超亲油/疏水功能中空纤维膜结构设计与成形机理

This project starts from the new principle and method of polymer processing. Based on the theory of polymer surface and interface, the super-oleophylic/hydrophobic graphene and the special morphology (such as slenderness, lightweight, large specific surface, paralleling assembly, forming a pipe, grid or sheet by twining or weaving, forming a floating assembly on the liquid surface, etc.) of the hollow fiber porous membrane were combined to play the synergic role during oil absorption and separation process. The super-oleophylic/hydrophobic functional hollow fiber membrane was fabricated by micro- and nano-structural graphene sheets as surface absorption layer and hydrophobic fluoropolymer hollow fiber porous membrane as the basilemma via the “directional intercalation” composite forming process. The “directional intercalation” referred to that the graphene sheets in dispersed solution diffused-absorbed and inlayed uniformly in a perpendicular direction to the axis of the basilemma under the external force during spinning. The interaction between graphene and organic molecules was simulated. The composition of grapheme in dispersion solution, the structure of basilemma, the composite forming method, morphology of graphene absorptive layer and the oil-water separation testing device were also studied and optimized. The mass transfer mechanism of as-prepared hollow fiber membrane in oil absorption and separation process were illustrated. The research will provide a scientific basis and technical support for developing a new-generation oil absorption and separation material which can be applicable to the high-efficiency separation and recycling of oil-water systems with excellent selective absorptive performances and fast absorption and also can be applied in separation, purification and concentration of organic liquids.

从高分子加工成型新原理、新方法角度出发，以高分子表面与界面理论为依据，将石墨烯超亲油/疏水特性与中空纤维多孔膜特殊形态（如纤细、质轻、比表面积大，可并联、缠绕或编织呈管状、网格状、片状等制成浮于液体表面的集合体）相结合，发挥吸油与分离功能协同作用，以微纳米结构石墨烯微片构筑表面吸附层，以疏水性含氟聚合物中空纤维多孔膜为基膜，“定向插层”复合成形（纺丝制膜过程在外力场作用下使分散液中石墨烯微片垂直于初生基膜轴向均匀、择优定向扩散-吸附并镶嵌在基膜表面），研究超亲油/疏水功能中空纤维膜，计算模拟石墨烯与有机物分子之间相互作用，优化石墨烯分散液组成、基膜结构、复合成形路线、石墨烯表面吸附层形态及油水分离试验装置等，阐明吸油与分离过程传质机理，为开发对油水体系选择吸附能力强和吸收速率快、适用于连续、高效处置油水体系以及有机物液体分离、提纯或浓缩的新一代吸油与分离功能材料提供科学依据和技术支撑。

本项目面向油水体系以及有机物液体的高效分离和环保需求，以高分子表面与界面理论为依据，将石墨烯超亲油/疏水特性与中空纤维多孔膜特殊形态（如纤细、质轻、比表面积大等，可并联、缠绕或编织呈管状、网格状、片状等制成浮于液体表面的集合体）相结合，首次提出吸油与分离功能协同作用机制，以微纳米结构的石墨烯微片构筑表面吸附层，分别采用溶液相转化法和热致相分离法纺制含氟聚合物中空纤维多孔基膜，纺丝制膜过程“定向插层”复合成形（在外磁场作用下使石墨烯微片垂直于初生基膜轴向择优定向），突破传统吸油材料间歇操作局限，研究出连续、高效吸油与分离（吸油-排油）中空纤维膜，其吸油而拒水，模拟了石墨烯与有机物分子之间相互作用，阐述了膜结构与性能关系，建立了中空纤维膜吸油与分离传质模型关系，开展了成果转化应用试验，发表19篇SCI、2篇EI期刊论文，授权4项国际、4项中国发明专利，组办“纤维新材料技术研讨会”学术会议一次，受邀学术报告5次，“连续吸油纤维材料”获第45届日内瓦国际发明展金奖、第二十四届全国发明展金奖，培养博士生4 名和硕士生4 名，2人入选中国科协“青年人才托举工程”，后续工作推进研究成果转化应用。