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Studies on Hydration Swelling and Bound Water Type of Sodium- and Polymer-Modified Calcium Bentonite
Joint Authors
Wan, Yong
Liu, Lei
Guo, Dongdong
Hui, Xinminnan
Yao, Yuan
Source
Advances in Polymer Technology
Issue
Vol. 2020, Issue 2020 (31 Dec. 2020), pp.1-11, 11 p.
Publisher
Hindawi Publishing Corporation
Publication Date
2020-10-09
Country of Publication
Egypt
No. of Pages
11
Main Subjects
Abstract EN
Modified calcium bentonite (Ca-bentonite) is extensively used in engineered barrier systems (EBSs) for municipal and industrial disposal sites due to its high swelling potential and low hydraulic conductivity.
However, few studies have focused on the micromechanism of hydration and swelling under the effect of inorganic chemical solution.
In this study, free swell index (FSI) and the type and content of modified Ca-bentonite bound water under the inorganic chemical solution were quantitatively studied by using the free swell test and nuclear magnetic resonance (NMR).
According to the results, modification of sodium and polymer significantly increases the FSI of Ca-bentonite, bringing it close to that of natural sodium bentonite.
In addition, the chemical stability of polymer-modified bentonite is significantly higher than that of sodium-modified bentonite but less than that of natural Na-bentonite.
The FSI of modified Ca-bentonite decreases with the increase of cation valence and ionic strength.
T2 distribution curves of the two types of modified bentonite are three-peak curves.
With the increase of ionic strength, the content of total water and permeated hydrated water (accounting for 69%–95%) in bentonite decreases gradually, whereas the surface hydration water (accounting for 2%–31%) and free water content (accounting for 0–15%) increase.
A uniform linear relationship exists between the FSI and corresponding total peak area of NMR (independent of ion valence, concentration, and bentonite type).
Furthermore, a linear relationship exists between the FSI of the same type of bentonite and the T2 relaxation time.
Research results can provide data and theoretical basis for quantitative analysis and mechanism of the hydration swelling of bentonite.
American Psychological Association (APA)
Wan, Yong& Guo, Dongdong& Hui, Xinminnan& Liu, Lei& Yao, Yuan. 2020. Studies on Hydration Swelling and Bound Water Type of Sodium- and Polymer-Modified Calcium Bentonite. Advances in Polymer Technology،Vol. 2020, no. 2020, pp.1-11.
https://search.emarefa.net/detail/BIM-1130433
Modern Language Association (MLA)
Wan, Yong…[et al.]. Studies on Hydration Swelling and Bound Water Type of Sodium- and Polymer-Modified Calcium Bentonite. Advances in Polymer Technology No. 2020 (2020), pp.1-11.
https://search.emarefa.net/detail/BIM-1130433
American Medical Association (AMA)
Wan, Yong& Guo, Dongdong& Hui, Xinminnan& Liu, Lei& Yao, Yuan. Studies on Hydration Swelling and Bound Water Type of Sodium- and Polymer-Modified Calcium Bentonite. Advances in Polymer Technology. 2020. Vol. 2020, no. 2020, pp.1-11.
https://search.emarefa.net/detail/BIM-1130433
Data Type
Journal Articles
Language
English
Notes
Includes bibliographical references
Record ID
BIM-1130433