Study On Hemocompatibility Ofsuperhydrophobic ZnO Nanofilms

Anticoagulant materials, as a kind of new functional materials, have received wide attention in the fields of materials science and biomedical science because of their excellent properties such as reparability, replace, illness diagnosis and therapy.The anticoagulation properties of the anticoagulant materials are mainly associated with their surface structures such as chemical composition, surface geometry and morphology, however, their correlation with the anticoagulation properties is unclear up to now. Considering the lower surface energy of the superhydrophobic surface, it is expected to be used to improve the blood compatibility of related materials. In this thesis, the blood compatibility of superhydrophobic ZnO nanofilms was investigated.The electrodeposition and hydro-thermal method were successfully used to prepare nanoscale ZnO films on copper surface. The crystal structure, chemical composition and surface morphology of the thin films were characterized by SEM, XRD, EDS and XPS. The surface wetting properties and the blood compatibility of ZnO nanofilms were evaluated by platelet adhesion test and hemolysis test.(1) It was found that the formation and structures of ZnO nanofilms were strongly associated with the growth parameters such as precursor concentration,electric deposition temperature, concentration of reaction solution, hydrothermal reaction temperature and reaction time. In the process of preparing ZnO nanofilms, it was found that the reaction temperature and reaction time had great influence on the growth of ZnO nanorods arrays. The diameter of nanorods increased obviously with the increase of temperature and reaction time. Secondly, it was easier to get the needle like structure when the precursor concentration was set to 10 mmol/L and the reaction temperature was set to 90?.(2) The experimental results showed that the surface wettability of the ZnO nanofilms was dependent on the surface roughness. When the value of the ratio of the diameter of the nano cone and the distance(d/l) was 0.25~0.55, the contact angle is consistent with the Cassie mode; When the value of d/l was 0.55~0.65, the wetting mode was transformed into Wenzel mode. After modified with low-surface-energy materials, the wetting mode of the thin films was consistent with the Cassie model.(3) In the platelet adhesion test, when the hydrophilic ZnO nanofilms with contact angle of less than 40° or when the superhydrophobic ZnO nanofilms withcontact angle of larger than 150° were used, the films had excellent anticoagulant properties. The surface free energy of the films had a limited impact on its anticoagulation properties, but the microstructure of the films had an obvious impact on the anticoagulant properties. In addition, the hemolysis rate of ZnO nanofilms was less than 5%, which indicated that the blood compatibility of the ZnO nanofilms after modified by polyethylene glycol was excellent.