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Rodney S. Ruoff - One of the best experts on this subject based on the ideXlab platform.

  • Graphene-Based ultracapacitors
    Nano Letters, 2008
    Co-Authors: Meryl D Stoller, Zhu Yanwu, Jinho An, Sungjin Park, Rodney S. Ruoff
    Abstract:

    The surface area of a single graphene sheet is 2630 m2/g, substantially higher than values derived from BET surface area measurements of activated Carbons used in current electrochemical double layer capacitors. Our group has pioneered a new Carbon Material that we call chemically modified graphene (CMG). CMG Materials are made from 1-atom thick sheets of Carbon, functionalized as needed, and here we demonstrate in an ultracapacitor cell their performance. Specific capacitances of 135 and 99 F/g in aqueous and organic electrolytes, respectively, have been measured. In addition, high electrical conductivity gives these Materials consistently good performance over a wide range of voltage scan rates. These encouraging results illustrate the exciting potential for high performance, electrical energy storage devices based on this new class of Carbon Material. Ultracapacitors

  • synthesis of graphene based nanosheets via chemical reduction of exfoliated graphite oxide
    Carbon, 2007
    Co-Authors: Sasha Stankovich, Kevin M. Kohlhaas, Son Binh T Nguyen, Alfred Kleinhammes, Richard D. Piner, Dmitriy A. Dikin, Yue Wu, Rodney S. Ruoff
    Abstract:

    Reduction of a colloidal suspension of exfoliated graphene oxide sheets in water with hydrazine hydrate results in their aggregation and subsequent formation of a high-surface-area Carbon Material which consists of thin graphene-based sheets. The reduced Material was characterized by elemental analysis, thermo-gravimetric analysis, scanning electron microscopy, X-ray photoelectron spectroscopy, NMR spectroscopy, Raman spectroscopy, and by electrical conductivity measurements.

  • Synthesis of graphene-based nanosheets via chemical reduction of exfoliated graphite oxide
    Carbon, 2007
    Co-Authors: Sasha Stankovich, Kevin M. Kohlhaas, Son Binh T Nguyen, Yuanyuan Jia, Alfred Kleinhammes, Richard D. Piner, Dmitriy A. Dikin, Yue Wu, Rodney S. Ruoff
    Abstract:

    Reduction of a colloidal suspension of exfoliated graphene oxide sheets in water with hydrazine hydrate results in their aggregation and subsequent formation of a high-surface-area Carbon Material which consists of thin graphene-based sheets. The reduced Material was characterized by elemental analysis, thermo-gravimetric analysis, scanning electron microscopy, X-ray photoelectron spectroscopy, NMR spectroscopy, Raman spectroscopy, and by electrical conductivity measurements. © 2007 Elsevier Ltd. All rights reserved.

D M Basko - One of the best experts on this subject based on the ideXlab platform.

Shuhong Yu - One of the best experts on this subject based on the ideXlab platform.

  • super elastic and fatigue resistant Carbon Material with lamellar multi arch microstructure
    Nature Communications, 2016
    Co-Authors: Fengchao Wang, Yang Lu, Jin Ge, Wei Shen, Yarong Zheng, Liang Xu, Linjun Wang, Weihong Xu, Hengan Wu, Shuhong Yu
    Abstract:

    Low-density compressible Materials enable various applications but are often hindered by structure-derived fatigue failure, weak elasticity with slow recovery speed and large energy dissipation. Here we demonstrate a Carbon Material with microstructure-derived super-elasticity and high fatigue resistance achieved by designing a hierarchical lamellar architecture composed of thousands of microscale arches that serve as elastic units. The obtained monolithic Carbon Material can rebound a steel ball in spring-like fashion with fast recovery speed (∼580 mm s−1), and demonstrates complete recovery and small energy dissipation (∼0.2) in each compress-release cycle, even under 90% strain. Particularly, the Material can maintain structural integrity after more than 106 cycles at 20% strain and 2.5 × 105 cycles at 50% strain. This structural Material, although constructed using an intrinsically brittle Carbon constituent, is simultaneously super-elastic, highly compressible and fatigue resistant to a degree even greater than that of previously reported compressible foams mainly made from more robust constituents. Low-density compressible Materials often suffer from fatigue-induced failure or limited elasticity. Here, the authors create a hierarchical multi-arch Carbon Material that achieves high compressibility, superior elasticity and fatigue resistance simultaneously, inspired by properties of arches in daily life.

A A Lappas - One of the best experts on this subject based on the ideXlab platform.

  • experimental study of pyrolysis for potential energy hydrogen and Carbon Material production from lignocellulosic biomass
    International Journal of Hydrogen Energy, 2008
    Co-Authors: A Zabaniotou, O Ioannidou, E V Antonakou, A A Lappas
    Abstract:

    Abstract Experimental results of slow, fast and catalytic pyrolysis of five lignocellulosic residues (corncobs and corn stalks, sunflower residues, olive kernels and olive tree prunings) are reported in this paper. Pyrolysis took place in two different reactor configurations: a captive sample wire mesh reactor for fast pyrolysis and a fixed bed reactor for non-catalytic and catalytic pyrolysis. Comparison of the experimental results showed that pyrolysis in the captive sample reactor produced more H2-rich gas than in the fixed bed reactor, while the fixed bed reactor configuration seemed to favor the production of liquid products. Analysis of gaseous, liquid and solid products was performed by GC and GC/MS. Pyrolysis results were assessed, and recommendations for the further use of their products were made.

Bożena Smreczak - One of the best experts on this subject based on the ideXlab platform.

  • Dissipation and sorption processes of polycyclic aromatic hydroCarbons (PAHs) to organic matter in soils amended by exogenous rich-Carbon Material
    Journal of Soils and Sediments, 2019
    Co-Authors: Aleksandra Ukalska-jaruga, Guillaume Debaene, Bożena Smreczak
    Abstract:

    Purpose The aim of the research was to assess the effect of biochar addition on aging, degradation, and sorption processes of polycyclic aromatic hydroCarbons (PAHs) to soil organic matter. The study was carried out as a sorption experiment in strictly controlled water and air conditions, which allowed for the accurate observation and prediction of PAH behavior in soils. Materials and methods Four soils were fortified with a PAH mixture (Fluorene-Flu, Anthracene-Ant, Phenanthrene-Phe, Pyrene-Pyr, Chrysene-Chry) at 20 mg kg^−1 of single-compound concentration level. The experiment was carried out in two trials: soils + 5PAHs amended with biochar and soil + 5PAHs without biochar addition with incubation times of 0, 1, 3, 6, and 9 months. After each interval time, the extractable (E-SOM) and stable organic matter (S-SOM) were measured as well as PAHs determined in two forms: total concentration (PAH-tot) and residual concentration (PAH-rest) after E-SOM extraction. The PAH loss and half-life times were estimated according to pseudo first-order kinetics equation. Results and discussion The amounts of PAH-tot in the soils without biochar decreased by an average of 92%, while in soil with biochar, this was 41% after 9 months of aging. The amount of PAHs-rest bounded with S-SOM after 9 months of incubation varied from 0.9 to 3.5% and 0.2 to 1.3% of the initial PAH concentration, respectively, for soils non-induced and induced by biochar. In soils without biochar, Flu, Ant, Phe, and Pyr exhibited similar T_1/2 (43–59 days), but Chry was characterized by a much higher and broader T_1/2 than other hydroCarbons (67–280 days). Biochar addition to the soils significantly influenced the half-life changes for all PAHs. The highest changes were noted for Phe (14-fold increase), and the lowest was for Flu (7-fold increase). Conclusions The addition of exogenous-rich Carbon Material such as biochar to the soil significantly changes the behavior and sorption potential of PAHs in the soil. Soils enriched with biochar are characterized by a higher persistence of PAHs, longer aging time, and lower affinity for sorption by native organic matter structures. Soils freshly polluted by PAH are mainly sorbed by E-SOM, which significantly increases their accessibility and reduces formation of bound-residues in the soil.