SiO_(2)纳米纤维膜的电纺制备及结构性能优化

Preparation of SiO_(2) Nanofiber Membrane by Electrospinning and Its Structure and Performance Optimization

通过对静电纺丝工艺和热处理制度的调控实现了SiO_(2)纳米纤维微观结构和力学性能的优化。本文以正硅酸乙酯(TEOS)为原料、以聚乙烯吡络烷酮(PVP)为助纺剂,通过静电纺丝法结合热处理工艺制备了SiO_(2)纳米纤维膜。通过热重-差热联用热分析仪、X射线衍射仪、傅里叶变换红外光谱仪、扫描电子显微镜和拉力试验机等手段对纳米膜进行了表征与测试,探究了聚合物浓度和升温速率对纳米膜微观形貌和力学性能的影响。研究表明,SiO_(2)/PVP复合膜经800℃煅烧后均生成了无定形态的SiO_(2)。随着PVP浓度的增加,煅烧后产物的微观形貌由骰子状微球向连续纤维发展,力学性能随之改善,PVP质量分数为25%时,连续纤维膜具有最佳的拉伸强度,为3.25 MPa;随着升温速率的增加,SiO_(2)/PVP连续纤维膜经800℃煅烧后,产物内部的残余热应力增加,纤维连续性降低,强度降低。本研究为SiO_(2)纳米纤维的功能化应用提供理论基础。

The optimization of the microstructure and mechanical properties of SiO_(2) nanofibers was achieved by adjusting the composition of the electrospining method and the heat treatment process.In this paper,tetraethyl orthosilicate(TEOS)was used as raw material,polyvinylpyrrolidone(PVP)was used as spinning aid,and SiO_(2) nano-membrane was prepared by electrospinning method combined with heat treatment process.The effects of polymer concentration and calcination rate on the microscopic morphology and mechanical properties of fiber membranes were studied.Using means of thermogravimetric and differential thermal analysis,X-ray diffractometer,fourier infrared spectrometer,scanning electron microscope and tensile testing machine,the fiber membrane was microscopically analyzed and tested.The results show that with the increase of PVP concentration,the morphology of the product develops from dice-shaped microspheres to continuous fibers,and the mechanical properties are improved accordingly.When the mass fraction of PVP is 25%,the fiber membrane has the best tensile strength,which is 3.25 MPa.With the increase of the heating rate,after the SiO_(2)/PVP continuous fiber membrane is calcined at 800℃,the residual thermal stress inside the product increases,the fiber continuity decreases,and the strength decreases.This research provides a theoretical basis for the functional application of SiO_(2) nanofibers.