Modulation of the interfacial architecture enhancing the efficiency and energy density of ferroelectric nanocomposites via the irradiation method

Electroactive poly(vinylidene fluoride-trifluoroethylene)/graphene composites for cardiac tissue engineering applications

Electroactive materials are increasingly being used in strategies to regenerate cardiac tissue. These materials, particularly those with electrical conductivity, are used to actively recreate the electromechanical nature of the cardiac tissue. In the present work, we describe a novel combination of poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)), a highly electroactive polymer, with graphene (G), exhibiting high electrical conductivity. G/P(VDF-TrFE) films have been characterized in terms of topographical, physico-chemical, mechanical, electrical, and thermal properties, and studied the response of cardiomyocytes adhering to them. The results indicate that the crystallinity and the wettability of the composites remain almost unaffected after G incorporation. In turn, surface roughness, Young modulus, and electric properties are higher in G/P(VDF-TrFE). Finally, the composites are highly biocompatible and able to support cardiomyocyte adhesion and proliferation, particularly surface treated ones, demonstrating the suitability of these materials for cardiac tissue engineering applications.

Surfactants for Electrophoretic Deposition of Polyvinylidene Fluoride–Silica Composites

This investigation is motivated by the numerous advantages of electrophoretic deposition (EPD) for the fabrication of polyvinylidene fluoride (PVDF) and composite coatings and the various applications of such coatings. It is demonstrated that gallic acid (GA), caffeic acid (CFA), cholic acid (CA) and 2,3,4 trihydroxybenzoic acid (THB) can be used as charging and dispersing agents for the EPD of PVDF. The deposition yield of PVDF increases in the following order: THB < CFA < CA < GA. Test results indicate that the chemical structure of the dispersants exerts influence on the deposition efficiency. Potentiodynamic and impedance spectroscopy studies show the corrosion protection properties of PVDF coatings. GA is used for the co-EPD of PVDF with nanosilica and micron-size silica. The silica content in the composite coatings is varied by the variation of silica content in the suspensions. The ability to use GA as a charging and dispersing agent for the co-EPD of materials of different types paves the way for the fabrication of advanced organic–inorganic composites using EPD.

Versatile Strategy for Electrophoretic Deposition of Polyvinylidene Fluoride-Metal Oxide Nanocomposites

Polyvinylidene fluoride (PVDF) is an advanced functional polymer which exhibits excellent chemical and thermal stability, and good mechanical, piezoelectric and ferroelectic properties. This work opens a new strategy for the fabrication of nanocomposites, combining the functional properties of PVDF and advanced inorganic nanomaterials. Electrophoretic deposition (EPD) has been developed for the fabrication of films containing PVDF and nanoparticles of TiO₂, MnO₂ and NiFe₂O₄. An important finding was the feasibility of EPD of electrically neutral PVDF and inorganic nanoparticles using caffeic acid (CA) and catechol violet (CV) as co-dispersants. The experiments revealed strong adsorption of CA and CV on PVDF and inorganic nanoparticles, which involved different mechanisms and facilitated particle dispersion, charging and deposition. The analysis of the deposition yield data, chemical structure of the dispersants and the microstructure and composition of the films provided an insight into the adsorption and dispersion mechanisms and the influence of deposition conditions on the deposition rate, film microstructure and composition. PVDF films provided the corrosion protection of stainless steel. Overcoming the limitations of other techniques, this investigation demonstrates a conceptually new approach for the fabrication of PVDF-NiFe₂O₄ films, which showed superparamagnetic properties. The approach developed in this investigation offers versatile strategies for the EPD of advanced organic-inorganic nanocomposites.

Enzymatic synthesis of fluorinated compounds

Fluorinated compounds are widely used in the fields of molecular imaging, pharmaceuticals, and materials. Fluorinated natural products in nature are rare, and the introduction of fluorine atoms into organic compound molecules can give these compounds new functions and make them have better performance. Therefore, the synthesis of fluorides has attracted more and more attention from biologists and chemists. Even so, achieving selective fluorination is still a huge challenge under mild conditions. In this review, the research progress of enzymatic synthesis of fluorinated compounds is summarized since 2015, including cytochrome P450 enzymes, aldolases, fluoroacetyl coenzyme A thioesterases, lipases, transaminases, reductive aminases, purine nucleoside phosphorylases, polyketide synthases, fluoroacetate dehalogenases, tyrosine phenol-lyases, glycosidases, fluorinases, and multienzyme system. Of all enzyme-catalyzed synthesis methods, the direct formation of the C-F bond by fluorinase is the most effective and promising method. The structure and catalytic mechanism of fluorinase are introduced to understand fluorobiochemistry. Furthermore, the distribution, applications, and future development trends of fluorinated compounds are also outlined. Hopefully, this review will help researchers to understand the significance of enzymatic methods for the synthesis of fluorinated compounds and find or create excellent fluoride synthase in future research.Key points• Fluorinated compounds are distributed in plants and microorganisms, and are used in imaging, medicine, materials science.• Enzyme catalysis is essential for the synthesis of fluorinated compounds.• The loop structure of fluorinase is the key to forming the C-F bond.