RESUMEN
Graphitic carbon-coated ZnPS3 is prepared via direct phosphosulfurization and high energy mechanical milling (HEMM) with multiwall carbon nanotubes (MWCNTs) and first introduced as an anode for lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). The HEMM process with MWCNTs reduces the particle size of as-synthesized ZnPS3 bulk to 100-500 nm and yields the ≈5 nm thick graphitic carbon coated ZnPS3 nanoparticles, which are the nanocomposites of 5 nm sized nanocrystallites embedded in the amorphous matrix. The ZnPS3 electrode undergoes the combined conversion and alloying reactions with Li and Na ions and exhibits high initial discharge and charge capacities in both LIBs and SIBs. The graphitic carbon-coated ZnPS3 electrode exhibits excellent high-rate capability and long-term cyclability. The superior electrochemical properties can be attributed to high electrical conductivity, high Li ion mobility, and high reversibility and structural stability derived from the graphitic carbon-coated nanoparticles. This study demonstrates that the novel graphitic carbon-coated ZnPS3 is a promising anode material for both LIBs and SIBs and the graphitic carbon coating methodology by HEMM is expected to apply to the various metal oxides, sulfides, and phosphides.
RESUMEN
Methods for reducing and preventing postoperative abdominal adhesions have been researched for decades; however, despite these efforts, the formation of postoperative peritoneal adhesions is continuously reported. Adhesions cause serious complications such as postoperative pain, intestinal obstruction, and infertility. Tissue adhesion barriers have been developed as films, membranes, knits, sprays, and hydrogels. Hydrogels have several advantages when used as adhesion barriers, including flexibility, low tissue adhesiveness, biodegradability, and non-toxic degraded products. Furthermore, compared with preformed hydrogels, injectable hydrogels can fill and cover spaces of any shape and do not require a surgical procedure for implantation. In this study, pullulan was modified through reaction with 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) to introduce carboxyl and phenyl groups as crosslinking sites. The grafting of tyramine on pullulan allows crosslinking branches on pullulan backbone. We successfully fabricated pullulan hydrogel with an enzymatic reaction using horseradish peroxidase (HRP) and hydrogen peroxide (H2O2). The chemical structure of modified pullulan was analyzed with ATR-FTIR and (1)H NMR spectroscopies. Rheological properties were tested by measuring storage modulus with varying H2O2, HRP, polymer solution concentrations and tyramine substitution rates. Cell viability and animal tests were performed. The modified pullulan hydrogel is an invaluable advance in anti-adhesion agents.
