Tunable Mechanical and Electrical Properties of Coaxial Electrospun Composite Nanofibers of P(VDF-TrFE) and P(VDF-TrFE-CTFE)

Abstract

The coaxial core/shell composite electrospun nanofibers consisting of relaxor ferroelectric P(VDF-TrFE-CTFE) and ferroelectric P(VDF-TrFE) polymers are successfully tailored towards superior structural, mechanical, and electrical properties over the individual polymers. The core/shell-TrFE/CTFE membrane discloses a more prominent mechanical anisotropy between the revolving direction (RD) and cross direction (CD) associated with a higher tensile modulus of 26.9 MPa and good strength-ductility balance, beneficial from a better degree of nanofiber alignment, the increased density, and C-F bonding. The interfacial coupling between the terpolymer P(VDF-TrFE-CTFE) and copolymer P(VDF-TrFE) is responsible for comparable full-frequency dielectric responses between the core/shell-TrFE/CTFE and pristine terpolymer. Moreover, an impressive piezoelectric coefficient up to 50.5 pm/V is achieved in the core/shell-TrFE/CTFE composite structure. Our findings corroborate the promising approach of coaxial electrospinning in efficiently tuning mechanical and electrical performances of the electrospun core/shell composite nanofiber membranes-based electroactive polymers (EAPs) actuators as artificial muscle implants.

In-Situ Synchrotron SAXS and WAXS Investigation on the Deformation of Single and Coaxial Electrospun P(VDF-TrFE)-Based Nanofibers

“…In Figure 4 d, the core/shell-TrFE/CTFE manifested (110, 200) β reflections of relaxor ferroelectric and ferroelectric crystallites, implying that the copolymer and terpolymer chains partly penetrated each other. The results were consistent with the previous report by Lam et al [ 14 ].…”

“…The other two samples, the core/shell structured nanocomposites, core/shell-TrFE/CTFE and core/shell-CTFE/TrFE, were prepared by the coaxial electrospinning method. More details can be referred to in the following reports [ 14 , 52 ].…”

“…Although it is a less-explored method, the coaxial electrospinning technique provides a way to manufacture complex electroactive systems with defined architecture and improved performance. Therefore, the understanding of the relationship between hierarchical structures, microstructure, and mechanical properties of electrospun EAPs has gained research attention [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ].…”

“…Chen et al showed that blending the ferroelectric copolymer P(VDF-TrFE) and the relaxor-based ferroelectric terpolymer P(VDF-TrFE-CTFE) can enhance the polarization and dielectric responses of the material [ 37 ]. An alternative method to combine P(VDF-TrFE) and P(VDF-TrFE-CTFE) is through the coaxial electrospinning technique [ 14 ]. In that study, the mechanical properties, dielectric properties, and structure of core-shell structured nanocomposite membranes, core/shell-copolymer/terpolymer, and core/shell-terpolymer/copolymer were studied.…”

“…The relationship between the phase transformation and mechanical properties of core/shell structured composites composed of core/shell-P(VDF-TrFE)/P(VDF-TrFE-CTFE) and core/shell- P(VDF-TrFE-CTFE)/P(VDF-TrFE), denoted as core/shell-TrFE/CTFE and core/shell-CTFE/TrFE, respectively, have been introduced in our previous study [ 14 ]. However, the coupling relationship between the crystalline structure and morphology during the tensile deformation of the same nanocomposites has not been examined yet.…”