静电纺丝制备微纳纤维的形貌表征与影响机理分析

静电纺丝作为一种广泛采用的纳米纤维制备技术,影响其纤维形貌的主要因素包括材料参数、工艺参数和环境因素等.采用聚氧化乙烯(PEO)溶液,通过研究溶液属性(分子量、质量分数、电导率)和工艺参数(工艺电压、电极间距、喷嘴内径等)对纤维形貌的影响,得出相关参数对纤维直径和形貌的作用规律.研究结果表明:当PEO质量分数由4%到8%时,图案形貌经历了球状颗粒-珠丝共存-纤维的演变过程;分子量由40万到60万时,纤维由珠丝结构变成均匀光滑的丝,进一步增大分子量,纤维开始变得粗细不均并出现锯齿结构;当电导率由151到355 s/cm时,纤维直径变粗5倍;工艺电压(25~30 kV)增加,纤维直径先增加后减小,梭形颗粒先增多后减少;电极间距(15~25 cm)的增加使PEO纤维的直径减小,梭形颗粒先增加后减少;喷嘴内径由160 m增大到600 m时,纤维先是变得均匀光滑,后出现黏并结构.这些研究结果能够更好地指导静电纺丝技术在生物医用、纳米装置及纳米制造等领域的应用.

Morphology characterization and influential mechanism analysis of electrospun micro/nano-fiber

Electrospinning attracts more eyes of scientists with the continuous rapid development of nanotechnology.The key problem in application is to improve the controllability of electrospinning parameters,such as material parameters,processing parameters and environmental factors,which would affect the morphology and consistency of electrospun fibers.In this paper,the effects of material and process parameters,including molecular weight,concentration,applied voltage,electrode spacing,diameter of nozzle,and topography of electrospun polyoxyethylene(PEO) fibers are experimentally investigated.The results show that the evolution of the morphology experienced from spherical particle to fiber with beads,and to fiber with the concentration of PEO from 4% to 8% increasingly.The fiber with beads structure changed into uniform and smooth fibers with molecular weight of PEO from the 4×10 5 to 6×10 5.When the molecular weight of PEO further added,the morphology of PEO fibers is started to become uneven and jagged structure.When the conductivity of PEO rises from 151 to 355 s/cm,the diameter is nearly five times thicker.As the applied voltage(25–30 kV) is increased,the diameter and spindle beads are increased at first and then decreased.With electrode spacing(15–25 cm) rising,PEO fibers become fine,but with more spindle beads.As nozzle diameter was increased from the 160 to 600 m,the fibers is uniform and smooth at first,then form bonding structures.These results are able to guide the electrospinning technology in the biomedical,nano-devices and nano-manufacturing and other fields.