ZnO纳米棒/碳布多尺度增强树脂基复合材料的制备及摩擦磨损机理研究

Wet transmission/brake system has an urgent need for carbon fabric reinforced resin composites. The extraordinary low surface energy of carbon fiber and poor interface between fiber and resin severely restrict the friction stability and service life of the composites. As such, this project develops a new thought about In-situ growth of ZnO nanorods onto carbon fabric to form multiscale reinforcement. Firstly, oxygen containing functional groups will be grafted onto carbon fibers based on Diels-Alder reaction without damaging its structure. Then, ZnO seed layer will be prepared and deposited on carbon fabric surface with sol-gel method. ZnO nanorods will be grown on carbon fabric with hydrothermal electrophoretic deposition method subsequently. The multiscale ZnO nanorods/carbon fabric reinforcement will be used to prepare composites by hot press. The Diels-Alder reaction mechanism will be revealed based on the study of graft regularity of oxygen containing functional groups onto carbon fibers. The effects of carbon fiber surface chemistry, seed layer and conditions on the growth process control of ZnO nanorods will be studied systemically to reveal growth mechanism. The interface enhancement mechanism will be revealed based on comprehensively study of the interfacial state of ZnO nanorods/carbon fibers as well as ZnO nanorods/resin. The relationship between multiscale reinforcement and microstructure of composites as well as mechanical property will be studied comprehensively. The effect and mechanism of multiscale reinforcement will be explored during friction process of the composites to establish the friction and wear model. The friction stability and service life of the composites will be greatly improved. The project will provide theoretical guidance for the design of multiscale composites.

湿式传动/制动系统对高性能碳布增强树脂基复合材料提出迫切需求，但由于碳布表面能低，与树脂界面结合性能差，严重影响了该复合材料的摩擦稳定性和使用寿命。鉴于此，本项目提出在碳布表面原位生长ZnO纳米棒，构筑多尺度增强体的新思路。首先通过双烯合成反应在碳布表面无损接枝含氧官能团，利用溶胶凝胶法在其表面制备ZnO晶种层后，采用水热电泳技术生长ZnO纳米棒，构筑ZnO纳米棒/碳布多尺度增强体，并热压成型树脂基复合材料。研究碳布表面含氧官能团无损接枝规律，揭示双烯合成反应机制；研究碳布表面化学状态、晶种层及生长条件等对ZnO纳米棒生长的影响规律，揭示其生长机理；探索ZnO纳米棒与碳纤维及树脂间的界面增强机理，建立多尺度增强体与复合材料微观结构及力学性能之间的关系；阐明多尺度增强体在摩擦过程中的作用机制，建立摩擦磨损模型，大幅度提高摩擦稳定性，并延长该复合材料的使用寿命，为该类复合材料的多尺度设计提供提导。

湿式传动/制动系统对高性能碳布增强树脂基复合材料提出了迫切需求，但由于碳布表面能低，与树脂界面结合性能差，严重影响了该复合材料的摩擦稳定性和使用寿命。针对上述问题，本项目提出了在碳布表面原位生长ZnO纳米棒，构筑多尺度增强体的新思路。首先通过双烯合成反应在碳布表面无损接枝含氧官能团，利用溶胶凝胶法在其表面制备ZnO晶种层后，采用水热电泳技术生长ZnO纳米棒，构筑ZnO纳米棒/碳布多尺度增强体，并热压成型树脂基复合材料。研究了碳布表面含氧官能团无损接枝规律，揭示出双烯合成反应机制。研究了碳布表面化学状态、晶种层及生长条件等对ZnO纳米棒生长的影响规律，揭示了其生长机理，建立了多尺度增强体与复合材料微观结构及力学性能之间的关系，阐明多尺度增强体在摩擦过程中的作用机制。通过改变生长液浓度对ZnO纳米棒在碳布表面的形态进行调控，获得了合适的生长液参数，当浓度为36mM时，所制备的ZnO纳米棒/碳布增强的复合材料具有最佳的力学和摩擦学性能，拉伸和弯曲强度分别为170.9MPa和62.5MPa。采用水热电泳法制备出ZnO纳米棒/碳布多尺度增强体，当水热电泳时间为30min时，碳纤维表面生长的ZnO纳米棒均一致密，结晶性良好。改性后的样品拉伸强度提高了33.1%，磨损率降低了55.4%。采用水热电泳法在碳纤维表面生长ZnO纳米棒，随后对ZnO纳米棒/碳布多尺度增强体进行PEI功能化接枝处理，实现了碳纤维、纳米棒和树脂基体之间的化学结合与机械啮合的有效协同。PEI-ZnO纳米棒/碳布增强复合材料的拉伸强度与弯曲强度分别为224.8MPa和96MPa，提升了155%和69%，磨损率仅为1.2×10-5mm3/(N∙m)，显著改善了使用寿命，上述研究工作将为该类复合材料的多尺度设计有益提导。