Targeted Synthesis of Polymer and Microporous Carbon Nanofibers via Temperature‐Dependent and Molecularly‐Triggered Interfacial Assembly

Abstract Microporous carbon nanofibers (CNFs) derived from polymer nanofibers (PNFs), featured with short radial diffusion length of ions, have been proposed as ideal electrode materials for energy storage devices. However, lacking precise control of selective formation of fibrous micelle templates, the targeted synthesis of microporous CNFs is still a challenge. To address this issue, PNFs are first fabricated by using triblock copolymer F127 as the structure directing agent via the temperature‐dependent and molecularly‐triggered interfacial assembly process. Two crucial factors are figured that determine the fibrous morphology of the assembled polymer. At suitable temperatures, F127 starts to form fibrous micelles, and molecular trigger hexamethylenetetramine generates formaldehyde and ammonia in situ. Then, phenolic polymer assemble around the fibrous micelles, following with the formation of PNFs. This feasible synthesis method can grow PNFs and precisely control the PNFs' diameters ranging from 30 to 80 nm. Microporous CNFs with high specific surface area of 1175 m 2 g −1 , and an average diameter of 40 nm can be prepared through carbonization of PNFs and an activation step. Taking such microporous CNFs as electrode materials for a supercapacitor, they exhibit an excellent specific capacitance 295 F g −1 at a high current density 50 A g −1 .