemical analysis showed that after modification of nanofibers by air plasma, the carboxyl group increased. • After air plasma treatment, reusability and storage stability of glucose oxidase immobilized on nanofibers improved. - Abstract: Polymeric nanofiber prepares a suitable situation for enzyme immobilization for variety of applications. In this research, we have fabricated polyvinyl alcohol (PVA)/malonic acid nanofibers using electrospinning. After fabrication of nanofibers, the effect of air, nitrogen, CO_2, and argon DBD (dielectric barrier discharge) plasmas on PVA/malonic acid nanofibers were analysed. Among them, air plasma had the most significant effect on glucose oxidase (GOx) immobilization. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectrum analysis and X-ray photoelectron spectroscopy (XPS) results revealed that in case of air plasma modified nanofibers, the carboxyl groups on the surface are increased. The scanning electron microscopy (SEM) images showed that, after GOx immobilization, the modified nanofibers with plasma has retained its nanofiber structure. Finally, we analysed reusability and storage stability of GOx immobilized on plasma modified and unmodified nanofibers. The results were more satisfactory for modified nanofibers with respect to unmodified ones.

Surface modification of polyvinyl alcohol/malonic acid nanofibers by gaseous dielectric barrier discharge plasma for glucose oxidase immobilization

Energy Technology Data Exchange (ETDEWEB)

Afshari, Esmail, E-mail: e.afshari@mail.sbu.ac.ir [Laser and Plasma Research Institute, Shahid Beheshti University, Evin, 1983963113 Tehran (Iran, Islamic Republic of); Mazinani, Saeedeh [Amirkabir Nanotechnology Research Institute (ANTRI), Amirkabir University of Technology, 15875-4413, Tehran (Iran, Islamic Republic of); Ranaei-Siadat, Seyed-Omid [Protein Research Center, Shahid Beheshti University, Evin, 1983963113 Tehran (Iran, Islamic Republic of); Ghomi, Hamid [Laser and Plasma Research Institute, Shahid Beheshti University, Evin, 1983963113 Tehran (Iran, Islamic Republic of)

2016-11-01

Highlights: • We fabricated polyvinyl alcohol/malonic acid nanofibers using electrospinning. • The surface nanofibers were modified by gaseous (air, nitrogen, CO{sub 2} and argon) dielectric barrier discharge. • Among them, air plasma had the most significant effect on glucose oxidase immobilization. • Chemical analysis showed that after modification of nanofibers by air plasma, the carboxyl group increased. • After air plasma treatment, reusability and storage stability of glucose oxidase immobilized on nanofibers improved. - Abstract: Polymeric nanofiber prepares a suitable situation for enzyme immobilization for variety of applications. In this research, we have fabricated polyvinyl alcohol (PVA)/malonic acid nanofibers using electrospinning. After fabrication of nanofibers, the effect of air, nitrogen, CO{sub 2}, and argon DBD (dielectric barrier discharge) plasmas on PVA/malonic acid nanofibers were analysed. Among them, air plasma had the most significant effect on glucose oxidase (GOx) immobilization. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectrum analysis and X-ray photoelectron spectroscopy (XPS) results revealed that in case of air plasma modified nanofibers, the carboxyl groups on the surface are increased. The scanning electron microscopy (SEM) images showed that, after GOx immobilization, the modified nanofibers with plasma has retained its nanofiber structure. Finally, we analysed reusability and storage stability of GOx immobilized on plasma modified and unmodified nanofibers. The results were more satisfactory for modified nanofibers with respect to unmodified ones.

Surface modification of polyester synthetic leather with tetramethylsilane by atmospheric pressure plasma

Energy Technology Data Exchange (ETDEWEB)

Kan, C.W., E-mail: tccwk@polyu.edu.hk [Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Kwong, C.H. [Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Ng, S.P. [Hong Kong Community College, The Hong Kong Polytechnic University (Hong Kong)

2015-08-15

Highlights: • Atmospheric pressure plasma treatment improved surface performance of polyester synthetic leather with tetramethylsilane. • XPS and FTIR confirmed the deposition of organosilanes on the sample's surface. • Contact angle increases to 138° after plasma treatment. - Abstract: Much works have been done on synthetic materials but scarcely on synthetic leather owing to its surface structures in terms of porosity and roughness. This paper examines the use of atmospheric pressure plasma (APP) treatment for improving the surface performance of polyester synthetic leather by use of a precursor, tetramethylsilane (TMS). Plasma deposition is regarded as an effective, simple and single-step method with low pollution. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) confirm the deposition of organosilanes on the sample's surface. The results showed that under a particular combination of treatment parameters, a hydrophobic surface was achieved on the APP treated sample with sessile drop static contact angle of 138°. The hydrophobic surface is stable without hydrophilic recovery 30 days after plasma treatment.

Surface modification of polyester synthetic leather with tetramethylsilane by atmospheric pressure plasma

International Nuclear Information System (INIS)

Kan, C.W.; Kwong, C.H.; Ng, S.P.

2015-01-01

Highlights: • Atmospheric pressure plasma treatment improved surface performance of polyester synthetic leather with tetramethylsilane. • XPS and FTIR confirmed the deposition of organosilanes on the sample's surface. • Contact angle increases to 138° after plasma treatment. - Abstract: Much works have been done on synthetic materials but scarcely on synthetic leather owing to its surface structures in terms of porosity and roughness. This paper examines the use of atmospheric pressure plasma (APP) treatment for improving the surface performance of polyester synthetic leather by use of a precursor, tetramethylsilane (TMS). Plasma deposition is regarded as an effective, simple and single-step method with low pollution. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) confirm the deposition of organosilanes on the sample's surface. The results showed that under a particular combination of treatment parameters, a hydrophobic surface was achieved on the APP treated sample with sessile drop static contact angle of 138°. The hydrophobic surface is stable without hydrophilic recovery 30 days after plasma treatment

Surface modification of biphasic calcium phosphate scaffolds by non-thermal atmospheric pressure nitrogen and air plasma treatment for improving osteoblast attachment and proliferation

International Nuclear Information System (INIS)

Choi, Yu-Ri; Kwon, Jae-Sung; Song, Doo-Hoon; Choi, Eun Ha; Lee, Yong-Keun; Kim, Kyoung-Nam; Kim, Kwang-Mahn

2013-01-01

Surface modifications induced by non-thermal plasma have been used extensively in biomedical applications. The attachment and proliferation of osteoblast cells are important in bone tissue engineering using scaffolds. Hence the effect of non-thermal plasma on hydroxyapatite/β-tri-calcium phosphate (HA/β-TCP) scaffolds in terms of improving osteoblast attachment and proliferation was investigated. Experimental groups were treated with non-thermal plasma for 10 min and 20 min and a control group was not treated with non-thermal plasma. For surface chemistry analysis, X-ray photoelectron spectroscopy (XPS) analysis was carried out. The hydrophilicity was determined from contact angle measurement on the surface. Atomic force microscopy analysis (AFM) was used to test the change in surface roughness and cell attachment and proliferation were evaluated using MC3T3-E1 osteoblast cells. XPS spectra revealed a decreased amount of carbon on the surface of the plasma-treated sample. The contact angle was also decreased following plasma treatment, indicating improved hydrophilicity of plasma-treated surfaces compared to the untreated disc. A significant increase in MC3T3E-1 cell attachment and proliferation was noted on plasma-treated samples as compared to untreated specimens. The results suggest that non-thermal atmospheric pressure nitrogen and air plasma treatments provide beneficial surface characteristics on HA/β-TCP scaffolds. - Highlights: ► Non-thermal plasma increased OH- and decreased C on biphasic scaffold. ► Non-thermal plasma had no effect on surface roughness. ► Non-thermal plasma resulted in hydrophilic surface. ► Non-thermal plasma resulted in better cell attachment and proliferation. ► Non-thermal plasma treatment on biphasic scaffold is useful for tissue engineering

Atmospheric pressure plasma surface modification of carbon fibres

DEFF Research Database (Denmark)

Kusano, Yukihiro; Løgstrup Andersen, Tom; Michelsen, Poul

2008-01-01

Carbon fibres are continuously treated with dielectric barrier discharge plasma at atmospheric pressure in various gas conditions for adhesion improvement in mind. An x-ray photoelectron spectroscopic analysis indicated that oxygen is effectively introduced onto the carbon fibre surfaces by He, He...

Accelerated differentiation of osteoblast cells on polycaprolactone scaffolds driven by a combined effect of protein coating and plasma modification

Energy Technology Data Exchange (ETDEWEB)

Yildirim, Eda D; Gueceri, Selcuk; Sun, Wei [Department of Mechanical Engineering and Mechanics, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States); Besunder, Robyn; Allen, Fred [Drexel University, School of Biomedical Engineering Science and Health System, 3141 Chestnut Street, Philadelphia, PA 19104 (United States); Pappas, Daphne, E-mail: edy22@drexel.ed [Army Research Laboratory, Aberdeen Proving Ground, MD 21005 (United States)

2010-03-15

A combined effect of protein coating and plasma modification on the quality of the osteoblast-scaffold interaction was investigated. Three-dimensional polycaprolactone (PCL) scaffolds were manufactured by the precision extrusion deposition (PED) system. The structural, physical, chemical and biological cues were introduced to the surface through providing 3D structure, coating with adhesive protein fibronectin and modifying the surface with oxygen-based plasma. The changes in the surface properties of PCL after those modifications were examined by contact angle goniometry, surface energy calculation, surface chemistry analysis (XPS) and surface topography measurements (AFM). The effects of modification techniques on osteoblast short-term and long-term functions were examined by cell adhesion, proliferation assays and differentiation markers, namely alkaline phosphatase activity (ALP) and osteocalcin secretion. The results suggested that the physical and chemical cues introduced by plasma modification might be sufficient for improved cell adhesion, but for accelerated osteoblast differentiation the synergetic effects of structural, physical, chemical and biological cues should be introduced to the PCL surface.

Use of Atmospheric-Pressure Plasma Jet for Polymer Surface Modification: An Overview

Energy Technology Data Exchange (ETDEWEB)

Kuettner, Lindsey A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-03-16

Atmospheric-pressure plasma jets (APPJs) are playing an increasingly important role in materials processing procedures. Plasma treatment is a useful tool to modify surface properties of materials, especially polymers. Plasma reacts with polymer surfaces in numerous ways thus the type of process gas and plasma conditions must be explored for chosen substrates and materials to maximize desired properties. This report discusses plasma treatments and looks further into atmospheric-pressure plasma jets and the effects of gases and plasma conditions. Following the short literature review, a general overview of the future work and research at Los Alamos National Laboratory (LANL) is discussed.

A combination of CO{sub 2} laser and plasma surface modification of poly(etheretherketone) to enhance osteoblast response

Energy Technology Data Exchange (ETDEWEB)

Zheng, Yanyan [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Xiong, Chengdong [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041 (China); Wang, Zhecun [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Li, Xiaoyu [State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041 (China); Zhang, Lifang, E-mail: zhanglfcioc@163.com [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041 (China)

2015-07-30

Highlights: • COOH and microgrooves containing micropores or microcraters structure were constructed on PEEK surface by a combination of CO{sub 2} laser and plasma treatment. • The mechanical properties of PEEK are maintained after single or dual surface treatment. • Pre-osteoblast cells (MC3T3-E1) adhesion, spreading and proliferation were improved remarkably on dual treated PEEK surface. • Cell pseudopodia protrude into the micropores or microcraters, in favor of forming firmer bone-implant integration. - Abstract: Poly(etheretherketone) (PEEK) is a rigid semicrystalline polymer that combines excellent mechanical properties, broad chemical resistance and bone-like stiffness and is widely used in biomedical fields. However, the bio-inert surface of PEEK tends to hinder its biomedical applications when direct osteointegration between the implants and the host tissue is desired. In this work, we demonstrate a dual modification method, which combines the laser and plasma surface treatment to combine advantages of both chemical states and microstructures for osteoblasts responses. While the plasma treatment introduces surface carboxyl groups (−COOH) onto PEEK surface, the laser treatment constructs microstructures over the PEEK surface. Our results indicated that −COOH as well as microgrooves containing micropores or microcraters structure are constructed on PEEK surface and plasma treatment has no apparent effect on the morphology of microstructures produced by laser micromachining. Unexpectedly, the superior mechanical properties of PEEK were maintained irrespective of the treatment used. Compared to native PEEK and single treated PEEK, dual modified PEEK is more favorable for pre-osteoblasts (MC3T3-E1) adhesion, spreading and proliferation. Moreover, cell pseudopodia protrude into the micropores or microcraters, in favor of forming firmer bone-implant integration. Our study illustrates enhanced osteoblasts responses to dual treated PEEK surface, which

Application of MEVVA discharge to material surface modification

International Nuclear Information System (INIS)

Gao Yu; Geng Man; Huang Yuming; Gong Xiaorong; Yu Yijun; Tang Deli; Tie Jun

1996-01-01

The authors describes some characteristics of the MEVVA discharge, the process of generating a cathode-arc plasma and the advantages of the MEVVA discharge compared with the kind of heating-vaporizing-ionizing source. Some practical parameters and the operating process of the MEVVA ion source as well as a plasma source with MEVVA discharge used in a PSII device are presented. Various plasmas having good-quality and high-performance are obtained with MEVVA discharges and have been widely used in sight-line processing and omnibearing ion implantation for material surface modification

Surface modification of fluorosilicone acrylate RGP contact lens via low-temperature argon plasma

International Nuclear Information System (INIS)

Yin Shiheng; Wang Yingjun; Ren Li; Zhao Lianna; Kuang Tongchun; Chen Hao; Qu Jia

2008-01-01

A fluorosilicone acrylate rigid gas permeable (RGP) contact lens was modified via argon plasma to improve surface hydrophilicity and resistance to protein deposition. The influence of plasma treatment on surface chemical structure, hydrophilicity and morphology of RGP lens was investigated by X-ray photoelectron spectrometer (XPS), contact angle measurements and scanning electron microscope (SEM), respectively. The contact angle results showed that the hydrophilicity of the contact lens was improved after plasma treatment. XPS results indicated that the incorporation of oxygen-containing groups on surface and the transformation of silicone into hydrophilic silicate after plasma treatment are the main reasons for the surface hydrophilicity improvement. SEM results showed that argon plasma with higher power could lead to surface etching

Gas-discharge plasma processes for surface modification and conversion of chemical substances. Application for fuel cells

Energy Technology Data Exchange (ETDEWEB)

Schroeder, K.; Meyer, D.; Rohland, B.; Heintze, M.; Zahn, R.J.; Hannemann, M.; Meusinger, J.; Ohl, A. [Institute of Non-Thermal Plasma Physics, Greifswald (Germany)]|[Gesellschaft fuer Angewandte Technik mbH Greifswald (Germany)]|[GAPC, Adam Opel AG, IPC, Ruesselsheim (Germany)

2001-07-01

The potential of plasma processes towards hydrogen and fuel cell technology will be demonstrated by two examples with preliminary results: 1. plasma modification of polymer electrolyte membranes for direct methanol fuel cells, and 2. plasma supported steam reforming.

Plasma surface modification of polypropylene track-etched membrane to improve its performance properties

Science.gov (United States)

Kravets, L. I.; Elinson, V. M.; Ibragimov, R. G.; Mitu, B.; Dinescu, G.

2018-02-01

The surface and electrochemical properties of polypropylene track-etched membrane treated by plasma of nitrogen, air and oxygen are studied. The effect of the plasma-forming gas composition on the surface morphology is considered. It has been found that the micro-relief of the membrane surface formed under the gas-discharge etching, changes. Moreover, the effect of the non-polymerizing gas plasma leads to formation of oxygen-containing functional groups, mostly carbonyl and carboxyl. It is shown that due to the formation of polar groups on the surface and its higher roughness, the wettability of the plasma-modified membranes improves. In addition, the presence of polar groups on the membrane surface layer modifies its electrochemical properties so that conductivity of plasma-treated membranes increase.

Surface characterization of alloy Ti-6Al-7Nb treated plasma

International Nuclear Information System (INIS)

Moura, J.K.L.; Macedo, H.R.A.; Brito, E.M.; Brandim, A.S.

2014-01-01

Plasma surface modifications are subject of numerous studies to improve the quality of a given material. Titanium and its alloys are widely used in biomedical applications and plasma treatment technique is increasingly used to improve the surface properties thereof. The research have a objective in the comparative analysis of the change in microstructure of Ti-6Al-7Nb alloys after treatment of plasma nitriding. The technical are: nitriding with cathode cage (NGC) and planar discharge. The characterization was obtained by MEV (Scanning Electronic Microscope) and hardness. The results was compared about the better surface modification that meets future prospects of the biocompatibility of the alloy.(author)

TEXTILE SURFACE MODIFICATION BY PYHSICAL VAPOR DEPOSITION – (REVIEW

Directory of Open Access Journals (Sweden)

YUCE Ismail

2017-05-01

Full Text Available Textile products are used in various branches of the industry from automotive to space products. Textiles produced for industrial use are generally referred to as technical textiles. Technical textiles are nowadays applied to several areas including transportation, medicine, agriculture, protection, sports, packaging, civil engineering and industry. There are rapid developments in the types of materials used in technical textiles. Therefore, modification and functionalization of textile surfaces is becoming more crucial. The improvements of the properties such as anti-bacterial properties, fire resistivity, UV radiation resistance, electrical conductivity, self cleaning, and super hydrophobic, is getting more concern with respect to developments in textile engineering. The properties of textile surfaces are closely related to the fiber structure, the differences in the polymer composition, the fiber mixture ratio, and the physical and chemical processes applied. Textile surface modifications can be examined in four groups under the name mechanical, chemical, burning and plasma. Surface modifications are made to improve the functionality of textile products. Textile surface modifications affect the properties of the products such as softness, adhesion and wettability. The purpose of this work is to reveal varieties of vapor deposition modifications to improve functionality. For this purpose, the pyhsical vapor deposition methods, their affects on textile products and their end-uses will be reviewed.

Modification of glassy carbon surfaces by atmospheric pressure cold plasma torch

DEFF Research Database (Denmark)

Mortensen, Henrik Junge; Kusano, Yukihiro; Leipold, Frank

2006-01-01

The effect of plasma treatment on glassy carbon (GC) surfaces was studied with adhesion improvement in mind. A newly constructed remote plasma source was used to treat GC plates. Pure He and a dilute NH3/He mixture were used as feed gases. Optical emission spectroscopy was performed for plasma to...

Microchannel-flowed-plasma modification of octadecyltrichlorosilane self-assembled-monolayers for liquid crystal alignment

International Nuclear Information System (INIS)

Zheng, W.; Chiang, C.-Y.; Underwood, I.

2013-01-01

We report that a chemical patterning technique based on local plasma modification of self-assembled monolayers has been utilized to fabricate surfaces for domain liquid crystal alignment. Highly hydrophobic octadecyltrichlorosilane monolayers deposited on glass substrates coated with Indium-Tin-Oxide were brought into contact with elastomeric stamps comprising trenches on a micro scale, and then exposed to an oxygen plasma. In the regions exposed to the plasma the monolayer was etched away leaving a patterned surface that exhibited surface energy differences between surface domains. The surfaces that bear the micropatterns have been shown to be capable of producing patterned alignment of nematic liquid crystal. - Highlights: • Chemical surface-patterning is used to fabricate liquid crystal alignment surface. • Highly hydrophobic octadecyltrichlorosilane monolayer is deposited on substrate. • O 2 plasma flow is used to etch the monolayer to form patterned surface. • The patterned surface exhibits surface energy differences between surface domains. • The surface borne the micropatterns is capable of domain liquid crystal alignment

Ion-Induced Surface Modification of Magnetically Operated Contacts

Directory of Open Access Journals (Sweden)

Karen Arushanov

2012-02-01

Full Text Available A study has been made of permalloy (iron-nickel contacts of reed switches before and after ion-induced surface modification using atomic force and optical microscopy, Auger electron and X-ray photoelectron spectroscopy. It has been found that the formation of surface nitride layers enhances corrosion and erosion resistance of contacts. We proposed to produce such layers directly into sealed reed switches by means of pulsing glow-discharge nitrogen plasma.

Surface modification of polyester synthetic leather with tetramethylsilane by atmospheric pressure plasma

Science.gov (United States)

Kan, C. W.; Kwong, C. H.; Ng, S. P.

2015-08-01

Much works have been done on synthetic materials but scarcely on synthetic leather owing to its surface structures in terms of porosity and roughness. This paper examines the use of atmospheric pressure plasma (APP) treatment for improving the surface performance of polyester synthetic leather by use of a precursor, tetramethylsilane (TMS). Plasma deposition is regarded as an effective, simple and single-step method with low pollution. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) confirm the deposition of organosilanes on the sample's surface. The results showed that under a particular combination of treatment parameters, a hydrophobic surface was achieved on the APP treated sample with sessile drop static contact angle of 138°. The hydrophobic surface is stable without hydrophilic recovery 30 days after plasma treatment.

Investigation of helium plasma stream parameters in experiments on surface modification

International Nuclear Information System (INIS)

Bandura, A.N.; Byrka, O.V.; Chebotarev, V.V.; Garkusha, I.E.; Tsarenko, A.V. and eds.

2005-01-01

The main objection of this study is adjustment of plasma treatment regimes for different materials that allows achieving optimal thickness of modified layer with simultaneously minimal value of surface roughness. With use of optical spectroscopy, detailed information about the basic plasma parameters - electron density, electron and ion temperatures, plasma stream duration and velocity, was obtained. Integrated spectra of plasma radiation were analyzed. The majority of helium and impurity spectral lines were investigated on a subject of Stark broadening. Plasma pressure and energy density values measured with piezodetectors and calorimeters are in good agreement with plasma parameters obtained by optical techniques

Modification of ink-jet paper by oxygen-plasma treatment

Energy Technology Data Exchange (ETDEWEB)

Vesel, A [Jozef Stefan Institute, Jamova 39, Ljubljana 1000 (Slovenia); Mozetic, M [Jozef Stefan Institute, Jamova 39, Ljubljana 1000 (Slovenia); Hladnik, A [Pulp and Paper Institute, Bogisiceva 8, Ljubljana 1001 (Slovenia); Dolenc, J [Pulp and Paper Institute, Bogisiceva 8, Ljubljana 1001 (Slovenia); Zule, J [Pulp and Paper Institute, Bogisiceva 8, Ljubljana 1001 (Slovenia); Milosevic, S [Institute of Physics, Bijenicka 46, Zagreb 10000 (Croatia); Krstulovic, N [Institute of Physics, Bijenicka 46, Zagreb 10000 (Croatia); Klanjsek-Gunde, M [National Institute of Chemistry, Hajdrihova 19, Ljubljana 1000 (Slovenia); Hauptmann, N [National Institute of Chemistry, Hajdrihova 19, Ljubljana 1000 (Slovenia)

2007-06-21

A study on oxygen-plasma treatment of ink-jet paper is presented. Paper was exposed to a weakly ionized, highly dissociated oxygen plasma with an electron temperature of 5 eV, a positive-ion density of 8 x 10{sup 15} m{sup -3} and a density of neutral oxygen atoms of 5 x 10{sup 21} m{sup -3}. Optical emission spectroscopy (OES) was applied as a method for detection of the reaction products during the plasma treatment of the paper. OES spectra between 250 and 1000 nm were measured continuously during the plasma treatment. The wettability of the samples before and after the plasma treatment was determined by measuring the contact angle of a water drop. The appearance of the surface-functional groups was determined by using high-resolution x-ray photoelectron spectroscopy (XPS), while changes in the surface morphology were monitored with scanning electron microscopy (SEM). Already after 1 s of the plasma treatment the surface, which was originally hydrophobic, changed to hydrophilic, as indicated by a high absorption rate of a water drop into the paper. The OES showed a rapid increase of the CO and OH bands for the first few seconds of the plasma treatment, followed by a slow decrease during the next 40 s. The intensity of the O atom line showed reversed behaviour. The XPS analyses showed a gradual increase of oxygen-rich functional groups on the surface, while SEM analyses did not show significant modification of the morphology during the first 10 s of the plasma treatment. The results were explained by degradation of the alkyl ketene dimer sizing agent during the first few seconds of the oxygen-plasma treatment.

Modification of ink-jet paper by oxygen-plasma treatment

International Nuclear Information System (INIS)

Vesel, A; Mozetic, M; Hladnik, A; Dolenc, J; Zule, J; Milosevic, S; Krstulovic, N; Klanjsek-Gunde, M; Hauptmann, N

2007-01-01

A study on oxygen-plasma treatment of ink-jet paper is presented. Paper was exposed to a weakly ionized, highly dissociated oxygen plasma with an electron temperature of 5 eV, a positive-ion density of 8 x 10 15 m -3 and a density of neutral oxygen atoms of 5 x 10 21 m -3 . Optical emission spectroscopy (OES) was applied as a method for detection of the reaction products during the plasma treatment of the paper. OES spectra between 250 and 1000 nm were measured continuously during the plasma treatment. The wettability of the samples before and after the plasma treatment was determined by measuring the contact angle of a water drop. The appearance of the surface-functional groups was determined by using high-resolution x-ray photoelectron spectroscopy (XPS), while changes in the surface morphology were monitored with scanning electron microscopy (SEM). Already after 1 s of the plasma treatment the surface, which was originally hydrophobic, changed to hydrophilic, as indicated by a high absorption rate of a water drop into the paper. The OES showed a rapid increase of the CO and OH bands for the first few seconds of the plasma treatment, followed by a slow decrease during the next 40 s. The intensity of the O atom line showed reversed behaviour. The XPS analyses showed a gradual increase of oxygen-rich functional groups on the surface, while SEM analyses did not show significant modification of the morphology during the first 10 s of the plasma treatment. The results were explained by degradation of the alkyl ketene dimer sizing agent during the first few seconds of the oxygen-plasma treatment

21 CFR 640.74 - Modification of Source Plasma.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Modification of Source Plasma. 640.74 Section 640...) BIOLOGICS ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.74 Modification of Source Plasma. (a) Upon approval by the Director, Center for Biologics Evaluation and Research, Food and...

Plasma Surface interaction in Controlled fusion devices

International Nuclear Information System (INIS)

1990-05-01

The subjects presented in the 9th conference on plasma surface interaction in controlled fusion devices were: the modifications of power scrape-off-length and power deposition during various configurations in Tore Supra plasmas; the effects observed in ergodic divertor experiments in Tore-Supra; the diffuse connexion induced by the ergodic divertor and the topology of the heat load patterns on the plasma facing components in Tore-Supra; the study of the influence of air exposure on graphite implanted by low energy high density deuterium plasma

Microwave and plasma-assisted modification of composite fiber surface topography

Science.gov (United States)

Paulauskas, Felix L [Knoxville, TN; White, Terry L [Knoxville, TN; Bigelow, Timothy S [Knoxville, TN

2003-02-04

The present invention introduces a novel method for producing an undulated surface on composite fibers using plasma technology and microwave radiation. The undulated surface improves the mechanical interlocking of the fibers to composite resins and enhances the mechanical strength and interfacial sheer strength of the composites in which they are introduced.

Stem cell responses to plasma surface modified electrospun polyurethane scaffolds.

Science.gov (United States)

Zandén, Carl; Hellström Erkenstam, Nina; Padel, Thomas; Wittgenstein, Julia; Liu, Johan; Kuhn, H Georg

2014-07-01

The topographical effects from functional materials on stem cell behavior are currently of interest in tissue engineering and regenerative medicine. Here we investigate the influence of argon, oxygen, and hydrogen plasma surface modification of electrospun polyurethane fibers on human embryonic stem cell (hESC) and rat postnatal neural stem cell (NSC) responses. The plasma gases were found to induce three combinations of fiber surface functionalities and roughness textures. On randomly oriented fibers, plasma treatments lead to substantially increased hESC attachment and proliferation as compared to native fibers. Argon plasma was found to induce the most optimal combination of surface functionality and roughness for cell expansion. Contact guided migration of cells and alignment of cell processes were observed on aligned fibers. Neuronal differentiation around 5% was found for all samples and was not significantly affected by the induced variations of surface functional group distribution or individual fiber topography. In this study the influence of argon, oxygen, and hydrogen plasma surface modification of electrospun polyurethane fibers on human embryonic stem cell and rat postnatal neural stem cell (NSC) responses is studied with the goal of clarifying the potential effects of functional materials on stem cell behavior, a topic of substantial interest in tissue engineering and regenerative medicine. Copyright © 2014 Elsevier Inc. All rights reserved.

Investigation the effects of metallic substrate surfaces due to ion-plasma treatment

International Nuclear Information System (INIS)

Shulaev, V.M.; Taran, V.S.; Timoshenko, A.I.; Gasilin, V.V.

2011-01-01

It has been found correlation between modification effects and duration of ion-plasma cleaning the substrate surface with titanium ions. Experiments were carried out using serial vacuum-arc equipment ''Bulat-6'' at the stationary mode in non-filtered titanium plasma, which contained considerable quantity of evaporated material droplets. The polished cylinder substrates (diameter and height 9,14,20 mm) have been treated. The substrates were manufactured of stainless steel 12X18H10T and non-oxygen copper M00b. The substrates surface roughness after ion-plasma treatment has been investigated with electron microscope JEOL JSM-840 and optic interference non-contact profilograph- profilometer ''Micron-alpha''. According obtained results the surface of copper and stainless steel substrates has been treated to intensive modification, i.e. substrate surface after treatment significantly differs from initial one. During final ion-plasma treatment a number of effects occur: purification from surface oxides is accompanied with metallic surface ''contamination'' by the cathode material macrodroplets, surface micromelting accompanied by roughness increase, the surface layer annealing with noticeable decrease of hardness.

Laser surface modification of Yttria Stabilized Zirconia (YSZ) thermal barrier coating on AISI H13 tool steel substrate

Science.gov (United States)

Reza, M. S.; Aqida, S. N.; Ismail, I.

2018-03-01

This paper presents laser surface modification of plasma sprayed yttria stabilized zirconia (YSZ) coating to seal porosity defect. Laser surface modification on plasma sprayed YSZ was conducted using 300W JK300HPS Nd: YAG laser at different operating parameters. Parameters varied were laser power and pulse frequency with constant residence time. The coating thickness was measured using IM7000 inverted optical microscope and surface roughness was analysed using two-dimensional Mitutoyo Surface Roughness Tester. Surface roughness of laser surface modification of YSZ H-13 tool steel decreased significantly with increasing laser power and decreasing pulse frequency. The re-melted YSZ coating showed higher hardness properties compared to as-sprayed coating surface. These findings were significant to enhance thermal barrier coating surface integrity for dies in semi-solid processing.

Hemocompatibility and oxygenation performance of polysulfone membranes grafted with polyethylene glycol and heparin by plasma-induced surface modification.

Science.gov (United States)

Wang, Weiping; Zheng, Zhi; Huang, Xin; Fan, Wenling; Yu, Wenkui; Zhang, Zhibing; Li, Lei; Mao, Chun

2017-10-01

Polyethylene glycol (PEG) and heparin (Hep) were grafted onto polysulfone (PSF) membrane by plasma-induced surface modification to prepare PSF-PEG-Hep membranes used for artificial lung. The effects of plasma treatment parameters, including power, gas type, gas flow rate, and treatment time, were investigated, and different PEG chains were bonded covalently onto the surface in the postplasma grafting process. Membrane surfaces were characterized by water contact angle, PEG grafting degree, attenuated total reflectance-Fourier transform infrared spectroscopy, ultraviolet-visible spectrophotometry, X-ray photoelectron spectroscopy, critical water permeability pressure, and scanning electron microscopy. Protein adsorption, platelet adhesion, and coagulation tests showed significant improvement in the hemocompatibility of PSF-PEG-Hep membranes compared to pristine PSF membrane. Gas exchange tests through PSF-PEG6000-Hep membrane showed that when the flow rate of porcine blood reached 5.0 L/min, the permeation fluxes of O 2 and CO 2 reached 192.6 and 166.9 mL/min, respectively, which were close to the gas exchange capacity of a commercial membrane oxygenator. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1737-1746, 2017. © 2016 Wiley Periodicals, Inc.

Tribocorrosion studies of metallic biomaterials: The effect of plasma nitriding and DLC surface modifications.

Science.gov (United States)

Zhao, Guo-Hua; Aune, Ragnhild E; Espallargas, Nuria

2016-10-01

The medical grade pure titanium, stainless steel and CoCrMo alloy have been utilized as biomaterials for load-bearing orthopedic prosthesis. The conventional surgery metals suffer from a combined effect of wear and corrosion once they are implanted, which may significantly accelerate the material degradation process. In this work, the tribocorrosion performance of the metallic biomaterials with different surface modifications was studied in the simulated body fluid for the purpose of investigating the effect of the surface treatments on the tribocorrosion performance and eventually finding the most suitable implantation materials. The metals were subjected to surface modifications by plasma nitriding in different treatment temperatures or physical vapor deposition (PVD) to produce diamond-like carbon (DLC) coating, respectively. The dry wear and tribocorrosion properties of the samples were evaluated by using a reciprocating ball-on-disc tribometer equipped with an electrochemical cell. Prior to the tribocorrosion tests, their electrochemical behavior was measured by the potentiodynamic polarization in phosphate buffer saline (PBS) solution at room temperature. Both stainless steel and CoCrMo after low temperature nitriding kept their passive nature by forming an expanded austenite phase. The DLC coated samples presented the low anodic corrosion current due to the chemical inertness of the carbon layer. During the tribocorrosion tests at open circuit potential, the untreated and low temperature nitrided samples exhibited significant potential drop towards the cathodic direction, which was a result of the worn out of the passive film. Galvanic coupling was established between the depassivated (worn) area and the still passive (unworn) area, making the materials suffered from wear-accelerated corrosion. The DLC coating performed as a solid lubricant in both dry wear and tribocorrosion tests, and the resulting wear after the tests was almost negligible. Copyright �

Surface modification by EUV laser beam based on capillary discharge

Czech Academy of Sciences Publication Activity Database

Frolov, Oleksandr; Koláček, Karel; Schmidt, Jiří; Štraus, Jaroslav; Prukner, Václav; Shukurov, A.

-, č. 58 (2011), s. 484-487 ISSN 2010-376X. [International Conference on Fusion and Plasma Physics. Bali, Indonésie, 26.10.2011-28.10.2011] R&D Projects: GA AV ČR KAN300100702; GA MŠk LA08024; GA MŠk(CZ) LC528 Institutional research plan: CEZ:AV0Z20430508 Keywords : soft x-ray * EUV * laser * radiation * source * capillary * discharge * plasma * ablation * surface modification Subject RIV: BL - Plasma and Gas Discharge Physics http://www.waset.org/journals/waset/v58/v58-99.pdf

Surface modification of argon/oxygen plasma treated vulcanized ethylene propylene diene polymethylene surfaces for improved adhesion with natural rubber

International Nuclear Information System (INIS)

Basak, Ganesh C.; Bandyopadhyay, Abhijit; Neogi, Sudarsan; Bhowmick, Anil K.

2011-01-01

Vulcanized ethylene propylene diene polymethylene (EPDM) rubber surface was treated in a radio frequency capacitatively coupled low pressure argon/oxygen plasma to improve adhesion with compounded natural rubber (NR) during co-vulcanization. The plasma modified surfaces were analyzed by means of contact angle measurement, surface energy, attenuated total reflection-infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, energy dispersive X-ray sulfur mapping and atomic force microscopy. Several experimental variables such as plasma power, length of exposure time and composition of the argon-oxygen gas mixture were considered. It was delineated that plasma treatment changed both surface composition and roughness, and consequently increased peel strength. The change in surface composition was mainly ascribed to the formation of C-O and -C=O functional groups on the vulcanized surfaces. A maximum of 98% improvement in peel strength was observed after plasma treatment.

Surface modification of argon/oxygen plasma treated vulcanized ethylene propylene diene polymethylene surfaces for improved adhesion with natural rubber

Energy Technology Data Exchange (ETDEWEB)

Basak, Ganesh C. [Rubber Technology Centre, Indian Institute of Technology, Kharagpur 721302 (India); Bandyopadhyay, Abhijit [Department of Polymer Science and Technology, University of Calcutta, Calcutta 700 009 (India); Neogi, Sudarsan [Department of Chemical Engineering, Indian Institute of Technology, Kharagpur 721302 (India); Bhowmick, Anil K., E-mail: anilkb@rtc.iitkgp.ernet.in [Rubber Technology Centre, Indian Institute of Technology, Kharagpur 721302 (India)

2011-01-15

Vulcanized ethylene propylene diene polymethylene (EPDM) rubber surface was treated in a radio frequency capacitatively coupled low pressure argon/oxygen plasma to improve adhesion with compounded natural rubber (NR) during co-vulcanization. The plasma modified surfaces were analyzed by means of contact angle measurement, surface energy, attenuated total reflection-infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, energy dispersive X-ray sulfur mapping and atomic force microscopy. Several experimental variables such as plasma power, length of exposure time and composition of the argon-oxygen gas mixture were considered. It was delineated that plasma treatment changed both surface composition and roughness, and consequently increased peel strength. The change in surface composition was mainly ascribed to the formation of C-O and -C=O functional groups on the vulcanized surfaces. A maximum of 98% improvement in peel strength was observed after plasma treatment.

Influence of ECR-RF plasma modification on surface and thermal properties of polyester copolymer

Directory of Open Access Journals (Sweden)

Fray Miroslawa El

2015-12-01

Full Text Available In this paper we report a study on influence of radio-frequency (RF plasma induced with electron cyclotron resonance (ECR on multiblock copolymer containing butylene terephthalate hard segments (PBT and butylene dilinoleate (BDLA soft segments. The changes in thermal properties were studied by DSC. The changes in wettability of PBT-BDLA surfaces were studied by water contact angle (WCA. We found that ECR-RF plasma surface treatment for 60 s led to decrease of WCA, while prolonged exposure of plasma led to increase of WCA after N2 and N2O2 treatment up to 70°–80°. The O2 reduced the WCA to 50°–56°. IR measurements confirmed that the N2O2 plasma led to formation of polar groups. SEM investigations showed that plasma treatment led to minor surfaces changes. Collectively, plasma treatment, especially O2, induced surface hydrophilicity what could be beneficial for increased cell adhesion in future biomedical applications of these materials.

Surface modification of electrospun fibre meshes by oxygen plasma for bone regeneration

International Nuclear Information System (INIS)

Nandakumar, A; Tahmasebi Birgani, Z; Santos, D; Mentink, A; Auffermann, N; Moroni, L; Van Blitterswijk, C; Habibovic, P; Van der Werf, K; Bennink, M

2013-01-01

Plasma treatment is a method to modify the physicochemical properties of biomaterials, which consequently may affect interactions with cells. Based on the rationale that physical cues on the surface of culture substrates and implants, such as surface roughness, have proven to alter cell behaviour, we used electrospinning to fabricate fibrous three-dimensional scaffolds made of a poly (ethylene oxide terephthalate)/poly (butylene terephthalate) copolymer to mimic the physical microenvironment of extracellular matrix and applied radio-frequency oxygen plasma treatment to create nanoscale roughness. Scanning electron microscopy (SEM) analysis revealed a fibre diameter of 5.49 ± 0.96 µm for as-spun meshes. Atomic force microscopy (AFM) measurements determined an exponential increase of surface roughness with plasma treatment time. An increase in hydrophilicity after plasma treatment was observed, which was associated with higher oxygen content in plasma treated scaffolds compared to untreated ones. A more pronounced adsorption of bovine serum albumin occurred on scaffolds treated with plasma for 15 and 30 min compared to untreated fibres. Clinically relevant human mesenchymal stromal cells (hMSCs) were cultured on untreated, 15 and 30 min treated scaffolds. SEM analysis confirmed cell attachment and a pronounced spindle-like morphology on all scaffolds. No significant differences were observed between different scaffolds regarding the amount of DNA, metabolic activity and alkaline phosphatase (ALP) activity after 7 days of culture. The amount of ALP positive cells increased between 7 and 21 days of culture on both untreated and 30 min treated meshes. In addition, ALP staining of cells on plasma treated meshes appeared more pronounced than on untreated meshes after 21 days of culture. Quantitative polymerase chain reaction showed significant upregulation of bone sialoprotein and osteonectin expression on oxygen plasma treated fibres compared to untreated fibres in

Plasma technology of the surface polymer activation

International Nuclear Information System (INIS)

Dutra, Jorge C.N.; Mello, Sandra C.; Massi, Marcos; Otani, Choyu; Maciel, Homero S.; Bittencourt, Edison

2005-01-01

A number of polymers, especially rubbers, require surface treatment to achieve a satisfactory level of adhesion. The surface of EPDM rubber vulcanized is high hydrophobicity and is not suited for a number of potential applications, in particular, for adhering to the polyurethane liner of solid rocket propellants. In this case, plasma treatment can be a very attractive process because it can efficiently increase the surface energy attributed to surface oxidation with the introduction of polar groups 1, 2. In order to investigate the influence of the parameters on the modifications of the treated surface samples of EPDM rubber by plasma generated by gas oxygen and argon, the water and methylene iodide contact angles were measured at room temperature with an image analyzing using the sessile drop technique 3 - 6 . (author)

Plasma surface interactions at the JET X-point tiles

International Nuclear Information System (INIS)

Martinelli, A.P.; Behrisch, R.; Coad, J.P.; Kock, L. de

1989-01-01

Operation with a magnetic divertor, which leads to a zero poloidal field inside the volume of the discharge vessel (the X-point) has led to substantial improvements in confinement time in JET. In this mode the diverted plasma is conducted to a large number of graphite tiles (X-point tiles) near the top of the vessel. The power handling capability of these tiles limits the maximum additional heating power to the discharge. The study of the surface modifications of the X-point tiles of JET is therefore of interest both to correlate the magnetic configuration and plasma particle and energy fluxes with the surface modifications, and also to get information about the erosion and deposition at these wall areas. (author) 5 refs., 4 figs

The modification of nanocomposite hybrid polymer surfaces by exposure to oxygen containing plasmas

Science.gov (United States)

Figueiredo, Ashley; Zimmermann, Katherine; Augustine, Brian; Hughes, Chris; Chusuei, Charles

2006-11-01

The wetting properties of the surfaces of the nanocomposite hybrid polymer poly[(propylmethacryl-heptaisobutyl- polyhedral oligomeric silsequioxane)-co-(methylmethacrylate)] (POSS-PMMA)has been studied before and after exposure to plasmas containing oxygen. The contact angle of water droplets on the surface showed a substantial decrease after plasma exposure indicating an increase in the hydrophilicity of the surface. A model was developed in which the plasma preferentially removed organic material including both the PMMA backbone and isobutyl groups from the corners of the POSS cages leaving behind a surface characterized by the silicon oxide-like POSS material. Measurements of surface concentrations of oxygen, silicon, and carbon by x-ray photoelectron spectroscopy (XPS) showed an increase in the amount of oxygen and silicon compared to carbon and the appropriate chemical shifts were observed in the XPS data to support the model of Si-O enrichment on the surface. Variable angle spectroscopic ellipsometry (VASE) and atomic force microscopy (AFM) measurements also supported the model and these results will be presented.

Tungsten and carbon surface change under high dose plasma exposure

International Nuclear Information System (INIS)

Martynenko, Y.V.; Khripunov, B.I.; Petrov, V.B.

2009-01-01

Study of surface composition dynamics has been made on the LENTA linear plasma simulator. Experiments have been made on tungsten and carbon materials subjected to steady-state plasma exposure. The achieved ion doses on the surface were 10 21 ion cm -2 . WL 10 tungsten containing 1% of La2O3 oxide and titanium-doped graphite RG-T were studied. The following experimental conditions were varied in these experiments: energy of ions, surface temperature, working gas. Irradiations of tungsten WL 10 were executed in deuterium plasma at low ion energies (about 20 eV) and at 200 eV for temperatures below 340 K. Graphite RG-T was exposed at 1300 K. Elevated surface temperature (about 1050K) was also characteristic of experiments on tungsten sample under nitrogen plasma impact (simulated inter-ELMs condition). Surface microstructure modification has been observed and surface composition changes were found on the materials showing influence of high dose plasma irradiations on element redistribution in the near surface layers. (author)

Nanoscale surface modifications to control capillary flow characteristics in PMMA microfluidic devices

Directory of Open Access Journals (Sweden)

Mukhopadhyay Subhadeep

2011-01-01

Full Text Available Abstract Polymethylmethacrylate (PMMA microfluidic devices have been fabricated using a hot embossing technique to incorporate micro-pillar features on the bottom wall of the device which when combined with either a plasma treatment or the coating of a diamond-like carbon (DLC film presents a range of surface modification profiles. Experimental results presented in detail the surface modifications in the form of distinct changes in the static water contact angle across a range from 44.3 to 81.2 when compared to pristine PMMA surfaces. Additionally, capillary flow of water (dyed to aid visualization through the microfluidic devices was recorded and analyzed to provide comparison data between filling time of a microfluidic chamber and surface modification characteristics, including the effects of surface energy and surface roughness on the microfluidic flow. We have experimentally demonstrated that fluid flow and thus filling time for the microfluidic device was significantly faster for the device with surface modifications that resulted in a lower static contact angle, and also that the incorporation of micro-pillars into a fluidic device increases the filling time when compared to comparative devices.

Hydrophilic surface modification of coronary stent using an atmospheric pressure plasma jet for endothelialization.

Science.gov (United States)

Shim, Jae Won; Bae, In-Ho; Park, Dae Sung; Lee, So-Youn; Jang, Eun-Jae; Lim, Kyung-Seob; Park, Jun-Kyu; Kim, Ju Han; Jeong, Myung Ho

2018-03-01

The first two authors contributed equally to this study. Bioactivity and cell adhesion properties are major factors for fabricating medical devices such as coronary stents. The aim of this study was to evaluate the advantages of atmospheric-pressure plasma jet in enhancing the biocompatibility and endothelial cell-favorites. The experimental objects were divided into before and after atmospheric-pressure plasma jet treatment with the ratio of nitrogen:argon = 3:1, which is similar to air. The treated surfaces were basically characterized by means of a contact angle analyzer for the activation property on their surfaces. The effect of atmospheric-pressure plasma jet on cellular response was examined by endothelial cell adhesion and XTT analysis. It was difficult to detect any changeable morphology after atmospheric-pressure plasma jet treatment on the surface. The roughness was increased after atmospheric-pressure plasma jet treatment compared to nonatmospheric-pressure plasma jet treatment (86.781 and 7.964 nm, respectively). The X-ray photoelectron spectroscopy results showed that the surface concentration of the C-O groups increased slightly from 6% to 8% after plasma activation. The contact angle dramatically decreased in the atmospheric-pressure plasma jet treated group (22.6 ± 15.26°) compared to the nonatmospheric-pressure plasma jet treated group (72.4 ± 15.26°) ( n = 10, p atmospheric-pressure plasma jet on endothelial cell migration and proliferation was 85.2% ± 12.01% and 34.2% ± 2.68%, respectively, at 7 days, compared to the nonatmospheric-pressure plasma jet treated group (58.2% ± 11.44% in migration, n = 10, p atmospheric-pressure plasma jet method. Moreover, the atmospheric-pressure plasma jet might affect re-endothelialization after stenting.

Recrystallization and modification of the stainless-steel surface relief under photonic heat load in powerful plasma discharges

Energy Technology Data Exchange (ETDEWEB)

Budaev, V. P., E-mail: budaev@mail.ru; Martynenko, Yu. V. [National Research Centre Kurchatov Institute (Russian Federation); Khimchenko, L. N. [Project Center ITER (Russian Federation); Zhitlukhin, A. M.; Klimov, N. S. [Troitsk Institute for Innovation and Fusion Research (Russian Federation); Pitts, R. A. [ITER Organization (France); Linke, J. [EURATOM Association, Forschungszentrum Jülich GmbH (Germany); Bazylev, B. [IHM, Karlsruhe Institute of Technology (Germany); Belova, N. E.; Karpov, A. V. [National Research Centre Kurchatov Institute (Russian Federation); Kovalenko, D. V.; Podkovyrov, V. L.; Yaroshevskaya, A. D. [Troitsk Institute for Innovation and Fusion Research (Russian Federation)

2013-11-15

Targets made of ITER-grade 316L(N)-IG stainless steel and Russian-grade 12Cr18Ni10Ti stainless steel with a close composition were exposed at the QSPA-T plasma gun to plasma photonic radiation pulses simulating conditions of disruption mitigation in ITER. After a large number of pulses, modification of the stainless-steel surface was observed, such as the formation of a wavy structure, irregular roughness, and cracks on the target surface. X-ray and optic microscopic analyses of targets revealed changes in the orientation and dimensions of crystallites (grains) over a depth of up to 20 μm for 316L(N)-IG stainless steel after 200 pulses and up to 40 μm for 12Cr18Ni10Ti stainless steel after 50 pulses, which is significantly larger than the depth of the layer melted in one pulse (∼10 μm). In a series of 200 tests of ITER-grade 316L(N)-IG ITER stainless steel, a linear increase in the height of irregularity (roughness) with increasing number of pulses at a rate of up to ∼1 μm per pulse was observed. No alteration in the chemical composition of the stainless-steel surface in the series of tests was revealed. A model is developed that describes the formation of wavy irregularities on the melted metal surface with allowance for the nonlinear stage of instability of the melted layer with a vapor/plasma flow above it. A decisive factor in this case is the viscous flow of the melted metal from the troughs to tops of the wavy structure. The model predicts saturation of the growth of the wavy structure when its amplitude becomes comparable with its wavelength. Approaches to describing the observed stochastic relief and roughness of the stainless-steel surface formed in the series of tests are considered. The recurrence of the melting-solidification process in which mechanisms of the hill growth compete with the spreading of the material from the hills can result in the formation of a stochastic relief.

Plasma surface functionalization and dyeing kinetics of Pan-Pmma copolymers

OpenAIRE

Labay, C.; Canal, C.; Rodríguez, C.; Caballero, G.; Canal, J.M.

2013-01-01

Fiber surface modification with air corona plasma has been studied through dyeing kinetics under isothermal conditions at 30 °C on an acrylic-fiber fabric with a cationic dye (CI Basic Blue 3) analyzing the absorption, desorption and fixing on the surface of molecules having defined cationic character. The initial dyeing rate in the first 60 s indicates an increase of 58.3% in the dyeing rate due to the effect of corona plasma on the acrylic fiber surface. At the end of the dyeing process...

Modification of preheated tungsten surface after irradiation at the GOL-3 facility

Energy Technology Data Exchange (ETDEWEB)

Shoshin, A.A., E-mail: shoshin@mail.ru [Budker Institute of Nuclear Physics SB RAS, Novosibirsk 630090 (Russian Federation); Novosibirsk State University, Novosibirsk 630090 (Russian Federation); Arakcheev, A.S.; Arzhannikov, A.V. [Budker Institute of Nuclear Physics SB RAS, Novosibirsk 630090 (Russian Federation); Novosibirsk State University, Novosibirsk 630090 (Russian Federation); Burdakov, A.V. [Budker Institute of Nuclear Physics SB RAS, Novosibirsk 630090 (Russian Federation); Novosibirsk State Technical University, Novosibirsk 630092 (Russian Federation); Huber, A. [Forschungszentrum Jülich GmbH, Institut für Energie- und Klimaforschung, 52425 Jülich (Germany); Ivanov, I.A. [Budker Institute of Nuclear Physics SB RAS, Novosibirsk 630090 (Russian Federation); Novosibirsk State University, Novosibirsk 630090 (Russian Federation); Kuklin, K.N. [Budker Institute of Nuclear Physics SB RAS, Novosibirsk 630090 (Russian Federation); Polosatkin, S.V.; Postupaev, V.V.; Sinitsky, S.L. [Budker Institute of Nuclear Physics SB RAS, Novosibirsk 630090 (Russian Federation); Novosibirsk State University, Novosibirsk 630090 (Russian Federation); Vasilyev, A.A. [Novosibirsk State University, Novosibirsk 630090 (Russian Federation)

2016-12-15

Highlights: • Preheated tungsten was irradiated at the GOL-3 facility with plasma loads corresponding to the ITER type I ELMs. • The crack pattern and the quantity of bubbles depend on the initial temperatures of the target. • The orientation of major crack networks correlates with the direction of machining of the samples. • Dust impact craters were found. - Abstract: The study is devoted to tungsten surface modification after irradiation at the GOL-3 facility with plasma loads corresponding to the ITER type I ELMs. In order to emulate heating with a steady plasma flux in the ITER divertor, some of the tungsten samples were preheated up to 500 °C. It was found out that the behavior of the surface modification (the crack pattern and the number of bubbles) depends on the initial temperature of the targets. While the orientation of major crack networks correlates with the direction of machining of the samples. Afterwards we have observed the process of craters’ formation caused by dust particle impacts.

Characterization of an atmospheric pressure air plasma source for polymer surface modification

Science.gov (United States)

Yang, Shujun; Tang, Jiansheng

2013-10-01

An atmospheric pressure air plasma source was generated through dielectric barrier discharge (DBD). It was used to modify polyethyleneterephthalate (PET) surfaces with very high throughput. An equivalent circuit model was used to calculate the peak average electron density. The emission spectrum from the plasma was taken and the main peaks in the spectrum were identified. The ozone density in the down plasma region was estimated by Absorption Spectroscopy. NSF and ARC-ODU

Surface modification of Ti-30Ta alloy by electrospun PCL deposition

Energy Technology Data Exchange (ETDEWEB)

Wada, C.M.; Rangel, A.L.R.; Souza, M.A. de; Claro, A.P.R.A.; Rezende, M.C.R. [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), SP (Brazil); Almeida, R. dos S. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil)

2014-07-01

Full text: Surface modifications techniques have been used for change the inert surface of the titanium alloys for better interaction. Ingots of the experimental alloy Ti30Ta were melted in an arc furnace and re-melted ten times at least. They were homogenized under vacuum at 1000 °C for 86. 4 ks to eliminate chemical segregation and cold-worked by swaging. Discs were immersed in aqueous NaOH solution for 24 h, dried at room temperature, immersed in HCl and dried at 40 °C in oven for 24 hours. Followed, PCL fibers were deposited on the Ti30Ta alloy discs surfaces by electrospinning. Plasma treatment was carried out for change PCL electrospun by using stainless steel plasma reactor. Samples were immersed in SBF 5x solution for apatite growth. Surfaces were evaluated by using SEM, X-rays diffraction and contact angle. Samples exhibited hydrophilic behavior after plasma treatment and SBF immersion. Results are very interesting for biomedical applications. (author)

Surface modification of Ti-30Ta alloy by electrospun PCL deposition

International Nuclear Information System (INIS)

Wada, C.M.; Rangel, A.L.R.; Souza, M.A. de; Claro, A.P.R.A.; Rezende, M.C.R.; Almeida, R. dos S.

2014-01-01

Full text: Surface modifications techniques have been used for change the inert surface of the titanium alloys for better interaction. Ingots of the experimental alloy Ti30Ta were melted in an arc furnace and re-melted ten times at least. They were homogenized under vacuum at 1000 °C for 86. 4 ks to eliminate chemical segregation and cold-worked by swaging. Discs were immersed in aqueous NaOH solution for 24 h, dried at room temperature, immersed in HCl and dried at 40 °C in oven for 24 hours. Followed, PCL fibers were deposited on the Ti30Ta alloy discs surfaces by electrospinning. Plasma treatment was carried out for change PCL electrospun by using stainless steel plasma reactor. Samples were immersed in SBF 5x solution for apatite growth. Surfaces were evaluated by using SEM, X-rays diffraction and contact angle. Samples exhibited hydrophilic behavior after plasma treatment and SBF immersion. Results are very interesting for biomedical applications. (author)

Effects of Surface Modification of Nanodiamond Particles for Nucleation Enhancement during Its Film Growth by Microwave Plasma Jet Chemical Vapour Deposition Technique

Directory of Open Access Journals (Sweden)

Chii-Ruey Lin

2014-01-01

Full Text Available The seedings of the substrate with a suspension of nanodiamond particles (NDPs were widely used as nucleation seeds to enhance the growth of nanostructured diamond films. The formation of agglomerates in the suspension of NDPs, however, may have adverse impact on the initial growth period. Therefore, this paper was aimed at the surface modification of the NDPs to enhance the diamond nucleation for the growth of nanocrystalline diamond films which could be used in photovoltaic applications. Hydrogen plasma, thermal, and surfactant treatment techniques were employed to improve the dispersion characteristics of detonation nanodiamond particles in aqueous media. The seeding of silicon substrate was then carried out with an optimized spin-coating method. The results of both Fourier transform infrared spectroscopy and dynamic light scattering measurements demonstrated that plasma treated diamond nanoparticles possessed polar surface functional groups and attained high dispersion in methanol. The nanocrystalline diamond films deposited by microwave plasma jet chemical vapour deposition exhibited extremely fine grain and high smooth surfaces (~6.4 nm rms on the whole film. These results indeed open up a prospect of nanocrystalline diamond films in solar cell applications.

Growth of surface structures correlated with structural and mechanical modifications of brass by laser-induced Si plasma ions implantation

Science.gov (United States)

Ahmad, Shahbaz; Bashir, Shazia; Rafique, M. Shahid; Yousaf, Daniel

2017-04-01

Laser-produced Si plasma is employed as an ion source for implantation on the brass substrate for its surface, structural, and mechanical modifications. Thomson parabola technique is employed for the measurement of energy and flux of Si ions using CR-39. In response to stepwise increase in number of laser pulses from 3000 to 12000, four brass substrates were implanted by laser-induced Si plasma ions of energy 290 keV at different fluxes ranging from 45 × 1012 to 75 × 1015 ions/cm2. SEM analysis reveals the formation of nano/micro-sized irregular shaped cavities and pores for the various ion fluxes for varying numbers of laser pulses from 3000 to 9000. At the maximum ion flux for 12,000 pulses, distinct and organized grains with hexagonal and irregular shaped morphology are revealed. X-ray diffractometer (XRD) analysis exhibits that a new phase of CuSi (311) is identified which confirms the implantation of Si ions in brass substrate. A significant decrease in mechanical properties of implanted brass, such as Yield Stress (YS), Ultimate Tensile Strength (UTS), and hardness, with increasing laser pulses from 3000 to 6000 is observed. However, with increasing laser pulses from 9000 to a maximum value of 12,000, an increase in mechanical properties like hardness, YS, and UTS is observed. The generation as well as annihilation of defects, recrystallization, and intermixing of Si precipitates with brass matrix is considered to be responsible for variations in surface, structural, and mechanical modifications of brass.

Micro glow plasma for localized nanostructural modification of carbon nanotube forest

Energy Technology Data Exchange (ETDEWEB)

Sarwar, Mirza Saquib us; Xiao, Zhiming; Saleh, Tanveer; Nojeh, Alireza; Takahata, Kenichi [University of British Columbia, Vancouver, British Columbia V6T 1Z4 (Canada)

2016-08-22

This paper reports the localized selective treatment of vertically aligned carbon nanotubes, or CNT forests, for radial size modification of the nanotubes through a micro-scale glow plasma established on the material. An atmospheric-pressure DC glow plasma is shown to be stably sustained on the surface of the CNT forest in argon using micromachined tungsten electrodes with diameters down to 100 μm. Experiments reveal thinning or thickening of the nanotubes under the micro glow depending on the process conditions including discharge current and process time. These thinning and thickening effects in the treated nanotubes are measured to be up to ∼30% and ∼300% in their diameter, respectively, under the tested conditions. The elemental and Raman analyses suggest that the treated region of the CNT forest is pure carbon and maintains a degree of crystallinity. The local plasma treatment process investigated may allow modification of material characteristics in different domains for targeted regions or patterns, potentially aiding custom design of micro-electro-mechanical systems and other emerging devices enabled by the CNT forest.

Surface stoichiometry modification and improved DC/RF characteristics by plasma treated and annealed AlGaN/GaN HEMTs

Science.gov (United States)

Upadhyay, Bhanu B.; Takhar, Kuldeep; Jha, Jaya; Ganguly, Swaroop; Saha, Dipankar

2018-03-01

We demonstrate that N2 and O2 plasma treatment followed by rapid thermal annealing leads to surface stoichiometry modification in a AlGaN/GaN high electron mobility transistor. Both the source/drain access and gate regions respond positively improving the transistor characteristics albeit to different extents. Characterizations indicate that the surface show the characteristics of that of a higher band-gap material like AlxOy and GaxOy along with N-vacancy in the sub-surface region. The N-vacancy leads to an increased two-dimensional electron gas density. The formation of oxides lead to a reduced gate leakage current and surface passivation. The DC characteristics show increased transconductance, saturation drain current, ON/OFF current ratio, sub-threshold swing and lower ON resistance by a factor of 2.9, 2.0, 103.3 , 2.3, and 2.1, respectively. The RF characteristics show an increase in unity current gain frequency by a factor of 1.7 for a 500 nm channel length device.

Improved adhesion of Ag NPs to the polyethylene terephthalate surface via atmospheric plasma treatment and surface functionalization

Science.gov (United States)

Shen, Tao; Liu, Yong; Zhu, Yan; Yang, De-Quan; Sacher, Edward

2017-07-01

Ag nanoparticles (NPs) have been widely applied, as important antibacterial materials, on textile and polymer surfaces. However, their adhesion to nonreactive polymer surfaces is generally too weak for many applications. Here, we propose a two-step process, atmospheric plasma treatment followed by a surface chemical modification process, which enhances their adhesion to polyethylene terephthalate (PET) surfaces. We found that, compared to either plasma treatments or surface chemical functionalizations, alone, this combination greatly enhanced their adhesion. The plasma treatment resulted in an increase of active sites (sbnd OH, sbnd CHdbnd O and COOH) at the PET surface, permitting increased bonding to 3-aminopropyltriethoxysilane (APTES), whose sbnd NH2 groups were then able to form a bonding complex with the Ag NPs.

Surface modification of cotton fabrics by gas plasmas for color strength and adhesion by inkjet ink printing

International Nuclear Information System (INIS)

Pransilp, Porntapin; Pruettiphap, Meshaya; Bhanthumnavin, Worawan; Paosawatyanyong, Boonchoat; Kiatkamjornwong, Suda

2016-01-01

Graphical abstract: - Highlights: • Both O_2 and N_2 plasma increased cotton surface wettability and higher K/S. • SF6 plasma gave hydrophobicity on cotton surface and increased contact angle to 138°. • Plasma treatment on cotton fabric produced surface roughness. • XPS confirmed the generation of new functional groups on cotton fabric. • Wettability and surface roughness controlled K/S and good ink adhesion. - Abstract: Surface properties of cotton fabric were modified by three types of gas plasma pretreatment, namely, oxygen (O_2), nitrogen (N_2) and sulfur hexafluoride (SF_6), to improve ink absorption of water-based pigmented inkjet inks and color reproduction of the treated surfaces. Effects of gas plasma exposure parameters of power, exposure time and gas pressure on surface physical and chemical properties of the treated fabrics were investigated. XPS (X-ray photoelectron spectroscopy) was used to identify changes in functional groups on the fabric surface while AFM (atomic force microscopy) and SEM (scanning electron microscopy) were used to reveal surface topography of the fabric. Color spectroscopic technique was used to investigate changes in color strength caused by different absorptions of the printed fabrics. The O_2 plasma treatments produced new functional groups, −O−C−O/C=O and O−C=O while N_2 plasma treatments produced additionally new functional groups, C−N and O=C−NH, onto the fabric surface which increased hydrophilic properties and surface energy of the fabric. For cotton fabric treated with SF_6 plasma, the fluorine functionalization was additionally found on the surface. Color strength values (K/S) increased when compared with those of the untreated fabrics. SF_6 plasma-treated fabrics were hydrophobic and caused less ink absorption. Fabric surface roughness caused by plasma etching increased fabric surface areas, captured more ink, and enhanced a larger ink color gamut and ink adhesion. Cotton fabrics exhibited higher

Modification of SrTiO3 single-crystalline surface after plasma flow treatment

Energy Technology Data Exchange (ETDEWEB)

Levin, Alexandr A.; Weissbach, Torsten; Leisegang, Tilmann; Meyer, Dirk C. [Institut fuer Strukturphysik, Technische Universitaet Dresden, 01062 Dresden (Germany); Kulagin, Nikolay A. [Kharkiv National University for Radioelectronics, av. Shakespeare 6-48, 61045 Kharkiv (Ukraine); Langer, Enrico [Institut fuer Festkoerperphysik, Technische Universitaet Dresden, 01062 Dresden (Germany)

2009-07-01

Surface of pure and transition metal-doped SrTiO3(STO) single crystals before and after hydrogen plasma-flow treatment (energy of 5..20 J/cm2) is investigated by wide-angle X-ray diffraction (WAXRD), fluorescence X-ray absorption near edge structure (XANES) and scanning electron microscopy (SEM) techniques. Plasma treatment results in the formation of a textured polycrystalline layer at the surface of the single-crystalline samples with different orientation. The formation of the quasi-ordered structures consisting of nanoscale-sized pyramids is observed by SEM. XANES evidences the change of the valency of the part of Ti4+ to Ti3+ due to the plasma treatment. The data obtained together with results of X-ray spectroscopy measurements gives evidences of the change of stoichiometry of the STO samples resulting in a change of their physical properties after plasma treatment.

Surface modification of polyimide (PI) film using water cathode atmospheric pressure glow discharge plasma

International Nuclear Information System (INIS)

Zheng Peichao; Liu Keming; Wang Jinmei; Dai Yu; Yu Bin; Zhou Xianju; Hao Honggang; Luo Yuan

2012-01-01

Highlights: ► Equipment called water cathode atmospheric pressure glow discharge was used to improve the hydrophilicity of polyimide films. ► The data shows good homogeneity and the variation trends of contact angles are different for polar and non-polar testing liquids. ► The thickness of liquid layer plays an important role in plasma processing and directly affects the treatment effect. ► Surface hydrophilicity after plasma treatment is improved partly due to the increase in the roughness. ► The hydrophilicity of polyimide films is still better than untreated ones after long-term storage. - Abstract: The industrial use of polyimide film is limited because of undesirable properties such as poor wettability. In the present paper, a new kind of equipment called water cathode atmospheric pressure glow discharge was used to improve the surface properties of polyimide films and made them useful to technical applications. The changes in hydrophilicity of modified polyimide film surfaces were investigated by contact angle, surface energy and water content measurements as a function of treatment time. The results obtained show good treatment homogeneity and that the variation trends of contact angles are different for polar and non-polar testing liquids, while surface energy and water content are significantly enhanced with the increase of treatment time until they achieve saturated values after 60 s plasma treatment. Also, the thickness of liquid layer plays an important role in plasma processing and directly affects the treatment effect. Changes in morphology of polyimide films were analyzed by atomic force microscope and the results indicate that surface hydrophilicity after plasma treatment are improved partly due to the increase in the roughness. In addition, polyimide films treated by plasma are subjected to an ageing process to determine the durability of plasma treatment. It is found that the hydrophilicity is still better than untreated ones though the

Surface characterization of polyethylene terephthalate films treated by ammonia low-temperature plasma

International Nuclear Information System (INIS)

Zheng Zhiwen; Ren Li; Feng Wenjiang; Zhai Zhichen; Wang Yingjun

2012-01-01

In order to study the surface characterization and protein adhesion behavior of polyethylene terephthalate film, low temperature ammonia plasma was used to modify the film. Effects of plasma conditions of the surface structures and properties were investigated. Results indicated that surface hydrophilicity of polyethylene terephthalate was significantly improved by ammonia plasma treatment. Ammonia plasma played the role more important than air treatment in the process of modification. Furthermore, by Fourier Transform Infrared spectra some new bonds such as -N=O and N-H which could result in the improvement of the surface hydrophilicity were successfully grafted on the film surface. Atom force microscope experiments indicated that more protein adsorbed on hydrophobic surfaces than hydrophilic ones, and the blobs arranged in a straight line at etching surface by plasma. Modified membrane after ammonia plasma treatment had a good cell affinity and could be effective in promoting the adhesion and growth of cells on the material surface. Timeliness experiments showed that the plasma treatment gave the material a certain performance only in a short period of time and the hydrophobicity recovered after 12 days.

Corrosion and surface modification on biocompatible metals: A review.

Science.gov (United States)

Asri, R I M; Harun, W S W; Samykano, M; Lah, N A C; Ghani, S A C; Tarlochan, F; Raza, M R

2017-08-01

Corrosion prevention in biomaterials has become crucial particularly to overcome inflammation and allergic reactions caused by the biomaterials' implants towards the human body. When these metal implants contacted with fluidic environments such as bloodstream and tissue of the body, most of them became mutually highly antagonistic and subsequently promotes corrosion. Biocompatible implants are typically made up of metallic, ceramic, composite and polymers. The present paper specifically focuses on biocompatible metals which favorably used as implants such as 316L stainless steel, cobalt-chromium-molybdenum, pure titanium and titanium-based alloys. This article also takes a close look at the effect of corrosion towards the implant and human body and the mechanism to improve it. Due to this corrosion delinquent, several surface modification techniques have been used to improve the corrosion behavior of biocompatible metals such as deposition of the coating, development of passivation oxide layer and ion beam surface modification. Apart from that, surface texturing methods such as plasma spraying, chemical etching, blasting, electropolishing, and laser treatment which used to improve corrosion behavior are also discussed in detail. Introduction of surface modifications to biocompatible metals is considered as a "best solution" so far to enhanced corrosion resistance performance; besides achieving superior biocompatibility and promoting osseointegration of biocompatible metals and alloys. Copyright © 2017 Elsevier B.V. All rights reserved.

Use of modern methods of fibre surface modification to obtain the multifunctional properties of textile materials

Directory of Open Access Journals (Sweden)

Jocić Dragan

2003-01-01

Full Text Available The modern textile fibre treatments aim to obtain the required level of beneficial effect while attempting to confine the modification to the fibre surface. Recently, much attention has been focused on different physical methods of fibre surface modification, cold plasma treatment being considered as very useful. Moreover, there are efficient chemical methods available, such as peroxide, biopolymer and enzyme treatment. Some interesting combinations of these physical and chemical surface modification methods as means to modify fibre surface topography and thus controlling the surface-related properties of the fibre are presented in this paper. The properties obtained are discussed on the basis of the physico-chemical changes in the surface layer of the fibre, being assessed by wettability and contact angle measurements, as well as by FTIR-ATR and XPS analysis. The SEM and AFM technique are used to assess the changes in the fibre surface topography and to correlate these changes to the effectiveness, uniformity and severity of the textile fibre surface modification treatments.

Enhancing Plasma Surface Modification using high Intensity and high Power Ultrasonic Acoustic Waves

DEFF Research Database (Denmark)

2010-01-01

high intensity and high power acoustic waves (102) by at least one ultrasonic high intensity and high power acoustic wave generator (101 ), wherein the ultrasonic acoustic waves are directed to propagate towards said surface (314) of the object (100) so that a laminar boundary layer (313) of a gas...... or a mixture of gases (500) flow in contact with said solid object (100) is thinned or destructed for at least a part of said surface (314). In this way, the plasma can more efficiently access and influence the surface of the solid object to be treated by the plasma, which speeds the process time up...

Surface modification of PET film by plasma-based ion implantation

International Nuclear Information System (INIS)

Sakudo, N.; Mizutani, D.; Ohmura, Y.; Endo, H.; Yoneda, R.; Ikenaga, N.; Takikawa, H.

2003-01-01

It has been reported that thin diamond like carbon (DLC) coating is very Amsterdam, Theenhancing the barrier characteristics of polyethylene terephthalate (PET) against CO 2 and O 2 gases. However, coating technique has a problem of DLC-deposit peeling. In this research, we develop a new technique to change the PET surface into DLC by ion implantation instead of coating the surface with the DLC deposit. The surface of PET film is modified by plasma-based ion implantation using pulse voltages of 10 kV in height and 5 μs in width. Attenuated total reflection FT-IR spectroscopy shows that the specific absorption peaks for PET decrease with dose, that is, the molecules of ethylene terephthalate are destroyed by ion bombardment. Then, laser Raman spectroscopy shows that thin DLC layer is formed in the PET surface area

Surface modification of ultra-high molecular weight polyethylene (UHMWPE) by argon plasma

International Nuclear Information System (INIS)

Liu Hengjun; Pei Yanan; Xie Dong; Deng Xingrui; Leng, Y.X.; Jin Yong; Huang Nan

2010-01-01

In this work, argon (Ar) plasma generated by microwave electron cyclotron resonance (MWECR) has been used to modify the UHMWPE in order to increase the wear resistance. The results showed that the wettability, anti-scratch and wear resistance of UHMWPE treated by the Ar plasma had been improved, comparing with native UHMWPE. The FTIR and XPS spectra indicated the improvement of wettability should come from the oxygen based functional groups generated on the surface of UHMWPE. The improvement of anti-scratch and wear resistance may come from the enhancement of crosslinking of UHMWPE by Ar plasma treatment.

Note: A single-chamber tool for plasma activation and surface functionalization in microfabrication

Energy Technology Data Exchange (ETDEWEB)

Bowman, Adam J.; Scherrer, Joseph R.; Reiserer, Ronald S., E-mail: ron.reiserer@vanderbilt.edu [Vanderbilt Institute for Integrative Biosystems Research and Education and Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235 (United States)

2015-06-15

We present a simple apparatus for improved surface modification of polydimethylsiloxane (PDMS) microfluidic devices. A single treatment chamber for plasma activation and chemical/physical vapor deposition steps minimizes the time-dependent degradation of surface activation that is inherent in multi-chamber techniques. Contamination and deposition irregularities are also minimized by conducting plasma activation and treatment phases in the same vacuum environment. An inductively coupled plasma driver allows for interchangeable treatment chambers. Atomic force microscopy confirms that silane deposition on PDMS gives much better surface quality than standard deposition methods, which yield a higher local roughness and pronounced irregularities in the surface.

In vitro cell-biological performance and structural characterization of selective laser sintered and plasma surface functionalized polycaprolactone scaffolds for bone regeneration

Energy Technology Data Exchange (ETDEWEB)

Van Bael, Simon, E-mail: simon.vanbael@mech.kuleuven.be [Department of Mechanical Engineering, Division of Production Engineering, Machine Design and Automation, Katholieke Universiteit Leuven, Celestijnenlaan 300b, 3001 Leuven (Belgium); Department of Mechanical Engineering, Division of Biomechanics and Engineering Design, Katholieke Universiteit Leuven, Celestijnenlaan 300c, bus 2419, 3001 Heverlee (Belgium); Prometheus, Division of Skeletal Tissue Engineering, Katholieke Universiteit Leuven, O and N 1, Herestraat 49, bus 813, 3000 Leuven (Belgium); Desmet, Tim [Polymer Chemistry and Biomaterials Research Group, Ghent University, Krijgslaan 281 S4 Bis, Ghent, 9000 (Belgium); Research Unit Plasma Technology (RUPT), Department of Applied Physics, Faculty of Engineering, Ghent University, Jozef Plateaustraat 22, 9000 Ghent (Belgium); Chai, Yoke Chin [Prometheus, Division of Skeletal Tissue Engineering, Katholieke Universiteit Leuven, O and N 1, Herestraat 49, bus 813, 3000 Leuven (Belgium); Pyka, Gregory [Prometheus, Division of Skeletal Tissue Engineering, Katholieke Universiteit Leuven, O and N 1, Herestraat 49, bus 813, 3000 Leuven (Belgium); Department of Metallurgy and Materials Engineering, Katholieke Universiteit Leuven, Kasteelpark Arenberg 44, bus 2450, 3001 Leuven (Belgium); Dubruel, Peter [Polymer Chemistry and Biomaterials Research Group, Ghent University, Krijgslaan 281 S4 Bis, Ghent, 9000 (Belgium); Research Unit Plasma Technology (RUPT), Department of Applied Physics, Faculty of Engineering, Ghent University, Jozef Plateaustraat 22, 9000 Ghent (Belgium); Kruth, Jean-Pierre [Department of Mechanical Engineering, Division of Production Engineering, Machine Design and Automation, Katholieke Universiteit Leuven, Celestijnenlaan 300b, 3001 Leuven (Belgium); Schrooten, Jan [Prometheus, Division of Skeletal Tissue Engineering, Katholieke Universiteit Leuven, O and N 1, Herestraat 49, bus 813, 3000 Leuven (Belgium)

2013-08-01

In the present study a structural characterization and in vitro cell-biological evaluation was performed on polycaprolactone (PCL) scaffolds that were produced by the additive manufacturing technique selective laser sintering (SLS), followed by a plasma-based surface modification technique, either non-thermal oxygen plasma or double protein coating, to functionalize the PCL scaffold surfaces. In the first part of this study pore morphology by means of 2D optical microscopy, surface chemistry by means of hydrophilicity measurement and X-ray photoelectron spectroscopy, strut surface roughness by means of 3D micro-computed tomography (CT) imaging and scaffold mechanical properties by means of compression testing were evaluated before and after the surface modifications. The results showed that both surface modifications increased the PCL scaffold hydrophilicity without altering the morphological and mechanical properties. In the second part of this study the in vitro cell proliferation and differentiation of human osteoprogenitor cells, over 14 days of culture in osteogenic and growth medium were investigated. The O{sub 2} plasma modification gave rise to a significant lower in vitro cell proliferation compared to the untreated and double protein coated scaffolds. Furthermore the double protein coating increased in vitro cell metabolic activity and cell differentiation compared to the untreated and O{sub 2} plasma PCL scaffolds when OM was used. - Highlights: • Polycaprolactone scaffolds are produced with selective laser sintering. • 2 types of plasma based surface functionalization were applied. • Plasma had no significant effect on strut roughness and pore morphology. • Plasma improved surface hydrophilicity. • In vitro cell differentiation increased with plasma protein coated functionalization.

In vitro cell-biological performance and structural characterization of selective laser sintered and plasma surface functionalized polycaprolactone scaffolds for bone regeneration

International Nuclear Information System (INIS)

Van Bael, Simon; Desmet, Tim; Chai, Yoke Chin; Pyka, Gregory; Dubruel, Peter; Kruth, Jean-Pierre; Schrooten, Jan

2013-01-01

In the present study a structural characterization and in vitro cell-biological evaluation was performed on polycaprolactone (PCL) scaffolds that were produced by the additive manufacturing technique selective laser sintering (SLS), followed by a plasma-based surface modification technique, either non-thermal oxygen plasma or double protein coating, to functionalize the PCL scaffold surfaces. In the first part of this study pore morphology by means of 2D optical microscopy, surface chemistry by means of hydrophilicity measurement and X-ray photoelectron spectroscopy, strut surface roughness by means of 3D micro-computed tomography (CT) imaging and scaffold mechanical properties by means of compression testing were evaluated before and after the surface modifications. The results showed that both surface modifications increased the PCL scaffold hydrophilicity without altering the morphological and mechanical properties. In the second part of this study the in vitro cell proliferation and differentiation of human osteoprogenitor cells, over 14 days of culture in osteogenic and growth medium were investigated. The O 2 plasma modification gave rise to a significant lower in vitro cell proliferation compared to the untreated and double protein coated scaffolds. Furthermore the double protein coating increased in vitro cell metabolic activity and cell differentiation compared to the untreated and O 2 plasma PCL scaffolds when OM was used. - Highlights: • Polycaprolactone scaffolds are produced with selective laser sintering. • 2 types of plasma based surface functionalization were applied. • Plasma had no significant effect on strut roughness and pore morphology. • Plasma improved surface hydrophilicity. • In vitro cell differentiation increased with plasma protein coated functionalization

Effects of Surface Modification of MWCNT on the Mechanical and Electrical Properties of Fluoro Elastomer/MWCNT Nanocomposites

Directory of Open Access Journals (Sweden)

Tao Xu

2012-01-01

Full Text Available Surface modification is a good way to improve the surface activity and interfacial strength of multiwalled carbon nanotubes (MWCNTs when used as fillers in the polymer composites. Among the reported methods for nanotube modification, mixed acid oxidation and plasma treatment is often used by introducing polar groups to the sidewall of MWCNT successfully. The purpose of this study is to evaluate the effect of different surface modification of MWCNT on the mechanical property and electrical conductivity of Fluoro-elastomer (FE/MWCNT nanocomposites. MWCNTs were surface modified by mixed oxidation and CF4 plasma treatment and then used to reinforce the fluoro elastomer (FE, a copolymer of trifluorochloroethylene and polyvinylidene fluoride. FE/MWCNT composite films were prepared from mixture solutions of ethylacetate and butylacetate, using untreated CNTs (UCNTs, acid-modified CNTs (ACNTs, and CF4 plasma-modified CNT (FCNTs. In each case, MWCNT content was 0.01 wt%, 0.05 wt%, 0.1 wt%, and 0.2 wt% with respect to the polymer. Morphology and mechanical properties were characterized by using scanning electron microscopy (SEM, Raman spectroscopy, as well as dynamic mechanical tests. The SEM results indicated that dispersion of ACNTs and especially FCNTs in FE was better than that of UCNTs. DMA indicated mechanical properties of FCNT composites were improved over ACNT and UCNT filled FE. The resulting electrical properties of the composites ranged from dielectric behavior to bulk conductivities of 10-2 Sm-1 and were found to depend strongly on the surface modification methods of MWCNTs.

Surface Modifications of Support Partitions for Stabilizing Biomimetic Membrane Arrays

DEFF Research Database (Denmark)

Perry, Mark; Hansen, Jesper Schmidt; Jensen, Karin Bagger Stibius

2011-01-01

with a high signal-to-noise (s/n) ratio. We demonstratesd this by reconstituting gA and α-hemolysin (α-HL) into BLM arrays. The improvement in membrane array lifetime and s/n ratio demonstrates that surface plasma polymerization of the supporting partition can be used to increase the stability of biomimetic......Black lipid membrane (BLM) formation across apertures in an ethylene tetra-fluoroethylene (ETFE) partition separating two aqueous compartments is an established technique for the creation of biomimetic membranes. Recently multi-aperture BLM arrays have attracted interest and in order to increase...... BLM array stability we studied the effect of covalently modifying the partition substrate using surface plasma polymerization with hydrophobic n-hexene, 1-decene and hexamethyldisiloxane (HMDSO) as modification groups. Average lifetimes across singlesided HMDSO modified partitions or using 1-decene...

A model for plasma modification of polypropylene using atmospheric pressure discharges

CERN Document Server

Dorai, R

2003-01-01

Atmospheric pressure plasmas are commonly used to improve the wetting and adhesion properties of polymers. In spite of their use, the mechanisms for achieving these properties are unclear. In this regard, we report on a computational investigation of the gas phase and surface kinetics during humid-air corona treatment of polypropylene (PP) and the resulting modification of its surface properties while varying energy deposition, relative humidity (RH), web speed, and gas temperature. Using results from a global plasma chemistry model validated against experiments, we found that increasing energy deposition increased the densities of alcohol, carbonyl, acid, and peroxy radicals on the PP surface. In doing so, significant amounts of gas phase O sub 3 and N sub x O sub y are produced. Increasing the RH increased the production of peroxy and acid groups, while decreasing those of alcohol and carbonyl groups. Production of O sub 3 decreased while that of HNO sub 3 increased. Increasing the temperature decreased the...

Green aqueous surface modification of polypropylene for novel polymer nanocomposites.

Science.gov (United States)

Thakur, Vijay Kumar; Vennerberg, Danny; Kessler, Michael R

2014-06-25

Polypropylene is one of the most widely used commercial commodity polymers; among many other applications, it is used for electronic and structural applications. Despite its commercial importance, the hydrophobic nature of polypropylene limits its successful application in some fields, in particular for the preparation of polymer nanocomposites. Here, a facile, plasma-assisted, biomimetic, environmentally friendly method was developed to enhance the interfacial interactions in polymer nanocomposites by modifying the surface of polypropylene. Plasma treated polypropylene was surface-modified with polydopamine (PDA) in an aqueous medium without employing other chemicals. The surface modification strategy used here was based on the easy self-polymerization and strong adhesion characteristics of dopamine (DA) under ambient laboratory conditions. The changes in surface characteristics of polypropylene were investigated using FTIR, TGA, and Raman spectroscopy. Subsequently, the surface modified polypropylene was used as the matrix to prepare SiO2-reinforced polymer nanocomposites. These nanocomposites demonstrated superior properties compared to nanocomposites prepared using pristine polypropylene. This simple, environmentally friendly, green method of modifying polypropylene indicated that polydopamine-functionalized polypropylene is a promising material for various high-performance applications.

Study on hydrophilicity of polymer surfaces improved by plasma treatment

International Nuclear Information System (INIS)

Lai Jiangnan; Sunderland, Bob; Xue Jianming; Yan, Sha; Zhao Weijiang; Folkard, Melvyn; Michael, Barry D.; Wang Yugang

2006-01-01

Surface properties of polycarbonate (PC), polypropylene (PP), polyethylene terephthalate (PET) samples treated by microwave-induced argon plasma have been studied with contact angle measurement, X-ray photoelectron spectroscopy (XPS) and scanned electron microscopy (SEM). It is found that plasma treatment modified the surfaces both in composition and roughness. Modification of composition makes polymer surfaces tend to be highly hydrophilic, which mainly depended on the increase of ratio of oxygen-containing group as same as other papers reported. And this experiment further revealed that C=O bond is Key factor to the improvement of the hydrophilicity of polymer surfaces. Our SEM observation on PET shown that the roughness of the surface has also been improved in micron scale and it has influence on the surface hydrophilicity

Modification of the surface properties of glass-ceramic materials at low-pressure RF plasma stream

Science.gov (United States)

Tovstopyat, Alexander; Gafarov, Ildar; Galeev, Vadim; Azarova, Valentina; Golyaeva, Anastasia

2018-05-01

The surface roughness has a huge effect on the mechanical, optical, and electronic properties of materials. In modern optical systems, the specifications for the surface accuracy and smoothness of substrates are becoming even more stringent. Commercially available pre-polished glass-ceramic substrates were treated with the radio frequency (RF) inductively coupled (13.56 MHz) low-pressure plasma to clean the surface of the samples and decrease the roughness. Optical emission spectroscopy was used to investigate the plasma stream parameters and phase-shifted interferometry to investigate the surface of the specimen. In this work, the dependence of RF inductively coupled plasma on macroscopic parameters was investigated with the focus on improving the surfaces. The ion energy, sputtering rate, and homogeneity were investigated. The improvements of the glass-ceramic surfaces from 2.6 to 2.2 Å root mean square by removing the "waste" after the previous operations had been achieved.

Surface modification of closed plastic bags for adherent cell cultivation

Science.gov (United States)

Lachmann, K.; Dohse, A.; Thomas, M.; Pohl, S.; Meyring, W.; Dittmar, K. E. J.; Lindenmeier, W.; Klages, C.-P.

2011-07-01

In modern medicine human mesenchymal stem cells are becoming increasingly important. However, a successful cultivation of this type of cells is only possible under very specific conditions. Of great importance, for instance, are the absence of contaminants such as foreign microbiological organisms, i.e., sterility, and the chemical functionalization of the ground on which the cells are grown. As cultivation of these cells makes high demands, a new procedure for cell cultivation has been developed in which closed plastic bags are used. For adherent cell growth chemical functional groups have to be introduced on the inner surface of the plastic bag. This can be achieved by a new, atmospheric-pressure plasma-based method presented in this paper. The method which was developed jointly by the Fraunhofer IST and the Helmholtz HZI can be implemented in automated equipment as is also shown in this contribution. Plasma process gases used include helium or helium-based gas mixtures (He + N2 + H2) and vapors of suitable film-forming agents or precursors such as APTMS, DACH, and TMOS in helium. The effect of plasma treatment is investigated by FTIR-ATR spectroscopy as well as surface tension determination based on contact angle measurements and XPS. Plasma treatment in nominally pure helium increases the surface tension of the polymer foil due to the presence of oxygen traces in the gas and oxygen diffusing through the gas-permeable foil, respectively, reacting with surface radical centers formed during contact with the discharge. Primary amino groups are obtained on the inner surface by treatment in mixtures with nitrogen and hydrogen albeit their amount is comparably small due to diffusion of oxygen through the gas-permeable bag, interfering with the plasma-amination process. Surface modifications introducing amino groups on the inner surface turned out to be most efficient in the promotion of cell growth.

Modification of adhered dust on plasma-facing surfaces due to exposure to ELMy H-mode plasma in DIII-D

Directory of Open Access Journals (Sweden)

I. Bykov

2017-08-01

Full Text Available Transient heat load tests have been conducted in the lower divertor of DIII-D using DiMES manipulator in order to study the behavior of dust on tungsten Plasma Facing Components (PFCs during ELMy H-mode discharges. Samples with pre-adhered, pre-characterized dust have been exposed at the outer strike point (OSP in a series of discharges with varied intra-(inter- ELM heat fluxes. We used C dust because of its high sublimation temperature and non-metal properties. Al dust as a surrogate for Be and W dust were employed as relevant to that in the ITER divertor. The poor initial thermal contact between the substrate and the particles led to overheating, sublimation and shrinking of the carbon dust, and wetting induced coagulation of Al dust. Little modification of the W dust was observed. An enhanced surface adhesion and improvement of the thermal contact of C and Al dust were the result of exposure. A post mortem “adhesive tape” sampling showed that 70% of Al, <5% of W and C particles could not be removed from the surface owing to the improved adhesion. Al and C but not W particles that could be lifted had W inclusions indicating damage to the substrate. This suggests that non destructive methods may be inefficient for removal of dust in ITER.

Ultralow energy ion beam surface modification of low density polyethylene.

Science.gov (United States)

Shenton, Martyn J; Bradley, James W; van den Berg, Jaap A; Armour, David G; Stevens, Gary C

2005-12-01

Ultralow energy Ar+ and O+ ion beam irradiation of low density polyethylene has been carried out under controlled dose and monoenergetic conditions. XPS of Ar+-treated surfaces exposed to ambient atmosphere show that the bombardment of 50 eV Ar+ ions at a total dose of 10(16) cm(-2) gives rise to very reactive surfaces with oxygen incorporation at about 50% of the species present in the upper surface layer. Using pure O+ beam irradiation, comparatively low O incorporation is achieved without exposure to atmosphere (approximately 13% O in the upper surface). However, if the surface is activated by Ar+ pretreatment, then large oxygen contents can be achieved under subsequent O+ irradiation (up to 48% O). The results show that for very low energy (20 eV) oxygen ions there is a dose threshold of about 5 x 10(15) cm(-2) before surface oxygen incorporation is observed. It appears that, for both Ar+ and O+ ions in this regime, the degree of surface modification is only very weakly dependent on the ion energy. The results suggest that in the nonequilibrium plasma treatment of polymers, where the ion flux is typically 10(18) m(-2) s(-1), low energy ions (<50 eV) may be responsible for surface chemical modification.

In vitro study of 3D PLGA/n-HAp/β-TCP composite scaffolds with etched oxygen plasma surface modification in bone tissue engineering

Energy Technology Data Exchange (ETDEWEB)

Roh, Hee-Sang [Department of Dental Materials, School of Dentistry, Chosun University, 309 Pilmun-daero, Dong-gu, Gwangju 61452 (Korea, Republic of); Jung, Sang-Chul [Department of Environmental Engineering, Sunchon National University, 255 Jungang-ro, Sunchon 57922 (Korea, Republic of); Kook, Min-Suk [Department of Oral and Maxillofacial Surgery, School of Dentistry, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 61186 (Korea, Republic of); Kim, Byung-Hoon, E-mail: kim5055@chosun.ac.kr [Department of Dental Materials, School of Dentistry, Chosun University, 309 Pilmun-daero, Dong-gu, Gwangju 61452 (Korea, Republic of)

2016-12-01

Highlights: • PLGA and PLGA/n-HAp/β-TCP scaffolds were successfully fabricated by 3D printing. • Oxygen plasma etching increases the wettability and surface roughness. • Bioceramics and oxygen plasma etching and could be used to improve the cell affinity. - Abstract: Three-dimensional (3D) scaffolds have many advantageous properties for bone tissue engineering application, due to its controllable properties such as pore size, structural shape and interconnectivity. In this study, effects on oxygen plasma surface modification and adding of nano-hydroxyapatite (n-HAp) and β-tricalcium phosphate (β-TCP) on the 3D PLGA/n-HAp/β-TCP scaffolds for improving preosteoblast cell (MC3T3-E1) adhesion, proliferation and differentiation were investigated. The 3D PLGA/n-HAp/β-TCP scaffolds were fabricated by 3D Bio-Extruder equipment. The 3D scaffolds were prepared with 0°/90° architecture and pore size of approximately 300 μm. In addition 3D scaffolds surface were etched by oxygen plasma to enhance the hydrophilic property and surface roughness. After oxygen plasma treatment, the surface chemistry and morphology were investigated by Fourier transform infrared spectroscopy, scanning electron microscopy, and atomic force microscopy. And also hydrophilic property was measured by contact angle. The MC3T3-E1 cell proliferation and differentiation were investigated by MTT assay and ALP activity. In present work, the 3D PLGA/HAp/beta-TCP composite scaffold with suitable structure for the growth of osteoblast cells was successfully fabricated by 3D rapid prototyping technique. The surface hydrophilicity and roughness of 3D scaffold increased by oxygen plasma treatment had a positive effect on cell adhesion, proliferation, and differentiation. Furthermore, the differentiation of MC3T3-E1 cell was significantly enhanced by adding of n-HAp and β-TCP on 3D PLGA scaffold. As a result, combination of bioceramics and oxygen plasma treatment showed a synergistic effect on

Site specific modification of the human plasma proteome by methylglyoxal

International Nuclear Information System (INIS)

Kimzey, Michael J.; Kinsky, Owen R.; Yassine, Hussein N.; Tsaprailis, George; Stump, Craig S.; Monks, Terrence J.; Lau, Serrine S.

2015-01-01

Increasing evidence identifies dicarbonyl stress from reactive glucose metabolites, such as methylglyoxal (MG), as a major pathogenic link between hyperglycemia and complications of diabetes. MG covalently modifies arginine residues, yet the site specificity of this modification has not been thoroughly investigated. Sites of MG adduction in the plasma proteome were identified using LC–MS/MS analysis in vitro following incubation of plasma proteins with MG. Treatment of plasma proteins with MG yielded 14 putative MG hotspots from five plasma proteins (albumin [nine hotspots], serotransferrin, haptoglobin [2 hotspots], hemopexin, and Ig lambda-2 chain C regions). The search results revealed two versions of MG-arginine modification, dihydroxyimidazolidine (R + 72) and hydroimidazolone (R + 54) adducts. One of the sites identified was R257 in human serum albumin, which is a critical residue located in drug binding site I. This site was validated as a target for MG modification by a fluorescent probe displacement assay, which revealed significant drug dissociation at 300 μM MG from a prodan–HSA complex (75 μM). Moreover, twelve human plasma samples (six male, six female, with two type 2 diabetic subjects from both genders) were analyzed using multiple reaction monitoring (MRM) tandem mass spectrometry and revealed the presence of the MG-modified albumin R257 peptide. These data provide insights into the nature of the site-specificity of MG modification of arginine, which may be useful for therapeutic treatments that aim to prevent MG-mediated adverse responses in patients. - Highlights: • Methylglyoxal (MG) selectively modifies arginine sites in human plasma proteome. • Dihydroxyimidazolidine and hydroimidazolone adducts on serum albumin identified • MG modification on albumin R257 associated with loss of drug site I binding capacity • MRM-tandem mass spectrometry enables sensitive detection of albumin MG-R257. • Site-specific MG modification may

Site specific modification of the human plasma proteome by methylglyoxal

Energy Technology Data Exchange (ETDEWEB)

Kimzey, Michael J.; Kinsky, Owen R. [Southwest Environmental Health Sciences Center, Department of Pharmacology & Toxicology, College of Pharmacy, The University of Arizona, Tucson, AZ 85721 (United States); Yassine, Hussein N. [Department of Medicine, The University of Arizona, Tucson, AZ 85721 (United States); Tsaprailis, George [Southwest Environmental Health Sciences Center, Department of Pharmacology & Toxicology, College of Pharmacy, The University of Arizona, Tucson, AZ 85721 (United States); Stump, Craig S. [Department of Medicine, The University of Arizona, Tucson, AZ 85721 (United States); Southern Arizona VA Health Care System, Tucson, AZ 85723 (United States); Monks, Terrence J. [Southwest Environmental Health Sciences Center, Department of Pharmacology & Toxicology, College of Pharmacy, The University of Arizona, Tucson, AZ 85721 (United States); Lau, Serrine S., E-mail: lau@pharmacy.arizona.edu [Southwest Environmental Health Sciences Center, Department of Pharmacology & Toxicology, College of Pharmacy, The University of Arizona, Tucson, AZ 85721 (United States)

2015-12-01

Increasing evidence identifies dicarbonyl stress from reactive glucose metabolites, such as methylglyoxal (MG), as a major pathogenic link between hyperglycemia and complications of diabetes. MG covalently modifies arginine residues, yet the site specificity of this modification has not been thoroughly investigated. Sites of MG adduction in the plasma proteome were identified using LC–MS/MS analysis in vitro following incubation of plasma proteins with MG. Treatment of plasma proteins with MG yielded 14 putative MG hotspots from five plasma proteins (albumin [nine hotspots], serotransferrin, haptoglobin [2 hotspots], hemopexin, and Ig lambda-2 chain C regions). The search results revealed two versions of MG-arginine modification, dihydroxyimidazolidine (R + 72) and hydroimidazolone (R + 54) adducts. One of the sites identified was R257 in human serum albumin, which is a critical residue located in drug binding site I. This site was validated as a target for MG modification by a fluorescent probe displacement assay, which revealed significant drug dissociation at 300 μM MG from a prodan–HSA complex (75 μM). Moreover, twelve human plasma samples (six male, six female, with two type 2 diabetic subjects from both genders) were analyzed using multiple reaction monitoring (MRM) tandem mass spectrometry and revealed the presence of the MG-modified albumin R257 peptide. These data provide insights into the nature of the site-specificity of MG modification of arginine, which may be useful for therapeutic treatments that aim to prevent MG-mediated adverse responses in patients. - Highlights: • Methylglyoxal (MG) selectively modifies arginine sites in human plasma proteome. • Dihydroxyimidazolidine and hydroimidazolone adducts on serum albumin identified • MG modification on albumin R257 associated with loss of drug site I binding capacity • MRM-tandem mass spectrometry enables sensitive detection of albumin MG-R257. • Site-specific MG modification may

SEM observations of particle track membrane surfaces modificated using plasma treatment

International Nuclear Information System (INIS)

Sartowska, B.; Buczkowski, M.; Starosta, W.

2003-01-01

This work presents results of scanning electron microscopy (SEM) observations of 0.4 μm membranes after plasma treatment with different parameters. The morphology changes at the surfaces and at the pore walls were observed. The character of changes in the membrane parameters according to the process conditions was determined

Energy conservation potential of surface modification technologies

Energy Technology Data Exchange (ETDEWEB)

Le, H.K.; Horne, D.M.; Silberglitt, R.S.

1985-09-01

This report assesses the energy conservation impact of surface modification technologies on the metalworking industries. The energy conservation impact of surface modification technologies on the metalworking industries is assessed by estimating their friction and wear tribological sinks and the subsequent reduction in these sinks when surface modified tools are used. Ion implantation, coatings, and laser and electron beam surface modifications are considered.

Nanomechanical and nanotribological properties of plasma nanotextured superhydrophilic and superhydrophobic polymeric surfaces

International Nuclear Information System (INIS)

Skarmoutsou, A; Charitidis, C A; Gnanappa, A K; Tserepi, A; Gogolides, E

2012-01-01

Oxygen plasma-induced surface modification of polymethylmethacrylate (PMMA), under plasma conditions favouring (maximizing) roughness formation, has been shown to create textured surfaces of roughness size and morphology dependent on the plasma-treatment time and subsequent morphology stabilization procedure. Superhydrophobic or superhydrophilic surfaces can thus be obtained, with potential applications in antireflective self-cleaning surfaces, microfluidics, wetting–dewetting control, anti-icing etc, necessitating determination of their mechanical properties. In this study, nanoindentation is used to determine the reduced modulus and hardness of the surface, while nanoscratch tests are performed to measure the coefficient of friction. The data are combined to assess the wear behaviour of such surfaces as a first guide for their practical applications. Short-time plasma treatment slightly changes mechanical, tribological and wear properties compared to untreated PMMA. However, a significant decrease in the reduced modulus and hardness and an increase in the coefficient of friction are observed after long plasma-treatment times. The C 4 F 8 plasma deposited thin hydrophobic layer on the polymeric surfaces (untreated and treated) reveals good adhesion, while its mechanical properties are greatly influenced by the substrate; it is also found that it effectively protects the polymeric surfaces, reducing plastic deformation. (paper)

Improving wettability of photo-resistive film surface with plasma surface modification for coplanar copper pillar plating of IC substrates

Science.gov (United States)

Xiang, Jing; Wang, Chong; Chen, Yuanming; Wang, Shouxu; Hong, Yan; Zhang, Huaiwu; Gong, Lijun; He, Wei

2017-07-01

The wettability of the photo-resistive film (PF) surfaces undergoing different pretreatments including the O2sbnd CF4 low-pressure plasma (OCLP) and air plasma (AP), is investigated by water contact angle measurement instrument (WCAMI) before the bottom-up copper pillar plating. Chemical groups analysis performed by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectra (XPS) shows that after the OCLP and wash treatment, the wettability of PF surface is attenuated, because embedded fluorine and decreased oxygen content both enhance hydrophobicity. Compared with OCLP treatment, the PF surface treatment by non-toxic air plasma displays features of Csbnd O, Osbnd Cdbnd O, Cdbnd O and sbnd NO2 by AIR-FTIR and XPS, and a promoted wettability by WCAM. Under the identical electroplating condition, the surface with a better wettability allows electrolyte to spontaneously soak all the places of vias, resulting in improved copper pillar uniformity. Statistical analysis of metallographic data shows that more coplanar and flat copper pillars are achieved with the PF treatment of air plasma. Such modified copper-pillar-plating technology meets the requirement of accurate impedance, the high density interconnection for IC substrates.

Surface emission of quark gluon plasma at RHIC and LHC

International Nuclear Information System (INIS)

Xiang Wenchang; Wan Renzhou; Zhou Daicui

2008-01-01

Within the framework of a factorization model, we study the behaviour of nuclear modification factor in Au-Au collisions at RHIC and Pb-Pb collisions at LHC. We find that the nuclear modification factor is inversely proportional to the radius of the quark-gluon plasma and is dominated by the surface emission of hard jets. We predict the nuclear modification factor P AALHS ∼0.15 in central Pb-Pb collisions at LHC. The study shows that the factorization model can be used to describe the centrality dependence of nuclear modification factor of the high transverse momentum particles produced in heavy ion collisions at both RHIC and LHC. (authors)

Surface modification of polypropylene membrane by polyethylene glycol graft polymerization

Energy Technology Data Exchange (ETDEWEB)

Abednejad, Atiye Sadat, E-mail: atiyeabednejad@gmail.com [Department of Biomedical Engineering, Faculty of New Sciences and Technologies, University of Tehran, P.O. Box 14395-1561, Tehran (Iran, Islamic Republic of); Amoabediny, Ghasem [Department of Life Science Engineering, Faculty of New Sciences and Technologies, University of Tehran, P.O. Box 14395-1561, Tehran (Iran, Islamic Republic of); Research Center for New Technologies in Life Science Engineering, University of Tehran, P.O. Box 63894-14179, Tehran (Iran, Islamic Republic of); Ghaee, Azadeh [Department of Biomedical Engineering, Faculty of New Sciences and Technologies, University of Tehran, P.O. Box 14395-1561, Tehran (Iran, Islamic Republic of)

2014-09-01

Polypropylene hollow fiber microporous membranes have been used in a wide range of applications, including blood oxygenator. The hydrophobic feature of the polypropylene surface causes membrane fouling. To minimize fouling, a modification consisting of three steps: surface activation in H{sub 2} and O{sub 2} plasma, membrane immersion in polyethylene glycol (PEG) and plasma graft polymerization was performed. The membranes were characterized by contact angle measurement, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), tensile test, scanning electron microscopy (SEM) and atomic force microscopy (AFM). Oxygen transfer of modified membranes was also tested. The stability of grafted PEG was measured in water and in phosphate buffer saline (PBS) at 37 °C. Blood compatibility of modified surfaces was evaluated by the platelet adhesion method. Water contact angel reduction from 110° to 72° demonstrates the enhanced hydrophilicity, and XPS results verify the presence of oxygenated functional groups due to the peak existence in 286 eV as a result of PEG grafting. The results clearly indicate that plasma graft-polymerization of PEG is an effective way for antifouling improvement of polypropylene membranes. Also, the results show that oxygen transfer changes in PEG grafted membranes are not significant. - Highlights: • H{sub 2} and O{sub 2} plasma graft polymerization of PEG on polypropylene membrane was carried out. • Changes in surface properties were investigated by FTIR, XPS, SEM, and AFM. • Surface wettability enhanced as a result of poly ethylene glycol grafting. • PEG grafting degree increase causes reduction of fouling and adhesion.

Ion bombardment modification of surfaces

International Nuclear Information System (INIS)

Auciello, O.

1984-01-01

Ion bombardment-induced modification of surfaces may be considered one of the significant scientific and technological developments of the last two decades. The understanding acquired concerning the underlying mechanisms of several phenomena occurring during ion-surface interactions has led to applications within different modern technologies. These include microelectronics, surface acoustical and optical technologies, solar energy conversion, thin film technology, ion implantation metallurgy, nuclear track technology, thermonuclear fusion, vacuum technology, cold welding technology, biomedicine (implantology). It has become clear that information on many relevant advances, regarding ion bombardment modification of surfaces is dispersed among journals involving fields sometimes not clearly related. This may result, in some cases, in a loss of the type of interdisciplinary exchange of ideas, which has proved to be so fruitful for the advancement of science and technology. This book has been planned in an attempt to collect at least some of today's relevant information about the experimental and theoretical knowledge related to surface modification and its application to technology. (Auth.)

The relationship between cellular adhesion and surface roughness in polystyrene modified by microwave plasma radiation

Directory of Open Access Journals (Sweden)

Biazar E

2011-03-01

Full Text Available Esmaeil Biazar1, Majid Heidari2, Azadeh Asefnezhad2, Naser Montazeri11Department of Chemistry, Islamic Azad University, Tonekabon Branch, Mazandaran; 2Department of Biomaterial Engineering, Faculty of Biomedical Engineering, Science and Research Branch, Islamic Azad University, Tehran, IranBackground: Surface modification of medical polymers can improve biocompatibility. Pure polystyrene is hydrophobic and cannot provide a suitable environment for cell cultures. The conventional method for surface modification of polystyrene is treatment with plasma. In this study, conventional polystyrene was exposed to microwave plasma treatment with oxygen and argon gases for 30, 60, and 180 seconds.Methods and results: Attenuated total reflection Fourier transform infrared spectra investigations of irradiated samples indicated clearly the presence of functional groups. Atomic force microscopic images of samples irradiated with inert and active gases indicated nanometric surface topography. Samples irradiated with oxygen plasma showed more roughness (31 nm compared with those irradiated with inert plasma (16 nm at 180 seconds. Surface roughness increased with increasing duration of exposure, which could be due to reduction of the contact angle of samples irradiated with oxygen plasma. Contact angle analysis showed reduction in samples irradiated with inert plasma. Samples irradiated with oxygen plasma showed a lower contact angle compared with those irradiated by argon plasma.Conclusion: Cellular investigations with unrestricted somatic stem cells showed better adhesion, cell growth, and proliferation for samples radiated by oxygen plasma with increasing duration of exposure than those of normal samples.Keywords: surface topography, polystyrene, plasma treatment, argon, oxygen

Plasma-aided surface technology for modification of materials referred to fire protection

International Nuclear Information System (INIS)

Dineff, P.; Gospodinova, D.; Kostova, L.; Vladkova, T.; Chen, E.

2008-01-01

There has been considerable interest in dielectric barrier air discharge at atmospheric pressure and room temperature over the past decade due to the increased number of industrial applications. New plasma-aided capillary impregnation technology for flame spreading stop and fire protection of porous materials was developed. Research, based on thermogravimetric analysis (TGA), differential thermal analysis (DTA), and differential scanning calorimetry (DSC), proves that plasma-chemical surface pre-treatment exert material change on chemical interaction between phosphorus containing flame retardant and wood matrix (Pinus sylvestris, Bulgaria; Pseudotsuga, Canada)

Cell adhesion and growth on ultrananocrystalline diamond and diamond-like carbon films after different surface modifications

Energy Technology Data Exchange (ETDEWEB)

Miksovsky, J. [Institute of Nanostructure Technologies and Analytics, Center for Interdisciplinary Nanostructure Science and Technology, University of Kassel (Germany); Institute of Physics ASCR, Prague (Czech Republic); Czech Technical University in Prague, Faculty of Biomedical Engineering, Kladno (Czech Republic); Voss, A. [Institute of Nanostructure Technologies and Analytics, Center for Interdisciplinary Nanostructure Science and Technology, University of Kassel (Germany); Kozarova, R. [Institute of Molecular Biology, Bulgarian Academy of Sciences, Sofia (Bulgaria); Kocourek, T.; Pisarik, P. [Institute of Physics ASCR, Prague (Czech Republic); Czech Technical University in Prague, Faculty of Biomedical Engineering, Kladno (Czech Republic); Ceccone, G. [Unit Nanobiosciences, European Commission Joint Research Centre, Ispra (Italy); Kulisch, W. [Institute of Nanostructure Technologies and Analytics, Center for Interdisciplinary Nanostructure Science and Technology, University of Kassel (Germany); Jelinek, M. [Institute of Physics ASCR, Prague (Czech Republic); Czech Technical University in Prague, Faculty of Biomedical Engineering, Kladno (Czech Republic); Apostolova, M.D. [Institute of Molecular Biology, Bulgarian Academy of Sciences, Sofia (Bulgaria); Reithmaier, J.P. [Institute of Nanostructure Technologies and Analytics, Center for Interdisciplinary Nanostructure Science and Technology, University of Kassel (Germany); Popov, C., E-mail: popov@ina.uni-kassel.de [Institute of Nanostructure Technologies and Analytics, Center for Interdisciplinary Nanostructure Science and Technology, University of Kassel (Germany)

2014-04-01

Graphical abstract: - Highlights: • UNCD and DLC films were modified by UV/O{sub 3} treatments, O{sub 2} or NH{sub 3}-containing plasmas. • Surface composition, wettability and surface energy change upon modifications. • Higher efficiency of UNCD modifications was observed. • Cell attachment and growth were influenced by the surface termination and roughness. - Abstract: Diamond and diamond-like carbon (DLC) films possess a set of excellent physical and chemical properties which together with a high biocompatibility make them attractive candidates for a number of medical and biotechnological applications. In the current work thin ultrananocrystalline diamond (UNCD) and DLC films were comparatively investigated with respect to cell attachment and proliferation after different surface modifications. The UNCD films were prepared by microwave plasma enhanced chemical vapor deposition, the DLC films by pulsed laser deposition (PLD). The films were comprehensively characterized with respect to their basic properties, e.g. crystallinity, morphology, chemical bonding nature, etc. Afterwards the UNCD and DLC films were modified applying O{sub 2} or NH{sub 3}/N{sub 2} plasmas and UV/O{sub 3} treatments to alter their surface termination. The surface composition of as-grown and modified samples was studied by X-ray photoelectron spectroscopy (XPS). Furthermore the films were characterized by contact angle measurements with water, formamide, 1-decanol and diiodomethane; from the results obtained the surface energy with its dispersive and polar components was calculated. The adhesion and proliferation of MG63 osteosarcoma cells on the different UNCD and DLC samples were assessed by measurement of the cell attachment efficiency and MTT assays. The determined cell densities were compared and correlated with the surface properties of as-deposited and modified UNCD and DLC films.

Surface modification by cold-plasma technique for dental implants—Bio-functionalization with binding pharmaceuticals

Directory of Open Access Journals (Sweden)

Masao Yoshinari

2011-08-01

At the bone tissue/implant interface, a thin calcium phosphate coating and rapid heating with infrared radiation were effective in controlling the dissolution without cracking the coating. These thin calcium phosphate coatings may directly promote osteogenisis, but also enable immobilization and subsequent drug delivery system (DDS of bisphosphonates. Simvastatin is also an effective candidate that is reported to increase the expression of BMP-2. The thin-film of hexamethyldisiloxane (HMDSO was plasma-polymerized onto titanium, and then HMDSO surface was activated by O2-plasma treatment. A quartz crystal microbalance (QCM-D technique demonstrated that simvastatin was immobilized on the plasma-treated surfaces due to introduction of O2-functional groups. At the soft tissue/implant interface, multi-grooved surface topographies and utilizing the adhesive proteins such as fibronectin or laminin-5 may help in providing a biological seal around the implant. At the oral fluid/implant interface, an alumina coating, F+-implantation and immobilization of anti-microbial peptides were responsible for inhibiting the biofilm accumulation.

Surface modification on 304 SS by plasma-immersed ion implantation to improve the adherence of a CVD diamond film

Energy Technology Data Exchange (ETDEWEB)

Nono, M.C.A.; Corat, E.J. (Instituto Nacional de Pesquisas Espaciais, Sao Jose dos Campos, SP (Brazil)); Ueda, M.; Stellati, C.; Barroso, J.J.; Conrad, J.R.; Shamim, M.; Fetherston, P.; Sridharan, K.

1999-02-01

The weak adherence of chemical vapor deposited (CVD) diamond films on steel substrates is an important factor that limits the technological applications of these materials. We are interested in enhancing the film-to-substrate adherence by using substrate surfaces with a previous modification by plasma-immersed ion implantation (PIII). In this work we present and discuss the preliminary results on phase formation, microstructure and adherence evaluations. CVD diamond films were deposited on 304 SS, the surface of which was modified by implanted carbon ions. The samples were first submitted to implantation with 30 keV carbon ions at different doses. Later, these surfaces were examined by Auger spectroscopy (SAM), scanning electron microscopy (SEM) and X-ray diffraction. We observed a metastable carbide phase formed from carbon and iron, which is considered to be a good polycrystalline material for the nucleation of CVD diamond crystals. The CVD diamond nucleation and film growth were observed by SEM and Raman spectroscopy. These results are discussed with the emphasis on the carbon diffusion barrier on the substrate surfaces. The preliminary results of diamond growth were encouraging. (orig.) 7 refs.

XIX Conference on Plasma Surface Interactions

International Nuclear Information System (INIS)

Kurnaev, V A; Gasparyan, Yu M

2016-01-01

The 19 th Conference on Plasma Surface Interactions (PSI-2016) was held at National Research Nuclear University MEPhI (Moscow Engineering Physics Institute) on 28-29 January 2016. This is a traditional annual meeting organized by MEPhI for many years and devoted to the recent achievements of Russian scientists and foreign colleagues in experimental and computer simulations of plasma and its components' interactions with plasma faced materials (PFM) for fusion devices and plasma technologies. The conference agenda covered a broad list of topics including: • plasma induced erosion and modification of materials; • radiation damage in materials; • lithium and liquid metals as PFM; • modeling of plasma surface interaction and processes in SOL of tokamak plasma; • diagnostics of plasma-surface interaction. The aim of the conference was to present and discuss new results in PSI in a wide audience with different areas of expertise. The important feature of the conference is to give PhD and undergraduate students the opportunity for approbation of results of their scientific activity and improve their knowledge in the novel directions of R and D in the field of fusion and plasma technologies. In total, more than 80 experienced and young researchers participated in the conference. These Proceedings contain 21 papers selected for publication, which were reviewed by the invited international team of editors (T. Tanabe, S. Petrovich, Ch. Grisolia, Yu. Martynenko, S. Krasheninnikov, L. Begrambekov, A. Pisarev). The Conference as well as editing of this issue were supported by National Research Nuclear University MEPhI in the framework of the Russian Academic Excellence Project (contract No. 02.a03.21.0005, 27.08.2013). Finally, we would like to thank all of the speakers, participants and organizing committee members for their contribution to the conference. Acknowledgements The organizers of the conference would like to thank for the support from National Research

Polytetrafluoroethylene surface modification by filamentary and homogeneous dielectric barrier discharges in air

International Nuclear Information System (INIS)

Fang Zhi; Hao Lili; Yang Hao; Xie Xiangqian; Qiu Yuchang; Edmund, Kuffel

2009-01-01

In this paper, polytetrafluoroethylene (PTFE) films are modified using non-equilibrium plasma generated by homogeneous DBD in air at medium pressure, and the results are compared to those treated by using filamentary DBD in air at atmospheric pressure. The surface properties of PTFE films before and after the treatments are studied using contact angle and surface energy measurement, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). It is found that the plasma treatments modify the PTFE surface in both morphology and composition. The PTFE films modified in both treatments show a remarkable decrease in water contact and a remarkable increase in surface energy. XPS analysis reveals that oxygen-containing polar groups are introduced onto the PTFE surface, and SEM analysis shows that the surfaces of the films are etched after both the treatments. It is found that homogeneous DBD is more effective in PTFE surface modification than filamentary DBD as it can make the contact angle decline to a lower level by introducing more oxygen-containing groups, and the possible reason for this effect is discussed.

Surface modification of polyester biomaterials for tissue engineering

International Nuclear Information System (INIS)

Jiao Yanpeng; Cui Fuzhai

2007-01-01

Surfaces play an important role in a biological system for most biological reactions occurring at surfaces and interfaces. The development of biomaterials for tissue engineering is to create perfect surfaces which can provoke specific cellular responses and direct new tissue regeneration. The improvement in biocompatibility of biomaterials for tissue engineering by directed surface modification is an important contribution to biomaterials development. Among many biomaterials used for tissue engineering, polyesters have been well documented for their excellent biodegradability, biocompatibility and nontoxicity. However, poor hydrophilicity and the lack of natural recognition sites on the surface of polyesters have greatly limited their further application in the tissue engineering field. Therefore, how to introduce functional groups or molecules to polyester surfaces, which ideally adjust cell/tissue biological functions, becomes more and more important. In this review, recent advances in polyester surface modification and their applications are reviewed. The development of new technologies or methods used to modify polyester surfaces for developing their biocompatibility is introduced. The results of polyester surface modifications by surface morphological modification, surface chemical group/charge modification, surface biomacromolecule modification and so on are reported in detail. Modified surface properties of polyesters directly related to in vitro/vivo biological performances are presented as well, such as protein adsorption, cell attachment and growth and tissue response. Lastly, the prospect of polyester surface modification is discussed, especially the current conception of biomimetic and molecular recognition. (topical review)

Enhancement of cell growth on honeycomb-structured polylactide surface using atmospheric-pressure plasma jet modification

Energy Technology Data Exchange (ETDEWEB)

Cheng, Kuang-Yao; Chang, Chia-Hsing; Yang, Yi-Wei; Liao, Guo-Chun; Liu, Chih-Tung; Wu, Jong-Shinn, E-mail: chongsin@faculty.nctu.edu.tw

2017-02-01

Graphical abstract: Atmospheric-pressure plasma enhances cell growth on two different pore sizes of honeycomb pattern on polylactide surface. - Highlights: • Different pore sizes of honeycomb pattern on PLA film are created. • The two-step plasma treatment provided the oxygen- and nitrogen-containing functional groups that had a major impact on cell cultivation. • The plasma treatment had a significant effect for cell proliferation. • The surface structures are the main influence on cell cultivation, while plasma treatment can indeed improve the growth environment. - Abstract: In this paper, we compare the cell growth results of NIH-3T3 and Neuro-2A cells over 72 h on flat and honeycomb structured PLA films without and with a two-step atmospheric-pressure nitrogen-based plasma jet treatment. We developed a fabrication system used for forming of a uniform honeycomb structure on PLA surface, which can produce two different pore sizes, 3–4 μm and 7–8 μm, of honeycomb pattern. We applied a previously developed nitrogen-based atmospheric-pressure dielectric barrier discharge (DBD) jet system to treat the PLA film without and with honeycomb structure. NIH-3T3 and a much smaller Neuro-2A cells were cultivated on the films under various surface conditions. The results show that the two-step plasma treatment in combination with a honeycomb structure can enhance cell growth on PLA film, should the cell size be not too smaller than the pore size of honeycomb structure, e.g., NIH-3T3. Otherwise, cell growth would be better on flat PLA film, e.g., Neuro-2A.

Improving wettability of photo-resistive film surface with plasma surface modification for coplanar copper pillar plating of IC substrates

International Nuclear Information System (INIS)

Xiang, Jing; Wang, Chong; Chen, Yuanming; Wang, Shouxu; Hong, Yan; Zhang, Huaiwu; Gong, Lijun; He, Wei

2017-01-01

Highlights: • Air atmosphere plasmacould generatehydrophilic groups of photo-resistive film. • Better wettability of photo-resistive filmled tohigher plating uniformity of copper pillars. • New flow isreduced cost, simplified process and elevated productivity. - Abstract: The wettability of the photo-resistive film (PF) surfaces undergoing different pretreatments including the O_2−CF_4 low-pressure plasma (OCLP) and air plasma (AP), is investigated by water contact angle measurement instrument (WCAMI) before the bottom-up copper pillar plating. Chemical groups analysis performed by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectra (XPS) shows that after the OCLP and wash treatment, the wettability of PF surface is attenuated, because embedded fluorine and decreased oxygen content both enhance hydrophobicity. Compared with OCLP treatment, the PF surface treatment by non-toxic air plasma displays features of C−O, O−C=O, C=O and −NO_2 by AIR-FTIR and XPS, and a promoted wettability by WCAM. Under the identical electroplating condition, the surface with a better wettability allows electrolyte to spontaneously soak all the places of vias, resulting in improved copper pillar uniformity. Statistical analysis of metallographic data shows that more coplanar and flat copper pillars are achieved with the PF treatment of air plasma. Such modified copper-pillar-plating technology meets the requirement of accurate impedance, the high density interconnection for IC substrates.

Plasma surface treatment to improve surface charge accumulation and dissipation of epoxy resin exposed to DC and nanosecond-pulse voltages

Science.gov (United States)

Zhang, Cheng; Lin, Haofan; Zhang, Shuai; Xie, Qin; Ren, Chengyan; Shao, Tao

2017-10-01

In this paper, deposition by non-thermal plasma is used as a surface modification technique to change the surface characteristics of epoxy resin exposed to DC and nanosecond-pulse voltages. The corresponding surface characteristics in both cases of DC and nanosecond-pulse voltages before and after the modification are compared and investigated. The measurement of the surface potential provides the surface charge distribution, which is used to show the accumulation and dissipation process of the surface charges. Morphology observations, chemical composition and electrical parameters measurements are used to evaluate the treatment effects. The experimental results show that, before the plasma treatment, the accumulated surface charges in the case of the DC voltage are more than that in the case of the nanosecond-pulse voltage. Moreover, the decay rate of the surface charges for the DC voltage is higher than that for the nanosecond-pulse voltage. However, the decay rate is no more than 41% after 1800 s for both types of voltages. After the plasma treatment, the maximum surface potentials decrease to 57.33% and 32.57% of their values before treatment for the DC and nanosecond-pulse voltages, respectively, indicating a decrease in the accumulated surface charges. The decay rate exceeds 90% for both types of voltages. These changes are mainly attributed to a change in the surface nanostructure, an increase in conductivity, and a decrease in the depth of energy level.

Plasma surface treatment to improve surface charge accumulation and dissipation of epoxy resin exposed to DC and nanosecond-pulse voltages

International Nuclear Information System (INIS)

Zhang, Cheng; Lin, Haofan; Zhang, Shuai; Ren, Chengyan; Shao, Tao; Xie, Qin

2017-01-01

In this paper, deposition by non-thermal plasma is used as a surface modification technique to change the surface characteristics of epoxy resin exposed to DC and nanosecond-pulse voltages. The corresponding surface characteristics in both cases of DC and nanosecond-pulse voltages before and after the modification are compared and investigated. The measurement of the surface potential provides the surface charge distribution, which is used to show the accumulation and dissipation process of the surface charges. Morphology observations, chemical composition and electrical parameters measurements are used to evaluate the treatment effects. The experimental results show that, before the plasma treatment, the accumulated surface charges in the case of the DC voltage are more than that in the case of the nanosecond-pulse voltage. Moreover, the decay rate of the surface charges for the DC voltage is higher than that for the nanosecond-pulse voltage. However, the decay rate is no more than 41% after 1800 s for both types of voltages. After the plasma treatment, the maximum surface potentials decrease to 57.33% and 32.57% of their values before treatment for the DC and nanosecond-pulse voltages, respectively, indicating a decrease in the accumulated surface charges. The decay rate exceeds 90% for both types of voltages. These changes are mainly attributed to a change in the surface nanostructure, an increase in conductivity, and a decrease in the depth of energy level. (paper)

The effects of surface modification on carbon felt electrodes for use in vanadium redox flow batteries

International Nuclear Information System (INIS)

Kim, Ki Jae; Kim, Young-Jun; Kim, Jae-Hun; Park, Min-Sik

2011-01-01

Highlights: ► We observed the physical and chemical changes on the surface of carbon felts after various surface modifications. ► The surface area and chemistry of functional groups formed on the surface of carbon felt are critical to determine the kinetics of the redox reactions of vanadium ions. ► By incorporation of the surface modifications into the electrode preparation, the electrochemical activity of carbon felts could be notably enhanced. - Abstract: The surface of carbon felt electrodes has been modified for improving energy efficiency of vanadium redox flow batteries. For comparative purposes, the effects of various surface modifications such as mild oxidation, plasma treatment, and gamma-ray irradiation on the electrochemical properties of carbon felt electrodes were investigated at optimized conditions. The cell energy efficiency was improved from 68 to 75% after the mild oxidation of the carbon felt at 500 °C for 5 h. This efficiency improvement could be attributed to the increased surface area of the carbon felt electrode and the formation of functional groups on its surface as a result of the modification. On the basis of various structural and electrochemical characterizations, a relationship between the surface nature and electrochemical activity of the carbon felt electrodes is discussed.

Fibroblastic response and surface characterization of O2-plasma-treated thermoplastic polyetherurethane

International Nuclear Information System (INIS)

Schlicht, Henning; Wintermantel, Erich; Haugen, Haavard J; Sabetrasekh, Roya

2010-01-01

Injection-molded samples of thermoplastic polyetherurethane (TPU) were treated with low-temperature oxygen plasma for different processing times in order to enhance cellular attachment for a gastric implant. Its effects were investigated by contact angle measurement, surface topography, cytotoxicity and cell colonization tests. No significant changes were found in the surface roughness of plasma treatment with plasma treatment time of less than 5 min. Longer treatment showed significantly higher surface roughness. It seems that there was a link between the changes in contact angle and enhanced cell growth on the treated surface, although only for the range up to plasma treatment times of 3 min. Prolonged treatment times did not cause any major changes in the water contact angle, but strongly improved the number of growing cells on the surface. Plasma treatment for 3-7 min led to a twofold increase in the number of cells compared to untreated samples and did not significantly alter the WST-1 nor worsened the lactate dehydrogenase activity compared to the control. Thus, it appears that O 2 plasma treatment is a suitable surface modification method for a gastric implant made of TPU in order to improve surface cell attachment where 3-7 min is the recommended treatment time.

Reconfigurable modified surface layers using plasma capillaries around the neutral inclusion regime

Energy Technology Data Exchange (ETDEWEB)

Varault, S. [ONERA—The French Aerospace Lab 2, Avenue Edouard Belin, BP4025, 31055 Toulouse Cedex (France); Universite Paul Sabatier—CNRS-Laplace 118, Route de Narbonne, F-31062 Toulouse Cedex 9 (France); Gabard, B. [ONERA—The French Aerospace Lab 2, Avenue Edouard Belin, BP4025, 31055 Toulouse Cedex (France); STAE—4, Rue Emile Monso, BP84234, 31030 Toulouse Cedex 4 (France); Crépin, T.; Bolioli, S. [ONERA—The French Aerospace Lab 2, Avenue Edouard Belin, BP4025, 31055 Toulouse Cedex (France); Sokoloff, J. [Universite Paul Sabatier—CNRS-Laplace 118, Route de Narbonne, F-31062 Toulouse Cedex 9 (France)

2014-02-28

We show both theoretically and experimentally reconfigurable properties achieved by plasma inclusions placed in modified surface layers generally used to tailor the transmission and beaming properties of electromagnetic bandgap based waveguiding structures. A proper parametrization of the plasma capillaries allows to reach the neutral inclusion regime, where the inclusions appear to be electromagnetically transparent, letting the surface mode characteristics unaltered. Varying the electron density of the plasma inclusions provoques small perturbations around this peculiar regime, and we observe significant modifications of the transmission/beaming properties. This offers a way to dynamically select the enhanced transmission frequency or to modify the radiation pattern of the structure, depending on whether the modified surface layer is placed at the entrance/exit of the waveguide.

Reconfigurable modified surface layers using plasma capillaries around the neutral inclusion regime

International Nuclear Information System (INIS)

Varault, S.; Gabard, B.; Crépin, T.; Bolioli, S.; Sokoloff, J.

2014-01-01

We show both theoretically and experimentally reconfigurable properties achieved by plasma inclusions placed in modified surface layers generally used to tailor the transmission and beaming properties of electromagnetic bandgap based waveguiding structures. A proper parametrization of the plasma capillaries allows to reach the neutral inclusion regime, where the inclusions appear to be electromagnetically transparent, letting the surface mode characteristics unaltered. Varying the electron density of the plasma inclusions provoques small perturbations around this peculiar regime, and we observe significant modifications of the transmission/beaming properties. This offers a way to dynamically select the enhanced transmission frequency or to modify the radiation pattern of the structure, depending on whether the modified surface layer is placed at the entrance/exit of the waveguide

Improved adhesion of Ag NPs to the polyethylene terephthalate surface via atmospheric plasma treatment and surface functionalization

Energy Technology Data Exchange (ETDEWEB)

Shen, Tao [Faculty of Materials Science and Engineering, Kunming University of Science and Technology, 253 Xuefu Rd, Kunming, Yunnan, 650093 (China); Liu, Yong [Faculty of Materials Science and Engineering, Kunming University of Science and Technology, 253 Xuefu Rd, Kunming, Yunnan, 650093 (China); Solmont Technology Wuxi Co., Ltd. 228 Linghu Blvd. Tianan Tech Park, A1-602, Xinwu District, Wuxi, Jiangsu 214135 (China); Zhu, Yan, E-mail: zhuyan@kmust.edu.cn [Faculty of Materials Science and Engineering, Kunming University of Science and Technology, 253 Xuefu Rd, Kunming, Yunnan, 650093 (China); Yang, De-Quan, E-mail: dequan.yang@gmail.com [Faculty of Materials Science and Engineering, Kunming University of Science and Technology, 253 Xuefu Rd, Kunming, Yunnan, 650093 (China); Solmont Technology Wuxi Co., Ltd. 228 Linghu Blvd. Tianan Tech Park, A1-602, Xinwu District, Wuxi, Jiangsu 214135 (China); Sacher, Edward [Regroupement Québécois de Matériaux de Pointe, Department of Engineering Physics, École Polytechnique de Montréal, Case Postale 6079, succursale Centre-Ville, Montréal, Québec H3C 3A7 (Canada)

2017-07-31

Highlights: • A two-step process has been developed to enhance the adhesion of immobilized Ag NPs to the PET surface. • The method is simple, easy to use and low-cost for mass production. • The increased density of active sites (−OH, −CH=O and COOH) at the PET surface, after plasma treatment, permits increased reaction with 3-aminopropyltriethoxysilane (APTES). • The presence of APTES with high surface density permits −NH{sub 2}-Ag complex formation, increasing the adhesion of the Ag NPs. - Abstract: Ag nanoparticles (NPs) have been widely applied, as important antibacterial materials, on textile and polymer surfaces. However, their adhesion to nonreactive polymer surfaces is generally too weak for many applications. Here, we propose a two-step process, atmospheric plasma treatment followed by a surface chemical modification process, which enhances their adhesion to polyethylene terephthalate (PET) surfaces. We found that, compared to either plasma treatments or surface chemical functionalizations, alone, this combination greatly enhanced their adhesion. The plasma treatment resulted in an increase of active sites (−OH, −CH=O and COOH) at the PET surface, permitting increased bonding to 3-aminopropyltriethoxysilane (APTES), whose −NH{sub 2} groups were then able to form a bonding complex with the Ag NPs.

Effects of topographical and mechanical property alterations induced by oxygen plasma modification on stem cell behavior.

Science.gov (United States)

Yang, Yong; Kulangara, Karina; Lam, Ruby T S; Dharmawan, Rena; Leong, Kam W

2012-10-23

Polymeric substrates intended for cell culture and tissue engineering are often surface-modified to facilitate cell attachment of most anchorage-dependent cell types. The modification alters the surface chemistry and possibly topography. However, scant attention has been paid to other surface property alterations. In studying oxygen plasma treatment of polydimethylsiloxane (PDMS), we show that oxygen plasma treatment alters the surface chemistry and, consequently, the topography and elasticity of PDMS at the nanoscale level. The elasticity factor has the predominant effect, compared with the chemical and topographical factors, on cell adhesions of human mesenchymal stem cells (hMSCs). The enhanced focal adhesions favor cell spreading and osteogenesis of hMSCs. Given the prevalent use of PDMS in biomedical device construction and cell culture experiments, this study highlights the importance of understanding how oxygen plasma treatment would impact subsequent cell-substrate interactions. It helps explain inconsistency in the literature and guides preparation of PDMS-based biomedical devices in the future.

Surface changes of biopolymers PHB and PLLA induced by Ar+ plasma treatment and wet etching

Science.gov (United States)

Slepičková Kasálková, N.; Slepička, P.; Sajdl, P.; Švorčík, V.

2014-08-01

Polymers, especially group of biopolymers find potential application in a wide range of disciplines due to their biodegradability. In biomedical applications these materials can be used as a scaffold or matrix. In this work, the influence of the Ar+ plasma treatment and subsequent wet etching (acetone/water) on the surface properties of polymers were studied. Two biopolymers - polyhydroxybutyrate with 8% polyhydroxyvalerate (PHB) and poly-L-lactic acid (PLLA) were used in these experiments. Modified surface layers were analyzed by different methods. Surface wettability was characterized by determination of water contact angle. Changes in elemental composition of modified surfaces were performed by X-ray Photoelectron Spectroscopy (XPS). Surface morphology and roughness was examined using Atomic Force Microscopy (AFM). Gravimetry method was used to study the mass loss. It was found that the modification from both with plasma and wet etching leads to dramatic changes of surface properties (surface chemistry, morphology and roughness). Rate of changes of these features strongly depends on the modification parameters.

Preparation and characterization of ethylenediamine and cysteamine plasma polymerized films on piezoelectric quartz crystal surfaces for a biosensor

International Nuclear Information System (INIS)

Mutlu, Selma; Coekeliler, Dilek; Shard, Alex; Goktas, Hilal; Ozansoy, Berna; Mutlu, Mehmet

2008-01-01

This paper describes a method for the modification of quartz crystal surfaces to be used as a transducer in biosensors that allow recognition and quantification of certain biomolecules (antibodies, enzymes, proteins, etc). Quartz crystal sensors were modified by a plasma based electron beam generator in order to detect the level of the toxin histamine within biological liquids (blood, serum) and food (wine, cheese, fish etc.). Cysteamine and ethylenediamine were used as precursors in the plasma. After each modification step, the layers on the quartz crystal were characterized by frequency measurements. Modified surfaces were also characterized by contact angle, X-ray photoelectron spectroscopy and atomic force microscopy to determine the physical and chemical characteristics of the surfaces after each modification. Finally, the performance of the sensors were tested by the response to histamine via frequency shifts. The frequency shifts of the sensors prepared by plasma polymerization of ethylenediamine and cysteamine were approximately 3230 Hz and 5630 Hz, respectively, whereas the frequency change of the unmodified crystal surface was around 575 Hz

Improving wettability of photo-resistive film surface with plasma surface modification for coplanar copper pillar plating of IC substrates

Energy Technology Data Exchange (ETDEWEB)

Xiang, Jing; Wang, Chong; Chen, Yuanming; Wang, Shouxu; Hong, Yan; Zhang, Huaiwu [State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054 (China); Gong, Lijun [Research and Development Department, Guangzhou Fastprint Circuit Tech Co., Ltd., Guangzhou 510663 (China); He, Wei, E-mail: heweiz@uestc.edu.cn [State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054 (China); Research and Development Department, Guangdong Guanghua Sci-Tech Co., Ltd., Shantou 515000 (China)

2017-07-31

Highlights: • Air atmosphere plasmacould generatehydrophilic groups of photo-resistive film. • Better wettability of photo-resistive filmled tohigher plating uniformity of copper pillars. • New flow isreduced cost, simplified process and elevated productivity. - Abstract: The wettability of the photo-resistive film (PF) surfaces undergoing different pretreatments including the O{sub 2}−CF{sub 4} low-pressure plasma (OCLP) and air plasma (AP), is investigated by water contact angle measurement instrument (WCAMI) before the bottom-up copper pillar plating. Chemical groups analysis performed by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectra (XPS) shows that after the OCLP and wash treatment, the wettability of PF surface is attenuated, because embedded fluorine and decreased oxygen content both enhance hydrophobicity. Compared with OCLP treatment, the PF surface treatment by non-toxic air plasma displays features of C−O, O−C=O, C=O and −NO{sub 2} by AIR-FTIR and XPS, and a promoted wettability by WCAM. Under the identical electroplating condition, the surface with a better wettability allows electrolyte to spontaneously soak all the places of vias, resulting in improved copper pillar uniformity. Statistical analysis of metallographic data shows that more coplanar and flat copper pillars are achieved with the PF treatment of air plasma. Such modified copper-pillar-plating technology meets the requirement of accurate impedance, the high density interconnection for IC substrates.

Surface modification of ceramics. Ceramics no hyomen kaishitsu

Energy Technology Data Exchange (ETDEWEB)

Hioki, T. (Toyota Central Research and Development Labs., Inc., Nagoya (Japan))

1993-07-05

Surface modification of ceramics and some study results using in implantation in surface modification are introduced. The mechanical properties (strength, fracture toughness, flaw resistance) of ceramics was improved and crack was repaired using surface modification by ion implantation. It is predicted that friction and wear properties are considerably affected because the hardness of ceramics is changed by ion implantation. Cementing and metalization are effective as methods for interface modification and the improvement of the adhesion power of the interface between metal and ceramic is their example. It was revealed that the improvement of mechanical properties of ceramics was achieved if appropriate surface modification was carried out. The market of ceramics mechanical parts is still small, therefore, the present situation is that the field of activities for surface modification of ceramics is also narrow. However, it is thought that in future, ceramics use may be promoted surely in the field like medicine and mechatronics. 8 refs., 4 figs.

Improving corrosion resistance of magnesium-based alloys by surface modification with hydrogen by electrochemical ion reduction (EIR) and by plasma immersion ion implantation (PIII)

Energy Technology Data Exchange (ETDEWEB)

Bakkar, A. [Institut fuer Materialpruefung und Werkstofftechnik, Dr. Doelling und Dr. Neubert GmbH, Freiberger Strasse 1, 38678 Clausthal (Germany); Department of Metallurgy and Materials Engineering, Suez Canal University, P.O. Box 43721, Suez (Egypt); Neubert, V. [Institut fuer Materialpruefung und Werkstofftechnik, Dr. Doelling und Dr. Neubert GmbH, Freiberger Strasse 1, 38678 Clausthal (Germany)]. E-mail: volkmar.neubert@tu-clausthal.de

2005-05-01

Magnesium-based hydrides are well known that they have a high hydrogen-storage capacity. In this study, two different methods have been provided for hydrogen surface modification of high purity magnesium (hp Mg) and AZ91 magnesium alloy. One was electrochemical ion reduction (EIR) of hydrogen from an alkaline electrolyte on such Mg-based cathode. The other was plasma immersion ion implantation (PIII or PI{sup 3}) into Mg-based substrate. The depth profile of H-modified surfaces was described by Auger electron spectroscopy (AES) and by secondary ion mass spectrometry (SIMS) measurements. Corrosion testing was carried out in Avesta cell by potentiodynamic polarisation in chloride-containing aqueous solutions of pH 7 and pH 12. A greatly significant improvement in the corrosion resistance of H-modified surfaces was verified.

Improving corrosion resistance of magnesium-based alloys by surface modification with hydrogen by electrochemical ion reduction (EIR) and by plasma immersion ion implantation (PIII)

International Nuclear Information System (INIS)

Bakkar, A.; Neubert, V.

2005-01-01

Magnesium-based hydrides are well known that they have a high hydrogen-storage capacity. In this study, two different methods have been provided for hydrogen surface modification of high purity magnesium (hp Mg) and AZ91 magnesium alloy. One was electrochemical ion reduction (EIR) of hydrogen from an alkaline electrolyte on such Mg-based cathode. The other was plasma immersion ion implantation (PIII or PI 3 ) into Mg-based substrate. The depth profile of H-modified surfaces was described by Auger electron spectroscopy (AES) and by secondary ion mass spectrometry (SIMS) measurements. Corrosion testing was carried out in Avesta cell by potentiodynamic polarisation in chloride-containing aqueous solutions of pH 7 and pH 12. A greatly significant improvement in the corrosion resistance of H-modified surfaces was verified

Study on surface adhesion of Plasma modified Polytetrafluoroethylene hollow fiber membrane

Science.gov (United States)

Chen, Jiangrong; Zhang, Huifeng; Liu, Guochang; Guo, Chungang; Lv, Jinglie; Zhangb, Yushan

2018-01-01

Polytetrafluoroethylene (PTFE) is popular membrane material because of its excellent thermal stability, chemical stability and mechanical stability. However, the low surface energy and non-sticky property of PTFE present challenges for modification. In the present study, plasma treatment was performed to improve the surface adhesion of PTFE hollow fiber membrane. The effect of discharge voltage, treatment time on the adhesion of PTFE hollow fiber membrane was symmetrically evaluated. Results showed that the plasma treatment method contributed to improve the surface activity and roughness of PTFE hollow fiber membrane, and the adhesion strength depend significantly on discharge voltage, which was beneficial to seepage pressure of PTFE hollow fiber membrane module. The adhesion strength of PTFE membrane by plasma treated at 220V for 3min reached as high as 86.2 N, far surpassing the adhesion strength 12.7 N of pristine membrane. Furthermore, improvement of content of free radical and composition analysis changes of the plasma modified PTFE membrane were investigated. The seepage pressure of PTFE membrane by plasma treated at 220V for 3min was 0.375 MPa, which means that the plasma treatment is an effective technique to improve the adhesion strength of membrane.

Covalent Surface Modifications of Carbon Nanotubes.

Energy Technology Data Exchange (ETDEWEB)

Pavia Sanders, Adriana [Sandia National Lab. (SNL-CA), Livermore, CA (United States); O' Bryan, Greg [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

2017-07-01

A report meant to document the chemistries investigated by the author for covalent surface modification of CNTs. Oxidation, cycloaddition, and radical reactions were explored to determine their success at covalently altering the CNT surface. Characterization through infrared spectroscopy, Raman spectroscopy, and thermo gravimetric analysis was performed in order to determine the success of the chemistries employed. This report is not exhaustive and was performed for CNT surface modification exploration as it pertains to the "Next Gen" project.

Hydrophobization of track membrane surface by ion-plasma sputtering method

Science.gov (United States)

Kuklin, I. E.; Khlebnikov, N. A.; Barashev, N. R.; Serkov, K. V.; Polyakov, E. V.; Zdorovets, M. V.; Borgekov, D. B.; Zhidkov, I. S.; Cholakh, S. O.; Kozlovskiy, A. L.

2017-09-01

This article reviews the possibility of applying inorganic coatings of metal compounds on PTM by ion-plasma sputtering. The main aim of this research is to increase the contact angle of PTM surfaces and to impart the properties of a hydrophobic material to it. After the modification, the initial contact angle increased from 70° to 120°.

RF-plasma vapor deposition of siloxane on paper. Part 2: Chemical evolution of paper surface

International Nuclear Information System (INIS)

Sahin, Halil Turgut

2013-01-01

Highlights: ► Investigate the detailed RF-cold plasma surface modified paper by XPS and ATR-FTIR. ► Some chemical analysis of RF-cold plasma surface modified paper after RF plasma treatment. ► Identify the connection between RF plasma treatment and the surface chemistry of paper surface. - Abstract: Survey and high-resolution (HR) XPS studies indicate that OMCTSO plasma treatment created a new silicon containing functional groups and changed the hydroxyl content on the surface of paper. Four intense survey XPS spectrum peaks were observed for the OMCTSO plasma treated paper. They were the Si 2p at 100 eV, Si 2s at 160 eV, C 1s at 285 eV, and O 1s at 525 eV for the plasma modified surface. It was realized that the macromolecular chain-breaking mechanisms and plasma-induced etching processes control the number and the availability of OH-functionalities during OMCTSO plasma exposure on paper. The reaction, initiated by these species, depends mainly on the nature of chemicals in the plasma as well as on the energy level of the plasma and the nature of the surface effects in the modification of the paper. The ATR-FTIR spectrum of paper treated with OMCTSO plasma has characteristic absorption bands attributed to the Si-O and Si-O-Si formations on the surface.

Simultaneous and long-lasting hydrophilization of inner and outer wall surfaces of polytetrafluoroethylene tubes by transferring atmospheric pressure plasmas

International Nuclear Information System (INIS)

Chen, Faze; Song, Jinlong; Huang, Shuai; Xu, Wenji; Sun, Jing; Liu, Xin; Xu, Sihao; Xia, Guangqing; Yang, Dezheng

2016-01-01

Plasma hydrophilization is a general method to increase the surface free energy of materials. However, only a few works about plasma modification focus on the hydrophilization of tube inner and outer walls. In this paper, we realize simultaneous and long-lasting plasma hydrophilization on the inner and outer walls of polytetrafluoroethylene (PTFE) tubes by atmospheric pressure plasmas (APPs). Specifically, an Ar atmospheric pressure plasma jet (APPJ) is used to modify the PTFE tube’s outer wall and meanwhile to induce transferred He APP inside the PTFE tube to modify its inner wall surface. The optical emission spectrum (OES) shows that the plasmas contain many chemically active species, which are known as enablers for various applications. Water contact angle (WCA) measurements, x-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) are used to characterize the plasma hydrophilization. Results demonstrate that the wettability of the tube walls are well improved due to the replacement of the surface fluorine by oxygen and the change of surface roughness. The obtained hydrophilicity decreases slowly during more than 180 d aging, indicating a long-lasting hydrophilization. The results presented here clearly demonstrate the great potential of transferring APPs for surface modification of the tube’s inner and outer walls simultaneously. (paper)

Surface changes of biopolymers PHB and PLLA induced by Ar{sup +} plasma treatment and wet etching

Energy Technology Data Exchange (ETDEWEB)

Slepičková Kasálková, N. [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic); Slepička, P., E-mail: petr.slepicka@vscht.cz [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic); Sajdl, P. [Department of Power Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic); Švorčík, V. [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic)

2014-08-01

Polymers, especially group of biopolymers find potential application in a wide range of disciplines due to their biodegradability. In biomedical applications these materials can be used as a scaffold or matrix. In this work, the influence of the Ar{sup +} plasma treatment and subsequent wet etching (acetone/water) on the surface properties of polymers were studied. Two biopolymers – polyhydroxybutyrate with 8% polyhydroxyvalerate (PHB) and poly-L-lactic acid (PLLA) were used in these experiments. Modified surface layers were analyzed by different methods. Surface wettability was characterized by determination of water contact angle. Changes in elemental composition of modified surfaces were performed by X-ray Photoelectron Spectroscopy (XPS). Surface morphology and roughness was examined using Atomic Force Microscopy (AFM). Gravimetry method was used to study the mass loss. It was found that the modification from both with plasma and wet etching leads to dramatic changes of surface properties (surface chemistry, morphology and roughness). Rate of changes of these features strongly depends on the modification parameters.

Vacuum-based surface modification of organic and metallic substrates

Science.gov (United States)

Torres, Jessica

Surface physico-chemical properties play an important role in the development and performance of materials in different applications. Consequently, understanding the chemical and physical processes involved during surface modification strategies is of great scientific and technological importance. This dissertation presents results from the surface modification of polymers, organic films and metallic substrates with reactive species, with the intent of simulating important modification processes and elucidating surface property changes of materials under different environments. The reactions of thermally evaporated copper and titanium with halogenated polytetrafluoroethylene (PTFE) and polyvinyl chloride (PVC) are used to contrast the interaction of metals with polymers. Results indicate that reactive metallization is thermodynamically favored when the metal-halogen bond strength is greater than the carbon-halogen bond strength. X-ray post-metallization treatment results in an increase in metal-halide bond formation due to the production of volatile halogen species in the polymer that react with the metallic overlayer. The reactions of atomic oxygen (AO) and atomic chlorine with polyethylene (PE) and self-assembled monolayers (SAMs) films were followed to ascertain the role of radical species during plasma-induced polymer surface modification. The reactions of AO with X-ray modified SAMs are initially the dominated by the incorporation of new oxygen containing functionality at the vacuum/film interface, leading to the production of volatile carbon containing species such as CO2 that erodes the hydrocarbon film. The reaction of atomic chlorine species with hydrocarbon SAMs, reveals that chlorination introduces C-Cl and C-Cl2 functionalities without erosion. A comparison of the reactions of AO and atomic chlorine with PE reveal a maximum incorporation of the corresponding C-O and C-Cl functionalities at the polymer surface. A novel method to prepare phosphorous

Corrosion principles and surface modification

International Nuclear Information System (INIS)

Kruger, J.

1982-01-01

This chapter examines the important strategies provided by the newer ideas of corrosion science and engineering that surface modification techniques must utilize to help prevent corrosion, especially the most damaging kind of aqueous corrosion, localized corrosion. Provides a brief introduction to the principles underlying the phenomenon of corrosion in order to use them to discuss surface modification strategies to combat corrosion. Discusses the electrochemistry of corrosion; the thermodynamics of corrosion; the kinetics of corrosion; thermodynamic strategies; and kinetic strategies (formation of more protective passive films; resistance to breakdown; ductility; repassivation)

Diagnostics of plasma-biological surface interactions in low pressure and atmospheric pressure plasmas

International Nuclear Information System (INIS)

Ishikawa, Kenji; Hori, Masaru

2014-01-01

Mechanisms of plasma-surface interaction are required to understand in order to control the reactions precisely. Recent progress in atmospheric pressure plasma provides to apply as a tool of sterilization of contaminated foodstuffs. To use the plasma with safety and optimization, the real time in situ detection of free radicals - in particular dangling bonds by using the electron-spin-resonance (ESR) technique has been developed because the free radical plays important roles for dominantly biological reactions. First, the kinetic analysis of free radicals on biological specimens such as fungal spores of Penicillium digitatum interacted with atomic oxygen generated plasma electric discharge. We have obtained information that the in situ real time ESR signal from the spores was observed and assignable to semiquinone radical with a g-value of around 2.004 and a line width of approximately 5G. The decay of the signal was correlated with a link to the inactivation of the fungal spore. Second, we have studied to detect chemical modification of edible meat after the irradiation. Using matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy (MALDI-TOF-MS) and ESR, signals give qualification results for chemical changes on edible liver meat. The in situ real-time measurements have proven to be a useful method to elucidate plasma-induced surface reactions on biological specimens. (author)

Plasma-surface interactions

International Nuclear Information System (INIS)

Goeckner, M J; Nelson, C T; Sant, S P; Jindal, A K; Joseph, E A; Zhou, B S; Padron-Wells, G; Jarvis, B; Pierce, R; Overzet, L J

2008-01-01

Materials processing is at a crossroads. Currently a large fraction of industrially viable materials processing is via plasmas. Until recently it has been economical to just examine the influence the plasma properties on the desired surface processes and through this ultimately optimize manufacturing. For example, it is well known that the surface processes (etch or deposition), occur in the top few mono-layers of the surface. Thus, in film growth one requires that molecules from the gas-phase land and bond on the surface. However as processing has reached the nano-scale, development of viable processes has become more and more difficult. In part, this is because of all of the free parameters that exist in plasmas. To overcome this economic issue, tool vendors and semiconductor companies have turned to complex computational models of processing plasmas. For those models to work, one requires a through understanding of all of the gas-phase and surface-phase processes that are exhibited in plasmas. Unfortunately, these processes, particularly those at the surface, are not well understood. In this article we describe a viable model of the surface-phase based on cross sections for processes that occur. While originally developed of fluorocarbon systems, the model also appears to be applicable to hydrocarbon systems.

Plasma-surface interactions

Energy Technology Data Exchange (ETDEWEB)

Goeckner, M J; Nelson, C T; Sant, S P; Jindal, A K; Joseph, E A; Zhou, B S; Padron-Wells, G; Jarvis, B; Pierce, R; Overzet, L J [Department of Electrical Engineering, University of Texas at Dallas (United States)], E-mail: goeckner@utdallas.edu

2008-10-01

Materials processing is at a crossroads. Currently a large fraction of industrially viable materials processing is via plasmas. Until recently it has been economical to just examine the influence the plasma properties on the desired surface processes and through this ultimately optimize manufacturing. For example, it is well known that the surface processes (etch or deposition), occur in the top few mono-layers of the surface. Thus, in film growth one requires that molecules from the gas-phase land and bond on the surface. However as processing has reached the nano-scale, development of viable processes has become more and more difficult. In part, this is because of all of the free parameters that exist in plasmas. To overcome this economic issue, tool vendors and semiconductor companies have turned to complex computational models of processing plasmas. For those models to work, one requires a through understanding of all of the gas-phase and surface-phase processes that are exhibited in plasmas. Unfortunately, these processes, particularly those at the surface, are not well understood. In this article we describe a viable model of the surface-phase based on cross sections for processes that occur. While originally developed of fluorocarbon systems, the model also appears to be applicable to hydrocarbon systems.

Active screen plasma nitriding enhances cell attachment to polymer surfaces

International Nuclear Information System (INIS)

Kaklamani, Georgia; Bowen, James; Mehrban, Nazia; Dong, Hanshan; Grover, Liam M.; Stamboulis, Artemis

2013-01-01

Active screen plasma nitriding (ASPN) is a well-established technique used for the surface modification of materials, the result of which is often a product with enhanced functional performance. Here we report the modification of the chemical and mechanical properties of ultra-high molecular weight poly(ethylene) (UHMWPE) using 80:20 (v/v) N 2 /H 2 ASPN, followed by growth of 3T3 fibroblasts on the treated and untreated polymer surfaces. ASPN-treated UHMWPE showed extensive fibroblast attachment within 3 h of seeding, whereas fibroblasts did not successfully attach to untreated UHMWPE. Fibroblast-coated surfaces were maintained for up to 28 days, monitoring their metabolic activity and morphology throughout. The chemical properties of the ASPN-treated UHMWPE surface were studied using X-ray photoelectron spectroscopy, revealing the presence of C-N, C=N, and C≡N chemical bonds. The elastic modulus, surface topography, and adhesion properties of the ASPN-treated UHMWPE surface were studied over 28 days during sample storage under ambient conditions and during immersion in two commonly used cell culture media.

Plasma surface oxidation of 316L stainless steel for improving adhesion strength of silicone rubber coating to metal substrate

Energy Technology Data Exchange (ETDEWEB)

Latifi, Afrooz, E-mail: afroozlatifi@yahoo.com [Department of Biomaterials, Biomedical Engineering Faculty, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Imani, Mohammad [Novel Drug Delivery Systems Dept., Iran Polymer and Petrochemical Institute, P.O. Box 14965/115, Tehran (Iran, Islamic Republic of); Khorasani, Mohammad Taghi [Biomaterials Dept., Iran Polymer and Petrochemical Institute, P.O. Box 14965/159, Tehran (Iran, Islamic Republic of); Daliri Joupari, Morteza [Animal and Marine Biotechnology Dept., National Institute of Genetic Engineering and Biotechnology, P.O. Box 14965/161, Tehran (Iran, Islamic Republic of)

2014-11-30

Highlights: • Stainless steel 316L was surface modified by plasma surface oxidation (PSO) and silicone rubber (SR) coating. • On the PSO substrates, concentration of oxide species was increased ca. 2.5 times comparing to non-PSO substrates. • The surface wettability was improved to 12.5°, in terms of water contact angle, after PSO. • Adhesion strength of SR coating on the PSO substrates was improved by more than two times comparing to non-PSO ones. • After pull-off test, the fractured area patterns for SR coating were dependent on the type of surface modifications received. - Abstract: Stainless steel 316L is one of the most widely used materials for fabricating of biomedical devices hence, improving its surface properties is still of great interest and challenging in biomaterial sciences. Plasma oxidation, in comparison to the conventional chemical or mechanical methods, is one of the most efficient methods recently used for surface treatment of biomaterials. Here, stainless steel specimens were surface oxidized by radio-frequency plasma irradiation operating at 34 MHz under pure oxygen atmosphere. Surface chemical composition of the samples was significantly changed after plasma oxidation by appearance of the chromium and iron oxides on the plasma-oxidized surface. A wettable surface, possessing high surface energy (83.19 mN m{sup −1}), was observed after plasma oxidation. Upon completion of the surface modification process, silicone rubber was spray coated on the plasma-treated stainless steel surface. Morphology of the silicone rubber coating was investigated by scanning electron microscopy (SEM). A uniform coating was formed on the oxidized surface with no delamination at polymer–metal interface. Pull-off tests showed the lowest adhesion strength of coating to substrate (0.12 MPa) for untreated specimens and the highest (0.89 MPa) for plasma-oxidized ones.

Surface Modification of Biomaterials: A Quest for Blood Compatibility

Directory of Open Access Journals (Sweden)

Achala de Mel

2012-01-01

Full Text Available Cardiovascular implants must resist thrombosis and intimal hyperplasia to maintain patency. These implants when in contact with blood face a challenge to oppose the natural coagulation process that becomes activated. Surface protein adsorption and their relevant 3D confirmation greatly determine the degree of blood compatibility. A great deal of research efforts are attributed towards realising such a surface, which comprise of a range of methods on surface modification. Surface modification methods can be broadly categorized as physicochemical modifications and biological modifications. These modifications aim to modulate platelet responses directly through modulation of thrombogenic proteins or by inducing antithrombogenic biomolecules that can be biofunctionalised onto surfaces or through inducing an active endothelium. Nanotechnology is recognising a great role in such surface modification of cardiovascular implants through biofunctionalisation of polymers and peptides in nanocomposites and through nanofabrication of polymers which will pave the way for finding a closer blood match through haemostasis when developing cardiovascular implants with a greater degree of patency.

Adhesive Stretchable Printed Conductive Thin Film Patterns on PDMS Surface with an Atmospheric Plasma Treatment.

Science.gov (United States)

Li, Chun-Yi; Liao, Ying-Chih

2016-05-11

In this study, a plasma surface modification with printing process was developed to fabricate printed flexible conductor patterns or devices directly on polydimethylsiloxane (PDMS) surface. An atmospheric plasma treatment was first used to oxidize the PDMS surface and create a hydrophilic silica surface layer, which was confirmed with photoelectron spectra. The plasma operating parameters, such as gas types and plasma powers, were optimized to obtain surface silica layers with the longest lifetime. Conductive paste with epoxy resin was screen-printed on the plasma-treated PDMS surface to fabricate flexible conductive tracks. As a result of the strong binding forces between epoxy resin and the silica surface layer, the printed patterns showed great adhesion on PDMS and were undamaged after several stringent adhesion tests. The printed conductive tracks showed strong mechanical stability and exhibited great electric conductivity under bending, twisting, and stretching conditions. Finally, a printed pressure sensor with good sensitivity and a fast response time was fabricated to demonstrate the capability of this method for the realization of printed electronic devices.

Nanoscale mechanical and tribological properties of fluorocarbon films grafted onto plasma-treated low-density polyethylene surfaces

International Nuclear Information System (INIS)

Cheng, Q; Komvopoulos, K

2012-01-01

Fluorocarbon (FC) films were grafted onto Ar plasma-treated low-density polyethylene (LDPE) surfaces by plasma polymerization and deposition. The evolution of the surface morphology of the grafted FC films was investigated at different scales with an atomic force microscope. Nanoscale sliding experiments performed with a surface force microscope provided insight into the nanotribological properties of Ar plasma-treated LDPE, with and without grafted FC films, in terms of applied normal load and number of sliding cycles. The observed trends are explained in the context of microstructure models accounting for morphological and structure changes at the LDPE surface due to the effects of plasma treatment (e.g., selective etching of amorphous phase, chain crosslinking and FC film grafting) and surface sliding (e.g., crystalline lamellae alignment along the sliding direction). Nanoindentation experiments elucidated the effect of plasma treatment on surface viscoelasticity and global contact stiffness. The results of this study demonstrate that plasma-assisted grafting of FC films is an effective surface modification method for tuning the nanomechanical/tribological properties of polymers. (paper)

Influence of atmospheric pressure plasma treatment on surface properties of PBO fiber

International Nuclear Information System (INIS)

Zhang Ruiyun; Pan Xianlin; Jiang Muwen; Peng Shujing; Qiu Yiping

2012-01-01

Highlights: ► PBO fibers were treated with atmospheric pressure plasmas. ► When 1% of oxygen was added to the plasma, IFSS increased 130%. ► Increased moisture regain could enhance plasma treatment effect on improving IFSS with long treatment time. - Abstract: In order to improve the interfacial adhesion property between PBO fiber and epoxy, the surface modification effects of PBO fiber treated by atmospheric pressure plasma jet (APPJ) in different time, atmosphere and moisture regain (MR) were investigated. The fiber surface morphology, functional groups, surface wettability for control and plasma treated samples were analyzed by scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and water contact angle measurements, respectively. Meanwhile, the fiber interfacial shear strength (IFSS), representing adhesion property in epoxy, was tested using micro-bond pull-out test, and single fiber tensile strength was also tested to evaluate the mechanical performance loss of fibers caused by plasma treatment. The results indicated that the fiber surface was etched during the plasma treatments, the fiber surface wettability and the IFSS between fiber and epoxy had much improvement due to the increasing of surface energy after plasma treatment, the contact angle decreased with the treatment time increasing, and the IFSS was improved by about 130%. The processing atmosphere could influence IFSS significantly, and moisture regains (MR) of fibers also played a positive role on improving IFSS but not so markedly. XPS analysis showed that the oxygen content on fiber surface increased after treatment, and C=O, O-C=O groups were introduced on fiber surface. On the other hand, the observed loss of fiber tensile strength caused by plasma treatment was not so remarkable to affect the overall performance of composite materials.

Surface treatment of aramid fiber by air dielectric barrier discharge plasma at atmospheric pressure

International Nuclear Information System (INIS)

Jia Caixia; Chen Ping; Liu Wei; Li Bin; Wang Qian

2011-01-01

Aramid fiber samples are treated by air dielectric barrier discharge (DBD) plasma at atmospheric pressure; the plasma treatment time is investigated as the major parameter. The effects of this treatment on the fiber surface physical and chemical properties are studied by using surface characterization techniques. Scanning electron microscopy (SEM) is performed to determine the surface morphology changes, X-ray photoelectron spectroscopy (XPS) is analyzed to reveal the surface chemical composition variations and dynamic contact angle analysis (DCAA) is used to examine the changes of the fiber surface wettability. In addition, the wetting behavior of a kind of thermoplastic resin, poly(phthalazinone ether sulfone ketone) (PPESK), on aramid fiber surface is also observed by SEM photos. The study shows that there seems to be an optimum treatment condition for surface modification of aramid fiber by the air DBD plasma. In this paper, after the 12 s, 27.6 W/cm 3 plasma treatment the aramid fiber surface roughness is significantly improved, some new oxygen-containing groups such as C-O, C=O and O=C-O are generated on the fiber surface and the fiber surface wettability is greatly enhanced, which results in the better wetting behavior of PPESK resin on the plasma-treated aramid fiber.

Functionalization of polymer surfaces by medium frequency non-thermal plasma

Science.gov (United States)

Felix, T.; Trigueiro, J. S.; Bundaleski, N.; Teodoro, O. M. N. D.; Sério, S.; Debacher, N. A.

2018-01-01

This work addresses the surface modification of different polymers by argon dielectric barrier discharge, using bromoform vapours. Atomic Force Microscopy and Scanning Electron Microscopy showed that plasma etching occurs in stages and may be related to the reach of the species generated and obviously the gap between the electrodes. In addition, the stages of flatten surface or homogeneity may be the result of the transient crosslinking promoted by the intense UV radiation generated by the non- thermal plasma. X-ray Photoelectron Spectroscopy analysis showed that bromine was inserted on the polymer surface as Csbnd Br bonds and as adsorbed HBr. The obtained results demonstrate that the highest degree of bromofunctionalization was achieved on polypropylene surface, which contains about 8,5% of Br. After its derivatization in ammonia, Br disappeared and about 6% of nitrogen in the form of amine group was incorporated at the surface. This result can be considered as a clear fingerprint of the Br substitution by the amine group, thus illustrating the efficiency of the proposed method for functionalization of polymer surfaces.

Surface martensitization of Carbon steel using Arc Plasma Sintering

Science.gov (United States)

Wahyudi, Haris; Dimyati, Arbi; Sebayang, Darwin

2018-03-01

In this paper new technology of surface structure modification of steel by short plasma exposure in Arc Plasma Sintering (APS) device is presented. APS is an apparatus working based on plasma generated by DC pulsed current originally used for synthesizing materials via sintering and melting. Plasma exposure in APS was applied into the specimens for 1 and 3 seconds which generate temperature approximately about 1300-1500°C. The SUP9, pearlitic carbon steel samples were used. The hardness, hardening depth and microstructure of the specimens have been investigated by Vickers micro hardness test and Scanning Electron Microscopy (SEM) supported by Energy Dispersive X-Ray Spectroscopy (EDX). The results have showed that the mechanical property was significantly improved due to the formation of single martensitic structures as identified by SEM. The hardness of treated surface evaluated by Vickers hardness test showed significant improvement nearly three time from 190 VHN before to 524 VHN after treatment. Furthermore, EDX confirmed that the formation of martensite layer occurred without altering its composition. The APS also produced uniform hardened layer up to 250 μm. The experiment has demonstrated that arc plasma process was successfully improved the mechanical properties of steel in relatively very short time.

Enhancing the formation and shear resistance of nitrifying biofilms on membranes by surface modification

DEFF Research Database (Denmark)

Lackner, Susanne; Holmberg, Maria; Terada, Akihiko

2009-01-01

Polypropylene (PP) membranes and polyethylene (PE) surfaces were modified to enhance formation and shear resistance of nitrifying biofilms for wastewater treatment applications. A combination of plasma polymerization and wet chemistry was employed to ultimately introduce poly(ethyleneglycol) (PEG......) chains with two different functional groups (-PEG-NH2 and -PEG-CH3). Biofilm growth experiments using a mixed nitrifying bacterial culture revealed that the specific combination of PEG chains with amino groups resulted in most biofilm formation on both PP and PE samples. Detachment experiments showed...... structure might be possible explanations of the superiority of the -PEG-NH2 modification. The success of the-PEG-NH2 modification was independent of the original surface and might, therefore, be used in wastewater treatment bioreactors to improve reactor performance by making biofilm formation more stable...

Tribological effects of polymer surface modification through plastic

Indian Academy of Sciences (India)

Tribological effects of polymer surface modification through plastic deformation. K O Low K J Wong ... In this regard, a surface modification technique through plastic deformation has been implemented. ... Bulletin of Materials Science | News.

Endothelial cell behaviour on gas-plasma-treated PLA surfaces: the roles of surface chemistry and roughness.

Science.gov (United States)

Shah, Amita; Shah, Sarita; Mani, Gopinath; Wenke, Joseph; Agrawal, Mauli

2011-04-01

Glow-discharge gas-plasma (GP) treatment has been shown to induce surface modifications such that cell adhesion and growth are enhanced. However, it is not known which gas used in GP treatment is optimal for endothelial cell function. Polylactic acid (PLA) films treated oxygen, argon, or nitrogen GP were characterized using contact angles, scanning electron microscopy, atomic force microscopy, optical profilometry, and x-ray photoelectron spectroscopy. All three GP treatments decreased the carbon atomic concentration and surface roughness and increased the oxygen atomic concentration. Human umbilical vein endothelial cells were cultured on the PLA films for up to 7 days. Based on proliferation and live/dead assays, surface chemistry was shown to have the greatest effect on the attachment, proliferation, and viability of these cells, while roughness did not have a significant influence. Of the different gases, endothelial cell viability, attachment and proliferation were most significantly increased on PLA surfaces treated with oxygen and argon gas plasma. Copyright © 2010 John Wiley & Sons, Ltd.

Effect of surface modifications and environment on the interfacial adhesion of polymer/aluminum alloy

Energy Technology Data Exchange (ETDEWEB)

Liu, X.F. [Xi' an High-technology Institute, Xi' an 710025 (China)], E-mail: xiaofang_liu@263.net; Wu, Q.Y.; Wang, H.G. [Xi' an High-technology Institute, Xi' an 710025 (China)

2008-06-15

This work investigates the influence of surface modifications and environmental conditions on the interfacial adhesion of epoxy resin films on a 6016 aluminum alloy, as measured by peeling experiments. The alloy surfaces were pretreated with an etching solution, and then modified, respectively, with aminopropyl silane solution, aminopropyl phosphonate solution, and hexamethyldisiloxane plasma. The modified surfaces were examined by scanning electron microscopy and their roughness was quantified by a fractal index. The peeling experiments show that the interfacial adhesion of epoxy on the aluminum alloy mainly results from the chemical and mechanical characteristics of the material surface. Environmental factors such as humidity can also weaken interfacial adhesion.

Effect of surface modifications and environment on the interfacial adhesion of polymer/aluminum alloy

International Nuclear Information System (INIS)

Liu, X.F.; Wu, Q.Y.; Wang, H.G.

2008-01-01

This work investigates the influence of surface modifications and environmental conditions on the interfacial adhesion of epoxy resin films on a 6016 aluminum alloy, as measured by peeling experiments. The alloy surfaces were pretreated with an etching solution, and then modified, respectively, with aminopropyl silane solution, aminopropyl phosphonate solution, and hexamethyldisiloxane plasma. The modified surfaces were examined by scanning electron microscopy and their roughness was quantified by a fractal index. The peeling experiments show that the interfacial adhesion of epoxy on the aluminum alloy mainly results from the chemical and mechanical characteristics of the material surface. Environmental factors such as humidity can also weaken interfacial adhesion

Copper circuit patterning on polymer using selective surface modification and electroless plating

Energy Technology Data Exchange (ETDEWEB)

Park, Sang Jin [Department of Materials Science and Engineering, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Ko, Tae-Jun [Institute for Multidisciplinary Convergence of Materials, Korea Institute of Science and Technology, Seoul 130-650 (Korea, Republic of); Department of Materials Science and Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of); Yoon, Juil [Department of Mechanical Systems Engineering, Hansung University, Seoul 136-792 (Korea, Republic of); Moon, Myoung-Woon [Institute for Multidisciplinary Convergence of Materials, Korea Institute of Science and Technology, Seoul 130-650 (Korea, Republic of); Oh, Kyu Hwan [Department of Materials Science and Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of); Han, Jun Hyun, E-mail: jhhan@cnu.ac.kr [Department of Materials Science and Engineering, Chungnam National University, Daejeon 305-764 (Korea, Republic of)

2017-02-28

Highlights: • A new simple two step method for the pattering of Cu circuits on PET substrate was proposed. • The simple patterning of the high adhesive Cu circuits was achieved by plasma treatment using a patterned mask coated with a catalyst material. • The high adhesive strength of Cu circuits was due to the nanostructure formed by oxygen plasma treatment. - Abstract: We have examined a potential new and simple method for patterning a copper circuit on PET substrate by copper electroless plating, without the pretreatment steps (i.e., sensitization and activation) for electroless plating as well as the etching processes of conventional circuit patterning. A patterned mask coated with a catalyst material, Ag, for the reduction of Cu ions, is placed on a PET substrate. Subsequent oxygen plasma treatment of the PET substrate covered with the mask promotes the selective generation of anisotropic pillar- or hair-like nanostructures coated with co-deposited nanoparticles of the catalyst material on PET. After oxygen plasma treatment, a Cu circuit is well formed just by dipping the plasma-treated PET into a Cu electroless plating solution. By increasing the oxygen gas pressure in the chamber, the height of the nanostructures increases and the Ag catalyst particles are coated on not only the top but also the side surfaces of the nanostructures. Strong mechanical interlocking between the Cu circuit and PET substrate is produced by the large surface area of the nanostructures, and enhances peel strength. Results indicate this new simple two step (plasma surface modification and pretreatment-free electroless plating) method can be used to produce a flexible Cu circuit with good adhesion.

Organic light emitting diode with surface modification layer

Science.gov (United States)

Basil, John D.; Bhandari, Abhinav; Buhay, Harry; Arbab, Mehran; Marietti, Gary J.

2017-09-12

An organic light emitting diode (10) includes a substrate (12) having a first surface (14) and a second surface (16), a first electrode (32), and a second electrode (38). An emissive layer (36) is located between the first electrode (32) and the second electrode (38). The organic light emitting diode (10) further includes a surface modification layer (18). The surface modification layer (18) includes a non-planar surface (30, 52).

Facile surface modification of silicone rubber with zwitterionic polymers for improving blood compatibility

International Nuclear Information System (INIS)

Liu, Pingsheng; Chen, Qiang; Yuan, Bo; Chen, Mengzhou; Wu, Shishan; Lin, Sicong; Shen, Jian

2013-01-01

A facile approach to modify silicone rubber (SR) membrane for improving the blood compatibility was investigated. The hydrophobic SR surface was firstly activated by air plasma, after which an initiator was immobilized on the activated surface for atom transfer radical polymerization (ATRP). Three zwitterionic polymers were then grafted from SR membrane via surface-initiated atom transfer radical polymerization (SI-ATRP). The surface composition, wettability, and morphology of the membranes before and after modification were characterized by X-ray photoelectron spectroscopy (XPS), static water contact angle (WCA) measurement, and atomic force microscopy (AFM). Results showed that zwitterionic polymers were successfully grafted from SR surfaces, which remarkably improved the wettability of the SR surface. The blood compatibility of the membranes was evaluated by protein adsorption and platelet adhesion tests in vitro. As observed, all the zwitterionic polymer modified surfaces have improved resistance to nonspecific protein adsorption and have excellent resistance to platelet adhesion, showing significantly improved blood compatibility. This work should inspire many creative uses of SR based materials for biomedical applications such as vessel, catheter, and microfluidics. Highlights: • Facile surface modification of silicone rubber with functional brushes • Modified SR surfaces have improved resistance to nonspecific protein adsorption. • Modified SR surfaces have excellent resistance to platelet adhesion. • Zwitteironic surface significant improvement in blood compatibility • Could inspire many creative uses of SR based materials for biomedical

Facile surface modification of silicone rubber with zwitterionic polymers for improving blood compatibility

Energy Technology Data Exchange (ETDEWEB)

Liu, Pingsheng [School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (China); Chen, Qiang, E-mail: chem100@nju.edu.cn [School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (China); High Technology Research Institute of Nanjing University, Changzhou 213164 (China); Yuan, Bo; Chen, Mengzhou; Wu, Shishan; Lin, Sicong [School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (China); Shen, Jian, E-mail: shenj1957@yahoo.com.cn [School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (China)

2013-10-15

A facile approach to modify silicone rubber (SR) membrane for improving the blood compatibility was investigated. The hydrophobic SR surface was firstly activated by air plasma, after which an initiator was immobilized on the activated surface for atom transfer radical polymerization (ATRP). Three zwitterionic polymers were then grafted from SR membrane via surface-initiated atom transfer radical polymerization (SI-ATRP). The surface composition, wettability, and morphology of the membranes before and after modification were characterized by X-ray photoelectron spectroscopy (XPS), static water contact angle (WCA) measurement, and atomic force microscopy (AFM). Results showed that zwitterionic polymers were successfully grafted from SR surfaces, which remarkably improved the wettability of the SR surface. The blood compatibility of the membranes was evaluated by protein adsorption and platelet adhesion tests in vitro. As observed, all the zwitterionic polymer modified surfaces have improved resistance to nonspecific protein adsorption and have excellent resistance to platelet adhesion, showing significantly improved blood compatibility. This work should inspire many creative uses of SR based materials for biomedical applications such as vessel, catheter, and microfluidics. Highlights: • Facile surface modification of silicone rubber with functional brushes • Modified SR surfaces have improved resistance to nonspecific protein adsorption. • Modified SR surfaces have excellent resistance to platelet adhesion. • Zwitteironic surface significant improvement in blood compatibility • Could inspire many creative uses of SR based materials for biomedical.

Surface Modifications in Adhesion and Wetting

Science.gov (United States)

Longley, Jonathan

Advances in surface modification are changing the world. Changing surface properties of bulk materials with nanometer scale coatings enables inventions ranging from the familiar non-stick frying pan to advanced composite aircraft. Nanometer or monolayer coatings used to modify a surface affect the macro-scale properties of a system; for example, composite adhesive joints between the fuselage and internal frame of Boeing's 787 Dreamliner play a vital role in the structural stability of the aircraft. This dissertation focuses on a collection of surface modification techniques that are used in the areas of adhesion and wetting. Adhesive joints are rapidly replacing the familiar bolt and rivet assemblies used by the aerospace and automotive industries. This transition is fueled by the incorporation of composite materials into aircraft and high performance road vehicles. Adhesive joints have several advantages over the traditional rivet, including, significant weight reduction and efficient stress transfer between bonded materials. As fuel costs continue to rise, the weight reduction is accelerating this transition. Traditional surface pretreatments designed to improve the adhesion of polymeric materials to metallic surfaces are extremely toxic. Replacement adhesive technologies must be compatible with the environment without sacrificing adhesive performance. Silane-coupling agents have emerged as ideal surface modifications for improving composite joint strength. As these coatings are generally applied as very thin layers (coatings using the buckling instability formed between two materials of a large elastic mismatch. The elastic modulus is found to effectively predict the joint strength of an epoxy/aluminum joint that has been reinforced with silane coupling agents. This buckling technique is extended to investigate the effects of chemical composition on the elastic modulus. Finally, the effect of macro-scale roughness on silane-reinforced joints is investigated

Fouling behavior of poly(ether)sulfone ultrafiltration membrane during concentration of whey proteins: Effect of hydrophilic modification using atmospheric pressure argon jet plasma.

Science.gov (United States)

Damar Huner, Irem; Gulec, Haci Ali

2017-12-01

The aim of the study was to investigate the effects of hydrophilic surface modification via atmospheric pressure jet plasma (ApJPls) on the fouling propensity of polyethersulfone (PES) ultrafiltration (UF) membranes during concentration of whey proteins. The distance from nozzle to substrate surface of 30mm and the exposure period of 5 times were determined as the most effective parameters enabling an increase in ΔG iwi value of the plain membrane from (-) 14.92±0.89mJ/m 2 to (+) 17.57±0.67mJ/m 2 . Maximum hydrophilicity and minimum surface roughness achieved by argon plasma action resulted in better antifouling behavior, while the hydraulic permeability and the initial permeate flux were decreased sharply due to the plasma-induced surface cross-linking. A quite steady state flux was obtained throughout the UF with the ApJPls modified PES membrane. The contribution of R frev to R t , which was 94% for the UF through the plain membrane, decreased to 43% after the plasma treatment. The overall results of this study highlighted the ApJPls modification decreased the fouling propensity of PES membrane without affecting the original protein rejection capability and improved the recovery of initial permeate flux after chemical cleaning. Copyright © 2017 Elsevier B.V. All rights reserved.

Enhancement of the Laser Transmission Weldability between Polyethylene and Polyoxymethylene by Plasma Surface Treatment

Directory of Open Access Journals (Sweden)

Huixia Liu

2017-12-01

Full Text Available Due to their large compatibility difference, polyethylene (PE and polyoxymethylene (POM cannot be welded together by laser transmission welding. In this study, PE and POM are pretreated using plasma that significantly enhances their laser transmission welding strength. To understand the mechanism underlying the laser welding strength enhancement, surface modification is analyzed using contact angle measurements, atomic force microscopy (AFM, optical microscopy, and X-ray photoelectron spectroscopy (XPS. Characterization results show that the plasma surface treatment improves the surface free energy, significantly enhancing the wettability of the materials. The increase in surface roughness and the generation of homogeneous bubbles contribute to the formation of mechanical micro-interlocking. The oxygen-containing groups introduced by the oxygen plasma treatment improve the compatibility of PE and POM, and facilitate the diffusion and entanglement of molecular chains and the formation of van der Waals force.

Formation of hydrophobic coating on glass surface using atmospheric pressure non-thermal plasma in ambient air

International Nuclear Information System (INIS)

Fang, Z; Qiu, Y; Kuffel, E

2004-01-01

Non-thermal plasmas under atmospheric pressure are of great interest in material surface processing because of their convenience, effectiveness and low cost. In this paper, the treatment of a glass surface for improving hydrophobicity using a non-thermal plasma generated by a dielectric barrier corona discharge (DBCD) with a needle array-to-plane electrode arrangement in atmospheric air is conducted, and the surface properties of the glass before and after the DBCD treatment are studied using contact angle measurement, surface resistance measurement and the wet flashover voltage test. The effects of the plasma dose (the product of average discharge power and treatment time) of DBCD on the surface modification are studied, and the mechanism of interaction between the plasma and glass surface is discussed. It is found that a layer of hydrophobic coating is formed on the glass surface through DBCD treatment, and the improvement of hydrophobicity depends on the plasma dose of the DBCD. It seems that there is an optimum plasma dose for the surface treatment. The test results of thermal ageing and chemical ageing show that the hydrophobic layer has quite stable characteristics

In vitro biocompatibility of titanium after plasma surface alloying with boron

Energy Technology Data Exchange (ETDEWEB)

Kaczmarek, Mariusz, E-mail: markacz@ump.edu.pl [Department of Immunology, Chair of Clinical Immunology, Poznan University of Medical Sciences, Rokietnicka 5D, 60-806 Poznan (Poland); Jurczyk, Mieczysława U. [Division Mother' s and Child' s Health, Poznan University of Medical Sciences, Polna 33, 60-535 Poznan (Poland); Miklaszewski, Andrzej [Institute of Materials Science and Engineering, Poznan University of Technology, Jana Pawla II 24, 61-138 Poznan (Poland); Paszel-Jaworska, Anna; Romaniuk, Aleksandra; Lipińska, Natalia [Department of Clinical Chemistry and Molecular Diagnostics, Poznan University of Medical Sciences, Przybyszewskiego 49, 60-355 Poznan (Poland); Żurawski, Jakub [Department of Immunobiochemistry, Chair of Biology and Environmental Sciences, Poznan University of Medical Sciences, Rokietnicka 8, 60-806 Poznan (Poland); Urbaniak, Paulina [Department of Cell Biology, Poznan University of Medical Sciences, Rokietnicka 5D, 60-806 Poznan (Poland); Jurczyk, Karolina [Department of Conservative Dentistry and Periodontology, Poznan University of Medical Sciences, Bukowska 70, 60-812 Poznan (Poland)

2016-12-01

Recently, the effect of different sizes of precursor powders during surface plasma alloying modification on the properties of titanium surface was studied. In this work we show in vitro test results of the titanium (α-Ti) after plasma surface alloying with boron (B). Ti-B nanopowders with 2 and 10 wt% B were deposited onto microcrystalline Ti substrate. The in vitro cytocompatibility of these biomaterials was evaluated and compared with a conventional microcrystalline Ti. During the studies, established cell line of human gingival fibroblasts and osteoblasts were cultured in the presence of tested materials, and its survival rate and proliferation activity were examined. For this purpose, MTT assay, flow cytometric and fluorescent microscopic evaluation were made. Biocompatibility tests carried out indicate that the Ti after plasma surface alloying with B could be a possible candidate for dental implants and other medicinal applications. Plasma alloying is a promising method for improving the properties of titanium, thus increasing the field of its applications. - Highlights: • this is first article carried out on the titanium after plasma surface alloying with different contents of boron; • microcrystalline titanium modified with boron changes the physicochemical features of conventional material; • Ti modified by boron is proper in terms of effects on survival and proliferative activity of cells of dental alveoli; • precursors with different content of boron in different ways influence the intensity and stability of cell growth;.

How to increase the hydrophobicity of PTFE surfaces using an r.f. atmospheric-pressure plasma torch

NARCIS (Netherlands)

Carbone, E.A.D.; Boucher, N.; Sferrazza, M.; Reniers, F.

2010-01-01

An experimental investigation of the surface modification of polytetrafluoroethylene (PTFE) by an Ar and Ar/O2 plasma created with an atmospheric-pressure radio frequency (r.f.) torch is presented here. The surfaces were analyzed by atomic force microscopy (AFM), XPS and water contact angle (WCA) to

Nanofibrillated Cellulose Surface Modification: A Review

Directory of Open Access Journals (Sweden)

Julien Bras

2013-05-01

Full Text Available Interest in nanofibrillated cellulose (NFC has increased notably over recent decades. This bio-based nanomaterial has been used essentially in bionanocomposites or in paper thanks to its high mechanical reinforcement ability or barrier property respectively. Its nano-scale dimensions and its capacity to form a strong entangled nanoporous network have encouraged the emergence of new high-value applications. It is worth noting that chemical surface modification of this material can be a key factor to achieve a better compatibility with matrices. In order to increase the compatibility in different matrices or to add new functions, surface chemical modification of NFC appears to be the prior choice to conserve its intrinsic nanofibre properties. In this review, the authors have proposed for the first time an overview of all chemical grafting strategies used to date on nanofibrillated cellulose with focus on surface modification such as physical adsorption, molecular grafting or polymer grafting.

Atmospheric pressure plasmas for surface modification of flexible and printed electronic devices: A review

Energy Technology Data Exchange (ETDEWEB)

Kim, Kyong Nam; Lee, Seung Min; Mishra, Anurag [Department of Materials Science and Engineering, Sungkyunkwan University, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); Yeom, Geun Young, E-mail: gyyeom@skku.edu [Department of Materials Science and Engineering, Sungkyunkwan University, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); SKKU Advanced Institute of Nano Technology (SAINT), Sungkyunkwan University, Suwon, Gyeonggi-do 440-746 (Korea, Republic of)

2016-01-01

Recently, non-equilibrium atmospheric pressure plasma, especially those operated at low gas temperatures, have become a topic of great interest for the processing of flexible and printed electronic devices due to several benefits such as the reduction of process and reactor costs, the employment of easy-to-handle apparatuses and the easier integration into continuous production lines. In this review, several types of typical atmospheric pressure plasma sources have been addressed, and the processes including surface treatment, texturing and sintering for application to flexible and printed electronic devices have been discussed.

Surface modification of Ti-_6Al-_4V titanium alloy by combined ion-plasma treatment

International Nuclear Information System (INIS)

Cherenda, N.N.; Shimanskij, V.I.; Laskovnev, A.P.; Basalaj, A.V.; Astashinskij, V.M.; Kuz'mitskij, A.M.

2015-01-01

Investigation results of phase and elemental composition, microhardness and friction coefficient of Ti-_6Al-_4V alloy samples precoated by titanium subjected to compression plasma flows treatment have been presented in this work. It has been established that the combined effect of ion-plasma flows diminishes aluminum and vanadium concentration in the surface layer, leads to the growth of its microhardness and decrease of the friction coefficient. (authors)

Surface modification of a proton exchange membrane and hydrogen storage in a metal hydride for fuel cells

Science.gov (United States)

Andrews, Lisa

Interest in fuel cell technology is rising as a result of the need for more affordable and available fuel sources. Proton exchange membrane fuel cells involve the catalysis of a fuel to release protons and electrons. It requires the use of a polymer electrolyte membrane to transfer protons through the cell, while the electrons pass through an external circuit, producing electricity. The surface modification of the polymer, NafionRTM, commonly researched as a proton exchange membrane, may improve efficiency of a fuel cell. Surface modification can change the chemistry of the surface of a polymer while maintaining bulk properties. Plasma modification techniques such as microwave discharge of an argon and oxygen gas mixture as well as vacuum-ultraviolet (VUV) photolysis may cause favorable chemical and physical changes on the surface of Nafion for improved fuel cell function. A possible increase in hydrophilicity as a result of microwave discharge experiments may increase proton conductivity. Grafting of acrylic acid from the surface of modified Nafion may decrease the permeation of methanol in a direct methanol fuel cell, a process which can decrease efficiency. Modification of the surface of Nafion samples were carried out using: 1) An indirect Ar/O2 gas mixture plasma investigating the reaction of oxygen radicals with the surface, 2) A direct Ar/O2 gas mixture plasma investigating the reaction of oxygen radicals and VUV radiation with the surface and, 3) VUV photolysis investigating exclusively the interaction of VUV radiation with the surface and any possible oxidation upon exposure to air. Acrylic acid was grafted from the VUV photolysed Nafion samples. All treated surfaces were analyzed using X-ray photoelectron spectroscopy (XPS). Fourier transform infrared spectroscopy (FTIR) was used to analyze the grafted Nafion samples. Scanning electron microscopy (SEM) and contact angle measurements were used to analyze experiments 2 and 3. Using hydrogen as fuel is a

Surface Modification of C17200 Copper-Beryllium Alloy by Plasma Nitriding of Cu-Ti Gradient Film

Science.gov (United States)

Zhu, Y. D.; Yan, M. F.; Zhang, Y. X.; Zhang, C. S.

2018-03-01

In the present work, a copper-titanium film of gradient composition was firstly fabricated by the dual magnetron sputtering through power control and plasma nitriding of the film was then conducted to modify C17200 Cu alloy. The results showed that the prepared gradient Cu-Ti film by magnetron sputtering was amorphous. After plasma nitriding at 650 °C, crystalline Cu-Ti intermetallics appeared in the multi-phase coating, including CuTi2, Cu3Ti, Cu3Ti2 and CuTi. Moreover, even though the plasma nitriding duration of the gradient Cu-Ti film was only 0.5 h, the mechanical properties of the modified Cu surface were obviously improved, with the surface hardness enhanced to be 417 HV0.01, the wear rate to be 0.32 × 10-14 m3/Nm and the friction coefficient to be 0.075 at the load of 10 N, which are all more excellent than the C17200 Cu alloy. In addition, the wear mechanism also changed from adhesion wear for C17200 Cu substrate to abrasive wear for the modified surface.

Evaluation of mechanism of non-thermal plasma effect on the surface of polypropylene films for enhancement of adhesive and hemo compatible properties

Energy Technology Data Exchange (ETDEWEB)

Navaneetha Pandiyaraj, K., E-mail: dr.knpr@gmail.com [Surface Engineering Laboratory, Department of Physics, Sri Shakthi Institute of Engineering and Technology, L& T by pass, Chinniyam Palayam (post), Coimbatore-641062 (India); Deshmukh, R.R. [Department of Physics, Institute of Chemical Technology, Matunga, Mumbai-400 019 (India); Arunkumar, A.; Ramkumar, M.C. [Surface Engineering Laboratory, Department of Physics, Sri Shakthi Institute of Engineering and Technology, L& T by pass, Chinniyam Palayam (post), Coimbatore-641062 (India); Ruzybayev, I.; Ismat Shah, S. [Department of Physics and Astronomy, Department of Materials Science and Engineering, University of Delaware, 208 Dupont Hall, Newark (United States); Su, Pi-Guey [Department of Chemistry, Chinese Culture University, Taipei 111, Taiwan (China); Periayah, Mercy Halleluyah; Halim, A.S. [School of Medical Sciences, Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan (Malaysia)

2015-08-30

Highlights: • Investigated the mechanism of effect of various gaseous plasma treatments on the surface properties of Polypropylene (PP) films. • The improvement in surface energy is basically due to the incorporation of polar functional groups onto the PP films. • The extent of surface modification and hydrophobic recovery depends upon the type of plasma forming gas. • Due to the significant morphological and chemical changes induced by the gaseous plasma treatment, improved the blood compatibility as well as adhesive strength of the PP films. - Abstract: The hydro-carbon based polymers have attracted attention of scientists for its use in bio-medical field as various implants due to inherent flexibility. However, they have poor surface properties; particularly they have low surface energy (SE). Hence, blood components (platelets, blood proteins, etc.)-polymer surface interaction is the major concern when it comes in contact with blood. Thus, surface modification is required to develop the perfect antithrombogenic property without affecting the materials bulk. The present study describes the improvement in adhesive and blood compatible properties of polypropylene (PP) by low temperature (non-thermal) plasma of various gases such as Ar, O{sub 2}, air and Ar + O{sub 2} for biomedical applications. The changes in surface morphological, chemical and hydrophilic modification induced by the gaseous plasma treatment were analyzed by atomic force microscopy (AFM), X-ray photo electron spectroscopy (XPS), electron spin resonance (ESR) spectroscopy and contact angle measurements, respectively. Moreover, the stability of plasma effect was also studied for the different storage conditions. Variation in adhesive strength of the plasma treated PP film was studied by T-Peel and Lap-Shear strength tests. The blood compatibility of the surface modified PP films was investigated by in vitro analysis. It was found that gaseous plasma treatment improved the blood compatibility

Evaluation of mechanism of non-thermal plasma effect on the surface of polypropylene films for enhancement of adhesive and hemo compatible properties

International Nuclear Information System (INIS)

Navaneetha Pandiyaraj, K.; Deshmukh, R.R.; Arunkumar, A.; Ramkumar, M.C.; Ruzybayev, I.; Ismat Shah, S.; Su, Pi-Guey; Periayah, Mercy Halleluyah; Halim, A.S.

2015-01-01

Highlights: • Investigated the mechanism of effect of various gaseous plasma treatments on the surface properties of Polypropylene (PP) films. • The improvement in surface energy is basically due to the incorporation of polar functional groups onto the PP films. • The extent of surface modification and hydrophobic recovery depends upon the type of plasma forming gas. • Due to the significant morphological and chemical changes induced by the gaseous plasma treatment, improved the blood compatibility as well as adhesive strength of the PP films. - Abstract: The hydro-carbon based polymers have attracted attention of scientists for its use in bio-medical field as various implants due to inherent flexibility. However, they have poor surface properties; particularly they have low surface energy (SE). Hence, blood components (platelets, blood proteins, etc.)-polymer surface interaction is the major concern when it comes in contact with blood. Thus, surface modification is required to develop the perfect antithrombogenic property without affecting the materials bulk. The present study describes the improvement in adhesive and blood compatible properties of polypropylene (PP) by low temperature (non-thermal) plasma of various gases such as Ar, O 2 , air and Ar + O 2 for biomedical applications. The changes in surface morphological, chemical and hydrophilic modification induced by the gaseous plasma treatment were analyzed by atomic force microscopy (AFM), X-ray photo electron spectroscopy (XPS), electron spin resonance (ESR) spectroscopy and contact angle measurements, respectively. Moreover, the stability of plasma effect was also studied for the different storage conditions. Variation in adhesive strength of the plasma treated PP film was studied by T-Peel and Lap-Shear strength tests. The blood compatibility of the surface modified PP films was investigated by in vitro analysis. It was found that gaseous plasma treatment improved the blood compatibility as well

Modifications in SnS thin films by plasma treatments

Energy Technology Data Exchange (ETDEWEB)

Martinez, H., E-mail: hm@fis.unam.mx [Instituto de Ciencias Fisicas, Universidad Nacional Autonoma de Mexico, Apartado Postal 48-3, 62210 Cuernavaca, Morelos (Mexico); Avellaneda, D. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon (Mexico)

2012-02-01

The present study shows the modifications of structural, optical and electrical characteristics that occur in tin sulfide (SnS) thin films treated in air and in nitrogen plasma at different pressure conditions. The films were obtained by the chemical bath deposition method, which results in SnS thin films with an orthorhombic crystalline structure, band gap (E{sub g}) of 1.1-1.2 eV, and electrical conductivities ({sigma}) in the order of 10{sup -6} {Omega}{sup -1}cm{sup -1}. The films treated with air plasma at pressures between 1 and 4 Torr, showed the presence of SnS{sub 2}, Sn{sub 2}S{sub 3}, and SnO{sub 2} phases, within the band gap values ranging from 0.9 to 1.5 eV. On the other hand, the films treated with nitrogen plasma presented the same phases, but showed a significant modification in the electrical conductivity, increasing from 10{sup -6} {Omega}{sup -1}cm{sup -1} (as-deposited) up to 10{sup -2}-10{sup -3} {Omega}{sup -1}cm{sup -1} (plasma treated). This result is a suitable range of conductivity for the improvement of the solar cells with SnS as an absorber material. Also, emission spectroscopy measurements were carried out in both air and nitrogen plasma treatments.

Reduced chemical warfare agent sorption in polyurethane-painted surfaces via plasma-enhanced chemical vapor deposition of perfluoroalkanes.

Science.gov (United States)

Gordon, Wesley O; Peterson, Gregory W; Durke, Erin M

2015-04-01

Perfluoralkalation via plasma chemical vapor deposition has been used to improve hydrophobicity of surfaces. We have investigated this technique to improve the resistance of commercial polyurethane coatings to chemicals, such as chemical warfare agents. The reported results indicate the surface treatment minimizes the spread of agent droplets and the sorption of agent into the coating. The improvement in resistance is likely due to reduction of the coating's surface free energy via fluorine incorporation, but may also have contributing effects from surface morphology changes. The data indicates that plasma-based surface modifications may have utility in improving chemical resistance of commercial coatings.

Influence of plasma modification on hygienic properties of textile fabrics with nonporous membrane coating

Science.gov (United States)

Voznesensky, E. F.; Ibragimov, R. G.; Vishnevskaya, O. V.; Sisoev, V. A.; Lutfullina, G. G.; Tihonova, N. V.

2017-11-01

The work investigated the possibility of using plasma modification to improve the hygienic properties of textile materials with nonporous membrane coating to improve vapor-, air-permeability and water-resistant. Determined that, after plasma modification changes degree of supramolecular orderliness of the polymers nonporous membrane coating and the base fabric.

Comparison of the properties polyamide 6.6 surfaces treated by plasma and by ionizing radiation

International Nuclear Information System (INIS)

Irineu, Rosa Maria da Silva

2010-01-01

This study aims to compare the surface properties of polyamide 6.6 plasma treatment and ionizing radiation, as well as determine the best technique and condition of the surface activation, adhesion of the same order and polyacrylic rubber used in manufacturing of automotive retainers. Treatment of polyamide 6.6 plasma was performed using an equipment 'Electronic Diener - Plasma - Surface-Technology LFG40' with nitrogen gas at a pressure of 1.40 kg/cm 2 . Samples of polyamide 6.6 were also treated with ionizing radiation, atmospheric pressure and in vacuum, using an industrial electron accelerator, Dynamitron JOB 188 with radiation dose of 5, 10, 20, 40, 50, 100, 200, 300, 400 and 500kGy with a dose rate of 11.22 kGy/s for all doses and rate of 11.22 kGy/s and 22.38 kGy/s for a dose of 20kGy. After the processes of surface modification of polyamide 6.6, part of the untreated samples, treated by plasma and by ionizing radiation were incorporated into the polyacrylic rubber, and another part was designed to characterize the surface using the techniques of SEM / EDS, FT- IR, PIXE / RBS, AFM and contact angle. Untreated samples and the irradiated samples did not join the polyacrylic rubber. The samples treated by plasma joined the polyacrylic rubber efficiently and showed differences in roughness in SEM and AFM, and an increase in contact angle when compared with untreated samples. The irradiated samples showed no significant differences in the analysis of properties used in this study when compared with untreated samples. Ionizing radiation was not effective in surface modification of polyamide 6.6 for adherence with polyacrylic rubber. (author)

Modification of rubber surface by UV surface grafting

International Nuclear Information System (INIS)

Shanmugharaj, A.M.; Kim, Jin Kuk; Ryu, Sung Hun

2006-01-01

Rubber surface is subjected to ultraviolet radiation (UV) in the presence of allylamine and radiation sensitizer benzophenone (BP). Fourier transform infrared spectral studies reveal the presence of allylamine on the surface. The presence of irregular needle shapes on the surface as observed in scanning electron micrographs also confirms the polymerized allylamine on the surface. Allylamine coatings have been further confirmed from atomic force microscopy (AFM) analysis. Thermogravimetric analysis (TGA) reveals that allylamine coating on the rubber surface lowers the thermal degradation rate. The contact angle between the water and rubber surface decreases for the modified rubber surface confirming the surface modification due to UV surface grafting

Effects of fiber density and plasma modification of nanofibrous membranes on the adhesion and growth of HaCaT keratinocytes.

Science.gov (United States)

Bacakova, Marketa; Lopot, Frantisek; Hadraba, Daniel; Varga, Marian; Zaloudkova, Margit; Stranska, Denisa; Suchy, Tomas; Bacakova, Lucie

2015-01-01

It may be possible to regulate the cell colonization of biodegradable polymer nanofibrous membranes by plasma treatment and by the density of the fibers. To test this hypothesis, nanofibrous membranes of different fiber densities were treated by oxygen plasma with a range of plasma power and exposure times. Scanning electron microscopy and mechanical tests showed significant modification of nanofibers after plasma treatment. The intensity of the fiber modification increased with plasma power and exposure time. The exposure time seemed to have a stronger effect on modifying the fiber. The mechanical behavior of the membranes was influenced by the plasma treatment, the fiber density, and their dry or wet state. Plasma treatment increased the membrane stiffness; however, the membranes became more brittle. Wet membranes displayed significantly lower stiffness than dry membranes. X-ray photoelectron spectroscopy (XPS) analysis showed a slight increase in oxygen-containing groups on the membrane surface after plasma treatment. Plasma treatment enhanced the adhesion and growth of HaCaT keratinocytes on nanofibrous membranes. The cells adhered and grew preferentially on membranes of lower fiber densities, probably due to the larger area of void spaces between the fibers. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Luminescent, water-soluble silicon quantum dots via micro-plasma surface treatment

International Nuclear Information System (INIS)

Wu, Jeslin J; Siva Santosh Kumar Kondeti, Vighneswara; Bruggeman, Peter J; Kortshagen, Uwe R

2016-01-01

Silicon quantum dots (SiQDs), with their broad absorption, narrow and size-tunable emission, and potential biocompatibility are highly attractive materials in biological imaging applications. The inherent hydrophobicity and instability of hydrogen-terminated SiQDs are obstacles to their widespread implementation. In this work, we successfully produced highly luminescent, hydrophilic SiQDs with long-term stability in water using non-thermal plasma techniques. Hydrogen-terminated SiQDs were produced in a low-pressure plasma and subsequently treated in water using an atmospheric-pressure plasma jet for surface modification. Preliminary assessments of the chemical mechanism(s) involved in the creation of water-soluble SiQDs were performed using Fenton’s reaction and various plasma chemistries, suggesting both OH and O species play a key role in the oxidation of the SiQDs. (letter)

Atmospheric pressure plasma jet's characterization and surface wettability driven by neon transformer

Science.gov (United States)

Elfa, R. R.; Nafarizal, N.; Ahmad, M. K.; Sahdan, M. Z.; Soon, C. F.

2017-03-01

Atmospheric pressure plasma driven by Neon transformer power supply argon is presented in this paper. Atmospheric pressure plasma system has attracted researcher interest over low pressure plasma as it provides a flexibility process, cost-efficient, portable device and vacuum-free device. Besides, another golden key of this system is the wide promising application in the field of work cover from industrial and engineering to medical. However, there are still numbers of fundamental investigation that are necessary such as device configuration, gas configuration and its effect. Dielectric barrier discharge which is also known as atmospheric pressure plasma discharge is created when there is gas ionization process occur which enhance the movement of atom and electron and provide energetic particles. These energetic particles can provide modification and cleaning property to the sample surface due to the bombardment of the high reactive ion and radicals to the sample surface. In order to develop atmospheric pressure plasma discharge, a high voltage and high frequency power supply is needed. In this work, we used a neon transformer power supply as the power supply. The flow of the Ar is feed into 10 mm cylinder quartz tube with different treatment time in order to investigate the effect of the plasma discharge. The analysis of each treatment time is presented by optical emission spectroscopy (OES) and water contact angle (WCA) measurement. The increase of gas treatment time shows increases intensity of reactive Ar and reduces the angle of water droplets in water contact angle. Treatment time of 20 s microslide glass surface shows that the plasma needle discharges have modified the sample surface from hydrophilic surface to superhydrophilic surface. Thus, this leads to another interesting application in reducing sample surface adhesion to optimize productivity in the industry of paintings, semiconductor and more.

Overview on the Surface Functionalization Mechanism and Determination of Surface Functional Groups of Plasma Treated Carbon Nanotubes.

Science.gov (United States)

Saka, Cafer

2018-01-02

The use of carbon materials for many applications is due to the unique diversity of structures and properties ranging from chemical bonds between the carbon atoms of the materials to nanostructures, crystallite alignment, and microstructures. Carbon nanotubes and other nanoscale carbonaceous materials draw much attention due to their physical and chemical properties, such as high strength, high resistance to corrosion, electrical and thermal conductivity, stability and a qualified adsorbent. Carbon-based nanomaterials, which have a relatively large specific area and layered structure, can be used as an adsorbent for efficient removal of organic and inorganic contaminants. However, one of the biggest obstacles to the development of carbon-based nanomaterials adsorbents is insolubility and the lack of functional groups on the surface. There are several approaches to introduce functional groups on carbon nanotubes. One of these approaches, plasma applications, now has an important place in the creation of surface functional groups as a flexible, fast, and environmentally friendly method. This review focuses on recent information concerning the surface functionalization and modification of plasma treated carbon nanotube. This review considers the surface properties, advantages, and disadvantages of plasma-applied carbon nanotubes. It also examines the reaction mechanisms involved in the functional groups on the surface.

Optimization of Phospholipase A1 Immobilization on Plasma Surface Modified Chitosan Nanofibrous Mat

Directory of Open Access Journals (Sweden)

Zahra Beig Mohammadi

2016-01-01

Full Text Available Phospholipase A1 is known as an effective catalyst for hydrolysis of various phospholipids in enzymatic vegetable oil degumming. Immobilization is one of the most efficient strategies to improve its activity, recovery and functional properties. In this study, chitosan-co-polyethylene oxide (90:10 nanofibrous mat was successfully fabricated and modified with atmospheric plasma at different times (2, 6 and 10 min to interact with enzyme molecules. Scanning electron microscopy images revealed that the membranes retained uniform nanofibrous and open porous structures before and after the treatment. PLA1 was successfully immobilized onto the membrane surfaces via covalent bonds with the functional groups of chitosan nanofibrous mat. Response surface methodology was used to optimize the immobilization conditions for reaching the maximum immobilization efficiency. Enzyme concentration, pH, and immobilization time were found to be significant key factors. Under optimum conditions (5.03 h, pH 5.63, and enzyme dosage 654.36 UI, the atmospheric plasma surface modified chitosan nanofibers reached the highest immobilization efficiency (78.50%. Fourier transform infrared spectroscopy of the control and plasma surface-modified chitosan nanofibers revealed the functional groups of nanofibers and their reaction with the enzyme. The results indicated that surface modification by atmospheric plasma induced an increase in PLA1 loading on the membrane surfaces.

Plasma surface modification of poly (L-lactic acid) and poly (lactic-co-glycolic acid) films for improvement of nerve cells adhesion

International Nuclear Information System (INIS)

Khorasani, M.T.; Mirzadeh, H.; Irani, S.

2008-01-01

Radio frequency (RF) plasma treatment in O 2 was applied to modify the surface of poly (L-lactic acid) (PLLA) and poly (D,L-lactic acid-coglycolic acid) (PLGA) as biodegradable polymers. The surface structure, morphology, wettability and surface chemistry of treated films were characterized by water drop contact angle measurement, scanning electron microscope (SEM), optical invert microscope, differential scanning calorimetry (DSC) and ATIR-FTIR spectroscopy. The cell affinity of the oxygen plasma treated film was evaluated by nervous tissue B65 cell culture in stationary conditions. The results showed that the hydrophilicity increased greatly after O 2 plasma treatment. The results showed that improved cell adhesion was attributed to the combination of surface chemistry and surface wettability during plasma treatment. Cell culture results showed that B65 nervous cell attachment and growth on the plasma treated PLLA was much higher than an unmodified sample and PLGA. Surface hydrophilicity and chemical functional groups with high polar component play an important role in enhancing cell attachment and growth

X-ray photoelectron spectroscopic depth profilometry of nitrogen implanted in materials for modification of their surface properties

International Nuclear Information System (INIS)

Sarkissian, A.H.; Paynter, R.; Stansfield, B.L.

1996-01-01

The modification of the surface properties of materials has a wide range of industrial applications. For example, the authors change the electrical characteristics of semiconductors, improve surface hardness, decrease friction, increase resistance to corrosion, improve adhesion, etc. Nitriding is one of the most common processes used in industry for surface treatment. Nitrogen ion implantation is one technique often used to achieve this goal. Ion implantation offers the power to control the deposition profile, and can be achieved by either conventional ion beam implantation or plasma assisted ion implantation. They have used the technique of plasma assisted ion implantation to implant nitrogen in several materials, including titanium, silicon and stainless steel. The plasma source is a surface ECR source developed at INRS-Energie et Materiaux. The depth profile of the implanted ions has been measured by X-ray photoelectron spectroscopy. They have also conducted simulations using the TRIM-95 code to predict the depth profile of the implanted ions. Comparisons of the measured results with those from simulations are used to deduce information regarding the plasma composition and the collisional effects in the plasma. A fast responding, current and voltage measuring circuit with fiber optic links is being developed, which allows more accurate quantitative measurements. Further experiments to study the characteristics of the plasma, and their effects on the characteristics of the implanted surfaces are in progress, and the results are presented at this meeting

Influence of tungsten microstructure and ion flux on deuterium plasma-induced surface modifications and deuterium retention

NARCIS (Netherlands)

Buzi, L.; De Temmerman, G.; Unterberg, B.; M. Reinhart,; Dittmar, T.; Matveev, D.; Linsmeier, C.; Breuer, U.; Kreter, A.; Van Oost, G.

2015-01-01

The influence of surface temperature, particle flux density and material microstructure on the surface morphology and deuterium retention was studied by exposing tungsten targets (20 μm and 40 μm grain size) to deuterium plasma at the same particle fluence (1026 m−2) and

Surface modification of Ti dental implants by Nd:YVO4 laser irradiation

International Nuclear Information System (INIS)

Braga, Francisco J.C.; Marques, Rodrigo F.C.; Filho, Edson de A.; Guastaldi, Antonio C.

2007-01-01

Surface modifications have been applied in endosteal bone devices in order to improve the osseointegration through direct contact between neoformed bone and the implant without an intervening soft tissue layer. Surface characteristics of titanium implants have been modified by addictive methods, such as metallic titanium, titanium oxide and hydroxyapatite powder plasma spray, as well as by subtractive methods, such as acid etching, acid etching associated with sandblasting by either AlO 2 or TiO 2 , and recently by laser ablation. Surface modification for dental and medical implants can be obtained by using laser irradiation technique where its parameters like repetition rate, pulse energy, scanning speed and fluency must be taken into accounting to the appropriate surface topography. Surfaces of commercially pure Ti (cpTi) were modified by laser Nd:YVO 4 in nine different parameters configurations, all under normal atmosphere. The samples were characterized by SEM and XRD refined by Rietveld method. The crystalline phases αTi, βTi, Ti 6 O, Ti 3 O and TiO were formed by the melting and fast cooling processes during irradiation. The resulting phases on the irradiated surface were correlated with the laser beam parameters. The aim of the present work was to control titanium oxides formations in order to improve implants osseointegration by using a laser irradiation technique which is of great importance to biomaterial devices due to being a clean and reproducible process

Plasma nitriding - an eco friendly surface hardening process

International Nuclear Information System (INIS)

Mukherjee, S.

2015-01-01

Surface hardening is a process of heating the metal such that the surface gets only hardened. This process is adopted for many components like gears, cams, and crankshafts, which desire high hardness on the outer surface with a softer core to withstand the shocks. So, to attain such properties processes like carburising, nitriding, flame hardening and induction hardening are employed. Amongst these processes nitriding is the most commonly used process by many industries. In nitriding process the steel material is heated to a temperature of around 550 C and then exposed to atomic nitrogen. This atomic nitrogen reacts with iron and other alloying elements and forms nitrides, which are very hard in nature. By this process both wear resistance and hardness of the product can be increased. The atomic nitrogen required for this process can be obtained using ammonia gas (gas nitriding), cyanide based salt bath (liquid nitriding) and plasma medium (plasma nitriding). However, plasma nitriding has recently received considerable industrial interest owing to its characteristic of faster nitrogen penetration, short treatment time, low process temperature, minimal distortion, low energy use and easier control of layer formation compared with conventional techniques such as gas and liquid nitriding. This process can be used for all ferrous materials including stainless steels. Plasma nitriding is carried out using a gas mixture of nitrogen and hydrogen gas at sub atmospheric pressures hence, making it eco-friendly in nature. Plasma nitriding allows modification of the surface layers and hardness profiles by changing the gas mixture and temperature. The wide applicable temperature range enables a multitude of applications, beyond the possibilities of gas or salt bath processes. This has led to numerous applications of this process in industries such as the manufacture of machine parts for plastics and food processing, packaging and tooling as well as pumps and hydraulic, machine

Production of atmospheric pressure microwave plasma with dielectric half-mirror resonator and its application to polymer surface treatment

Science.gov (United States)

Sasai, Kensuke; Keyamura, Kazuki; Suzuki, Haruka; Toyoda, Hirotaka

2018-06-01

For the surface treatment of a polymer tube, a ring-shaped atmospheric pressure microwave plasma (APMP) using a coaxial waveguide is studied. In this APMP, a dielectric plate is used not only as a partial mirror for cavity resonation but also for the precise alignment of the discharge gap for ring-shaped plasma production. The optimum position of the dielectric plate is investigated by electromagnetic wave simulation. On the basis of simulation results, a ring-shaped plasma with good uniformity along the ring is produced. The coaxial APMP is applied to the surface treatment of ethylene tetrafluoroethylene. A very fast surface modification within 3 s is observed.

Surface conductivity dependent dynamic behaviour of an ultrafine atmospheric pressure plasma jet for microscale surface processing

Energy Technology Data Exchange (ETDEWEB)

Abuzairi, Tomy [Graduate School of Science and Technology, Shizuoka University, Hamamatsu 432-8561 (Japan); Department of Electrical Engineering, Faculty of Engineering, Universitas Indonesia, Depok 16424 (Indonesia); Okada, Mitsuru [Department of Engineering, Shizuoka University, Hamamatsu 432-8561 (Japan); Bhattacharjee, Sudeep [Department of Physics, Indian Institute of Technology, Kanpur 208016 (India); Nagatsu, Masaaki, E-mail: nagatsu.masaaki@shizuoka.ac.jp [Graduate School of Science and Technology, Shizuoka University, Hamamatsu 432-8561 (Japan); Department of Engineering, Shizuoka University, Hamamatsu 432-8561 (Japan); Research Institute of Electronics, Shizuoka University, Hamamatsu 432-8561 (Japan)

2016-12-30

Highlights: • Spatio-temporal behaviors of capillary APPJs are studied for various substrates. • Plasma irradiation area depended on the substrate conductivity and permittivity. • Surface irradiation area was significantly broadened in polymer-like substrate. • Effect of applying a substrate bias on the APPJ irradiation area was investigated. - Abstract: An experimental study on the dynamic behaviour of microcapillary atmospheric pressure plasma jets (APPJs) with 5 μm tip size for surfaces of different conductivity is reported. Electrical and spatio-temporal characteristics of the APPJs are monitored using high voltage probe, current monitor and high speed intensified charge couple device camera. From these experimental results, we presented a simple model to understand the electrical discharge characteristics of the capillary APPJs with double electrodes, and estimated the velocity of the ionization fronts in the jet and the electron density to be 3.5–4.2 km/s and 2–7 × 10{sup 17} m{sup −3}. By analyzing the dynamics of the microcapillary APPJs for different substrate materials, it was found that the surface irradiation area strongly depended on the substrate conductivity and permittivity, especially in the case of polymer-like substrate, surface irradiation area was significantly broadened probably due to the repelling behaviour of the plasma jets from the accumulated electrical charges on the polymer surface. The effect of applying a substrate bias in the range from −900 V to +900 V on the plasma irradiation onto the substrates was also investigated. From the knowledge of the present results, it is helpful for choosing the substrate materials for microscale surface modification.

Surface conductivity dependent dynamic behaviour of an ultrafine atmospheric pressure plasma jet for microscale surface processing

International Nuclear Information System (INIS)

Abuzairi, Tomy; Okada, Mitsuru; Bhattacharjee, Sudeep; Nagatsu, Masaaki

2016-01-01

Highlights: • Spatio-temporal behaviors of capillary APPJs are studied for various substrates. • Plasma irradiation area depended on the substrate conductivity and permittivity. • Surface irradiation area was significantly broadened in polymer-like substrate. • Effect of applying a substrate bias on the APPJ irradiation area was investigated. - Abstract: An experimental study on the dynamic behaviour of microcapillary atmospheric pressure plasma jets (APPJs) with 5 μm tip size for surfaces of different conductivity is reported. Electrical and spatio-temporal characteristics of the APPJs are monitored using high voltage probe, current monitor and high speed intensified charge couple device camera. From these experimental results, we presented a simple model to understand the electrical discharge characteristics of the capillary APPJs with double electrodes, and estimated the velocity of the ionization fronts in the jet and the electron density to be 3.5–4.2 km/s and 2–7 × 10"1"7 m"−"3. By analyzing the dynamics of the microcapillary APPJs for different substrate materials, it was found that the surface irradiation area strongly depended on the substrate conductivity and permittivity, especially in the case of polymer-like substrate, surface irradiation area was significantly broadened probably due to the repelling behaviour of the plasma jets from the accumulated electrical charges on the polymer surface. The effect of applying a substrate bias in the range from −900 V to +900 V on the plasma irradiation onto the substrates was also investigated. From the knowledge of the present results, it is helpful for choosing the substrate materials for microscale surface modification.

Polymeric membranes: surface modification for minimizing (bio)colloidal fouling.

Science.gov (United States)

Kochkodan, Victor; Johnson, Daniel J; Hilal, Nidal

2014-04-01

This paper presents an overview on recent developments in surface modification of polymer membranes for reduction of their fouling with biocolloids and organic colloids in pressure driven membrane processes. First, colloidal interactions such as London-van der Waals, electrical, hydration, hydrophobic, steric forces and membrane surface properties such as hydrophilicity, charge and surface roughness, which affect membrane fouling, have been discussed and the main goals of the membrane surface modification for fouling reduction have been outlined. Thereafter the recent studies on reduction of (bio)colloidal of polymer membranes using ultraviolet/redox initiated surface grafting, physical coating/adsorption of a protective layer on the membrane surface, chemical reactions or surface modification of polymer membranes with nanoparticles as well as using of advanced atomic force microscopy to characterize (bio)colloidal fouling have been critically summarized. Copyright © 2013 Elsevier B.V. All rights reserved.

Laser modification of macroscopic properties of metal surface layer

Science.gov (United States)

Kostrubiec, Franciszek

1995-03-01

Surface laser treatment of metals comprises a number of diversified technological operations out of which the following can be considered the most common: oxidation and rendering surfaces amorphous, surface hardening of steel, modification of selected physical properties of metal surface layers. In the paper basic results of laser treatment of a group of metals used as base materials for electric contacts have been presented. The aim of the study was to test the usability of laser treatment from the viewpoint of requirements imposed on materials for electric contacts. The results presented in the paper refer to two different surface treatment technologies: (1) modification of infusible metal surface layer: tungsten and molybdenum through laser fusing of their surface layer and its crystallization, and (2) modification of surface layer properties of other metals through laser doping of their surface layer with foreign elements. In the paper a number of results of experimental investigations obtained by the team under the author's supervision are presented.

Surface Modification of Biomaterials: A Quest for Blood Compatibility

OpenAIRE

de Mel, Achala; Cousins, Brian G.; Seifalian, Alexander M.

2012-01-01

Cardiovascular implants must resist thrombosis and intimal hyperplasia to maintain patency. These implants when in contact with blood face a challenge to oppose the natural coagulation process that becomes activated. Surface protein adsorption and their relevant 3D confirmation greatly determine the degree of blood compatibility. A great deal of research efforts are attributed towards realising such a surface, which comprise of a range of methods on surface modification. Surface modification ...

Development of an Organosilicon-Based Superhydrophobic/Icephobic Surface Using an Atmospheric Pressure Plasma Jet =

Science.gov (United States)

Asadollahi, Siavash

the surface, and then through multiple seemingly random electric arcs on the surface. The formation of these discharges is facilitated by the near-infinite conductivity of the air plasma column. The micro-porous micro-roughened structure developed in this step is then used as the substrate for coating deposition. In the next step, first the plasma jet is slightly modified with a quartz tube surrounding the jet-head. This modification allows for ignition and maintenance of a very weak plasma while hindering the diffusion of oxygen into the plasma and thus increasing the amount of organic deposition on the surface. This is confirmed by the chemical characterization of the surfaces developed using the modified jet. Furthermore, it is shown that this modification can significantly affect surface morphology, leading to a finer surface structure with different levels of roughness. Hydrophobic materials are then deposited on the surface in the presence of HMDSO using nitrogen plasma. Several samples are prepared with different precursor flow rates, plasma generation powers and number of deposition passes. All coatings are characterized regarding their surface morphology, chemical composition, wetting behavior and icephobic characteristics. It is shown that at low precursor flow rates, coating deposition is not enough for a full coverage of the surface. On the other hand, at high flow rates coating deposition can completely cover the surface features originated from the air plasma treatment process, thus negating the effects of an important roughness level. At the median flow rate, which was identified to be 5 g/h, the coating can fully cover the surface while maintaining the pre-existing surface features. It is also shown that by increasing the number of plasma deposition passes, surface features become slightly larger while the amount of organic deposition on the surface increases. Finally, it is shown that in high plasma generation powers, the amount of oxide deposition on

Plasma-nitride α-βTi alloy: layer characterization and mechanical properties modification

International Nuclear Information System (INIS)

Raveh, A.; Bussiba, A.; Bettelheim, A.; Katz, Y.

1993-01-01

Beyond continuous efforts to develop advanced processing methods or new directions in surface modification, the foundations for assessment of appropriate surface layers still remain very challenging. In this context, Ti-6Al-4V α-β alloy was investigated mainly after plasma nitriding by nitrogen or by a nitrogen mixture with hydrogen and/or argon. The current study objectives consist in gradually developing some aspects of the microstructure and property relationship. As such, the study centred on the characterization of refined layers as well as confronting critical questions of how layers and interfacial microstructure might affect the near-surface mechanical properties (i.e. microhardness, fatigue resistance and erosion). In particular, the effects on fatigue behaviour are emphasized by utilizing single edge notched specimens and fatigue stepdown techniques. It is found that two distinct sublayers, comprising δ-TiN and δ-TiN + ε-Ti 2 N phases, were formed with alloying elements in a segregated zone, followed by a solid solution of N in the Ti. Here, the far field affected zone extended up to about 20 μm. It was observed that the formation of the uppermost sublayer (δ-TiN phase) with a composition including H, NH, and N, as well as Ti depleted of Al and V, has a strong effect on the layer properties. A microhardness value as high as 29.4 GPa (3000 kgf mm -2 ) was obtained with significant improvements in the erosion resistance and fatigue life. It was found that in some controlled plasma nitriding conditions the fatigue life for crack initiation increased by more than a factor of 3. Accordingly, the cyclic crack initiation behaviour is described, revealing substantial influences due to crack tip field perturbations, or fracture resistance modifications. Finally, the role of extrinsic crack tip shielding effects as related to closure or to the local effective driving force for microcracking onset is elaborated. (orig.)

PDX modification to produce a bean-shaped high-beta plasma

International Nuclear Information System (INIS)

Materna, P.; Chrzanowski, J.; Heitzenroeder, P.; Lee, K.; Pereira, M.

1983-01-01

Princeton's PDX tokamak is being converted to produce bean-shaped plasmas which hopefully will reach beta of 10%. The work, which is nearly complete, involves repositioning active coils, adding passive coils, and making external modifications

Laser-pulsed Plasma Chemistry: Laser-initiated Plasma Oxidation Of Niobium

OpenAIRE

Marks R.F.; Pollak R.A.; Avouris Ph.; Lin C.T.; Thefaine Y.J.

1983-01-01

We report the first observation of the chemical modification of a solid surface exposed to an ambient gas plasma initiated by the interaction of laser radiation with the same surface. A new technique, which we designate laser-pulsed plasma chemistry (LPPC), is proposed for activating heterogeneous chemical reactions at solid surfaces in a gaseous ambient by means of a plasma initiated by laser radiation. Results for niobium metal in one atmosphere oxygen demonstrate single-pulse, self-limitin...

Excimer laser surface modification: Process and properties

Energy Technology Data Exchange (ETDEWEB)

Jervis, T.R.; Nastasi, M. [Los Alamos National Lab., NM (United States); Hirvonen, J.P. [Technical Research Institute, Espoo (Finland). Metallurgy Lab.

1992-12-01

Surface modification can improve materials for structural, tribological, and corrosion applications. Excimer laser light has been shown to provide a rapid means of modifying surfaces through heat treating, surface zone refining, and mixing. Laser pulses at modest power levels can easily melt the surfaces of many materials. Mixing within the molten layer or with the gas ambient may occur, if thermodynamically allowed, followed by rapid solidification. The high temperatures allow the system to overcome kinetic barriers found in some ion mixing experiments. Alternatively, surface zone refinement may result from repeated melting-solidification cycles. Ultraviolet laser light couples energy efficiently to the surface of metallic and ceramic materials. The nature of the modification that follows depends on the properties of the surface and substrate materials. Alloying from both gas and predeposited layer sources has been observed in metals, semiconductors, and ceramics as has surface enrichment of Cr by zone refinement of stainless steel. Rapid solidification after melting often results in the formation of nonequilibrium phases, including amorphous materials. Improved surface properties, including tribology and corrosion resistance, are observed in these materials.

Surface wettability and energy effects on the biological performance of poly-3-hydroxybutyrate films treated with RF plasma

Energy Technology Data Exchange (ETDEWEB)

Syromotina, D.S. [Department of Experimental Physics, National Research Tomsk Polytechnic University, 634050 Tomsk (Russian Federation); Surmenev, R.A., E-mail: rsurmenev@gmail.com [Department of Experimental Physics, National Research Tomsk Polytechnic University, 634050 Tomsk (Russian Federation); Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, 70569 Stuttgart (Germany); Surmeneva, M.A. [Department of Experimental Physics, National Research Tomsk Polytechnic University, 634050 Tomsk (Russian Federation); Boyandin, A.N.; Nikolaeva, E.D. [Institute of Biophysics of Siberian Branch of Russian Academy of Sciences, 50/50 Akademgorodok, Krasnoyarsk 660036 (Russian Federation); School of Fundamental Biology and Biotechnology, Siberian Federal University, 79 Svobodny pr., 660041 Krasnoyarsk (Russian Federation); Prymak, O.; Epple, M. [Inorganic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE), University of Duisburg-Essen, 45117 Essen (Germany); Ulbricht, M. [Technical Chemistry II and Center for Nanointegration Duisburg-Essen (CeNIDE), University of Duisburg-Essen, 45141 Essen (Germany); Oehr, C. [Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, 70569 Stuttgart (Germany); Volova, T.G. [Institute of Biophysics of Siberian Branch of Russian Academy of Sciences, 50/50 Akademgorodok, Krasnoyarsk 660036 (Russian Federation); School of Fundamental Biology and Biotechnology, Siberian Federal University, 79 Svobodny pr., 660041 Krasnoyarsk (Russian Federation)

2016-05-01

The surface properties of poly-3-hydroxybutyrate (P3HB) membranes were modified using oxygen and an ammonia radio-frequency (RF, 13.56 MHz) plasma. The plasma treatment procedures used in the study only affected the surface properties, including surface topography, without inducing any significant changes in the crystalline structure of the polymer, with the exception being a power level of 250 W. The wettability of the modified P3HB surfaces was significantly increased after the plasma treatment, irrespective of the treatment procedure used. It was revealed that both surface chemistry and surface roughness changes caused by the plasma treatment affected surface wettability. A treatment-induced surface aging effect was observed and resulted in an increase in the water contact angle and a decrease in the surface free energy. However, the difference in the water contact angle between the polymers that had been treated for 4 weeks and the untreated polymer surfaces was still significant. A dependence between cell adhesion and proliferation and the polar component of the surface energy was revealed. The increase in the polar component after the ammonia plasma modification significantly increased cell adhesion and proliferation on biodegradable polymer surfaces compared to the untreated P3HB and the P3HB modified using an oxygen plasma. - Highlights: • Plasma treatment affected the topography of poly(3-hydroxybutyrate) (P3HB). • Plasma treatment resulted in improvement of the surface wettability. • No alteration of the bulk properties of the polymers was observed. • The ammonia plasma treatment at 150 W improved the cell adhesion and proliferation.

Laser surface modification of PEEK

Energy Technology Data Exchange (ETDEWEB)

Riveiro, A., E-mail: ariveiro@uvigo.es [Applied Physics Department, University of Vigo ETSII, Lagoas-Marcosende, 9, Vigo 36310 (Spain); Centro Universitario de la Defensa, Escuela Naval Militar, Plaza de Espana 2, 36920 Marin (Spain); Soto, R.; Comesana, R.; Boutinguiza, M.; Val, J. del; Quintero, F.; Lusquinos, F.; Pou, J. [Applied Physics Department, University of Vigo ETSII, Lagoas-Marcosende, 9, Vigo 36310 (Spain)

2012-09-15

Highlights: Black-Right-Pointing-Pointer Role of laser irradiation wavelength on the surface modification of PEEK (polyether-ether-ketone) was investigated. Black-Right-Pointing-Pointer Adequate processing conditions to improve wettability, roughness, and cell adhesion characteristics are determined. Black-Right-Pointing-Pointer A design of experiments (DOE) methodology was performed. Black-Right-Pointing-Pointer UV (355 nm) radiation is the most promising laser radiation for improving the adhesive surface properties of PEEK. - Abstract: Polyether-ether-ketone (PEEK) is a synthetic thermoplastic polymer with excellent mechanical and chemical properties, which make it attractive for the field of reconstructive surgery. Nevertheless, this material has a poor interfacial biocompatibility due to its large chemical stability which induces poor adhesive bonding properties. The possibilities of enhancing the PEEK adhesive properties by laser treatments have been explored in the past. This paper presents a systematic approach to discern the role of laser irradiation wavelength on the surface modification of PEEK under three laser wavelengths ({lambda} = 1064, 532, and 355 nm) with the aim to determine the most adequate processing conditions to increase the roughness and wettability, the main parameters affecting cell adhesion characteristics of implants. Overall results show that the ultraviolet ({lambda} = 355 nm) laser radiation is the most suitable one to enhance surface wettability of PEEK.

Influence of nitriding atmosphere on the modification of surface titanium with focus on the behavior of blood platelets adhesion

International Nuclear Information System (INIS)

Vitoriano, J.O.; Alves, C.; Braz, D.C.; Camara, R.B.G.; Rocha, H.A.O.

2014-01-01

The present study aimed to analyze the influence of surface modification of titanium on the adhesion of blood platelets, through techniques of adhesion and morphological analyzes. Discs of titanium grade II received different surface treatments with plasma of Ar + N_2 + H_2 and Ar + H_2, forming two experimental groups including only polished samples used as standard. Before and after treatment the samples were characterized according to topography, crystalline structure and wettability, using atomic force microscopy, X-ray diffraction, Raman spectroscopy and testing of sessile drop, respectively. Platelet rich plasma (PRP) was applied on the modified surfaces in a culture plates. Images obtained by electron microscopy of adhered platelets were analyzed to verify the behavior of platelets in the different experimental conditions. (author)

Surface modification of thermoplastic poly(vinyl alcohol)/saponite nanocomposites via surface-initiated atom transfer radical polymerization enhanced by air dielectric discharges barrier plasma treatment

International Nuclear Information System (INIS)

Zhen Weijun; Lu Canhui

2012-01-01

To improve the water resistance of thermoplastic poly(vinyl alcohol)/saponite nanocomposites (TPVA), a simple two-step method was developed for the covalent immobilization of atom transfer radical polymerization (ATRP) initiators on the TPVA surfaces enhanced by air dielectric barrier discharges (DBD) plasma treatment, and hydrophobic poly(methyl methacrylate) (PMMA) brushes were then grafted onto the surface of TPVA via surface-initiated atom transfer radical polymerization (SI-ATRP). The chemical composition, morphology and hydrophobicity of the modified TPVA surfaces were characterized by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), respectively. The water resistance of the surface-functionalized PMMA was evaluated by the contact angle and water adsorption method. It was shown that air DBD plasma treatment activated the TPVA surface and accelerated the immobilization of ATRP initiator on the TPVA surface. Compared with TPVA control, TPVA modified by SI-ATRP can be grafted well-defined and covalently tethered network PMMA brushes onto the surface and the hydrophobicity of TPVA were significantly enhanced.

Surface modification of porous nanocrystalline TiO2 films for dye-sensitized solar cell application by various gas plasmas

International Nuclear Information System (INIS)

Kim, Youngsoo; Yoon, Chang-Ho; Kim, Kang-Jin; Lee, Yeonhee

2007-01-01

Titanium dioxide (TiO 2 ) film for dye-sensitized solar cells (DSSCs) has surface defects such as oxygen vacancies created during the annealing process. The authors used a plasma treatment technique to reduce defects on TiO 2 surfaces. They investigated the influence of different gas plasma treatments of TiO 2 film on the photoelectric performance of DSSC. Short-circuit photocurrent density (J sc ), open-circuit photovoltage (V oc ), and the amount of adsorbed dye for DSSCs were measured. As a result, the solar-to-electricity conversion efficiencies of the O 2 - and N 2 -treated cells increased by 15%-20% compared to untreated cells. On the other hand, solar energy conversion efficiency of CF 4 -plasma treated cells decreased drastically. The increased amount of adsorbed dye on the TiO 2 film was measured by time-of-flight secondary ion mass spectrometry. TiO 2 surfaces modified by plasma treatment were characterized using analytical instruments such as x-ray photoelectron spectroscopy and near-edge x-ray absorption fine structure

3D Plasma Nanotextured® Polymeric Surfaces for Protein or Antibody Arrays, and Biomolecule and Cell Patterning.

Science.gov (United States)

Tsougeni, Katerina; Ellinas, Kosmas; Koukouvinos, George; Petrou, Panagiota S; Tserepi, Angeliki; Kakabakos, Sotirios E; Gogolides, Evangelos

2018-01-01

Plasma micro-nanotexturing is a generic technology for topographical and chemical modification of surfaces and their implementation in microfluidics and microarrays. Nanotextured surfaces with desirable chemical functionality (and wetting behavior) have shown excellent biomolecule immobilization and cell adhesion. Specifically, nanotextured hydrophilic areas show (a) strong binding of biomolecules and (b) strong adhesion of cells, while nanotextured superhydrophobic areas show null adsorption of (a) proteins and (b) cells. Here we describe the protocols for (a) biomolecule adsorption control on nanotextured surfaces for microarray fabrication and (b) cell adhesion on such surfaces. 3D plasma nanotextured® substrates are commercialized through Nanoplasmas private company, a spin-off of the National Centre for Scientific Research Demokritos.

Surface Modification of Graphene Oxides by Plasma Techniques and Their Application for Environmental Pollution Cleanup.

Science.gov (United States)

Wang, Xiangxue; Fan, Qiaohui; Chen, Zhongshan; Wang, Qi; Li, Jiaxing; Hobiny, Aatef; Alsaedi, Ahmed; Wang, Xiangke

2016-02-01

Graphene oxides (GOs) have come under intense multidisciplinary study because of their unique physicochemical properties and possible applications. The large amount of oxygen-containing functional groups on GOs leads to a high sorption capacity for the removal of various kinds of organic and inorganic pollutants from aqueous solutions in environmental pollution cleanup. However, the lack of selectivity results in difficulty in the selective removal of target pollutants from aqueous solutions in the presence of other coexisting pollutants. Herein, the surface grafting of GOs with special oxygen-containing functional groups using low-temperature plasma techniques and the application of the surface-modified GOs for the efficient removal of organic and inorganic pollutants in environmental pollution are reviewed. This paper gives an account of our research on the application of GO-based nanomaterials in environmental pollution cleanup, including: (1) the synthesis and surface grafting of functional groups on GOs, summarizing various types of low-temperature plasma techniques for the synthesis of graphene/GOs; and (2) the application of graphene/GOs and their composites for the efficient removal of organic and inorganic pollutants from aqueous solutions, including the interaction mechanism according to recently published results. © 2015 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Negative ion surface plasma source development for plasma trap injectors in Novosibirsk

International Nuclear Information System (INIS)

Bel'chenko, Yu.I.; Dimov, G.I.; Dudnikov, V.G.; Kupriyanov, A.S.

1989-01-01

Work on high-current ion sources carried out at the Novosibirsk Institute of Nuclear Physics (INP) is presented. The INP investigations on ''pure plasma'' planotron and ''pure surface'' secondary emission systems of H - generation, which preceded the surface-plasma concept developed in Novosibirsk, are described. The physical basis of the surface-plasma method of negative-ion production is considered. The versions and operating characteristics of different surface-plasma sources including the multi-ampere (approx-gt 10A) source are discussed. Research on efficient large-area (∼10 2 cm 2 ) negative ion surface-plasma emitters is described. The INP long-pulse multiaperture surface- plasma generators, with a current of about 1A, are described. 38 refs., 17 figs

Collaborative Research: Atmospheric Pressure Plasma-Biomaterial Surface Interactions - Bridging Understanding of APP Sources to Rational Modification of Biomolecules

Energy Technology Data Exchange (ETDEWEB)

Graves, David Barry [Univ. of California, Berkeley, CA (United States)

2017-11-24

The overriding objective of this work is to bridge the gap between understanding of atmospheric pressure plasma (APP) sources and predictive chemical modifications of biomolecules. A key aspect of this problem is to understand what oxidizing species are created in water adjacent to APP jets that would ultimately affect aqueous biomolecules. We report the production of highly oxidative species in solutions exposed to a self-pulsed corona discharge in air. We examine how the properties of the target solution (pH, conductivity) and the discharge power affect the discharge stability and the production of H2O2. Indigo carmine, a common organic dye, is used as an indicator of oxidative strength and in particular, hydroxyl radical (OH•) production. The observed rate of indigo oxidation in contact with the discharge far exceeds that predicted from reactions based on concentrations of species measured in the bulk solution. The generation of H2O2 and the oxidation of indigo carmine indicate a high concentration of highly oxidizing species such as OH• at the plasma-liquid interface. These results indicate that reactions at the air plasma-liquid interface play a dominant role in species oxidation during direct non-equilibrium atmospheric pressure plasma (NE-APP) treatment.

Modification of steel surface by plasma electrolytic saturation with nitrogen and carbon

Energy Technology Data Exchange (ETDEWEB)

Kusmanov, S.A., E-mail: sakusmanov@yandex.ru; Kusmanova, Yu.V., E-mail: yulia.kusmanova@yandex.ru; Smirnov, A.A., E-mail: sciencealexsm@gmail.com; Belkin, P.N., E-mail: belkinp@yandex.ru

2016-06-01

The effect of the electrolyte composition with ammonia, acetone, and ammonium chloride on the structure and properties of low carbon steel was studied in anode plasma electrolytic nitrocarburising. An X-ray diffractometer, a scanning electron microscopy (SEM) and an optical microscope were used to characterize the phase composition of the modified layer and its surface morphology. Surface roughness was studied with a profilometer–profilograph. The hardness of the treated and untreated samples was measured using a microhardness tester. The sources of nitrogen and carbon are shown to be the products of evaporation and thermal decomposition of the electrolyte components. It is established that the influence of concentration of ammonia, acetone, and ammonium chloride on the size of the structural components of the hardened layer is explained by the competition of the anode dissolution, high-temperature oxidation and diffusion of the saturating component. The electrolyte composition (10–12.5% ammonium chloride, 5% acetone, 5% ammonia) and processing mode (800 °C, 5–10 min) of low carbon steels allowing to obtain the hardened surface layer up to 0.2 mm with microhardness 930 HV and with decrease in the roughness (R{sub a}) from 1.013 to 0.054 μm are proposed. The anode plasma electrolytic nitricarburising is able to decrease friction coefficient of the treated low carbon steel from 0.191 to 0.169 and wear rate from 13.5 mg to 1.0 mg. - Highlights: • Aqueous solution (12.5% NH{sub 4}Cl, 5% ammonia, 5% acetone) is proposed for PEN/C steels. • Microhardness of steel (0.2% C) is 930 HV due to PEN/C for 5–10 min at 800 °C. • Anode PEN/C of low carbon steel decreases its roughness (R{sub a}) from 1.013 to 0.054 μm. • Anode PEN/C decreases friction coefficient of low carbon steel from 0.191 to 0.169 • Anode PEN/C decreases wear loss of low carbon steel from 13.5 mg to 1.0 mg.

Wettability and XPS analyses of nickel–phosphorus surfaces after plasma treatment: An efficient approach for surface qualification in mechatronic processes

International Nuclear Information System (INIS)

Vivet, L.; Joudrier, A.-L.; Bouttemy, M.; Vigneron, J.; Tan, K.L.; Morelle, J.M.; Etcheberry, A.; Chalumeau, L.

2013-01-01

Electroless nickel-high-phosphorus Ni–P plating is known for its physical properties. In case of electronic and mechatronic assembly processes achieved under ambient conditions the wettability of the Ni–P layer under ambient temperature and ambient air stays a point of surface quality investigation. This contribution will be devoted to the study of the surface properties of Ni–P films for which we performed air plasma treatment. We focus our attention on the evolution of the surface wettability, using the classical sessile drop technique. Interpreting the results with the OWRK model we extract the polar and disperse surface tension components from which we deduced typical evolution of the surface properties with the different treatment settings. By controlling the variations of the parameters of the plasma exposure we are able to change the responses of our Ni–P sample from total hydrophobic to total hydrophilic behaviours. All the intermediate states can be reached by adapting the treatment parameters. So it is demonstrated that the apparent Ni–P surface properties can be fully adapted and the surface setting can be well characterized by wettability measurements. To deep our knowledge of the surface modifications induced by plasma we performed parallel SEM and XPS analyses which provide informations on the structure and the chemical composition of the surface for each set of treatment parameters. Using this double approach we were able to propose a correlation between the evolution of surface chemical composition and surface wettability which are completely governed by the plasma treatment conditions. Chemical parameters as the elimination of the carbon contamination, the progressive surface oxidation, and the slight incorporation of nitrogen due to the air plasma interaction are well associated with the evolution of the wettability properties. So a complete engineering for the Ni–P surface preparation has been established. The sessile drop method can

Wettability and XPS analyses of nickel-phosphorus surfaces after plasma treatment: An efficient approach for surface qualification in mechatronic processes

Science.gov (United States)

Vivet, L.; Joudrier, A.-L.; Bouttemy, M.; Vigneron, J.; Tan, K. L.; Morelle, J. M.; Etcheberry, A.; Chalumeau, L.

2013-06-01

Electroless nickel-high-phosphorus Ni-P plating is known for its physical properties. In case of electronic and mechatronic assembly processes achieved under ambient conditions the wettability of the Ni-P layer under ambient temperature and ambient air stays a point of surface quality investigation. This contribution will be devoted to the study of the surface properties of Ni-P films for which we performed air plasma treatment. We focus our attention on the evolution of the surface wettability, using the classical sessile drop technique. Interpreting the results with the OWRK model we extract the polar and disperse surface tension components from which we deduced typical evolution of the surface properties with the different treatment settings. By controlling the variations of the parameters of the plasma exposure we are able to change the responses of our Ni-P sample from total hydrophobic to total hydrophilic behaviours. All the intermediate states can be reached by adapting the treatment parameters. So it is demonstrated that the apparent Ni-P surface properties can be fully adapted and the surface setting can be well characterized by wettability measurements. To deep our knowledge of the surface modifications induced by plasma we performed parallel SEM and XPS analyses which provide informations on the structure and the chemical composition of the surface for each set of treatment parameters. Using this double approach we were able to propose a correlation between the evolution of surface chemical composition and surface wettability which are completely governed by the plasma treatment conditions. Chemical parameters as the elimination of the carbon contamination, the progressive surface oxidation, and the slight incorporation of nitrogen due to the air plasma interaction are well associated with the evolution of the wettability properties. So a complete engineering for the Ni-P surface preparation has been established. The sessile drop method can be

In-situ investigation of laser surface modifications of WC-Co hard metals inside a scanning electron microscope

Science.gov (United States)

Mueller, H.; Wetzig, K.; Schultrich, B.; Pompe, Wolfgang; Chapliev, N. I.; Konov, Vitaly I.; Pimenov, S. M.; Prokhorov, Alexander M.

1989-05-01

The investigation of laser interaction with solid surfaces and of the resulting mechanism of surface modification are of technical interest to optimize technological processes, and they are also of fundamental scientific importance. Most instructive indormation is available with the ail of the in-situ techniques. For instance, measuring of the photon emission of the irradiated surface ane the plasma torch (if it is produced) simultaneously to laser action, makes it possible to gain a global characterization of the laser-solid interaction. In order to obtain additional information about surface and structure modifications in microscopic detail , a laser and scanning electron microscope were combined in to a tandem equipment (LASEM). Inside this eqiipment the microscopic observation is carried out directly at the laser irradiated area without any displacement of the sample. In this way, the stepwise development of surface modification during multipulse irradiation is visible in microscopic details and much more reliable information about the surface modification process is obtainable in comparison to an external laser irradiation. Such kind of equipments were realized simultaneously and independently in the Institut of General Physics (Moscow) and the Central Institute of Solid State Physics and Material Research (Dresden) using a CO2 and a LTd-glass-laser, respectively. In the following the advantages and possibilities of a LASEM shall be demonstrated by some selected investigations of WC-CO hardmeta. The results were obtained in collaboration by both groups with the aid of the pulsed CO2-laser. The TEA CO2 laser was transmitted through a ZnSe-window into the sample chamber of the SEM and focused ofAo tfte sample surface. It was operated in TEM - oo mode with a repetition rate of about 1 pulse per second. A peak power density of about 160 MW/cm2 was achieved in front of the sample surface.

MODIFICATION OF SURFACE KONDENSITSIONNYH AEROSOLS WELDING AND METALLURGICHESKIH PRODUCTIONS

Directory of Open Access Journals (Sweden)

A. A. Ennan

2016-04-01

Full Text Available Chemical modification of surface kondensitsionnyh aerosols (KA which formation when heat treatment metals (process of weld, foundry processes with application chlorosilanes are suggested. Adsorbtion vapor of water on modification powders KA decreases and changes in varies from modifier and conditions modification are setted.

Comparison of several innovative bridge cable surface modifications

DEFF Research Database (Denmark)

Kleissl, Kenneth; Georgakis, Christos T.

Over the last two decades, several bridge cable manufacturers have introduced surface modifications on the high-density polyethylene (HDPE) sheathing that is installed for the protection of inner cable strands or wires. The modifications are based on research undertaken predominantly in Europe...

LASER SURFACE MODIFICATION OF TITANIUM ALLOYS — A REVIEW

OpenAIRE

Y. S. TIAN; C. Z. CHEN; D. Y. WANG; T. Q. LEI

2005-01-01

Recent developments of laser surface modification of titanium alloys for increasing their corrosion, wear and oxidation resistance are introduced. The effects of laser processing parameters on the resulting surface properties of titanium alloys are reviewed. The problems to be solved and the prospects in the field of laser modification of Ti alloys are discussed. Due to the intrinsic properties, a laser beam can be focused onto the metallic surface to produce a broad range of treatments depen...

Surface chemical changes of atmospheric pressure plasma treated rabbit fibres important for felting process

Energy Technology Data Exchange (ETDEWEB)

Štěpánová, Vlasta, E-mail: vstepanova@mail.muni.cz [Department of Physical Electronics, Faculty of Science Masaryk University, Kotlářská 2, 611 37 Brno (Czech Republic); Slavíček, Pavel; Stupavská, Monika; Jurmanová, Jana [Department of Physical Electronics, Faculty of Science Masaryk University, Kotlářská 2, 611 37 Brno (Czech Republic); Černák, Mirko [Department of Physical Electronics, Faculty of Science Masaryk University, Kotlářská 2, 611 37 Brno (Czech Republic); Department of Experimental Physics, Faculty of Mathematics, Physics and Informatics, Comenius University, Mlynská dolina F2, 842 48 Bratislava (Slovakia)

2015-11-15

Graphical abstract: - Highlights: • Rabbit fibres plasma treatment is an effective method for fibres modification. • Atmospheric pressure plasma treatment is able to affect fibres properties. • Surface changes on fibres after plasma treatment were analysed via SEM, ATR-FTIR, XPS. • Significant increase of fibres wettability after plasma treatment was observed. • Plasma treatment at atmospheric pressure can replace the chemical treatment of fibres. - Abstract: We introduce the atmospheric pressure plasma treatment as a suitable procedure for in-line industrial application of rabbit fibres pre-treatment. Changes of rabbit fibre properties due to the plasma treatment were studied in order to develop new technology of plasma-based treatment before felting. Diffuse Coplanar Surface Barrier Discharge (DCSBD) in ambient air at atmospheric pressure was used for plasma treatment. Scanning electron microscopy was used for determination of the fibres morphology before and after plasma treatment. X-ray photoelectron spectroscopy and attenuated total reflectance-Fourier transform infrared spectroscopy were used for evaluation of reactive groups. The concentration of carbon decreased and conversely the concentration of nitrogen and oxygen increased after plasma treatment. Aging effect of plasma treated fibres was also investigated. Using Washburn method the significant increase of fibres wettability was observed after plasma treatment. New approach of pre-treatment of fibres before felting using plasma was developed. Plasma treatment of fibres at atmospheric pressure can replace the chemical method which consists of application of strong acids on fibres.

Plasma surface interaction processes and possible synergisms

International Nuclear Information System (INIS)

Behrisch, R.; Roberto, J.B.

1984-08-01

The process determining the plasma surface interaction in today's high temperature plasma experiments are investigated following several lines. First, in plasma devices, the particle and energy fluxes to the different first wall areas the fluxes from the walls back into the plasma are measured and the boundary plasma parameters are determined. The surface composition and structure of the walls, limiters and divertor plates are analyzed following exposure to many discharges. Secondly, the different surface processes which are expected to contribute to the plasma surface interaction (particularly to hydrogen particle balance and impurity introduction) are studied in simulation experiments using well defined particle beams

Surface modification of polymethyl methacrylate intraocular lenses by plasma for improvement of antithrombogenicity and transmittance

Energy Technology Data Exchange (ETDEWEB)

Zhang Lihua; Wu Di; Chen Yashao; Wang Xiaoli; Zhao Guowei; Wan Haiyan [Key Laboratory of Applied Surface and Colloid Chemistry (Shaanxi Normal University), Ministry of Education, School of Chemistry and Materials Science, Chang' an South Road 199, Xi' an 710062 (China); Huang Changzheng [Able Eye Device Co. Ltd, Zhengzhou 450008 (China)

2009-05-15

To improve antithrombogenicity and reduce ultraviolet transmittance, polymethyl methacrylate intraocular lenses (PMMA IOLs) were pretreated with Ar plasma and combined with heparin (Hp), with polyglycol (PEG) and with both Hp and PEG in a plasma atmosphere. The resulting modified PMMA IOLs denoted as PEG-PMMA, Hp-PMMA and Hp-PEG-PMMA were characterized by attenuated total reflectance Fourier transfer infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), ultraviolet-visible spectroscopy (UV-vis), contact angle (CA) and platelet adhesion experiments. The results indicated that Hp and PEG had been successfully immobilized onto the surfaces of PMMA IOLs. Antithrombogenicity was improved remarkably and ultraviolet transmittance was reduced as well.

Plasma processing and chemistry

NARCIS (Netherlands)

Schram, D.C.; Mullen, van der J.J.A.M.; Sanden, van de M.C.M.

1994-01-01

The growing field of applications of plasma as deposition, etching, surface modification and chemical conversion has stimulated a renewed interest in plasma science in the atomic physical chemistry regime. The necessity to optimize the various plasma processing techniques in terms of rates, and

Plasma arc cutting: Microstructural modifications of hafnium cathodes during first cycles

Energy Technology Data Exchange (ETDEWEB)

Rotundo, F., E-mail: fabio.rotundo@unibo.it [Dept. of Mechanical Engineering (DIEM), Alma Mater Studiorum, Universita di Bologna, Via Saragozza 8, 40123 Bologna (Italy); Martini, C.; Chiavari, C.; Ceschini, L. [Dept. of Metals Science, Electrochemistry and Chemical Techniques (SMETEC), Alma Mater Studiorum, Universita di Bologna, Viale Risorgimento 4, 40136 Bologna (Italy); Concetti, A.; Ghedini, E.; Colombo, V. [Dept. of Mechanical Engineering (DIEM), Alma Mater Studiorum, Universita di Bologna, Via Saragozza 8, 40123 Bologna (Italy); Dallavalle, S. [Cebora S.p.A., Via Andrea Costa 24, 40057 Cadriano di Granarolo (Italy)

2012-06-15

In the present work, the microstructural modifications of the Hf insert in plasma arc cutting (PAC) electrodes operating at 250 A were experimentally investigated during first cycles, in order to understand those phenomena occurring on and under the Hf emissive surface and involved in the electrode erosion process. Standard electrodes were subjected to an increasing number of cutting cycles (CCs) on mild steel plates in realistic operative conditions, with oxygen/air as plasma/shield gas. Microstructural analysis was performed for each electrode at different erosion stages by means of scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS) and Raman spectroscopy. Electrodes cross sections were also observed by means of optical microscopy (both in bright field and in reflected polarised light) after chemical etching. In the insert, three typical zones were found after cutting: monoclinic HfO{sub 2} layer; thermally-modified transition zone with O{sub 2}-Hf solid solution; unmodified Hf. The erosion cavity and the oxide layer thickness increase with the number of cutting cycles. Macrocracking was observed in the oxide layer, while microcracking and grain growth were detected in the remelted Hf. Moreover, detachment was found at the Hf/Cu interface. Based on thermodynamics and kinetics of the Hf high temperature oxidation, conclusions can be drawn on the erosion mechanism involved. - Highlights: Black-Right-Pointing-Pointer Hf microstructural modifications in cathodes after plasma arc cutting cycles investigated. Black-Right-Pointing-Pointer 3 zones identified after cutting: HfO{sub 2} layer; remelted zone with O{sub 2}-Hf solid solution; unmodified Hf. Black-Right-Pointing-Pointer Hf-based ejections both in arc-on and arc-off phases; erosion cavity deepens with cutting cycles. Black-Right-Pointing-Pointer Detachment at the Hf/Cu interfaces, worsening heat dissipation and oxidation/erosion phenomena. Black-Right-Pointing-Pointer The use

Effects of aluminium surface morphology and chemical modification on wettability

Energy Technology Data Exchange (ETDEWEB)

Rahimi, M., E-mail: mar@sbi.aau.dk [Department of Energy and Environment, Danish Building Research Institute, Aalborg University, A.C. Meyers Vænge 15, 2450 København SV (Denmark); Fojan, P.; Gurevich, L. [Department of Physics and Nanotechnology, Aalborg University, Skjernvej 4, DK-9220 Aalborg East (Denmark); Afshari, A. [Department of Energy and Environment, Danish Building Research Institute, Aalborg University, A.C. Meyers Vænge 15, 2450 København SV (Denmark)

2014-03-01

Highlights: • Successful surface modification procedures on aluminium samples were performed involving formation of the layer of hydrophilic hyperbranched polyethyleneglycol (PEG) via in situ polymerization, molecular vapour deposition of a monolayer of fluorinated silane, and a combination of those. • The groups of surfaces with hydrophobic behavior were found to follow the Wenzel model. • A transition from Cassie–Baxter's to Wenzel's regime was observed due to changing of the surface roughness upon mechanical polishing in aluminium samples. - Abstract: Aluminium alloys are some of the predominant metals in industrial applications such as production of heat exchangers, heat pumps. They have high heat conductivity coupled with a low specific weight. In cold working conditions, there is a risk of frost formation on the surface of aluminium in the presence of water vapour, which can lead to the deterioration of equipment performance. This work addresses the methods of surface modification of aluminium and their effect of the underlying surface morphology and wettability, which are the important parameters for frost formation. Three groups of real-life aluminium surfaces of different morphology: unpolished aluminium, polished aluminium, and aluminium foil, were subjected to surface modification procedures which involved the formation of a layer of hydrophilic hyperbranched polyethyleneglycol via in situ polymerization, molecular vapour deposition of a monolayer of fluorinated silane, and a combination of those. The effect of these surface modification techniques on roughness and wettability of the aluminium surfaces was elucidated by ellipsometry, contact angle measurements and atomic force microscopy. We demonstrated that by employing different types of surface modifications the contact angle of water droplets on aluminium samples can be varied from 12° to more than 120°. A crossover from Cassie–Baxter to Wenzel regime upon changing the surface

Etching of Niobium Sample Placed on Superconducting Radio Frequency Cavity Surface in Ar/CL2 Plasma

International Nuclear Information System (INIS)

Upadhyay, Janardan; Phillips, Larry; Valente, Anne-Marie

2011-01-01

Plasma based surface modification is a promising alternative to wet etching of superconducting radio frequency (SRF) cavities. It has been proven with flat samples that the bulk Niobium (Nb) removal rate and the surface roughness after the plasma etchings are equal to or better than wet etching processes. To optimize the plasma parameters, we are using a single cell cavity with 20 sample holders symmetrically distributed over the cell. These holders serve the purpose of diagnostic ports for the measurement of the plasma parameters and for the holding of the Nb sample to be etched. The plasma properties at RF (100 MHz) and MW (2.45 GHz) frequencies are being measured with the help of electrical and optical probes at different pressures and RF power levels inside of this cavity. The niobium coupons placed on several holders around the cell are being etched simultaneously. The etching results will be presented at this conference.

Etching of Niobium Sample Placed on Superconducting Radio Frequency Cavity Surface in Ar/CL2 Plasma

Energy Technology Data Exchange (ETDEWEB)

Janardan Upadhyay, Larry Phillips, Anne-Marie Valente

2011-09-01

Plasma based surface modification is a promising alternative to wet etching of superconducting radio frequency (SRF) cavities. It has been proven with flat samples that the bulk Niobium (Nb) removal rate and the surface roughness after the plasma etchings are equal to or better than wet etching processes. To optimize the plasma parameters, we are using a single cell cavity with 20 sample holders symmetrically distributed over the cell. These holders serve the purpose of diagnostic ports for the measurement of the plasma parameters and for the holding of the Nb sample to be etched. The plasma properties at RF (100 MHz) and MW (2.45 GHz) frequencies are being measured with the help of electrical and optical probes at different pressures and RF power levels inside of this cavity. The niobium coupons placed on several holders around the cell are being etched simultaneously. The etching results will be presented at this conference.

Preparation and surface characterization of plasma-treated and biomolecular-micropatterned polymer substrates

Science.gov (United States)

Langowski, Bryan Alfred

A micropatterning process creates distinct microscale domains on substrate surfaces that differ from the surfaces' original chemical/physical properties. Numerous micropatterning methods exist, each having relative advantages and disadvantages in terms of cost, ease, reproducibility, and versatility. Polymeric surfaces micropatterned with biomolecules have many applications, but are specifically utilized in tissue engineering as cell scaffolds that attempt to controlled tissue generation in vivo and ex vivo. As the physical and chemical cues presented by micropatterned substrates control resulting cellular behavior, characterization of these cues via surface-sensitive analytical techniques is essential in developing cell scaffolds that mimic complex in vivo physicochemical environments. The initial focus of this thesis is the chemical and physical characterization of plasma-treated, microcontact-printed (muCP) polymeric substrates used to direct nerve cell behavior. Unmodified and oxygen plasma-treated poly(methyl methacrylate) (PMMA) substrates were analyzed by surface sensitive techniques to monitor plasma-induced chemical and physical modifications. Additionally, protein-micropattern homogeneity and size were microscopically evaluated. Lastly, poly(dimethylsiloxane) (PDMS) stamps and contaminated PMMA substrates were characterized by spectroscopic and microscopic methods to identify a contamination source during microcontact printing. The final focus of this thesis is the development of microscale plasma-initiated patterning (muPIP) as a versatile, reproducible micropatterning method. Using muPIP, polymeric substrates were micropatterned with several biologically relevant inks. Polymeric substrates were characterized following muPIP by surface-sensitive techniques to identify the technique's underlying physical and chemical bases. In addition, neural stem cell response to muPIP-generated laminin micropatterns was microscopically and biologically evaluated

Fabrication and surface-modification of implantable microprobes for neuroscience studies

International Nuclear Information System (INIS)

Cao, H; Nguyen, C M; Chiao, J C

2012-01-01

In this work implantable micro-probes for central nervous system (CNS) studies were developed on silicon and polyimide substrates. The probes which contained micro-electrode arrays with different surface modifications were designed for implantation in the CNS. The electrode surfaces were modified with nano-scale structures that could greatly increase the active surface area in order to enhance the electrochemical current outputs while maintaining micro-scale dimensions of the electrodes and probes. The electrodes were made of gold or platinum, and designed with different sizes. The silicon probes were modified by silicon nanowires fabricated with the vapor–liquid–solid mechanism at high temperatures. With polyimide substrates, the nanostructure modification was carried out by applying concentrated gold or silver colloid solutions onto the micro-electrodes at room temperature. The surfaces of electrodes before and after modification were observed by scanning electron microscopy. The silicon nanowire-modified surface was characterized by cyclic voltammetry. Experiments were carried out to investigate the improvement in sensing performance. The modified electrodes were tested with H 2 O 2 , electrochemical L-glutamate and dopamine. Comparisons between electrodes with and without nanostructure modification were conducted showing that the modifications have enhanced the signal outputs of the electrochemical neurotransmitter sensors

Fabrication and surface-modification of implantable microprobes for neuroscience studies

Science.gov (United States)

Cao, H.; Nguyen, C. M.; Chiao, J. C.

2012-06-01

In this work implantable micro-probes for central nervous system (CNS) studies were developed on silicon and polyimide substrates. The probes which contained micro-electrode arrays with different surface modifications were designed for implantation in the CNS. The electrode surfaces were modified with nano-scale structures that could greatly increase the active surface area in order to enhance the electrochemical current outputs while maintaining micro-scale dimensions of the electrodes and probes. The electrodes were made of gold or platinum, and designed with different sizes. The silicon probes were modified by silicon nanowires fabricated with the vapor-liquid-solid mechanism at high temperatures. With polyimide substrates, the nanostructure modification was carried out by applying concentrated gold or silver colloid solutions onto the micro-electrodes at room temperature. The surfaces of electrodes before and after modification were observed by scanning electron microscopy. The silicon nanowire-modified surface was characterized by cyclic voltammetry. Experiments were carried out to investigate the improvement in sensing performance. The modified electrodes were tested with H2O2, electrochemical L-glutamate and dopamine. Comparisons between electrodes with and without nanostructure modification were conducted showing that the modifications have enhanced the signal outputs of the electrochemical neurotransmitter sensors.

Erratum to 'Surface Modification of PBO Fibers for Composites by Coaxial Atmospheric Dielectric Barrier Discharge (PLA-PLA)'

International Nuclear Information System (INIS)

2013-01-01

There is a mistake in the funding number (National Natural Science Foundation of China (No. 10875146)) of article Surface Modification of PBO Fibers for Composites by Coaxial Atmospheric Dielectric Barrier Discharge (PLA-PLA), written by HU Qianqian, XU Jinzhou, ZHOU Zhenxing, ZHANG Jing, published in Plasma Science and Technology, 2013, Vol. 15, Issue 5, page number 429, it should be corrected as National Natural Science Foundation of China (No. 11075033). (erratum)

Investigation of surface halide modification of nitrile butadiene rubber

Science.gov (United States)

Sukhareva, K. V.; Mikhailov, I. A.; Andriasyan, Yu O.; Mastalygina, E. E.; Popov, A. A.

2017-12-01

The investigation is devoted to the novel technology of surface halide modification of rubber samples based on nitrile butadiene rubber (NBR). 1,1,2-trifluoro-1,2,2-trichlorethane was used as halide modifier. The developed technology is characterized by production stages reduction to one by means of treating the rubber compound with a halide modifier. The surface halide modification of compounds based on nitrile butadiene rubber (NBR) was determined to result in increase of resistance to thermal oxidation and aggressive media. The conducted research revealed the influence of modification time on chemical resistance and physical-mechanical properties of rubbers under investigation.

Modification of the poly(ethylene) terephthalate track membrane structure and surface in the plasma of non-polymerized gases

International Nuclear Information System (INIS)

Kravets, L.I.; Dmitriev, S.N.; Apel, P.Y.

1999-01-01

An investigation of the properties of poly(ethylene) terephthalate track membranes (PETTMs) treated with a plasma RF-discharge in non-polymerized gases has been performed. The influence of the plasma treatment conditions on the basic properties of the membranes has been studied. It was arranged that the effect of non-polymerized gases plasma on the PETTMs results to etching a membrane's surface layer. The membranes' pore size and the form in this case change. It is shown that it is possible to change the structure of track membranes directly by gas discharge etching

Charged particle modification of surfaces in the outer solar system

International Nuclear Information System (INIS)

Johnson, R.E.

1987-01-01

Voyager reflectance spectra data have indicated clear leading/trailing differences in the albedo of the icy Galilean and Saturian satellites. For the Galilean satellites, these have been analyzed by Nelson, et al. and, more recently, by McEwen. They have described the longitudinal dependence of this data and attempted to interpret this in terms of plasma and meteorite modification of the surface. Primary attention has been paid to Europa at which the leading/trailing differences are the largest. This data was reanalyzed extracting the single grain albedo (w) and constructing the Espat-function, W = (1-w)/w from this. Because w is near unity, W is approximately 2(alpha)D where alpha is the absorption coefficient and D is the grain size. In doing so, a direct comparison to the longitudinal plasma bombardment flux was found for the first time. This occurs primarily in the UV and is probably due to an absorption associated with implanted S, as the UV band of Voyager overlaps the IUE data of Lane et al. The relative importance of grain size effects and implant impurity effects can now be studied

Improvement of Surface Wettability and Hydrophilization of Poly-paraphenylene benzobisoxazole Fiber with Fibrillation Combined Oxygen Plasma Treatment

Directory of Open Access Journals (Sweden)

Xiwen Wang

2012-01-01

Full Text Available A new surface modification method fibrillation combined with oxygen plasma treatment to improve the wettability and hydrophily of PBO fiber was studied in this paper. The surface chemical structure and morphology of PBO fiber were characterized by the methods of FTIR, XPS and SEM. The wettability and hydrophlic characters changes on the surface were evaluated by the dynamic contact angle system and image analysis. The results show that the increase surface roughness by fibrillation could improve the wettability. Fibrillation combined oxygen plasma treatment has a better effect than oxygen plasma treatment to improve the wettability and hdyrophlization of PBO fiber. The specific area of PBO fiber increased to 10.7 m2/g from 0.7 m2/g, contact angle decreased to 43.2° from 84.4° and WRV increased to 208.4% from 13.7%. The modified fibers have a good dispersion in water for hydrophilization improvement.

Surface modification effects on defect-related photoluminescence in colloidal CdS quantum dots.

Science.gov (United States)

Lee, TaeGi; Shimura, Kunio; Kim, DaeGwi

2018-05-03

We investigated the effects of surface modification on the defect-related photoluminescence (PL) band in colloidal CdS quantum dots (QDs). A size-selective photoetching process and a surface modification technique with a Cd(OH)2 layer enabled the preparation of size-controlled CdS QDs with high PL efficiency. The Stokes shift of the defect-related PL band before and after the surface modification was ∼1.0 eV and ∼0.63 eV, respectively. This difference in the Stokes shifts suggests that the origin of the defect-related PL band was changed by the surface modification. Analysis by X-ray photoelectron spectroscopy revealed that the surface of the CdS QDs before and after the surface modification was S rich and Cd rich, respectively. These results suggest that Cd-vacancy acceptors and S-vacancy donors affect PL processes in CdS QDs before and after the surface modification, respectively.

Surface Modification Of Implants For Bone Surgery

Directory of Open Access Journals (Sweden)

Marciniak J.

2015-09-01

Full Text Available The study discusses the methods of surface modification methods for AISAI 316 L steel and Ti6Al4V ELI titanium alloy, dedicated to complex design implants used in bone surgery. Results of structural tests have been presented along with those evaluating the physicochemical properties of the formed surface layers. Clinical feasibility of the surface layers has also been evaluated.

Surface modification of protein enhances encapsulation in chitosan nanoparticles

Science.gov (United States)

Koyani, Rina D.; Andrade, Mariana; Quester, Katrin; Gaytán, Paul; Huerta-Saquero, Alejandro; Vazquez-Duhalt, Rafael