Highly Durable Antimicrobial Tantalum Nitride/Copper Coatings on Stainless Steel Deposited by Pulsed Magnetron Sputtering

Thangavel Elangovan; Athinarayanan Balasankar; Selvaraj Arokiyaraj; Ramaseshan Rajagopalan; Rani P George; Tae Hwan Oh; Parasuraman Kuppusami; Subramaniyan Ramasundaram

doi:10.3390/mi13091411

Highly Durable Antimicrobial Tantalum Nitride/Copper Coatings on Stainless Steel Deposited by Pulsed Magnetron Sputtering

Micromachines (Basel). 2022 Aug 27;13(9):1411. doi: 10.3390/mi13091411.

Authors

Thangavel Elangovan¹, Athinarayanan Balasankar², Selvaraj Arokiyaraj³, Ramaseshan Rajagopalan⁴, Rani P George⁵, Tae Hwan Oh⁶, Parasuraman Kuppusami⁷, Subramaniyan Ramasundaram⁶

Affiliations

¹ Smart Energy Materials Research Lab (SEMRL), Department of Energy Science, Periyar University, Salem 636011, India.
² Department of Physics, Gobi Arts & Science College, Gobichettipalayam 638476, India.
³ Department of Food Science & Biotechnology, Sejong University, Seoul 05006, Korea.
⁴ Materials Science Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, India.
⁵ Department of Nanoscience and Nanotechnology, Bharathiar University, Coimbatore 641046, India.
⁶ School of Chemical Engineering, Yeungnam University, Gyeongsan 38436, Korea.
⁷ Center for Nanoscience and Nanotechnology, Sathyabama Institute of Science and Technology, Chennai 600119, Tamilnadu, India.

Abstract

Highly durable and antimicrobial tantalum nitride/copper (TaN/Cu) nanocomposite coatings were deposited on D-9 stainless steel substrates by pulsed magnetron sputtering. The Cu content in the coating was varied in the range of 1.42-35.42 atomic % (at.%). The coatings were characterized by electron probe microanalyzer, X-ray diffraction, scanning electron microscope and atomic force microscope. The antibacterial properties of the TaN/Cu coatings against gram-negative Pseudomonas aeruginosa were evaluated using a cell culture test. The peak hardness and Young's modulus of TaN/Cu with 10.46 at.% Cu were 24 and 295 GPa, respectively, which amounted to 15 and 41.67% higher than Cu-free TaN. Among all, TaN/Cu with 10.46 at.% exhibited the lowest friction coefficient. The TaN/Cu coatings exhibited significantly higher antibacterial activity than Cu-free TaN against Pseudomonas aeruginosa. On TaN, the bacterial count was about 4 × 10⁶ CFU, whereas it was dropped to 1.2 × 10² CFU in case of TaN/Cu with 10.46 at.% Cu. The bacterial count was decreased from 9 to 6 when the Cu content increased from 25.54 to 30.04 at.%. Live bacterial cells were observed in the SEM images of TaN, and dead cells were found on TaN/Cu. Overall, TaN/Cu with 10.46 at.% Cu was found to be a potential coating composition in terms of higher antimicrobial activity and mechanical durability.

Keywords: antibacterial activity; coating; copper; magnetron sputtering; nanocomposite; tantalum nitride.

Grants and funding

This work was financially supported by General Research Grand of Periyar University, Salem, Tamilnadu, India. The authors thank M. Vijayalakshmi, Associate Director, Physical Metallurgy Group, T. Jayakumar, Director, Metallurgy and Materials Group and Shri S. C. Chetal, Director, Indira Gandhi Centre for Atomic Research for granding facility for material preparation and characterization.