| 現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
The project aimed to understand the adsorption kinetics of the water-soluble polymer onto colloidal particles from the viewpoint of the single-particle level. We have successfully developed a novel technology to investigate the kinetics of polymer adsorption onto a single colloidal particle using an optical tweezer and microfluidics. The kinetics were evaluated using different parameters such as polymer concentration, volumetric flow rate, pH, particle size, and molecular weight. Moreover, the dynamics of particle aggregation with adsorbed PEO were studied using force measurement via optical tweezers.
The effect of water-soluble, nonionic polymer on electric double-layer (EDL) was investigated in terms of the long-range interaction forces between silica particles of different sizes using optical tweezers. Different molecular weights of polyethylene oxide (PEO) with higher silica affinity were used. Based on the force measurements using optical tweezers, we emphasize that the adsorption of nonionic polymer onto the surface of the silica particles does not affect the EDL surrounding the particles. These are important pieces of information to understand the flocculation dynamics of colloidal particles with adsorbed polymer layer.
The kinetics adsorption of similar and oppositely charged polyelectrolytes was also investigated using single-particle adsorption studies and electrophoretic mobility analysis. The effect of homopolymer and copolymer on the flocculation and stabilization of colloidal silica was also studied. This is an ongoing experiment.
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| 今後の研究の推進方策 |
Based on the developed methodology, we will investigate in detail the kinetics of polyelectrolyte adsorption onto the silica particle from a single particle viewpoint. The effect of salt, polymer concentration, and types of polyelectrolytes on the kinetics of adsorption to colloidal particles will be investigated using optical tweezers, microfluidic and electrophoretic mobility analysis. Adsorption of polyelectrolytes with opposite and similar charge properties with the colloidal particles will be explored. The dynamics of aggregation of colloidal particles with adsorbed polyelectrolyte will be investigated using the force measurements between two different size particles, which is crucial for the fate of wastewater particulates.
The utilization of biopolymers with different functional properties as novel natural-based polymeric flocculants will be evaluated. Different biopolymers, i.e., carrageenans, pectin, etc., will be used. The adsorption kinetics of biopolymers on the surface of the colloidal particles will be analyzed using optical tweezers, microfluidics, and electrophoretic mobility analysis. The effect of the molecular weight will also be studied by controlling the molecular weight of biopolymers using physical and chemical depolymerization procedures.
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