蘸取预制泰勒锥的纳米纤维高产电纺制造基础研究

It is important to manufacture nanofibers with high throughput in their applications of materials, biomedicine, energy and micro/nano devices etc. In order to overcome the intrinsic problems of poor productivity, jet instability and solution solidification in traditional electrospinning, a novel method of high-throughput electrospinning via dip-in prefabricated Taylor cone is brought forward. tips array are used to insert into the planar surface of polymer solution and withdraw quickly to prefabricate Taylor cones. Under the strong electric field, steady jets are issued from the crests of the cones and they turn into nanofibers after encountering bending instabilies and solvent volatilization. Such method can realize the organic integration of high throughput, low voltage, free of cleaning and good results (diameter, surface morphology and deposition distribution). This project focuses on the fundamentals and key technologies of high-throughput electrospinning via dip-in prefabricated Taylor cone, including mechanism and basic rules of high-throughput, critical conditions of stable and continuous jet, behavior of dipping and the design rules of Taylor cone array, etc. The objective of this project is to clarify the intrinsic mechanism of high throughput in electrospinning via dip-in prefabricated Taylor cone and to set up the relationship between critical voltage and solution concentration, electrode distance, tips array configuration and withdrawal speed, etc. The dipping behavior to prefabricate Taylor cone will be optimized and the effect of Taylor cone distribution on the electrospinning results will be revealed. In summary, this work may benefit better understanding such scientific problems of high-throughput electrospinning and electrohydrodynamic control behaviors.

实现纳米纤维的批量制造是其在材料、生物医学、能源及微纳米器件等领域获得应用的关键。针对传统电纺的效率低、射流不稳定和溶液粘稠化等缺陷，提出蘸取预制泰勒锥的高产电纺方法：针尖阵列插入水平聚合物溶液表面后迅速抽离，溶液变形成泰勒锥，强电场作用下锥顶产生稳定射流，经不稳定运动和溶剂挥发得到纳米纤维，实现了高产量、低电压、无需清洗和电纺结果（纤维直径、表面质量和沉积分布）良好的有机结合。本项目研究蘸取预制泰勒锥的纳米纤维高产电纺制造的基本问题和关键技术，主要包括：电纺的高产机理与基本规律、泰勒锥稳定持续射流临界条件、蘸取预制泰勒锥行为方式和阵列化泰勒锥的设计规则等。阐明蘸取预制泰勒锥电纺高产的内在机制；构建临界电压与溶液浓度、电极间距、针尖阵列结构和针尖抽离速度等的关系；优化蘸取泰勒锥行为方式；揭示阵列泰勒锥的分布对电纺结果的作用规律，有助于加深对批量电纺、电液动力学控制行为这一类科学问题的认识。

纳米纤维的制造及其应用研究业已成为国际学术界和工业界的焦点。高效稳定制备直径可控、一致性好、沉积分布均匀的纳米纤维是其在材料、生物医学、能源及微纳米器件等领域获得应用的关键。项目研究了蘸取预制泰勒锥与射流在不同条件下的形态，揭示了大泰勒锥尺寸和高速射流特征是蘸取预制泰勒锥高产电纺的根本原因，掌握了其基本行为规律；考察了电压、插入深度等对泰勒锥持续喷射的影响；研究了针尖间距和诱导方式等对泰勒锥的影响规律，明确了泰勒锥的设计规则，阵列针尖间距需1cm以上。分析了各工艺参数与纳米纤维直径和产量的关系；研制了一套 3m×3m×2.5m 的针尖诱导蘸取预制泰勒锥电纺的自动化装备，工作电压 70kV下产量 50g/h以上。基于纳米纤维开发出了PI/PVDF/PI和PVDF/PI两种高安全性锂电池隔膜，其电化学性能和热稳定性等都高于商业化隔膜。项目研究进一步加深了对批量电纺和电液体动力学控制行为的理解。.项目实施形成如下成果：.1. 学术成果：发表了论文7篇，SCI收录3篇（其中1区论文1篇，2区论文2篇）， EI收录2篇；申请发明专利3项目，授权发明专利9项；.2. 学术交流：参加国际会议3次（其中一篇会议论文获3M-NANO最佳会议论文提名奖），1人前往加州大学伯克利分校学术交流；.3. 人才培养：培养硕士研究生4人（已毕业3人），其中胡兴旺和黄少华同学获得国家奖学金。