等离子相沉积PTFE膜的结构、成膜机理及其超疏水性研究

This project aims at the specific issue that the medical needles of microsyringe have a bad surface hydrophobicity. We will start from two aspects: the choice of the materials with low surface free energy and the constructing of microscopic surface structure. To ensure high surface cleanliness of the medical devices, using low-power electron beam evaporation and plasma assisted activation technique, PTFE films are prepared on different substrates to satisfy the requirement of its super-hydrophobicity. On the one hand, the surface of the substrate would be treated by chemical and plasma etching to activate the substrate and simultaneusly to build the secondary micro/nano structure. On the other hand, PTFE powder is chose to act as evaporation target, by designing the excitation and activation process, the concentrations of radical and positive and negative ions fragment in the intermediate products of plasma phase are adjusted to make the growth of the films along the vertical direction to the substrate surface. The obtained films possess a certain micro-roughness and low surface energy. Design a special device collecting plasma phase, and the mass to charge ratio and distribution of molecule fragments from active gas are determined by mass spectrometer. The essence of polymerization reaction of plasma phase during the formation of the films is investigated by XPS C60 stripping method. The residual concentration of radicals in the polymer films with different thickness are determined by EPR technique. The reaction process of adsorption,radical coupling and graft growth of films will be also analyzed and moreover,a radical coupling formation mechanism of PTFE films and theoretical model of dynamics process will be established. Meanwhile, these could be useful to deduce some ideas and opinions for explaining the formation mechanism of polymeric films, which is not yet clear, prepared by PVD method.

本项目针对医用微量注射器针尖表面疏水性差的具体问题，选择低的表面能的PTFE做靶材，构筑类荷叶的微观表面结构。采用真空低功率电子束蒸发，基底Ar+离子活化技术，在不同基底上沉积PTFE薄膜，以达到超疏水性的要求。对基底表面进行化学清洗和Ar+离子活化，并构筑微纳米二次结构。设计特殊装置收集等离子相，导入质谱仪确定碎片的质量及分布；调节碎片自由基和正、负离子浓度，使PTFE分子链纵向生长，获得一定微观粗糙度的低表面能分子结构的膜层。C60剥离XPS法探讨成膜过程中等离子相中碎片的"着床"和接枝生长的本质。利用EPR确定在不同厚度处，聚合物膜中的残余自由基浓度；阐述自由基成膜机理，建立薄膜生长动力学理论模型。为目前尚未明确的等离子相沉积法制备聚合物膜的成膜机理提出模型并提供证据。

本项目以聚四氟乙烯（PTFE）粉料为靶材，采用真空低功率电子束蒸发及栅网辉光放电等离子处理或激光等离子体辅助技术，调节电子束高压、束流和沉积时间等工艺参数，分别在不同基底表面沉积制备了PTFE薄膜，研究了薄膜的成分、结构和微观形貌，分析PTFE薄膜的生长机理并建立了PTFE薄膜的动力学生长模型，深入探讨了薄膜的结构和厚度对其性能的影响，完成了其超疏水性能的评定，并根据本研究所获得的最佳工艺参数，为改善医用微量注射器针表面疏水性薄膜提供了制备技术。此外，还探索了AgCl/PTFE复合薄膜的形貌、结构、疏水性能和抗菌性能；石蜡/PTFE双疏性能薄膜材料的结构和性能；AgNO3/聚乙二醇双层复合膜的制备工艺、结构、成分和性能；掺金聚苯胺复合薄膜分子结构和电学性质；介质组成和退火温度对乙酸铜-聚乙烯双层体系复合薄膜结构和相态的影响；Cr掺杂和Cr过渡层对类金刚石薄膜性能的影响；Ti掺杂量对DLC薄膜的制备、结构、成分和性能的影响；不同退火温度下N掺杂TiO2复合膜的晶格结构和性能；液相法制备的碳基银复合物中银纳米粒子结构、形貌和性能。积极探索了所制备的各类聚合物基复合薄膜材料在电学、光学、生物医学性能。