title: Tuning bio-inspired skin-core structure of nascent fiber via interplay of polymer phase transitions.
abstract: The properties of polymer fibers are determined by their inner structures. We performed dynamic Monte Carlo simulations of early-stage solidification in the fluid filaments of stretched polymer solutions after extrusion into a coagulation bath upon fiber spinning. We observed that the radial temperature gradient dominates polymer crystallization to form an oriented crystalline skin (from single to multiple layers), while the radial non-solvent influx dominates phase separation to form a concentrated but less oriented core. The skin-core structure offers fibers a balanced performance between strength and toughness similar to plant stems, which can be tuned by the interplay of phase transitions. Our molecular-level observations facilitate a systematic understanding of the microscopic mechanism of fiber-spinning, which will pave a way towards making excellent polymer fibers.
authors.affiliation: Key Laboratory of High Performance Polymer Materials and Technology, State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China. wbhu@nju.edu.cn.
authors.forename: Qi
authors.initials: Q
authors.lastname: Liu
authors.forename: Huanhuan
authors.initials: H
authors.lastname: Gao
authors.forename: Liyun
authors.initials: L
authors.lastname: Zha
authors.forename: Zuming
authors.initials: Z
authors.lastname: Hu
authors.forename: Yu
authors.initials: Y
authors.lastname: Ma
authors.forename: Muhuo
authors.initials: M
authors.lastname: Yu
authors.forename: Lei
authors.initials: L
authors.lastname: Chen
authors.forename: Wenbing
authors.initials: W
authors.lastname: Hu
mesh_terms: D003460:Crystallization; D056004:Molecular Dynamics Simulation; D009010:Monte Carlo Method; D057139:Nanofibers / Q000737:chemistry*; D044367:Phase Transition; D011108:Polymers / Q000737:chemistry*; D012997:Solvents; D013696:Temperature
chemical_list: D011108:Polymers; D012997:Solvents