Shrinking core like fluid solid reactions—A dispersion model accounting for fluid phase volume change and solid phase particle size distributions

Knorr, Tilman; Kaiser, Michl; Glenk, F.; Etzold, Bastian J. M.

doi:10.1016/j.ces.2011.11.002

Cited by 28 publications

(26 citation statements)

References 39 publications

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“…Briefly, CDC can be produced by reactive extraction of metals from carbides using chlorine gas at high temperatures, with the precursor and synthesis temperature governing the resulting porosity and degree of graphitization [16][17][18][19][20]. This process is characterized by the temperature influence on the structure of the resulting CDC and the shrinking core reaction mechanism (SCM), hence, the conversion of the material from the outside towards the center during selective extraction [21,22]. We took advantage of accessible pore diameters (0.6 -1.5 nm) of TiC-CDC produced by Cl 2 etching in the 400-1200 °C temperature range [23,24].…”

Section: A N U S C R I P Tmentioning

confidence: 99%

Synthesis of carbon core–shell pore structures and their performance as supercapacitors

Ariyanto

Dyatkin

Zhang

et al. 2015

Microporous and Mesoporous Materials

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High-power supercapacitors require excellent electrolyte mobility within the pore network and high electrical conductivity for maximum capacitance and efficiency. Achieving high power typically requires sacrificing energy densities, as the latter demands a high specific surface area and narrow porosity that impedes ion transport. We present a novel solution for this optimization problem: a nanustructured core-shell carbonaceous material that exhibits a microporous carbon core surrounded by a mesoporous, graphitic shell. Our tunable synthesis parameters yielded a structure that features either a sharp or a gradual transition between the core and shell sections. Electrochemical supercapacitor testing using organic electrolyte revealed that these novel core-shell materials outperform carbons with homogeneous pore structures. The hybrid core-shell materials showed a combination of good capacitance retention, typical for the carbon present in the shell and high specific capacitance, typical for the core material. These materials achieved power densities in excess of 40 kW kg -1 at energy densities reaching 27 Wh kg -1 .

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Section: A N U S C R I P Tmentioning

confidence: 99%

Synthesis of carbon core–shell pore structures and their performance as supercapacitors

Ariyanto

Dyatkin

Zhang

et al. 2015

Microporous and Mesoporous Materials

Self Cite

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“…Now, we turn our attention to the full utilization of in-situ intercalative crosslinking for the performance improvement of the composite, which need the guidance of the understanding on epoxy-MGO reaction. Epoxy-MGO reaction can be studied based on Shrinking Core Model (SCM), the best representation for reacting fluid-particle systems [34][35][36]. In this work, the original sphere-shell model was modified with a cylinder-shell model customized for the special layered-structure of MGO sheet, as depicted in Figure 8.…”

Section: Promoting Intercalative Crosslinkingmentioning

confidence: 99%

Targeted kinetic strategy for improving the thermal conductivity of epoxy composite containing percolating multi-layer graphene oxide chains

Zhou

Koga

Nogi

et al. 2015

Express Polym. Lett.

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Abstract. By adding 2 wt% multi-layer graphene oxide (MGO) to an epoxy resin, the thermal conductivity of the composite reached a maximum, 2.03 times that of the epoxy. The presence of 2 wt%MGO percolating chains leads to an unprecedentedly sharp rise in energy barrier at final curing stage, but an increased epoxy curing degree (! IR ) is observed; however, this ! IR difference nearly disappears after aging or thermal annealing. These results suggest that the steep concentration gradient of -OH, originated from the 2 wt%MGO percolating chains, exerts the vital driving force on the residual isolated/ trapped epoxy to conquer barrier for epoxy-MGO reaction. A modified Shrinking Core Model customized for the special layered-structure of MGO sheet was proposed to understand the resistance variation during the intercalative epoxy-MGO reaction. It shows that the promoted intercalative crosslinking is highly desirable for further improving the thermal conductivity of the composite, but it meets with increased resistance. Guided by the kinetic studies, targeted optimization on the cure processing strategy was accordingly proposed to promote the intercalative crosslinking, a thermal conductivity, 2.96 times that of the epoxy, was got with only a small amount (30°C) increase of the post-heating temperature.

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“…These include the homogeneous, unreacted core, grain, random pore and modified volumetric models, in addition to a variety of customised models developed for specific cases (Chang and Kuo, 1999;Gómez-Barea et al, 2008;Haseli et al, 2008;Homma et al, 2005;Kasaoka et al, 1985;Molina and Mondragón, 1998;Silcox et al, 1989). Single particle reaction models, such as those mentioned above, can be combined with reactor models to allow prediction of realistic reactor scale behaviour (Kern and Jess, 2005;Knorr et al, 2012). A volumetric model is one in which the rate of chemical reaction is uniform through the diameter of a reacting particle.…”

Section: Introductionmentioning

confidence: 98%

An Unreacted Shrinking Core Model for Calcination and Similar Solid-to-Gas Reactions

Amiri

Ingram

Maynard

et al. 2014

Chemical Engineering Communications

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A variation on the unreacted shrinking core model has been developed for calcination and similar non-catalytic solid-to-gas decomposition reactions in which no gaseous reactant is involved and the reaction rate decreases with increasing product gas concentration. The numerical solution of the model has been validated against an analytical solution for the isothermal case. The model parameters have been tuned using literature data for the thermal dehydration (calcination) of gibbsite to alumina over a wide range of temperatures, from 490 K to 923 K. The model results for gibbsite conversion are agreed well with the published experimental data. A reaction order with respect to water vapour concentration of n = -1 was found to give a good fit to the data and yield activation energies consistent with literature values. Predictions of the non-isothermal unreacted shrinking core model compare well with a more complex distributed model developed previously by the authors.

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Shrinking core like fluid solid reactions—A dispersion model accounting for fluid phase volume change and solid phase particle size distributions

Cited by 28 publications

References 39 publications

Synthesis of carbon core–shell pore structures and their performance as supercapacitors

Synthesis of carbon core–shell pore structures and their performance as supercapacitors

Targeted kinetic strategy for improving the thermal conductivity of epoxy composite containing percolating multi-layer graphene oxide chains

An Unreacted Shrinking Core Model for Calcination and Similar Solid-to-Gas Reactions

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