Relationship between Dislocation Density and Antibacterial Activity of Cryo-Rolled and Cold-Rolled Copper

Materials

Dinesh Kalyanasundaram¹  Vinod Parmar¹  Kandarp Changela²  K. Hariharan³  S.K. Panigrahi³  B. Srinivas³  Sujata Mohanty⁴  Manimuthu Mani Sankar⁴ 

[1] Centre for Biomedical Engineering, Indian Institute of Technology Delhi, New Delhi 110016, India;Department of Mechanical Engineering, Indian Institute of Technology Delhi, New Delhi 110016, India;Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036, India;Stem Cell Research Facility, All India Institute of Medical Sciences, New Delhi 110029, India;

关键词: defects;    nano-crystalline;    cryo-rolling;    antibacterial;    dislocation;    copper;    leaching;    nanostructuring;   

DOI  :  10.3390/ma12020200

来源: DOAJ

【 摘 要 】

In the present work, cold rolling and cryo-rolling were performed on 99% commercially pure copper substrates. Both cold and cryo-rolling processes caused severe plastic deformation that led to an increase in dislocation density by 14× and 28× respectively, as compared to the pristine material. Increases in average tensile strengths, by 75% (488 MPa) and 150% (698 MPa), were observed in the two rolled materials as the result of the enhancement in dislocation density. In addition to strength, enhanced antibacterial property of cryo-rolled copper was observed in comparison to cold rolled and pristine copper. Initial adhesion and subsequent proliferation of bio-film forming Gram-positive bacteria Staphylococcus aureus was reduced by 66% and 100% respectively for cryo-rolled copper. Approximately 55% protein leakage, as well as ethidium bromide (EtBr) uptake, were observed confirming rupture of cell membrane of S. aureus. Inductively coupled plasma-mass spectroscopy reveals higher leaching of elemental copper in nutrient broth media from the cryo-rolled copper. Detailed investigations showed that increased dislocation led to leaching of copper ions that caused damage to the bacterial cell wall and consequently killing of bacterial cells. Cryo-rolling enhanced both strength, as well as antibacterial activity, due to the presence of dislocations.

【 授权许可】

Unknown