scholarly journals In Vitro Corrosion Studies of Surface Modified NiTi Alloy for Biomedical Applications

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Manju Chembath ◽  
J. N. Balaraju ◽  
M. Sujata
Keyword(s):  
Contact Angle ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Niti Alloy ◽  
Passive Layer ◽  
Water Contact ◽  
Force Microscopy ◽  
Corrosion Studies ◽  
Surface Modified

Electropolishing was conducted on NiTi alloy of composition 49.1 Ti-50.9 Ni at.% under potentiostatic regime at ambient temperature using perchloric acid based electrolyte for 30 sec followed by passivation treatment in an inorganic electrolyte. The corrosion resistance and biocompatibility of the electropolished and passivated alloys were evaluated and compared with mechanically polished alloy. Various characterization techniques like scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy were employed to analyze the properties of surface modified and mechanically polished alloys. Water contact angle measurements made on the passivated alloy after electropolishing showed a contact angle of 35.6°, which was about 58% lower compared to mechanically polished sample, implying more hydrophilicity. The electrochemical impedance studies showed that, for the passivated alloy, threefold increase in the barrier layer resistance was obtained when compared to electropolished alloy due to the formation of compact titanium oxide. The oxide layer thickness of the passivated samples was almost 18 times higher than electropolished samples. After 14 days immersion in Hanks’ solution, the amount of nickel released was 315 ppb which was nearly half of that obtained for mechanically polished NiTi alloy, confirming better stability of the passive layer.

Surface Modification of Polyvinylidenefluoride-Trifluoroethylene Film Using Argon Gas Plasma

2012 ◽  
Vol 626 ◽  
pp. 317-323 ◽  
Author(s):  
Rozana Mohd Dahan ◽  
Muhamad Naiman Sarip ◽  
Yap Seong Ling ◽  
Mohamad Hafiz Mohd Wahid ◽  
Adillah Nurashikin Arshad ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Photoelectron Spectroscopy ◽  
Argon Plasma ◽  
Water Contact ◽  
Force Microscopy ◽  
Atomic Force ◽  
Gas Plasma ◽  
Good Biocompatibility ◽  
Surface Modified

This study investigates the surface properties of plasma surface modified spin coated PVDF-TrFE (70/30) film using Atomic Force Microscopy (AFM), Water Contact Angle (WCA) and X-ray Photoelectron Spectroscopy (XPS). The surfaces of the spin coated PVDF-TrFE film were modified using 13.56 MHz rf Argon plasma. The exposure time of the charged particle PVDF-TrFE films were varied for 1, 3 and 5mins. Prior to modification, the average surface roughness obtained was 8.615nm, but upon modification, the surface roughness was found to increase to 12.466nm. The value of the contact angle of the modified film was reduced from 90o to 43o and the XPS analysis showed dehydrofluorination of PVDF-TrFE films surfaces. The improved in surface roughness and the increased in wettability of the modified film, resulted in good biocompatibility of the modified PVDF-TrFE thin films. This phenomenon has created interest in researchers for developing functional polymer used for applications in areas such are biomedical, bio-analytical assays, textile and even food industry.

scholarly journals The Covalent Tethering of Poly(ethylene glycol) to Nylon 6 Surface via N,N′-Disuccinimidyl Carbonate Conjugation: A New Approach in the Fight against Pathogenic Bacteria

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2181
Author(s):  
Sumita Swar ◽  
Veronika Máková ◽  
Ivan Stibor
Keyword(s):  
Photoelectron Spectroscopy ◽  
Pathogenic Bacteria ◽  
Polymer Surface ◽  
Nylon 6 ◽  
Secondary Amines ◽  
Surface Immobilization ◽  
Water Contact ◽  
Force Microscopy ◽  
Poly Ethylene

Different forms of unmodified and modified Poly(ethylene glycols) (PEGs) are widely used as antifouling and antibacterial agents for biomedical industries and Nylon 6 is one of the polymers used for biomedical textiles. Our recent study focused on an efficient approach to PEG immobilization on a reduced Nylon 6 surface via N,N′–disuccinimidyl carbonate (DSC) conjugation. The conversion of amide functional groups to secondary amines on the Nylon 6 polymer surface was achieved by the reducing agent borane-tetrahydrofuran (BH3–THF) complex, before binding the PEG. Various techniques, including water contact angle and free surface energy measurements, atomic force microscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, and Fourier-transform infrared spectroscopy, were used to confirm the desired surface immobilization. Our findings indicated that PEG may be efficiently tethered to the Nylon 6 surface via DSC, having an enormous future potential for antifouling biomedical materials. The bacterial adhesion performances against S. aureus and P. aeruginosa were examined. In vitro cytocompatibility was successfully tested on pure, reduced, and PEG immobilized samples.

Wettability Control of Gold Surfaces Modified with Benzenethiol Derivatives: Water Contact Angle and Thermal Stability

2016 ◽  
Vol 16 (4) ◽  
pp. 3295-3300 ◽  
Author(s):  
Shingo Tatara ◽  
Yasutaka Kuzumoto ◽  
Masatoshi Kitamura
Keyword(s):  
Thermal Stability ◽  
Contact Angle ◽  
Water Contact Angle ◽  
Photoelectron Spectroscopy ◽  
Water Contact ◽  
Wide Range ◽  
Water Wettability ◽  
Modified Surface ◽  
Surface Modified ◽  
Activation Energy Of Desorption

The water wettability of Au surfaces has been controlled using various benzenethiol derivatives including 4-methylbenzenethiol, pentafluorobenzenethiol, 4-fluorobenzenethiol, 4-methoxybenzenethiol, 4-nitrobenzenethiol, and 4-hydroxybenzenethiol. The water contact angle of the Au surface modified with the benzenethiol derivative was found to vary in the wide range of 30.9° to 88.3°. The contact angle of the modified Au films annealed was also measured in order to investigate their thermal stability. The change in the contact angle indicated that the modified surface is stable at temperatures below about 400 K. Meanwhile, the activation energy of desorption from the modified surface was estimated from the change in the contact angle. The modified Au surface was also examined using X-ray photoelectron spectroscopy.

scholarly journals Surface Modification of Polyethersulfone (PES) with UV Photo-Oxidation

Technologies ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 36
Author(s):  
Ibrahim Cisse ◽  
Sarah Oakes ◽  
Shreen Sachdev ◽  
Marc Toro ◽  
Shin Lutondo ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Atomic Force Microscopy ◽  
Photoelectron Spectroscopy ◽  
Water Contact ◽  
X Ray ◽  
Force Microscopy ◽  
Photo Oxidation ◽  
Atomic Force ◽  
Modified Surfaces

Polyethersulfone (PES) films are widely employed in the construction of membranes where there is a desire to make the surface more hydrophilic. Therefore, UV photo-oxidation was studied in order to oxidize the surface of PES and increase hydrophilicity. UV photo-oxidation using low pressure mercury lamps emitting both 253.7 and 184.9 nm radiation were compared with only 253.7 nm photons. The modified surfaces were characterized using X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and water contact angle (WCA) measurements. Both sets of lamps gave similar results, showing an increase of the oxygen concentration up to a saturation level of ca. 29 at.% and a decrease in the WCA, i.e., an increase in hydrophilicity, down to ca. 40°. XPS detected a decrease of sp2 C-C aromatic group bonding and an increase in the formation of C-O, C=O, O=C-O, O=C-OH, O-(C=O)-O, and sulphonate and sulphate moieties. Since little change in surface roughness was observed by AFM, the oxidation of the surface caused the increase in hydrophilicity.

scholarly journals UV Photo-Oxidation of Polybenzimidazole (PBI)

Technologies ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 52
Author(s):  
Devon Shedden ◽  
Kristen M. Atkinson ◽  
Ibrahim Cisse ◽  
Shin Lutondo ◽  
Tyshawn Roundtree ◽  
...  
Keyword(s):  
Contact Angle ◽  
Photoelectron Spectroscopy ◽  
Treatment Time ◽  
Aerospace Industry ◽  
Water Contact ◽  
X Ray ◽  
Force Microscopy ◽  
Photo Oxidation ◽  
Redox Flow Batteries ◽  
Atomic Force

Since polybenzimidazole (PBI) is often used in the aerospace industry, high-temperature fuel cells, and in redox flow batteries, this research investigated the surface modification of PBI film with 253.7 and 184.9 nm UV photo-oxidation. As observed by X-ray photoelectron spectroscopy (XPS), the oxygen concentration on the surface increased up to a saturation level of 20.2 ± 0.7 at %. With increasing treatment time, there were significant decreases in the concentrations of C-C sp2 and C=N groups and increases in the concentrations of C=O, O-C=O, O-(C=O)-O, C-N, and N-C=O containing moieties due to 253.7 nm photo-oxidation of the aromatic groups of PBI and reaction with ozone produced by 184. 9 nm photo-dissociation of oxygen. Because no significant changes in surface topography were detected by Atomic Force Microscopy (AFM) and SEM measurements, the observed decrease in the water contact angle down to ca. 44°, i.e., increase in hydrophilic, was due to the chemical changes on the surface.

Effect of Exposure Time on Plasma Modified Polyvinylidenefluoride-Trifluoroethylene (PVDF-TrFE) Film Surfaces

2014 ◽  
Vol 895 ◽  
pp. 138-141 ◽  
Author(s):  
Muhamad Naiman Sarip ◽  
Rozana Mohd Dahan ◽  
Yap Seong Ling ◽  
Mohamad Hafiz Mohd Wahid ◽  
Adillah Nurashikin Arshad ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Exposure Time ◽  
Food Industry ◽  
Argon Plasma ◽  
Water Contact ◽  
Force Microscopy ◽  
Atomic Force ◽  
Good Biocompatibility ◽  
Surface Modified

This study investigates the plasma surface modified spin coated PVDF-TrFE (70/30) film of 200nm thick using Atomic Force Microscopy (AFM), Water Contact Angle (WCA) and Fourier Transform Infrared Spectroscopy (FTIR). The surface of the spin coated PVDF-TrFE film were modified using 13.56 MHz rf Argon plasma. The exposure time of the charged particle on PVDF-TrFE films were varied for 1, 3, 5, 7 and 9mins. Prior to modification, the average surface roughness observed was 3.5nm. However upon modification, the surface roughness was increased to 9.5nm. The contact angle of the surface modified film was reduced from 89° to 58°. The increase in surface roughness and wettability of the modified film provided good biocompatibility. This finding created great interest in developing functional polymer suitable for applications in areas such are biomedical, bio-analytical assays, textile and even food industry.

scholarly journals The Study on the Anti-corrosion Performance of NiTi Alloy in Human Body Solution with the Fabricating Processes of Laser Irradiation and PDMS Modification

2021 ◽  
Vol 18 (1) ◽  
pp. 77-91
Author(s):  
Chengjuan Yang ◽  
Weiran Cao ◽  
Zhen Yang ◽  
Meng Wang ◽  
Xiubing Jing ◽  
...  
Keyword(s):  
Laser Irradiation ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Niti Alloy ◽  
Hydrophobic Surface ◽  
Niti Shape Memory Alloy ◽  
Corrosion Performance ◽  
Hydrophobic Surfaces ◽  
Sliding Angle ◽  
Water Contact

AbstractThis paper presents a new and safe method of fabricating super-hydrophobic surface on NiTi Shape Memory Alloy (SMA), which aims to further improve the corrosion resistance performance and biocompatibility of NiTi SMA. The super-hydrophobic surfaces with Water Contact Angle (WCA) of 155.4° ± 0.9° and Water Sliding Angle (WSA) of 4.4° ± 1.1° were obtained by the hybrid of laser irradiation and polydimethylsiloxane (PDMS) modification. The forming mechanism was systematically revealed via Scanning Electron Microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS). The anti-corrosion of samples was investigated in Simulated Body Fluid (SBF) via the potentiodynamic polarization (PDP) and Electrochemical Impedance Spectroscopy (EIS) tests. PDMS super-hydrophobic coatings showed superior anti-corrosion performance. The Ni ions release experiment was also conducted and the corresponding result demonstrated that the super-hydrophobic samples effectively inhibited the release of Ni ions both in electrolyte and SBF. Besides, biocompatibility was further analyzed, indicating that the prepared super-hydrophobic surfaces present a huge potential advantage in biocompatibility.

scholarly journals Change in Interface Characteristics of ITO Modified with n-decyltrimethoxysilane

Crystals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 645
Author(s):  
Myung-Gyun Baek ◽  
Johng-Eon Shin ◽  
Dong-Hyun Hwang ◽  
Sung-Hoon Kim ◽  
Hong-Gyu Park ◽  
...  
Keyword(s):  
Contact Angle ◽  
Work Function ◽  
Indium Tin Oxide ◽  
Photoelectron Spectroscopy ◽  
Deposition Time ◽  
Interfacial Properties ◽  
Average Roughness ◽  
Light Emitting ◽  
Force Microscopy ◽  
Angle Measurements

Herein, we examined changes in the interfacial properties of organic light-emitting diodes when n-decyltrimethoxysilane (CH3SAM) was deposited on the surface of an indium tin oxide (ITO) electrode for various deposition times. It was revealed that the interfacial properties varied with deposition time. As the latter increased, so did the measured value of the contact angle, and ITO substrate exhibited a lower wettability. The contact angle measurements for bare ITO at 1, 10, 30, and 90 min were 57.41°, 63.43°, 73.76°, 81.47°, respectively, and the highest value obtained was 93.34°. In addition, the average roughness and work function of the ITO were measured using atomic force microscopy and X-ray photoelectron spectroscopy. As the deposition time of CH3SAM on the ITO substrates increased, it was evident that the former was well aligned with the latter, improving surface modification. The work function of CH3SAM, modified on the ITO substrates, improved by approximately 0.11 eV from 5.05–5.16 eV. The introduction of CH3SAM to the ITO revealed the ease of adjustment of the characteristics of ITO substrates.

Improvement of Interfacial Adhesion in PP/PS Blends Enhanced with Polyethylene-Polyamine Surface Treated Carbon Fiber

2014 ◽  
Vol 1061-1062 ◽  
pp. 170-174
Author(s):  
Jian Li
Keyword(s):  
Contact Angle ◽  
Carbon Fiber ◽  
Photoelectron Spectroscopy ◽  
Interfacial Adhesion ◽  
Morphological Changes ◽  
Water Contact ◽  
Polyethylene Polyamine ◽  
Adhesion Behavior ◽  
Interlaminar Shear ◽  
Treated Carbon

The effects of surface treatment of a carbon fiber (CF) by Polyethylene-polyamine (PEPA) on the interfacial adhesion behavior and morphology of polypropylene/polystyrene (PP/PS) matrix blends filled CF composites were investigated. Effects of surface treated a commercial CF on mechanical properties are studied. Contact angle was measured to examine the changes in wettability of the carbon fiber. The chemical and morphological changes were characterized by using X-ray photoelectron spectroscopy (XPS). PP/PS/CF composites were fabricated with and without PEPA treatment, and their interlaminar fracture toughnesses were compared. The results showed that the interlaminar shear strength (ILSS) of composites has been greatly improved filled PEPA modification CF. The water contact angle of resin sample decreased 50% after addition of PEPA surface treated CF.

Surface Modification Of Polymers With Grafting And Coating Of Silane Hybrids And Their Bioactivity

1999 ◽  
Vol 576 ◽  
Author(s):  
Masaaki Kubo ◽  
Seisuke Takashima ◽  
Kanji Tsuru ◽  
Satoshi Hayakawa ◽  
Akiyoshi Osaka ◽  
...  
Keyword(s):  
Contact Angle ◽  
High Density Polyethylene ◽  
Body Fluid ◽  
Chemical Species ◽  
Hydrated Silica ◽  
Bioactive Materials ◽  
Poly Vinyl Chloride ◽  
Essential Chemical ◽  
Surface Modified

ABSTRACTHydrated silica rich Si-OH and Si-0- groups serve in a body environment as sites for nucleation of apatite, and are known as an essential chemical species for bioactive materials. Organic polymers having surface modified with the hydrated silica will show bioactivity: bone tissues grow toward the apatite layer and bond to materials. Thus MOPS-M (3-methacryloxypropyltrimethoxysilane) was grafted under emulsion polymerization procedure to high density polyethylene (HDPE), poly (vinyl chloride) (PVC) and polyamide (PA) substrates to examine in vitro deposition of apatite (bioactivity) after soaking in a simulated body fluid (Kokubo solution). Bioactivity was confirmed for the grafted PVC and PA substrates and discussed in terms of contact angle and relative amount of grafted silane molecules.

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