Ionogels combine
the virtues of polymers
and ionic liquids (ILs) and have greater potential for supercapacitors
(SCs) than hydrogels and organic gels. Undoubtedly, the self-healing
ability of ionogels dramatically improves the reliability of related
SCs. Herein, we reported a dynamic diol-borate ester-cross-linked
polyvinyl alcohol (PVA) ionogel electrolyte for smart double-layer
capacitors. The results indicated that 1-ethyl-3-methylimidazolium
chloride (EmimCl) could form a strong interaction with the hydroxy
groups on PVA, thereby depressing the crystallization efficiently.
The resultant ionogel exhibited an amorphous nature with excellent
ionic conductivity up to 2.43 × 10–3 S/cm,
high flexibility, and 95% healing efficiency when the IL content was
90 vol %. It could be inferred from the fact that EmimCl acted not
only as an ion provider to improve the ionic conductivity but also
as a plasticizer to enhance the chain mobility and self-healing efficiency.
Based on the unique properties of PVA-boric acid/EmimCl ionogels,
a flexible and self-healable SC was assembled. The as-prepared SC
delivered a specific capacitance of 90 F/g at 0.1 A/g and retained
98% capacitance after 3000 charge–discharge cycles at a current
density of 2 A/g. More interestingly, it could tolerate physical bending
and healing without significant performance deterioration. The present
study provides a novel strategy to prepare self-healable ionogel electrolytes
that can be applied to smart energy storage devices.
In this work, thermoplastic poly (vinyl alcohol) (PVA) with improved processability for fused deposition modeling (FDM) was successfully prepared via intermolecular complexation and plasticization. The glycerol and water, which were non-toxic and have a complementary structure with PVA, were adapted to realize FDM processing of PVA, thus providing a novel biomaterial with FDM processability. The result showed that the water and glycerol could interrupt hydrogen bonding in PVA and reduce the melting point of PVA to 127.4°C. Moreover, the water fraction of the plasticizer had a significant effect on the FDM processability and usability of the final parts.When the water fraction was greater than 75%, the PVA/plasticizer was unsuitable for FDM processing. However, when the water fraction was lower than 25%, the glycerol precipitated from the modified PVA. Thus, a mixture of 50% water and 50% glycerol was most suitable for FDM processing. A 0.3 mm layer thickness with a nozzle temperature of 175°C was chosen as the optimal processing condition for FDM using thermoplastic PVA. Finally, complex PVA parts with high dimensional accuracy, good mechanical properties, and designated structures were fabricated by FDM machine.
Preparation of biological scaffolds with complex shapes and controllable internal structures is a significant development direction for the tissue engineering field. Due to its simplicity, low‐cost and cost‐effectiveness, fused deposition molding (FDM) is one of the most popular 3D printing technologies. In this paper, polyvinyl alcohol/polylactic acid/hydroxyapatite composites were fabricated successfully. On this basis, composite scaffolds with different pore structures were designed and constructed by using FDM technology. The material structure was characterized by scanning electron microscopy (SEM) and dynamic thermomechanical analyzer. The results showed that the cross‐sectional morphology of the system presented a “sea‐island” structure. The introduction of PLA and HA significantly increased the modulus of the material, which was beneficial to achieve its FDM processing. The compressibility, mineralization behavior, and biocompatibility of the viscoelastic characteristics to natural cartilage subjected to the condition of filling angle of 45° was systemically invesitgated. Notably, the concentrations of Ca2+ and PO43− in simulated body fluid were reduced by 34.7% and 58.2% on 8th day, indicating a good bone formation and mineralization ability, which was further corroborated by SEM and fourier‐transform infrared spectroscopy (FTIR) results. Biotoxicity test showed that the scaffold presented excellent biocompatibility.
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