Dynamics of polyelectrolyte adsorption and colloidal flocculation studied using model colloids
| Project/Area Number |
20F20388
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| Research Category |
Grant-in-Aid for JSPS Fellows
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| Allocation Type | Single-year Grants |
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| Section | 外国 |
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| Review Section |
Basic Section 41030:Rural environmental engineering and planning-related
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| Research Institution | University of Tsukuba |
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Principal Investigator |
小林 幹佳 筑波大学, 生命環境系, 准教授 (20400179)
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| Co-Investigator(Kenkyū-buntansha) |
GEONZON LESTER 筑波大学, 生命環境系, 外国人特別研究員
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| Project Period (FY) |
2020-11-13 – 2023-03-31
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| Project Status |
Completed (Fiscal Year 2022)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 2022: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2021: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2020: ¥600,000 (Direct Cost: ¥600,000)
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| Keywords | polymer adsorption / microfluidics / optical tweezers / hydrodynamic flow / kinetics of adsorption / Water-soluble polymer / water-soluble polymer / colloids / adsorption |
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| Outline of Research at the Start |
本課題は，水処理や土壌保全において重要となる高分子によるコロイド粒子の凝集（flocculation）ダイナミクスを対象にしている．高分子による凝集過程を理解するためには，高分子の粒子への吸着，高分子を被覆した粒子同士の相互作用の詳細な検討が不可欠である．しかし凝集過程では，吸着した高分子の形態，粒子の帯電状況を反映するゼータ電位，高分子を被覆した粒子間相互作用が複雑に時々刻々と変化しており，その理解の深化を困難にしている．本研究では，高分子の吸着形態の変化，高分子を被覆した粒子の帯電と凝集速度の測定・解析を目指す.
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| Outline of Annual Research Achievements |
A novel technique for investigating the adsorption kinetics of water-soluble polymer onto a single particle was developed using microfluidics and optical tweezers. The adsorption kinetics of polyethylene oxide (PEO) and charged polyacrylamide-based polymer onto a silica particle in terms of layer thickness were studied. The long-range interaction forces between silica particles in aqueous solutions with different molecular weights of PEO were studied. The effect of different parameters such as pH, flow rate, salt concentrations, and particle size were evaluated. The adsorption of PEO onto silica particles was found to be highly dependent on the solution pH. The effect of pH was also found to be influenced by the flow rate. The thickness was observed to be independent of pH, while it was observed to decrease at a high flow rate and high pH. This is attributed to the decrease in the affinity between the silica surface and the polymer, in addition to the influence of fluid force. The effect of charge density and salt concentrations was studied. All polyelectrolytes exhibited dependence on salt concentration. The attractive interactions control the adsorption process of cationic polyelectrolytes. Meanwhile, the layer thickness is dependent on the charge density and salt concentration, due to the differences in the loop and tail conformation of the adsorbed polyelectrolyte. This presents a novel perspective in understanding polymer adsorption kinetics by directly evaluating the layer thickness on a single particle viewpoint that is not accessible to bulk measurements.
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| Research Progress Status |
令和4年度が最終年度であるため、記入しない。
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| Strategy for Future Research Activity |
令和4年度が最終年度であるため、記入しない。
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Report
(3 results)
Research Products
(11 results)
