Adsorption behavior of carbonic acid on γ‐dicalcium silicate surface from molecular simulations

2021 ◽  
Author(s):  
Meicheng Zhao ◽  
Linnu Lu ◽  
Yong Tao ◽  
Yongjia He ◽  
Fazhou Wang ◽  
...  
Keyword(s):  
Carbonic Acid ◽  
Molecular Simulations ◽  
Dicalcium Silicate ◽  
Adsorption Behavior ◽  
Silicate Surface

Hydroxyl radical initiated oxidation of formic acid on mineral aerosols surface: a mechanistic, kinetic and spectroscopic study

2015 ◽  
Vol 12 (2) ◽  
pp. 236 ◽  
Author(s):  
Cristina Iuga ◽  
C. Ignacio Sainz-Díaz ◽  
Annik Vivier-Bunge
Keyword(s):  
Free Radical ◽  
Formic Acid ◽  
Gas Phase ◽  
Atmospheric Aerosols ◽  
Carbonic Acid ◽  
Radical Reactions ◽  
Acid Molecule ◽  
Formyl Radical ◽  
Volatile Organic ◽  
Silicate Surface

Environmental context The presence of air-borne mineral dust containing silicates in atmospheric aerosols should be considered in any exploration of volatile organic compound chemistry. This work reports the mechanisms, relative energies and kinetics of free-radical reactions with formic acid adsorbed on silicate surface models. We find that silicate surfaces are more likely to act as a trap for organic radicals than to have a catalytic effect on their reactions. Abstract Heterogeneous reactions of atmospheric volatile organic compounds on aerosol particles may play an important role in atmospheric chemistry. Silicate particles are present in air-borne mineral dust in atmospheric aerosols, and radical reactions can be different in the presence of these mineral particles. In this work, we use quantum-mechanical calculations and computational kinetics to explore the reaction of a hydroxyl free radical with a formic acid molecule previously adsorbed on several models of silicate surfaces. We find that the reaction is slower and takes place according to a mechanism that is different than the one in the gas phase. It is especially interesting to note that the reaction final products, which are the formyl radical attached to the cluster surface, and a water molecule, are much more stable than those formed in the gas phase, the overall reaction being highly exothermic in the presence of the surface model. This suggests that the silicate surface is a good trap for the formed formyl radical. In addition, we have noted that, if a second hydroxyl radical approaches the adsorbed formyl radical, the formation of carbonic acid on the silicate surface is a highly exothermic and exergonic process. The carbonic acid molecule remains strongly attached to the surface, thus blocking CO2 formation in the formic acid oxidation reaction. The spectroscopic properties of the systems involved in the reaction have been calculated, and interesting frequency shifts have been identified in the main vibration modes.

Competitive adsorption behavior of hydrocarbon(s)/CO2 mixtures in a double-nanopore system using molecular simulations

Fuel ◽  
2019 ◽  
Vol 252 ◽  
pp. 612-621 ◽  
Author(s):  
Yueliang Liu ◽  
Xiaomin Ma ◽  
Huazhou Andy Li ◽  
Jian Hou
Keyword(s):  
Competitive Adsorption ◽  
Molecular Simulations ◽  
Adsorption Behavior

Hydration Mechanism of Reactive and Passive Dicalcium Silicate Polymorphs from Molecular Simulations

2015 ◽  
Vol 119 (34) ◽  
pp. 19869-19875 ◽  
Author(s):  
Qianqian Wang ◽  
Hegoi Manzano ◽  
Yanhua Guo ◽  
Iñigo Lopez-Arbeloa ◽  
Xiaodong Shen
Keyword(s):  
Molecular Simulations ◽  
Dicalcium Silicate ◽  
Hydration Mechanism

scholarly journals Understanding static, dynamic and cooperative porosity in molecular materials

2016 ◽  
Vol 7 (8) ◽  
pp. 4875-4879 ◽  
Author(s):  
Daniel Holden ◽  
Samantha Y. Chong ◽  
Linjiang Chen ◽  
Kim E. Jelfs ◽  
Tom Hasell ◽  
...  
Keyword(s):  
Molecular Simulations ◽  
Adsorption Properties ◽  
Adsorption Behavior ◽  
Porous Solids ◽  
Molecular Materials

The practical adsorption properties of molecular porous solids can be dominated by dynamic flexibility but these effects are still poorly understood. Here, we combine molecular simulations and experiments to rationalize the adsorption behavior of a flexible porous organic cage.

Molecular Simulations of Methane Adsorption Behavior in Illite Nanopores Considering Basal and Edge Surfaces

2018 ◽  
Vol 32 (4) ◽  
pp. 4783-4796 ◽  
Author(s):  
Youzhi Hao ◽  
Lanfeng Yuan ◽  
Peichao Li ◽  
Wenhui Zhao ◽  
Daolun Li ◽  
...  
Keyword(s):  
Molecular Simulations ◽  
Methane Adsorption ◽  
Adsorption Behavior

Adsorption Behavior of Organic Corrosion Inhibitors on Metal Surfaces—Some New Insights from Molecular Simulations

CORROSION ◽  
10.5006/2976 ◽  
2019 ◽  
Vol 75 (1) ◽  
pp. 90-105 ◽  
Author(s):  
Sumit Sharma ◽  
Xueying Ko ◽  
Yathish Kurapati ◽  
Himanshu Singh ◽  
Srdjan Nešić
Keyword(s):  
Metal Surfaces ◽  
Corrosion Inhibitors ◽  
Molecular Simulations ◽  
Adsorption Behavior ◽  
Organic Corrosion Inhibitors

Microstructural characterization of laser-melted/roller-quenched dicalcium silicate

1988 ◽  
Vol 46 ◽  
pp. 582-583
Author(s):  
C. J. Chan ◽  
K. R. Venkatachari ◽  
W. M. Kriven ◽  
J. F. Young
Keyword(s):  
Particle Size ◽  
Raw Materials ◽  
Shape Change ◽  
Microstructural Characterization ◽  
Particle Size Effect ◽  
Dicalcium Silicate ◽  
Laser Melting ◽  
Uniform Size ◽  
Cell Shape Change ◽  
Wide Range

Dicalcium silicate (Ca2SiO4) is a major component of Portland cement. It has also been investigated as a potential transformation toughener alternative to zirconia. It has five polymorphs: α, α'H, α'L, β and γ. Of interest is the β-to-γ transformation on cooling at about 490°C. This transformation, accompanied by a 12% volume increase and a 4.6° unit cell shape change, is analogous to the tetragonal-to-monoclinic transformation in zirconia. Due to the processing methods used, previous studies into the particle size effect were limited by a wide range of particle size distribution. In an attempt to obtain a more uniform size, a fast quench rate involving a laser-melting/roller-quenching technique was investigated.The laser-melting/roller-quenching experiment used precompacted bars of stoichiometric γ-Ca2SiO4 powder, which were synthesized from AR grade CaCO3 and SiO2xH2O. The raw materials were mixed by conventional ceramic processing techniques, and sintered at 1450°C. The dusted γ-Ca2SiO4 powder was uniaxially pressed into 0.4 cm x 0.4 cm x 4 cm bars under 34 MPa and cold isostatically pressed under 172 MPa. The γ-Ca2SiO4 bars were melted by a 10 KW-CO2 laser.

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