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Full-Text Articles in Engineering
Enhancement Of Cement Paste With Carboxylated Carbon Nanotubes And Poly(Vinyl Alcohol), Yuyang Zhao, Jinrui Zhang, Gang Qiao, Dongshuai Hou, Biqin Dong, Hongyan Ma
Enhancement Of Cement Paste With Carboxylated Carbon Nanotubes And Poly(Vinyl Alcohol), Yuyang Zhao, Jinrui Zhang, Gang Qiao, Dongshuai Hou, Biqin Dong, Hongyan Ma
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Cement has been a major consumable material for construction in the world since its invention, but its low flexural strength is the main defect affecting the service life of structures. To adapt cement-based materials to a more stringent environment, carboxylated carbon nanotubes (CNTs-COOH) and poly(vinyl alcohol) (PVA) are proposed to enhance the mechanical properties of cement paste. This study systematically verifies the synergistic effect of CNTs-COOH/PVA on the performance of cement paste. First, UV-Vis spectroscopy and FTIR spectroscopy prove that CNTs-COOH can provide attachment sites for PVA and PVA can improve the dispersion and stability of CNTs-COOH in water, which …
Molecular Insight Into The Fluidity Of Cement Pastes: Nano-Boundary Lubrication Of Cementitious Materials, Muhan Wang, Kaixuan Zhang, Xiang Ji, Pan Wang, Hongyan Ma, Jun Zhang, Dongshuai Hou
Molecular Insight Into The Fluidity Of Cement Pastes: Nano-Boundary Lubrication Of Cementitious Materials, Muhan Wang, Kaixuan Zhang, Xiang Ji, Pan Wang, Hongyan Ma, Jun Zhang, Dongshuai Hou
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
The workability mechanism of fresh concrete at the molecular level remains essentially unexplored. To understand the molecular origin for cement fluidity, molecular dynamics and Density Function Theory (DFT) were utilized to construct a shear model of Calcium-Silicate-Hydrate (C-S-H) layers. The structure, dynamics, and reactivity of ultra-confined pore solution between C-S-H gels are systematically investigated. Under shear loading, periodic oscillation of friction force is observed as the typically Couette flow and the interfacial friction force is reduced from 35.2 Kcal/mol·Å to 3.3 Kcal/mol·Å with water content increasing. All of the systems contain breakage of noncovalent bonds of water-Ca and water-water in …
Mechanical Properties Of Hydrogenated Amorphous Silicon (A-Si:H) Particles, Taizhi Jiang, Fardin Khabaz, Aniket Marne, Chenglin Wu, Raluca Gearba, Revanth Bodepudi, Roger T. Bonnecaze, Kenneth M. Liechti, Brian A. Korgel
Mechanical Properties Of Hydrogenated Amorphous Silicon (A-Si:H) Particles, Taizhi Jiang, Fardin Khabaz, Aniket Marne, Chenglin Wu, Raluca Gearba, Revanth Bodepudi, Roger T. Bonnecaze, Kenneth M. Liechti, Brian A. Korgel
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
A nanoindenter was used to compress individual particles of hydrogenated amorphous silicon (a-Si:H) ranging in diameter from 290 nm to 780 nm. The colloidal synthesis used to produce the particles enables the hydrogen content to be manipulated over a wide range, from about 5 at. % to 50 at. %, making these a-Si:H particles promising for applications in lithium ion batteries, hydrogen storage, and optical metamaterials. Force-displacement curves generated using a tungsten probe flattened with focused ion beam exhibited elastic and then plastic deformations, followed by fracture and crushing of the particles. For particles with 5% and 50% H, Young's …
Chemical And Hydrodynamic Mechanisms For Long-Term Geological Carbon Storage, Susan J. Altman, Wen Deng, For Full List Of Authors, See Publisher's Website.
Chemical And Hydrodynamic Mechanisms For Long-Term Geological Carbon Storage, Susan J. Altman, Wen Deng, For Full List Of Authors, See Publisher's Website.
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Geological storage of CO₂ (GCS), also referred to as carbon sequestration, is a critical component for decreasing anthropogenic CO₂ atmospheric emissions. Stored CO₂ will exist as a supercritical phase, most likely in deep, saline, sedimentary reservoirs. Research at the Center for Frontiers of Subsurface Energy Security (CFSES), a Department of Energy, Energy Frontier Research Center, provides insights into the storage process. The integration of pore-scale experiments, molecular dynamics simulations, and study of natural analogue sites has enabled understanding of the efficacy of capillary, solubility, and dissolution trapping of CO₂ for GCS. Molecular dynamics simulations provide insight on relative wetting of …