Effect of Interfacial Interaction on the Conformational Variation of Poly(vinylidene fluoride) (PVDF) Chains in PVDF/Graphene Oxide (GO) Nanocomposite Fibers and Corresponding Mechanical Properties

Abstract

Poly­(vinylidene fluoride) (PVDF)/graphene oxide (GO) nanocomposite fibers were dry-jet wet spun at the GO concentrations of 0, 1, and 2 wt % with respect to the polymer. The as-spun fibers were drawn in the draw ratio (DR) range of 2–6.5, and the correlation between the PVDF chain conformation and the mechanical properties of the fibers upon drawing has been studied by two-dimensional correlation spectroscopy of Fourier-transformed infrared, wide-angle X-ray diffraction, differential scanning calorimetry, and tensile testing. The PVDF/GO nanocomposite fibers exhibited that the mobile PVDF crystals due to the conformational defects and kinks were nucleated because of the polar interaction between PVDF chains and functional groups of GO, whereas the control PVDF fiber showed the conventional conversion of crystal polymorphs (α and γ phases to β phase). As a result, the nanocomposite fiber showed dramatically improved toughness (enhanced by 1123% at a DR of 2 and 120% at a DR of 6.5) as compared to that of the control fiber. Furthermore, the tensile strength and modulus of the PVDF/GO (2 wt %) fiber were 394 MPa and 4.6 GPa, respectively, whereas those of the control PVDF fiber were 295 MPa and 3.9 GPa, respectively.

Oxidative stress in alpha and beta cells as a selection criterion for biocompatible biomaterials

“…Multiple biomaterial properties can influence the mechanical characteristics of biomaterials, including their chemical structure, thickness, (pore) size, and the manufacturing parameters. Taking into account some variation related to differences in manufacturing, we could confirm that the mechanical characteristics of all biomaterials we measured were in agreement with results from previous studies [42][43][44][45]. These characteristics could mainly be attributed to the chemical structure, where the block copolymers comprising soft, hydrophilic PEO segments are crosslinked with hard, semicrystalline PBT segments providing both strength and elasticity compared to a polymer made from only one monomer subunit like PVDF [45].…”

Electrospun Polyvinylidene Fluoride-Based Fibrous Scaffolds with Piezoelectric Characteristics for Bone and Neural Tissue Engineering

“…Nanofillers with high surface-to-volume ratios can enhance their interactions with the polymer matrices. These nanomaterials include carbon nanofiber, carbon nanotube, graphene oxide (GO), and barium titanate [57,58,59,60,74,75,76,77,78,79,80,81]. Furthermore, metal (e.g., silver) and metal oxide nanoparticles like zinc oxide, and titania can also induce β-PVDF formation [82,92,93,94,95].…”

“…Aided by recent advances in nanotechnology, a wide range of nanomaterials can be synthesized for biomedical and industrial applications [61,62,63,64,65,66,67,68,69,70,71,72]. In particular, clay nanoplatelets, carbon nanotubes, graphene/graphene oxide and silica nanoparticles have been reported to be very effective to induce β-phase in PVDF [57,59,73,74,75,76,77,78,79,80,81,82]. As is generally recognized, electrospinning can fabricate micro- and nanofibers with interconnecting pores, resembling the natural ECM in tissues [83].…”

Remarkable elasticity and enzymatic degradation of bio-based poly(butylene adipate-co-furanoate): replacing terephthalate

“…2DCOS is one of the most powerful and versatile spectral analysis tools that can establish the sequence of spectral changes under a given condition (in our case, the degradation time is a perturbation factor for the spectral change). 60 Synchronous and asynchronous 2DCOS obtained from the transient IR spectra of PBAF50 could identify the coincidental and sequential changes in the spectral intensities (Fig. 5b).…”

“…The peak position of loss tangent (tan δ) indicates the glass transition temperature (T g ) of each polymer. 57 Thus, the peak intensity (i.e., the tan δ value) of PBAF50 (0.44) is almost twice that of PBAT50 (0.25). Theoretically, a higher tan δ value corresponds to a higher T g value and less solid-like characteristics of a polymer owing to the enhanced segmental motion of the chains.…”