Structure and haemocompatibility of ZnO films deposited by radio frequency sputtering.
ZnO films were first deposited on silicon and glass substrates using radio frequency sputtering and then annealed in air at different temperatures from 300 to 700 degrees C. The microstructures, surface energy and optical properties of ZnO films were examined by x-ray diffraction, Raman spectroscopy, contact angle test and UV-visible optical absorption spectroscopy, respectively. Results show that a perfectly oriented ZnO (0 0 2) thin film is obtained in all ZnO samples. Raman spectroscopy, in combination with those derived by UV-visible optical absorption spectroscopy, provides us with an accurate description of ZnO nature, revealing that, after annealing, ZnO films exhibit better crystallinity and narrower optical energy gap. The contact angle test denotes that the adhesive work and polar component of the surface energy of ZnO films increase steadily with the annealing temperature, which leads to more active interaction between annealed ZnO films and blood plasma. The platelet adhesion experiment shows that there are fewer platelets adhered to the surface of ZnO films compared to the polyurethane (PU) used in clinical application, suggesting ZnO's better compatibility with blood. As the annealing temperature increases, the number of platelets adhered to ZnO films increases correspondingly, which we believe is due to the narrower optical energy gap. Therefore, the appropriate surface properties and the wide optical energy gap of ZnO thin films are believed to be the main factors responsible for the excellent haemocompatibility.
Ye
Jia-Ying
JY
State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-Sen University, Guangzhou 510275, People's Republic of China.
Huang
Zhan-Yun
ZY
Min
Chen
C
Pan
Shi-Rong
SR
Chen
Di-Hu
DH
D001672:Biocompatible Materials / Q000737:chemistry*; D001792:Blood Platelets / Q000166:cytology* / Q000502:physiology*; D002470:Cell Survival; D002478:Cells, Cultured; D003460:Crystallization / Q000379:methods; D006358:Hot Temperature; D006801:Humans; D008422:Materials Testing; D008567:Membranes, Artificial; D010316:Particle Size; D010973:Platelet Adhesiveness / Q000502:physiology*; D011846:Radio Waves; D013499:Surface Properties; D015034:Zinc Oxide / Q000737:chemistry* / Q000528:radiation effects*
D001672:Biocompatible Materials; D008567:Membranes, Artificial; D015034:Zinc Oxide