Adsorption kinetics of polyacrylamide-based polyelectrolyte onto a single silica particle studied using microfluidics and optical tweezers
Adsorption kinetics of polyacrylamide-based polyelectrolyte onto a single silica particle studied using microfluidics and optical tweezers
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使用微流体和光镊研究聚丙烯酰胺基聚电解质在单个二氧化硅颗粒上的吸附动力学
DOI：
10.1016/j.jcis.2022.10.067
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发表时间：
2023
影响因子：
9.9
通讯作者：
Adachi Yasuhisa
中科院分区：
文献类型：
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作者：
Geonzon Lester C.;Kobayashi Motoyoshi;Sugimoto Takuya;Adachi Yasuhisa
假设聚电解质吸附被认为是重要的调整表面性质和命运的颗粒；然而，通常在宏观表面上进行研究。为了深入了解聚电解质是如何吸附到单个颗粒上的，必须利用能够在受控流场中阐明单颗粒水平吸附动力学的技术。实验采用电泳迁移率测量方法，结合微流体和光学镊子的单粒子动力学研究，研究了聚电解质的吸附动力学。我们直接评估了吸附在带负电的二氧化硅颗粒上的聚电解质的厚度δH，以推断吸附的聚电解质的构象。研究了电荷密度和盐浓度的影响。结果：所有聚电解质均表现出与δ汉盐浓度的相关性。吸引相互作用控制着阳离子聚电解质的吸附过程。δ h依赖于电荷密度，表明弱电荷聚电解质有更多的环和尾确认。阴离子聚电解质表现出δ hon盐浓度的初始速率和饱和值的依赖性，这归因于带电段与二氧化硅表面之间的排斥。在这里，我们提出了对聚电解质吸附动力学的新见解，特别是从单粒子的角度来看静电相互作用的影响，这是传统体积测量无法达到的。
HypothesisPolyelectrolyte adsorption is considered important in tuning the surface property and the fate of particles; however, often studied on macroscopic surfaces. To gain insights into how polyelectrolytes are adsorbed onto a single particle, it is imperative to utilize techniques capable of elucidating adsorption kinetics on a single-particle level in a controlled flow field.ExperimentsThe polyelectrolyte adsorption kinetics was investigated by electrophoretic mobility measurements combined with the kinetics study onto a single-particle viewpoint using microfluidics and optical tweezers. We directly evaluated the thickness,δH, of adsorbed polyelectrolyte onto a negatively-charged silica particle to deduce the adsorbed polyelectrolyte’s conformation. The effect of charge density and salt concentrations were studied.FindingsAll polyelectrolytes exhibited dependence ofδHon salt concentration. The attractive interactions control the cationic polyelectrolytes adsorption process. TheδHdepends on charge density indicating more loops and tail confirmation for the weakly-charged polyelectrolytes. The anionic polyelectrolytes showed a dependence of the initial rate and saturation value ofδHon salt concentrations, attributed to the repulsion between charged segments and the silica surfaces. Here, we present new insights into the polyelectrolyte adsorption kinetics, particularly the influence of electrostatic interaction from the single-particle perspective, inaccessible to conventional bulk measurements.