Plasma Surface Modification of Medical-Grade Ultra-High Molecular Weight Polyethylene for Improved Tribological Properties

1998 ◽  
Vol 550 ◽  
Author(s):  
C.M. Klapperich ◽  
K. Komvopoulos ◽  
L. Pruitt
Keyword(s):  
Molecular Weight ◽  
Contact Angle ◽  
Plasma Treatment ◽  
High Molecular Weight ◽  
Photoelectron Spectroscopy ◽  
Total Joint Replacement ◽  
Surface Hydrophobicity ◽  
Surface Chemical ◽  
Water Contact ◽  
Ultra High Molecular Weight

AbstractUltra-high molecular weight polyethylene (UHMWPE) is the principal material used to replace damaged cartilage in total joint replacement surgeries. This publication presents preliminary results from a new class of surface treatments to modify the surface chemistry and microstructure of UHMWPE under controlled processing conditions. Radio frequency plasmas were used to lightly crosslink the subsurface of UHMWPE and to modify the surface chemical state through the attachment of low-surface-energy fluorocarbon groups. A pin-on-disk apparatus was used to slide CoCrWNi pins with spherical tips on polished disks of plasma- treated and untreated UHMWPE immersed in a bath of preserved bovine serum. The wear resistance and surface chemical composition of tested specimens were characterized by surface profilometry and X-ray photoelectron spectroscopy (XPS), respectively. Changes in the surface hydrophobicity due to plasma treatment were evaluated using contact angle measurements. The prospect of surface plasma treatment in orthopedic applications is elucidated in the context of the obtained friction, wear, distilled water contact angle, and XPS results.

scholarly journals Surface Treatment of Ultra-High Molecular Weight Polyethylene (UHMWPE) by Cold Atmospheric Plasma (CAP) for Biocompatibility Enhancement

2021 ◽  
Vol 11 (4) ◽  
pp. 1703
Author(s):  
Jack Turicek ◽  
Nicole Ratts ◽  
Matey Kaltchev ◽  
Nazieh Masoud
Keyword(s):  
Molecular Weight ◽  
Contact Angle ◽  
High Molecular Weight ◽  
Water Contact Angle ◽  
Plasma Source ◽  
Atmospheric Plasma ◽  
Water Contact ◽  
Artificial Joints ◽  
Joint Replacements ◽  
Ultra High Molecular Weight

Ultra-high molecular weight polyethylene (UHMWPE) is one of the most commonly used polymers in joint replacements because of its biologically inert properties and low friction coefficient. However, it has downfalls relating to its wear, adhesion, and lubrication. In this study, UHMWPE samples were treated with a tubular helium cold atmospheric pressure (CAP) plasma source in order to improve three properties of the polymer: (1) its wear resistance, which was characterized by durometer hardness, (2) its lubrication characterized by water contact angle, and (3) its adhesion characterized by both root mean square surface roughness (Rq) and water contact angle. The polymer was treated by two different parts of the plasma plume (the base and the tip) at two different helium flow rates (1 L/min and 2.5 L/min), for different treatment times. Results of the plasma treatment showed a decrease in the contact angle of between 32 and 54 degrees, a significant increase in the roughness by up to 10 times the pristine surface, and no substantial change in the hardness. These improvements to the adhesion and lubrication properties of the polymer examined suggest that the treated surface could be more suitable for use in artificial joints.

Surface Modification of Ultra-High Molecular Weight Polyethylene with Crosslinked Hyaluronic Acid and its Antiwear Performance

2015 ◽  
Vol 642 ◽  
pp. 94-98
Author(s):  
Chau Chang Chou ◽  
Yu Hsiang Hao ◽  
Fu Yin Hsu
Keyword(s):  
Molecular Weight ◽  
Hyaluronic Acid ◽  
High Molecular Weight ◽  
Incident Light ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Coated Sample ◽  
Infrared Spectrometry ◽  
Water Contact ◽  
Ultra High Molecular Weight

The surface of high-pressure crystallized ultra-high molecular weight polyethylene (UHMWPE) was modified for application as an artificial cartilage material. A UHMWPE surface pretreated by a series of processes, including treatment with O2-plasma and ethylenediamine solution, was coated with hyaluronic acid (HA). After that, adipic acid dihydrazide (AAD) was added to partially crosslink the HA coating in order to enhance its durability. The modified samples were verified by water contact angle measurement and Fourier transform infrared spectrometry. Both HA layers, original and crosslinked, were also quantitatively evaluated by carbohydrate chemistry assay according to the absorbance of the incident light. The tribological performance of the samples was evaluated by a pin-on-disk test rig lubricated by normal saline under an average pressure of 18 MPa and at a sliding speed of 0.03 m/s for 45 h. The wear resistance of the HA-coated UHMWPE specimens promoted by the crosslink process was superior to that of the original HA-coated sample, and that resistance was maintained after immersion in saline solution for one month.

scholarly journals Continuous Plasma Treatment of Ultra-High-Molecular-Weight Polyethylene (UHMWPE) Fibres for Adhesion Improvement

2009 ◽  
Vol 6 (S1) ◽  
pp. S375-S381 ◽  
Author(s):  
Steluta Teodoru ◽  
Yukihiro Kusano ◽  
Noemi Rozlosnik ◽  
Poul K. Michelsen
Keyword(s):  
Molecular Weight ◽  
Plasma Treatment ◽  
High Molecular Weight ◽  
Ultra High Molecular Weight

Nanoindentation properties of compression-moulded ultra-high molecular weight polyethylene

2003 ◽  
Vol 217 (5) ◽  
pp. 357-366 ◽  
Author(s):  
S P Ho ◽  
L Riester ◽  
M Drews ◽  
T Boland ◽  
M LaBerge
Keyword(s):  
Molecular Weight ◽  
Elastic Modulus ◽  
High Molecular Weight ◽  
Mechanical Response ◽  
Total Joint Replacement ◽  
Scanning Calorimetry ◽  
Nanomechanical Properties ◽  
Significant Difference ◽  
Ultra High Molecular Weight ◽  
Penetration Depths

This paper investigates the elastic modulus and hardness of untreated and treated compression-moulded ultra-high molecular weight polyethylene (UHMWPE) tibial inserts of a total knee replacement (TKR) prosthesis. Investigations were carried out at a nanoscale using a Nanoindenter™ at penetration depths of 100, 250 and 500 nm. The nanomechanical properties of surface and subsurface layers of the compression-moulded tibial inserts were studied using the untreated UHMWPE. The nanomechanical properties of intermediate and core layers of the compression-moulded tibial insert were studied using the cryoultrasectioned and etched UHMWPE treated samples. The cryoultrasectioning temperature (-150°C) of the samples was below the glass transition temperature, Tg(-122± 2°C), of UHMWPE. The measurement of the mechanical response of crystalline regions within the nanostructure of UHMWPE was accomplished by removing the amorphous regions using a time-varying permanganic-etching technique. The percentage crystallinity of UHMWPE was measured using differential scanning calorimetry (DSC) and the Tg of UHMWPE was determined by dynamic mechanical analysis (DMA). Atomic force microscopy (AFM) was used to assess the effect of surface preparation on the samples average surface roughness, Ra. In this study, it was demonstrated that the untreated UHMWPE samples had a significantly lower ( p<0.0001) elastic modulus and hardness relative to treated UHMWPE cryoultrasectioned and etched samples at all penetration depths. No significant difference ( p > 0.05) in elastic modulus and hardness between the cryoultrasectioned and etched samples was observed. These results suggest that the surface nanomechanical response of an UHMWPE insert in a total joint replacement (TJR) prosthesis is significantly lower compared with the bulk of the material. Additionally, it was concluded that the nanomechanical response of material with higher percentage crystallinity (67 per cent) was predominantly determined by the crystalline regions within the semi-crystalline UHMWPE nanostructure.

scholarly journals Germination of Phaseolus vulgaris L. Seeds after a Short Treatment with a Powerful RF Plasma

2021 ◽  
Vol 22 (13) ◽  
pp. 6672
Author(s):  
Nina Recek ◽  
Matej Holc ◽  
Alenka Vesel ◽  
Rok Zaplotnik ◽  
Peter Gselman ◽  
...  
Keyword(s):  
Contact Angle ◽  
Phaseolus Vulgaris ◽  
Plasma Treatment ◽  
Water Contact Angle ◽  
Photoelectron Spectroscopy ◽  
Rf Plasma ◽  
Phaseolus Vulgaris L ◽  
Short Treatment ◽  
Water Contact ◽  
Radicle Growth

Seeds of common bean (Phaseolus vulgaris L.), of the Etna variety, were treated with low-pressure oxygen plasma sustained by an inductively coupled radiofrequency discharge in the H-mode for a few seconds. The high-intensity treatment improved seed health in regard to fungal contamination. Additionally, it increased the wettability of the bean seeds by altering surface chemistry, as established by X-ray photoelectron spectroscopy, and increasing surface roughness, as seen with a scanning electron microscope. The water contact angle at the seed surface dropped to immeasurably low values after a second of plasma treatment. Hydrophobic recovery within a month returned those values to no more than half of the original water contact angle, even for beans treated for the shortest time (0.5 s). Increased wettability resulted in accelerated water uptake. The treatment increased the bean radicle length, which is useful for seedling establishment in the field. These findings confirm that even a brief plasma treatment is a useful technique for the disinfection and stimulation of radicle growth. The technique is scalable to large systems due to the short treatment times.

scholarly journals Plasma Treatments to Improve the Bonding of Thermo-Treated Cherry Wood

Coatings ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 656
Author(s):  
Qingzhu Zheng ◽  
Weifeng Zhang ◽  
Huiping Lin ◽  
Junwen Yu ◽  
Wenbin Yang ◽  
...  
Keyword(s):  
Contact Angle ◽  
Plasma Treatment ◽  
Chemical Property ◽  
Bonding Strength ◽  
Surface Chemical ◽  
Water Contact ◽  
Surface Chemical Property ◽  
O2 Plasma Treatment ◽  
O2 Plasma ◽  
N2 Plasma

Thermal treatment can significantly improve the dimensional stability of wood, but it will decrease the bonding strength. In this work, the bonding strength of thermo-treated cherry wood boards was improved by plasma treatment. The change of wettability, surface morphology, and surface chemical property of cherry wood before and after plasma treatment was investigated by water contact angle measurement, Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). The plasma treatment significantly improved the wettability of thermo-treated cherry wood by decreasing its water contact angle from 109.95° to 53.18°. N2 or O2 was used as the plasma atmosphere, and it was found that N2 plasma treatment afforded cherry wood a rougher surface. The AFM roughness of cherry wood was increased from 19 nm to 31.9 nm after N2 plasma treatment. XPS results revealed an additional C–N group for N2 plasma treatment and the content of C=O, O–C–O, and O–C=O increased for O2 plasma treatment, respectively, indicating that the surface chemical property of cherry wood was modified. Due to the surface character, the bonding strength increased by 21.17% for N2 plasma treatment and 15.32% for O2 plasma treatment.

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