Structural energy and power systems offer both mechanical and electrochemical performance in a single multifunctional platform. These are of growing interest because they potentially offer reduction in mass and/or volume for aircraft, satellites, and ground transportation. To this end, flexible graphene-based supercapacitors have attracted much attention due to their extraordinary mechanical and electrical properties, yet they suffer from poor strength. This problem may be exacerbated with the inclusion of functional guest materials, often yielding strengths of <15 MPa. Here, we show that graphene paper supercapacitor electrodes containing aramid nanofibers as guest materials exhibit extraordinarily high tensile strength (100.6 MPa) and excellent electrochemical stability. This is achieved by extensive hydrogen bonding and π-π interactions between the graphene sheets and aramid nanofibers. The trade-off between capacitance and mechanical properties is evaluated as a function of aramid nanofiber loading, where it is shown that these electrodes exhibit multifunctionality superior to that of other graphene-based supercapacitors, nearly rivaling those of graphene-based pseudocapacitors. We anticipate these composite electrodes to be a starting point for structural energy and power systems that harness the mechanical properties of aramid nanofibers.

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Field-based mapping, sandstone petrology, palaeocurrent measurements and zircon cathodoluminescence images, as well as detrital zircon U–Pb geochronology were integrated to investigate the provenance of the Upper Carboniferous – Upper Triassic sedimentary rocks from the northern Bogda Mountains, and further to constrain their tectonic evolution. Variations in sandstone composition suggest that the Upper Carboniferous – Lower Triassic sediments displayed less sedimentary recycling than the Middle–Upper Triassic sediments. U–Pb isotopic dating using the LA-ICP-MS method on zircons from 12 sandstones exhibited similar zircon U–Pb age distribution patterns with major age groups at 360–320 Ma and 320–300 Ma, and with some grains giving ages of > 541 Ma, 541–360 Ma, 300–250 Ma and 250–200 Ma. Coupled with the compiled palaeocurrent data, the predominant sources were the Late Carboniferous volcanic rocks of the North Tianshan and Palaeozoic magmatic rocks of the Yili–Central Tianshan. There was also input from the Bogda Mountains in Middle–Late Triassic time. The comprehensive geological evidence indicates that the Upper Carboniferous – Lower Permian strata were probably deposited in an extensional context which was related to a rift or post-collision rather than arc-related setting. Conspicuously, the large range of U–Pb ages of the detrital zircons, increased sedimentary lithic fragments, fluvial deposits and contemporaneous Triassic zircon ages argue for a Middle–Late Triassic orogenic movement, which was considered to be the initial uplift of the Bogda Mountains.

Purpose The cornea is a main barrier to drug penetration after topical application. The aim of this study was to evaluate the abilities of micelles generated from a positively charged triblock copolymer to penetrate the cornea after topical application. Methods The triblock copolymer poly(ethylene glycol)-poly(ε-caprolactone)- g -polyethyleneimine was synthesized, and the physicochemical properties of the self-assembled polymeric micelles were investigated, including hydrodynamic size, zeta potential, morphology, drug-loading content, drug-loading efficiency, and in vitro drug release. Using fluorescein diacetate as a model drug, the penetration capabilities of the polymeric micelles were monitored in vivo using a two-photon scanning fluorescence microscopy on murine corneas after topical application. Results The polymer was successfully synthesized and confirmed using nuclear magnetic resonance and Fourier transform infrared. The polymeric micelles had an average particle size of 28 nm, a zeta potential of approximately +12 mV, and a spherical morphology. The drug-loading efficiency and drug-loading content were 75.37% and 3.47%, respectively, which indicates that the polymeric micelles possess a high drug-loading capacity. The polymeric micelles also exhibited controlled-release behavior in vitro. Compared to the control, the positively charged polymeric micelles significantly penetrated through the cornea. Conclusion Positively charged micelles generated from a triblock copolymer are a promising vehicle for the topical delivery of hydrophobic agents in ocular applications.

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