1
|
Experimental study on 3D vibrated packing densification of mono-sized dodecahedral particles. POWDER TECHNOL 2020. [DOI: 10.1016/j.powtec.2020.04.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
2
|
Cao T, Zhang L, Sun G, Wang C, Zhang Y, Yan N, Xu A. Model for Predicting the Tortuosity of Transport Paths in Cement-Based Materials. MATERIALS 2019; 12:ma12213623. [PMID: 31690002 PMCID: PMC6862200 DOI: 10.3390/ma12213623] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 10/27/2019] [Accepted: 10/31/2019] [Indexed: 11/16/2022]
Abstract
The tortuosity of the pore structure is an important factor affecting medium (water and harmful ions) transport in cement-based materials. In this study, a new tortuosity model was established to reveal the effect of aggregate size, morphology, and graded media on the transport path in cement-based materials. Based on the stereological principle and the geometric algorithm, the distribution model of the ideal pebble and polygonal aggregate in cement-based materials was given first. Then, based on the image processing technology and MATLAB software, the morphology of the actual aggregate was also characterized to prove the similarity relationship between the ideal aggregate and actual aggregate. The reliability of the tortuosity model was verified by the mercury intrusion porosimetry test and data from other literature. Based on the tortuosity model, the influences of the aggregate particle shape parameters, hydration degree, and water-to-cement ratio on the tortuosity of the transport path were analyzed. Finally, the tortuosity model was further simplified to facilitate engineering application.
Collapse
Affiliation(s)
- Tongning Cao
- School of Materials Science and Engineering, Shijiazhuang Tiedao University, Shijiazhuang 050043, China.
| | - Lijuan Zhang
- Foundational subjects department, Shijiazhuang TieDao University SiFang College, Shijiazhuang 051132, China.
| | - Guowen Sun
- School of Materials Science and Engineering, Shijiazhuang Tiedao University, Shijiazhuang 050043, China.
- Key Laboratory of Smart Material and Structures Mechanics, Hebei Province, Shijiazhuang Tiedao University, Shijiazhuang 050043, China.
| | - Caihui Wang
- School of Materials Science and Engineering, Shijiazhuang Tiedao University, Shijiazhuang 050043, China.
| | - Ying Zhang
- School of Materials Science and Engineering, Shijiazhuang Tiedao University, Shijiazhuang 050043, China.
| | - Na Yan
- School of Materials Science and Engineering, Shijiazhuang Tiedao University, Shijiazhuang 050043, China.
| | - Aoxue Xu
- School of Foreign Studies, Hebei Normal University, Shijiazhuang 050024, China.
| |
Collapse
|
3
|
Xu W, Zhu Z, Zhang D. Continuum percolation-based tortuosity and thermal conductivity of soft superball systems: shape dependence from octahedra via spheres to cubes. SOFT MATTER 2018; 14:8684-8691. [PMID: 30191226 DOI: 10.1039/c8sm01488d] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Understanding the effect of particle shape on the percolation threshold, tortuosity and thermal conductivity of soft (geometrical overlapping) particle systems is very crucial for the design and optimization of such materials, including colloids, polymers, and porous and fracture media. In this work, we first combine the excluded-volume theory with the Monte Carlo simulations to determine the percolation threshold for a family of soft superballs, the shape of which interpolates between octahedra and cubes via spheres. Then, we propose two continuum percolation-based models to respectively obtain the tortuosity and effective thermal conductivity of soft superball systems considering their percolation behavior, where monodisperse overlapping superballs are uniformly distributed in a homogeneous solid matrix. Specifically, both models cover the whole feasible range of superball volume fractions, including near the percolation threshold. Comparison with extensive experimental, numerical and theoretical results confirms that the present models are capable of precisely predicting the percolation threshold, tortuosity and thermal conductivity of such systems. Furthermore, we apply the proposed models to probe the influence of particle shape on these important parameters. Our results show that the decreasing percolation threshold and tortuosity as soft particles become more anisotropic is consistent with increasing conductivity. It suggests that the anisotropic-shaped inclusion phase is more conducting than the spherical inclusion phase. The present theoretical strategies and conclusions may provide sound guidance for the synthesis of colloidal and polymer superballs.
Collapse
Affiliation(s)
- Wenxiang Xu
- Institute of Materials and Structures Mechanics, College of Mechanics and Materials, Hohai University, Nanjing, 211100, P. R. China.
| | | | | |
Collapse
|
4
|
Chen H, Zhu Z, Liu L, Sun W, Miao C. Aggregate shape effect on the overestimation of ITZ thickness: Quantitative analysis of Platonic particles. POWDER TECHNOL 2016. [DOI: 10.1016/j.powtec.2015.11.036] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
5
|
Xu W, Wang H, Niu Y, Bai J. Insight into interfacial effect on effective physical properties of fibrous materials. I. The volume fraction of soft interfaces around anisotropic fibers. J Chem Phys 2016; 144:014703. [PMID: 26747814 DOI: 10.1063/1.4939126] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
With advances in interfacial properties characterization technologies, the interfacial volume fraction is a feasible parameter for evaluating effective physical properties of materials. However, there is a need to determine the interfacial volume fraction around anisotropic fibers and a need to assess the influence of such the interfacial property on effective properties of fibrous materials. Either ways, the accurate prediction of interfacial volume fraction is required. Towards this end, we put forward both theoretical and numerical schemes to determine the interfacial volume fraction in fibrous materials, which are considered as a three-phase composite structure consisting of matrix, anisotropic hard spherocylinder fibers, and soft interfacial layers with a constant dimension coated on the surface of each fiber. The interfacial volume fraction actually represents the fraction of space not occupied by all hard fibers and matrix. The theoretical scheme that adopts statistical geometry and stereological theories is essentially an analytic continuation from spherical inclusions. By simulating such three-phase chopped fibrous materials, we numerically derive the interfacial volume fraction. The theoretical and numerical schemes provide a quantitative insight that the interfacial volume fraction depends strongly on the fiber geometries like fiber shape, geometric size factor, and fiber size distribution. As a critical interfacial property, the present contribution can be further drawn into assessing effective physical properties of fibrous materials, which will be demonstrated in another paper (Part II) of this series.
Collapse
Affiliation(s)
- Wenxiang Xu
- Institute of Soft Matter Mechanics, College of Mechanics and Materials, Hohai University, Nanjing 211100, People's Republic of China
| | - Han Wang
- Institute of Soft Matter Mechanics, College of Mechanics and Materials, Hohai University, Nanjing 211100, People's Republic of China
| | - Yanze Niu
- Institute of Soft Matter Mechanics, College of Mechanics and Materials, Hohai University, Nanjing 211100, People's Republic of China
| | - Jingtao Bai
- Department of New Energy Engineering, College of Energy and Electrical Engineering, Hohai University, Nanjing 211100, People's Republic of China
| |
Collapse
|
6
|
Xu W, Chen H, Duan Q, Chen W. Strategy for interfacial overlapping degree in multiphase materials with complex convex particles. POWDER TECHNOL 2015. [DOI: 10.1016/j.powtec.2015.06.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
7
|
Xu W, Chen H, Chen W, Jiang L. Prediction of transport behaviors of particulate composites considering microstructures of soft interfacial layers around ellipsoidal aggregate particles. SOFT MATTER 2014; 10:627-638. [PMID: 24651952 DOI: 10.1039/c3sm52718b] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The effect of microstructures of interfacial layers on transport behaviors of particulate composites has been found to be significant, thus microstructural characteristics of interfacial layers should be considered in the analysis for better prediction of transport properties of particulate composites. However, it is very difficult to determine the volume fraction of soft interfacial layers around polydisperse three-dimensional (3D) ellipsoidal aggregate particles and to practically estimate the influence of such a microstructural characteristic on transport properties of particulate composites by traditional experimental methods and simple models proposed so far. In this article, an approximate analytical model for the volume fraction of soft interfacial layers is proposed on the basis of a theory of the nearest-surface distribution functions and geometric characteristics of polydisperse ellipsoidal particle systems. A theoretical model that adopts a three-phase composite ellipsoid structure by a generalized self-consistent scheme is further presented to predict the effective transport properties of particulate composites containing such soft interfacial layers. To test the developed models, numerical results of the soft interfacial volume fraction from the previous work, experimental data in the literature, the Hashin-Shtrikman bounds model and the Maxwell-Garnett model for the effective electrical conductivity are compared respectively. Finally, by virtue of the present models, the effects of key factors on the effective electrical conductivity of particulate composites are investigated in a quantitative manner.
Collapse
Affiliation(s)
- Wenxiang Xu
- Institute of Soft Matter Mechanics, College of Mechanics and Materials, Hohai University, Nanjing 210098, China.
| | | | | | | |
Collapse
|
8
|
Xu W, Chen W, Chen H. Modeling of soft interfacial volume fraction in composite materials with complex convex particles. J Chem Phys 2014; 140:034704. [PMID: 25669404 DOI: 10.1063/1.4861664] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Affiliation(s)
- Wenxiang Xu
- Institute of Soft Matter Mechanics, College of Mechanics and Materials, Hohai University, Nanjing 210098, China
| | - Wen Chen
- Institute of Soft Matter Mechanics, College of Mechanics and Materials, Hohai University, Nanjing 210098, China
| | - Huisu Chen
- Jiangsu Key Laboratory of Construction Materials, School of Materials Science and Engineering, Southeast University, Nanjing 211189, China
| |
Collapse
|
9
|
Xu W, Chen H, Chen W, Tian X, Zhao H. Modeling Study of the Valid Apparent Interface Thickness in Particulate Materials with Ellipsoidal Particles. Ind Eng Chem Res 2013. [DOI: 10.1021/ie403009c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Wenxiang Xu
- Institute
of Soft Matter Mechanics, College of Mechanics and Materials, Hohai University, Nanjing 210098, China
- Jiangsu Key Laboratory of Construction Materials, School of Materials
Science and Engineering, Southeast University, Nanjing 211189, China
| | - Huisu Chen
- Jiangsu Key Laboratory of Construction Materials, School of Materials
Science and Engineering, Southeast University, Nanjing 211189, China
| | - Wen Chen
- Institute
of Soft Matter Mechanics, College of Mechanics and Materials, Hohai University, Nanjing 210098, China
| | - Xia Tian
- Institute
of Soft Matter Mechanics, College of Mechanics and Materials, Hohai University, Nanjing 210098, China
| | - Haitao Zhao
- College of Civil and Transporting Engineering, Hohai University, Nanjing 210098, China
| |
Collapse
|
10
|
Xu W, Chen H, Chen W, Zhu Z. Theoretical estimation for the volume fraction of interfacial layers around convex particles in multiphase materials. POWDER TECHNOL 2013. [DOI: 10.1016/j.powtec.2013.09.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|