Controllable preparation of carbon nanofiber membranes for enhanced flexibility and permeability

The electrospinning-produced carbon nanofiber membranes (CNFM) have been applied in many fields for their three-dimensional porous networks, however, the natural fragility impedes their practical applications. Introducing plasticizers into carbon fibers has been proven an efficient way to increase the flexibility of CNFM but the extent is limited. This work explored dual plasticizers strategy to improve the flexibility of CNFM. The addition of zinc acetate and tetraethyl orthosilicate leads to bigger carbon nanofibers and higher mean pore diameters. They can be transformed into SiO₂ and ZnO nanoparticles that embed in the carbon fibers, and act as plasticizers to inhibit stress diffusion. The Young's modulus of the optimal SZCNFM-2.0-1.5-700 is 31.0 MPa, which is lower than single plasticizer can reduce. The mechanism of dual plasticizers collaboratively improving the flexibility of SZCNFM was proved based on the characterization results. The SZCNFM-2.0-1.5-700 with well flexibility also revealed high permeability, for instance, the gravity-induced cyclohexane flux is 486.67 L m⁻² h⁻¹. Furthermore, the SZCNFM-2.0-1.5-700 requires only half the time compared to the commercial filter membrane when separating the same amount of Pd@CN suspension in the suction filter.