Flocculation Mechanism and Microscopic Statics Analysis of Polyacrylamide Gel in Underwater Cement Slurry
Zeta potential testing, Fourier infrared spectroscopy, and total organic carbon analysis were employed in this manuscript to explore the flocculation mechanism of polyacrylamide (PAM) on slurry with a high content of polycarboxylate ether (PCE). Through the combination of assessments of chemical bon...
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MDPI AG
2025-02-01
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| author | Hao Lu Bo Dai Chunhe Li Hua Wei Jinhui Wang |
| author_facet | Hao Lu Bo Dai Chunhe Li Hua Wei Jinhui Wang |
| author_sort | Hao Lu |
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| description | Zeta potential testing, Fourier infrared spectroscopy, and total organic carbon analysis were employed in this manuscript to explore the flocculation mechanism of polyacrylamide (PAM) on slurry with a high content of polycarboxylate ether (PCE). Through the combination of assessments of chemical bond shifts, adsorption indicators, and intrinsic viscosity of high-molecular-weight polymer systems, the microscale flocculation mechanisms of different PAM dosages in cement suspensions were elucidated, showcasing stages of “adsorption–lubrication–entanglement”. Initially (PAM < 0.3%), with PAM introduction, the polymer primarily underwent adsorption interactions, including hydrogen bonding between the ester group, amine group, and water molecules; chelation between the ester group and Ca<sup>2+</sup> and Al<sup>3+</sup> on the cement surface; and bridging between PAM’s long-chain structure and cement particles. As the PAM content increased, the cement particles’ adsorption capacity saturated (PAM < 0.67%). The entropy loss of polymer conformation could not be offset by adsorption energy, leading to its exclusion from the interface and depletion attractive forces. Slurry movement shifted from inter-particle motion to high-molecular-weight polymer sliding in interstitial fluid, forming a lubrication effect. With further PAM content no less than 0.67%, the polymer solution reached a critical entanglement concentration, and the contact of the rotation radius of the long-chain molecules led to entanglement domination. By introducing bridging adsorption, depletion attraction, and entanglement forces, the cohesion of cement-based polymer suspensions was subsequently determined. The results showed a linear correlation between cohesion and PAM concentration raised to powers of 0.30, 1.0, and 0.75 at different interaction stages, and a multiscale validation from microscopic flocculation mechanisms to macroscopic performance was finally completed through a comparative analysis with macroscopic anti-washout performance. |
| format | Article |
| id | doaj-art-a5bfae3d85034ffc98884eeeb1e263cd |
| institution | DOAJ |
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| publishDate | 2025-02-01 |
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| spelling | doaj-art-a5bfae3d85034ffc98884eeeb1e263cd2025-08-20T02:45:00ZengMDPI AGGels2310-28612025-02-011129910.3390/gels11020099Flocculation Mechanism and Microscopic Statics Analysis of Polyacrylamide Gel in Underwater Cement SlurryHao Lu0Bo Dai1Chunhe Li2Hua Wei3Jinhui Wang4Nanjing Hydraulic Research Institutes, Materials & Structural Engineering Department, Nanjing 210029, ChinaNanjing Hydraulic Research Institutes, Dam Safety Management Department, Nanjing 210029, ChinaCivil and Environmental Engineering, University of Miyazaki, 1-1 Gakuenkibanadainishi, Miyazaki 889-2192, JapanNanjing Hydraulic Research Institutes, Materials & Structural Engineering Department, Nanjing 210029, ChinaJiangxi Academy of Water Science and Engineering, Nanchang 330029, ChinaZeta potential testing, Fourier infrared spectroscopy, and total organic carbon analysis were employed in this manuscript to explore the flocculation mechanism of polyacrylamide (PAM) on slurry with a high content of polycarboxylate ether (PCE). Through the combination of assessments of chemical bond shifts, adsorption indicators, and intrinsic viscosity of high-molecular-weight polymer systems, the microscale flocculation mechanisms of different PAM dosages in cement suspensions were elucidated, showcasing stages of “adsorption–lubrication–entanglement”. Initially (PAM < 0.3%), with PAM introduction, the polymer primarily underwent adsorption interactions, including hydrogen bonding between the ester group, amine group, and water molecules; chelation between the ester group and Ca<sup>2+</sup> and Al<sup>3+</sup> on the cement surface; and bridging between PAM’s long-chain structure and cement particles. As the PAM content increased, the cement particles’ adsorption capacity saturated (PAM < 0.67%). The entropy loss of polymer conformation could not be offset by adsorption energy, leading to its exclusion from the interface and depletion attractive forces. Slurry movement shifted from inter-particle motion to high-molecular-weight polymer sliding in interstitial fluid, forming a lubrication effect. With further PAM content no less than 0.67%, the polymer solution reached a critical entanglement concentration, and the contact of the rotation radius of the long-chain molecules led to entanglement domination. By introducing bridging adsorption, depletion attraction, and entanglement forces, the cohesion of cement-based polymer suspensions was subsequently determined. The results showed a linear correlation between cohesion and PAM concentration raised to powers of 0.30, 1.0, and 0.75 at different interaction stages, and a multiscale validation from microscopic flocculation mechanisms to macroscopic performance was finally completed through a comparative analysis with macroscopic anti-washout performance.https://www.mdpi.com/2310-2861/11/2/99PAMadsorptionlubricationentanglementmicroscopic statics analysis |
| spellingShingle | Hao Lu Bo Dai Chunhe Li Hua Wei Jinhui Wang Flocculation Mechanism and Microscopic Statics Analysis of Polyacrylamide Gel in Underwater Cement Slurry Gels PAM adsorption lubrication entanglement microscopic statics analysis |
| title | Flocculation Mechanism and Microscopic Statics Analysis of Polyacrylamide Gel in Underwater Cement Slurry |
| title_full | Flocculation Mechanism and Microscopic Statics Analysis of Polyacrylamide Gel in Underwater Cement Slurry |
| title_fullStr | Flocculation Mechanism and Microscopic Statics Analysis of Polyacrylamide Gel in Underwater Cement Slurry |
| title_full_unstemmed | Flocculation Mechanism and Microscopic Statics Analysis of Polyacrylamide Gel in Underwater Cement Slurry |
| title_short | Flocculation Mechanism and Microscopic Statics Analysis of Polyacrylamide Gel in Underwater Cement Slurry |
| title_sort | flocculation mechanism and microscopic statics analysis of polyacrylamide gel in underwater cement slurry |
| topic | PAM adsorption lubrication entanglement microscopic statics analysis |
| url | https://www.mdpi.com/2310-2861/11/2/99 |
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