病毒拦截用类蝉翼聚合物二维纳米网的相分离成型机制及其空气滑移效应研究

现有医用防护口罩使用的驻极纤维滤材普遍存在驻极易失效、寿命短的问题，加快了防护口罩的消耗，给当前疫情防控带来了巨大压力。本项目拟研究单层连续纳米网状过滤材料的相分离成型机制，阐明材料微观网孔结构对其过滤性能的调控规律，获得长效稳定、高效低阻的口罩用过滤材料。近期申请者利用高分子液膜在微米尺度纤维框架内的相分离，初步制备出具有类蝉翼结构的单层连续二维纳米网，但其还存在网孔形状不规则、孔径分布不均匀的不足，导致其过滤效率还未达到实际应用要求。为此，本项目拟研究单层连续二维纳米网的可控成型及其空气滑移机制，确立纳米网相分离成型的边界条件，掌握微观网孔结构的调控规律，明晰纳米网精细结构与其动态力学稳定性及阻力压降特性间的构效关系，确立材料达到最佳过滤性能时的精细结构特征，实现其对0.3μm模拟病毒气溶胶过滤效率≥99.97%，阻力压降≤150Pa的目标，以满足医卫领域长效病毒防护的应用需求。

The major problem of conventional electret fibrous filters is that the electret effect can easily decay, resulting in their short service life and rapid consumption, which causes tremendous pressure for the epidemic prevention and control. Herein, we will study the phase separation of continuously-structured single-layer nanonets, elaborate the influence of the nanonets structure on the filtration properties, to finally obtain air filtration materials for face mask with high efficiency, low pressure drop, and long-term stability. Recently, we have preliminarily prepared single-layer nanonets similar to cicada's wings by using phase separation of polymer solution on the surface of fibrous substrate. However, the irregular pore shape and pore size of the nanonets prevent their practical applications. In this work, we will study the controllable fabrication of the single-layer nanonets and their air slip-effect, establish the phase separation parameters of nanonets, and acquire the controlling method of the nanonets structures. Furthermore, we will reveal the relationship between the nanonets structures and their mechanical stability and the pressure drop, indicate the structure features of nanonet-filters with the best application performance, and finally achieve the nanonet-filters with the filtration efficiency ≥99.97% and the pressure drop ≤150 Pa for the 0.3 μm viral aerosol, which would satisfy the practical applications in the field of viral protection.