功能微纳米聚合物纤维材料

Functional Polymeric Micro/Nano-fibrous Materials

纤维直径细化带来的尺寸效应和表面效应赋予微纳米纤维许多独特的性质,使其成为当前纤维材料领域研究的重点和前沿.在众多的微纳米纤维加工方法中,静电纺丝法因具有可纺原料种类丰富、纤维结构可调性好、多元技术结合性强等优势而成为当前制备微纳米聚合物纤维的重要方法之一.近年来,本课题组在静电纺微纳米聚合物纤维材料的可控加工及应用方面开展了系列研究,本专论主要介绍了其中关于超细纳米蛛网材料、致密粘连微纳米纤维膜、多级网孔纤维气凝胶的结构成型机制及其特效应用方面的工作,并对功能微纳米聚合物纤维材料的未来发展方向进行了展望.

Benefiting from intensive size effect and surface effect arising from thin fibers,micro/nano-fibrous membranes exhibit many fascinating properties and have become a hot spot and leading edge in the fiber materials.Among the existing processing approaches for micro/nano-fibers,electrospinning has proven to be one of the most effective and promising method due to its integrated characteristics,including broad availability to varieties of polymers,adjustable porous structure,and superior technological convergence.In recent years,our research group have endeavored systematic researches on the controllable fabrication and applications of electrospun micro/nano-fibrous materials,especially in the terms of ultra-thin nanonets,compactly bonded membranes and porous fibrous aerogels.This review mainly puts focus on the formation mechanisms and applications of these distinctive micro/nano-fibrous materials,which are summarized as follows.Firstly,the twodimensional nanonets with extremely small diameters(<20 nm)are fabricated by a novel electrospinning/netting technique,and the deformation-phase transition of the charged jets/droplets from polymer solution during the period is also revealed,which have broken the bottleneck of the thinning on diameter of electrospun fibers.And the novel nanonets demonstrate lower air resistance due to the slip flow of air molecules on the periphery of nanofibers,holding great promise as an exceptional candidate for air filtration.Secondly,compactly bonded membranes with stable porous structures are constructed directly through the regulation of the relative humidity,and the effects of relative humidity on electrospinning jet stretching and solidification are investigated.Additionally,hydrophobicly modified compactly bonded membranes demonstrate excellent waterproofness and breathability,thus implying their potential application in selective separation of gas-liquid medium.Thirdly,the ultralight polymeric micro/nano-fibrous aerogels with hierarchical cellular structure and superelasticity are prepared via a novel three-dimensional fibrous framework reconstruction method,which exhibit the integrated properties of extremely low density(minimum of 0.12 mg/cm3),super recyclable compressibility and multifunctionality of combining the thermal insulation,sound absorption,emulsion separation and elasticityresponsive electric conduction.The future perspectives of micro/nano-fibrous materials were also given at the end of this review.