Polyaniline Protrusions on MoS₂ Nanosheets for PVDF Scaffolds with Improved Electrical Stimulation

Abstract

Piezoelectric polyvinylidene fluoride (PVDF) provided an opportunity for non-invasive in situ electrical stimulation of cell behavior, yet its electroactive β phase was difficult to obtain due to its instability in the molten state. Herein, polyaniline (PANI) protrusions were in situ oxidation-polymerized on molybdenum disulfide (MoS2) nanosheets (PANI-MoS2). Then, PANI-MoS2 was introduced into laser additive-manufactured PVDF scaffolds. On the one hand, PANI protrusions produced steric hindrance between adjacent MoS2 nanosheets and inhibited the stacking and aggregating of MoS2. On the other hand, PANI-MoS2 could serve as a platform to achieve interfacial polarization locking. Specifically, Mo–S dipoles in MoS2 and π electron clouds over the N atom in PANI locked −CH2 dipoles in PVDF through electrostatic and hydrogen bond interactions, respectively, which forced −CH2 to align perpendicularly to the basal plane of MoS2 and bialy to one side of the PVDF main chain, thereby forming a full-reverse planar zigzag configuration of the polarized β phase and maintaining its stable existence. The results demonstrated that the β phase of the scaffolds was significantly increased from 43 to 90%, which resulted in an enhanced electrical output performance. The improved electrical output greatly promoted osteoblast-like cell proliferation and differentiation. Furthermore, owing to the pulling-out effect of MoS2 and improved interfacial stress transfer between MoS2 and the polymer matrix, the mechanical properties of scaffolds were also enhanced. These findings suggested that the piezoelectric scaffolds had great potential in bone tissue engineering.

PPy/PANI@MoS2 Composites with a Dual-Channel Architecture for Advanced Asymmetric Supercapacitors

“…The other observed PANI characteristic peaks include C–N (∼1296 cm –1 ) and CN (∼1240 cm –1 ) stretching absorptions of the aromatic amine and the C–H in-plane (∼1083 and 1046 cm –1 ) and out-of-plane (∼881 cm –1 ) bending vibration . The composite materials displayed the FTIR fingerprints of PPy and PANI and two additional FTIR peaks at ∼880 cm –1 (S–S bond) and 630 cm –1 (Mo–S bond). , Notably, some FTIR peaks were slightly shifted within the composite, consistent with the interaction between the different components. In addition, based on the thermogravimetry (TG) results shown in Figure S5, the mass fractions of PP-Fe and MoS 2 in the PPMS-Fe composite are estimated at about 42.2% and 57.8%, respectively.…”

Synergistic enhancement of dielectric properties of polymer matrix composites by micro‐nano bicomponent ceramics and conductive particles

“…The reason for the shift of diffraction peak may be that the original stable C‐F structure of PVDF was destroyed by the addition of niobium and cobalt. PVDF with β and γ phases generally has excellent dielectric properties and breakdown field strength [32, 33]; through high electric field polarisation, we can obtain the α , β and γ phases. Due to β , the spontaneous polarisation intensity of the phase is large, so it has a high dielectric constant.…”

Piezoelectric nanogenerator induced work function on a metal phenolic coordination framework from copper oxide nanospheres for efficient biomechanical energy harvesting and physiological monitoring

“…Stress, depression, poor diet and lack of exercise could be major factors behind the cause of such ailments. 63 Unlike other organs, abnormalities pertaining to the heart are often very subtle and cannot be perceived easily by themselves, thus sudden heart attacks are now prevalent all over the world. In this scenario, by measuring one's heart rate and arterial pulse several quick diagnostics can be completed.…”