Formation of Nanocones on Highly Oriented Pyrolytic Graphite by Oxygen Plasma

Materials

Alenka Vesel¹  Kristina Eleršič²  Martina Modic²  Ita Junkar² 

[1] Plasma Laboratory, Institute Jozef Stefan, Jamova 39, Ljubljana 1000, Slovenia;

关键词: highly oriented pyrolytic graphite (HOPG);    oxygen plasma treatment;    nanocone formation;    platelet adhesion;   

DOI  :  10.3390/ma7032014

来源: mdpi

【 摘 要 】

Improvement in hemocompatibility of highly oriented pyrolytic graphite (HOPG) by formation of nanostructured surface by oxygen plasma treatment is reported. We have showed that by appropriate fine tuning of plasma and discharge parameters we are able to create nanostructured surface which is densely covered with nanocones. The size of the nanocones strongly depended on treatment time. The optimal results in terms of material hemocompatibility were obtained after treatment with oxygen plasma for 15 s, when both the nanotopography and wettability were the most favorable, since marked reduction in adhesion and activation of platelets was observed on this surface. At prolonged treatment times, the rich surface topography was lost and thus also its antithrombogenic properties. Chemical composition of the surface was always more or less the same, regardless of its morphology and height of the nanocones. Namely, on all plasma treated samples, only a few atomic percent of oxygen was found, meaning that plasma caused mostly etching, leading to changes in the surface morphology. This indicates that the main preventing mechanism against platelets adhesion was the right surface morphology.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland