36 research outputs found
Wet-Spinning of Continuous Montmorillonite-Graphene Fibers for Fire-Resistant Lightweight Conductors
All-inorganic fibers composed of neat 2D crystals possessing fascinating performance (<i>e</i>.<i>g</i>., alternately stacking layers, high mechanical strength, favorable electrical conductivity, and fire-resistance) are discussed in detail. We developed a wet-spinning assmebly strategy to achieve continuous all-inorganic fibers of montmorillonite (MMT) nanoplatelets by incorporation of a graphene oxide (GO) liquid crystal (LC) template at a rate of 9 cm/s, and the templating role of GO LC is confirmed by <i>in situ</i> confocal laser scanning microscopy and polarized optical microscopy inspections. After protofibers underwent thermal reduction, the obtained binary complex fibers composed of neat 2D crystals integrate the outstanding fire-retardance of MMT nanoplatelets and the excellent conductivity of graphene nanosheets. High-resolution transmission electron microscopy and scanning electron microscope observations reveal the microstructures of fibers with compactly stacking layers. MMT-graphene fibers show increaing tensile strengths (88–270 MPa) and electrical conductivities (130–10500 S/m) with increasing graphene fraction. MMT-graphene (10/90) fibers are used as fire-resistant (bearing temperature in air: 600–700 °C), lightweight (ρ < 1.62 g/cm<sup>3</sup>) conductors (conductivity: up to 1.04 × 10<sup>4</sup> S/m) in view of their superior performance in high-temperature air beyond commercial T700 carbon fibers. We attribute the fire-resistance of MMT-graphene fibers to the armor-like protection of MMT layers, which could shield graphene layers from the action of oxidative etching. The composite fibers worked well as fire-resistant conductors when being heated to glowing red by an alcohol lamp. Our GO LC-templating wet-spinning strategy may also inspire the continuous assembly of other layered crystals into high-performance composite fibers
Wet-Spinning of Continuous Montmorillonite-Graphene Fibers for Fire-Resistant Lightweight Conductors
All-inorganic fibers composed of neat 2D crystals possessing fascinating performance (<i>e</i>.<i>g</i>., alternately stacking layers, high mechanical strength, favorable electrical conductivity, and fire-resistance) are discussed in detail. We developed a wet-spinning assmebly strategy to achieve continuous all-inorganic fibers of montmorillonite (MMT) nanoplatelets by incorporation of a graphene oxide (GO) liquid crystal (LC) template at a rate of 9 cm/s, and the templating role of GO LC is confirmed by <i>in situ</i> confocal laser scanning microscopy and polarized optical microscopy inspections. After protofibers underwent thermal reduction, the obtained binary complex fibers composed of neat 2D crystals integrate the outstanding fire-retardance of MMT nanoplatelets and the excellent conductivity of graphene nanosheets. High-resolution transmission electron microscopy and scanning electron microscope observations reveal the microstructures of fibers with compactly stacking layers. MMT-graphene fibers show increaing tensile strengths (88–270 MPa) and electrical conductivities (130–10500 S/m) with increasing graphene fraction. MMT-graphene (10/90) fibers are used as fire-resistant (bearing temperature in air: 600–700 °C), lightweight (ρ < 1.62 g/cm<sup>3</sup>) conductors (conductivity: up to 1.04 × 10<sup>4</sup> S/m) in view of their superior performance in high-temperature air beyond commercial T700 carbon fibers. We attribute the fire-resistance of MMT-graphene fibers to the armor-like protection of MMT layers, which could shield graphene layers from the action of oxidative etching. The composite fibers worked well as fire-resistant conductors when being heated to glowing red by an alcohol lamp. Our GO LC-templating wet-spinning strategy may also inspire the continuous assembly of other layered crystals into high-performance composite fibers
Effects of PM<sub>2.5</sub>, extreme weather conditions and demographic characteristics on non-accidental mortality.
<p>Effects of PM<sub>2.5</sub>, extreme weather conditions and demographic characteristics on non-accidental mortality.</p
Number of the days with two or more extreme meteorological conditions.
<p>Number of the days with two or more extreme meteorological conditions.</p
Sevoflurane preconditioning inhibited the apoptosis of neuron-like PC12 cells against hypoxia and serum deprivation.
<p>(A) Flow cytometry of neuron-like PC12 cells apoptosis. (B) Quantification of apoptotic cells. Data are presented as mean ± SEM of six independent experiments. *<i>P</i><0.05 versus control group. #<i>P</i><0.05 versus H/SD group. & <i>P</i><0.05 versus MSCs group.</p
La Charente
18 juillet 18951895/07/18 (A24,N10718)-1895/07/18.Appartient à l’ensemble documentaire : PoitouCh
Demographic characteristics of the subjects who died during the study period.
<p>Demographic characteristics of the subjects who died during the study period.</p
Flow cytometry of MSCs surface markers.
<p>X axis represents fluorescence intensity and Y axis expresses cell counts.</p
Sevoflurane preconditioning promoted the migration of MSCs against hypoxia and serum deprivation.
<p>(A) Representative microscopy images of MSCs penetrating through the transwell chambers (×100 magnification). (B) Quantification of migration. Data are presented as mean ± SEM of six independent experiments. *<i>P</i><0.05 versus control group. #<i>P</i><0.05 versus H/SD group.</p
Time trends of daily PM<sub>2.5</sub> concentrations and deaths.
<p>Time trends of daily PM<sub>2.5</sub> concentrations and deaths.</p