Tongji University

About: Tongji University is a education organization based out in Shanghai, China. It is known for research contribution in the topics: Computer science & Population. The organization has 76116 authors who have published 81176 publications receiving 1248911 citations. The organization is also known as: Tongji & Tóngjì Dàxué.

Carbon nanotube/polyaniline composite nanofibers: facile synthesis and chemosensors.

Abstract: An initiator is applied to synthesize single-walled carbon nanotube/polyaniline composite nanofibers for use as high-performance chemosensors. The composite nanofibers possess widely tunable conductivities (10(-4) to 10(2) S/cm) with up to 5.0 wt % single-walled carbon nanotube (SWCNT) loadings. Chemosensors fabricated from the composite nanofibers synthesized with a 1.0 wt % SWCNT loading respond much more rapidly to low concentrations (100 ppb) of HCl and NH(3) vapors compared to polyaniline nanofibers alone (120 s vs 1000 s). These nanofibrillar SWCNT/polyaniline composite nanostructures are promising materials for use as low-cost disposable sensors and as electrodes due to their widely tunable conductivities.

Rapid and effective adsorption of lead ions on fine poly(phenylenediamine) microparticles.

Abstract: Fine microparticles of poly(p-phenylenediamine) (PpPD) and poly(m-phenylenediamine) (PmPD) were directly synthesized by a facile oxidative precipitation polymerization and their strong ability to adsorb lead ions from aqueous solution was examined. It was found that the degree of adsorption of the lead ions depends on the pH, concentration, and temperature of the lead ion solution, as well as the contact time and microparticle dose. The adsorption data fit the Langmuir isotherm and the process obeyed pseudo-second-order kinetics. According to the Langmuir equation, the maximum adsorption capacities of lead ions onto PpPD and PmPD microparticles at 30 degrees C are 253.2 and 242.7 mg g(-1), respectively. The highest adsorptivity of lead ions is up to 99.8 %. The adsorption is very rapid with a loading half-time of only 2 min as well as initial adsorption rates of 95.24 and 83.06 mg g(-1) min(-1) on PpPD and PmPD particles, respectively. A series of batch experiment results showed that the PpPD microparticles possess an even stronger capability to adsorb lead ions than the PmPD microparticles, but the PmPD microparticles, with a more-quinoid-like structure, show a stronger dependence of lead-ion adsorption on the pH and temperature of the lead-ion solution. A possible adsorption mechanism through complexation between Pb(2+) ions and ==N-- groups on the macromolecular chains has been proposed. The powerful lead-ion adsorption on the microparticles makes them promising adsorbents for wastewater cleanup.

One-step strategy to three-dimensional graphene/VO2 nanobelt composite hydrogels for high performance supercapacitors

Abstract: A facile one-step strategy has been developed to prepare 3D graphene/VO2 nanobelt composite hydrogels, which can be readily scaled-up for mass production by using commercial V2O5 and graphene oxide as precursors. During the formation of the graphene/VO2 architecture, 1D VO2 nanobelts and 2D flexible graphene sheets are self-assembled to form interconnected porous microstructures through hydrogen bonding, which facilitates charge and ion transport in the electrode. Due to the hierarchical network framework and the pseudocapacitance contribution from VO2 nanobelts, the hybrid electrode demonstrates excellent capacitive performances. In the two-electrode configuration, the graphene/VO2 nanobelt composite hydrogel exhibits a specific capacitance of 426 F g−1 at 1 A g−1 in the potential range of −0.6 to 0.6 V, which greatly surpasses that of each individual counterpart (191 F g−1 and 243 F g−1 at 1 A g−1 for VO2 nanobelt and graphene hydrogel, respectively). The hybrid electrode also shows an improved rate capability and cycling stability, which is indicative of a positive synergistic effect of VO2 and graphene on the improvement of electrochemical performance. These findings reveal the importance and great potential of graphene composite hydrogels in the development of energy storage devices with high power and energy densities.