Electrosynthesis and pseudocapacitance performance of ionic liquid – Cr (η6-C6H5) complex functionalized reduced graphene oxide/poly ortho aminophenol nanocomposite film

Tailoring poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) membrane microstructure for lithium-ion battery separator applications

Novel battery separators based on poly(vinylidene fluoride-co-trifluoroethylene-chlorofluoroethylene)- P(VDF-TrFE-CFE)- were produced by different processing techniques (non-solvent and thermally induced phase separation, salt leaching and electrospinning), in order to evaluate their effect on separator morphology, degree of porosity and pore size, electrochemical parameters and battery cycling behavior. It has been demonstrated that the different processing techniques have a significant influence on the morphology and mechanical properties of membranes. The degree of porosity varies between 23 % and 66 %, for membranes obtained by salt leaching and thermally induced phase separation, respectively. The membranes present a high ionic conductivity value ranging between 1.8 mS.cm-1 for the electrospun membrane and 0.20 mS.cm-1 for the membrane processed by thermally induced phase separator. The lithium transference number value for all membranes is above 0.20, the highest value of 0.55 being obtained for samples prepared by salt leaching and thermally induced phase separation. For all membranes, battery capacity values have been obtained at different C-rates with excellent reversibility. P(VDF-TrFE-CFE) samples present an excellent battery performance at 1C-rate after 100 cycles with 74 mAh.g-1 and excellent coulombic efficiency, for membrane processed by the salt leaching technique. This work demonstrates that P(VDF-TrFE-CFE) terpolymer can be used as a porous membrane in lithium-ion battery separator application, the membrane processing technique allowing to tailor its morphology and, consequently, battery performance.

Bimetal-organic framework derived Cu(NiCo)2S4/Ni3S4 electrode material with hierarchical hollow heterostructure for high performance energy storage

Rational design of electrical active materials with high performance for energy storage and conversion is of great significance. Herein, Cu(NiCo)₂S₄/Ni₃S₄, a three-dimensional (3D) hierarchical hollow heterostructured electrode material, is designed by etching the well-defined bimetal organic framework (MOF) via sequential in-situ ion-exchange processes. This trimetallic sulfides with unique structure provide large surface area, hierarchical pore distribution and enhanced electrical conductivity, can enrich the active sites for redox reactions, facilitate electrolyte penetration and rapid charge transfer kinetics. As a result, the Cu(NiCo)₂S₄/Ni₃S₄ electrode exhibits a high specific capacitance of 1320 F/g at 1 A/g and excellent rate performance (only 15% of capacitance is attenuated when the current density is increased by 20 times). Furthermore, a fabricated hybrid supercapacitor of Cu(NiCo)₂S₄/Ni₃S₄/AC can deliver a maximum energy density of 40.8 Wh/kg, remarkable power density of 7859.2 W/kg and superior cycling stability (85% retention of capacitance after 5000 cycles), demonstrating great potential for practical applications in energy storage and conversion devices.

Sericin grafted multifunctional curcumin loaded fluorinated graphene oxide nanomedicines with charge switching properties for effective cancer cell targeting

Fluorinated graphene has recently gained much attention for cancer drug delivery, owing to its peculiar properties including high electronegativity difference, magnetic resonance imaging contrast agent, and the photothermal effect. However, the hydrophobic nature of fluorinated graphene greatly hinders its application as a biological material. Herein, a novel green method is reported for synthesis of a pH-sensitive charge-reversal and water-soluble fluorinated graphene oxide, modified with polyethyleneimine anchored to sericin-polypeptide (FPS). This nanocarrier was further loaded with curcumin (Cur), and characterized as a nanocarrier for anti-cancer drug delivery. The synthesized nanocarriers contain two different pH-sensitive amide linkages, which are negatively charged in blood pH (≈7.4) and can prolong circulation times. The amide linkages undergo hydrolysis once they reach the mildly acidic condition (pH≈6.5, corresponding to tumor extracellular matrix), and subsequently once reached the lower acidic condition (pH≈5.5, corresponded to endo/lysosomes microenvironment), the FPS charge can be switched to positive (≈+28 mV), which aids the nuclear release. This nanocarrier was designed to selectively enhance cell internalization and nuclear-targeted delivery of curcumin in HeLa, SkBr3 and PC-3 cancer cells. Moreover, FPS-Cur demonstrated high curcumin loading capacity, prolonged curcumin release and promotion of apoptosis in HeLa, SkBr3 and PC-3 cells. Therefore, with its pH-responsive charge-reversal properties, FPS-Cur would be a promising candidate for chemotherapy of cervical, breast and prostate cancers.