Tribological performance of biomedical grade UHMWPE/nano-Al2O3/Vitamin-C hybrid composite for cartilage replacements

2021 ◽  
Vol 291 ◽  
pp. 129515
Author(s):  
Omar Hussain ◽  
Babar Ahmad ◽  
Shahid Saleem
Keyword(s):  
Vitamin C ◽  
Hybrid Composite ◽  
Tribological Performance

Fabrication and tribological behavior of novel UHMWPE/vitamin-C/graphene nanoplatelets based hybrid composite for joint replacement

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Omar Hussain ◽  
Shahid Saleem Sheikh ◽  
Babar Ahmad
Keyword(s):  
Composite Materials ◽  
Vitamin C ◽  
Human Serum ◽  
Hybrid Composite ◽  
Wear Behavior ◽  
Tribological Performance ◽  
Graphene Nanoplatelets ◽  
Morphological Examination ◽  
Content Type ◽  
Weight Percentage

Purpose This study aims to fabricate and investigate the tribological performance of ultra-high molecular weight polyethylene (UHMWPE)-based composite materials reinforced with 0.5, 1 and 2 weight percentage of graphene nanoplatelets (GNPs) while keeping the weight percentage of vitamin C constant at 2% for each composite. Design/methodology/approach In this paper, the composites were fabricated using hot pressing, and the dispersion of GNP/vitamin C/UHMWPE hybrid composite was investigated by X-ray diffraction. Experimental trials were performed according to ASTM F732 on a reciprocating sliding tribometer (pin-on-disc) at human body temperature of 37 ± 1 °C, for a load of 52 N, to assess the role of these fillers on the tribological properties of UHMWPE against Ti6Al4V counter body material under dry and lubricating (human serum) environment. Findings In this study, it has been observed that friction and wear behavior of the developed composites improve with increase in weight percentage of GNP, and human serum adheres to the surface of the composite pins upon sliding, resulting in the formation of a film, which results in better wear resistance of the composite pins under human serum lubrication than dry sliding. Scanning electron microscope was used to investigate the worn surface morphological examination of the composite materials. Specific wear rate of 0.76 × 10−7 mm3/Nm was attained for 2 Wt.% GNP-filled composite under human serum lubrication. Practical implications The results indicate the compatibility of the composite material used in this study and suggested the in vitro implant application. Originality/value The presented work includes novel study of synergistic effect of GNP (which acts as a solid lubricant) and vitamin C (added as an antioxidant) on the tribological performance of UHMWPE under dry and human serum lubrication.

Tribological Performance and Action Mechanism of Cadmium Dialkyldithiophosphate

2005 ◽  
Vol 48 (2) ◽  
pp. 171-175 ◽  
Author(s):  
Hu Jianqiang ◽  
Wei Xianyong ◽  
Yao Junbing ◽  
Xie Feng ◽  
Zhu Huanqin ◽  
...  
Keyword(s):  
Tribological Performance ◽  
Action Mechanism

Striae Gravidarum, Vitamin C and Other Related Factors

2011 ◽  
Vol 81 (1) ◽  
pp. 43-48 ◽  
Author(s):  
Rahime Bedir Findik ◽  
Nurcihan Karakurt Hascelik ◽  
Kadir Okhan Akin ◽  
Ayse Nurcan Unluer ◽  
Jale Karakaya
Keyword(s):  
Family History ◽  
Vitamin C ◽  
Pregnant Women ◽  
Smoking Status ◽  
Multiple Logistic Regression Analysis ◽  
Blood Levels ◽  
Significant Relation ◽  
Related Factors ◽  
Thigh Circumference ◽  
Striae Gravidarum

Background: Striae gravidarum, a clinical condition commonly seen in pregnant women, produces serious cosmetic problems and may lead to psychological problems. Aim: The present study investigated whether there was any relation between the presence of striae in primigravid pregnant women and blood vitamin C levels, and factors thought to contribute to the formation of striae such as family history, weight gained during pregnancy, smoking status, abdominal and thigh circumference, and age. Methods: Overall, 69 primigravid women attending routine antenatal follow-up and, using prophylactic iron and vitamin preparations, underwent investigation. All were pregnant 36 or more weeks. Scoring was based on striae examination and whether striae were present. The relation between the presence of striae, vitamin C blood levels, and other factors was investigated. Results and Conclusions: Multiple logistic regression analysis showed a significant relation between the presence of striae and blood vitamin C levels (p = 0.046) and between the presence of striae and family history (p = 0.023). No significant relation was found between the presence of striae and age, weight gained during pregnancy, abdominal and thigh circumference, or smoking status. It was concluded that further, more comprehensive studies on the issue are required.

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