Polylactide (PLA) fibers were electrospun from the solutions of PLA dissolved in the mixtures of its good and poor solvents, and the formation mechanism of the poor solvent-induced porous structure on the fibers was investigated. From a systematic study using the pairs of a variety of good/poor solvents for electrospinning, the conditions, specifically the solvent properties, for producing uniform fibers with controllable pores that appear not only on the surface but also throughout the fibers were proposed. The water miscibility of the good/poor solvents is crucial, which is because the ambient moisture that condenses during electrospinning plays an important role in the formation of the pores. Furthermore, the evaporation rate of the good/poor solvents is another key factor that affects the pore size and pore distribution on fibers because the solvent evaporation rate regulates the moisture condensation and the phase-separated scale that are closely related to fiber morphology. The principles generalized in this work can be applied to other low-polar polymers for controlling the porosity of fibers. In addition, this work demonstrates that the porous PLA fibers can be electrospun from low-toxic solvents and that with a large surface area and storage space provided by the pores, the PLA porous fibers are highly capable of adsorbing oils, with a capacity double that of the smooth counterpart.

中文翻译：

---

非溶剂诱导多孔聚乳酸电纺纤维的形成机理

聚乳酸（PLA）纤维由溶解在其良、不良溶剂混合物中的PLA溶液电纺而成，并研究了不良溶剂诱导多孔结构在纤维上的形成机制。从使用各种好/差溶剂对进行静电纺丝的系统研究中，提出了用于生产具有可控孔的均匀纤维的条件，特别是溶剂特性，这些孔不仅出现在表面上，而且出现在整个纤维上。良好/不良溶剂的水混溶性至关重要，这是因为在静电纺丝过程中凝结的环境水分在孔的形成中起着重要作用。此外，良/差溶剂的蒸发速率是影响纤维孔径和孔分布的另一个关键因素，因为溶剂蒸发速率调节与纤维形态密切相关的水分凝结和相分离尺度。这项工作中概括的原理可以应用于其他低极性聚合物，以控制纤维的孔隙率。此外，这项工作表明，多孔 PLA 纤维可以用低毒溶剂电纺，并且具有大的表面积和孔隙提供的存储空间，PLA 多孔纤维具有很强的吸附油的能力，其容量是其两倍。光滑的对应物。这项工作中概括的原理可以应用于其他低极性聚合物，以控制纤维的孔隙率。此外，这项工作表明，多孔 PLA 纤维可以用低毒溶剂电纺，并且具有大的表面积和孔隙提供的存储空间，PLA 多孔纤维具有很强的吸油能力，其容量是其两倍。光滑的对应物。这项工作中概括的原理可以应用于其他低极性聚合物，以控制纤维的孔隙率。此外，这项工作表明，多孔 PLA 纤维可以用低毒溶剂电纺，并且具有大的表面积和孔隙提供的存储空间，PLA 多孔纤维具有很强的吸油能力，其容量是其两倍。光滑的对应物。