A Low-Strain Cathode by sp-Carbon Induced Conversion in Multi-Level Structure of Graphdiyne

A multi-level architecture alternatively formed by the conformal graphdiyne (GDY) and CuS is well engineered for Li-free cathode. Such a proof-of-concept architecture efficiently integrates the advantages of GDY and produces new functional heterojunctions (sp-C-S-Cu hybridization bond). The layer-by-layer 2D confinement effect successfully avoids structural collapse, the selective transport greatly inhibits the shuttling of active components, and the interfacial sp-C-S-Cu hybridization bond significantly regulates the phase conversion reaction. Such new sp-C-S-Cu hybridization of GDY greatly improves the reaction dynamics and reversibility, and the cathode delivers an energy density up to 934 Wh kg-1 and an unattenuated lifespan of 1200 cycles at high rate. Our results indicate that the success of the GDY-based interface strategy will greatly promote the efficient utilization of the conversion-type cathodes.

Study of volume swelling and interfacial tension of the polystyrene-carbon dioxide-dimethyl ether system

We investigated the interaction of blended carbon dioxide (CO2) and dimethyl ether (DME) with polystyrene (PS) through volume swelling and interfacial tension. The experiments were carried out over a temperature range of 423-483 K, and the pressure was varied from 6.89 MPa to 20.68 MPa. With an incremental concentration of DME in the blend, the volume swelling increased while the interfacial tension between the PS/blend gas mixture and the blend gas decreased. The validity of the Simha-Somcynsky (SS) equation of state (EOS) for the ternary system was established by comparing experimentally measured volume swelling to that obtained via SS-EOS.

Synthesis and characterization of monodispersed P(St-co-DMAEMA) nanoparticles as pH-sensitive drug delivery system

Monodispersed poly(styrene-co-N,N'-dimethylaminoethyl methacrylate) nanoparticles (P(St-co-DMAEMA) NPs) were synthesized by emulsion polymerization. Zeta potential, volume swelling ratio and in vitro release of fluorescer coumarin-6 from the NPs were determined in buffer of various pH. With an optimized formulation, the diameter of NPs is 100 nm approximately and the polydispersity index (PI) is less than 0.1. The NPs have a hydrophilic surface and alterable surface charge which is almost neutral at normal physiological pH, but becomes much more positive under acidic conditions. The volume swelling ratios and in vitro release of coumarin-6 are highly dependent on pH, which are significantly increased at the lower pH and higher DMAEMA/St molar ratio. More than 70% of the loaded coumarin-6 could be released in 24 h at pH2, which is 2.3-folds higher than that at normal physiological pH. The P(St-co-DMAEMA) NPs show promising applications to targeted drug delivery to tumors.