Christoulaki Anastasia, Lairez Didier, Dubois Emmanuelle, Jouault Nicolas
Sorbonne Université, CNRS, Laboratoire PHENIX, F-75005 Paris, France.
Laboratoire des Solides Irradiés (LSI), École Polytechnique, CNRS, CEA, Institut Polytechnique de Paris, 91128 Cedex Palaiseau, France.
ACS Macro Lett. 2020 Jun 16;9(6):794-798. doi: 10.1021/acsmacrolett.0c00172. Epub 2020 May 18.
It remains a great experimental challenge to obtain quantitative information on the polyelectrolyte (PE) behavior confined in charged nanoporous materials. Here, we propose an original approach using transverse streaming potential measurements (TSPMs), an efficient technique providing information on the electrical surface properties of nanoporous materials through the ζ-potential determination. We conduct TSPMs within the thin double-layer approximation on a model system composed of individual nanochannels, a nanoporous anodic aluminum oxide (AAO) membrane, filled with a well-known PE, sodium polystyrenesulfonate (NaPSS). We demonstrate that TSPMs can provide the AAO ζ-potential under different experimental conditions and monitor the PE penetration in AAO with positive or negative surface charge. On the positive surface, the PE irreversibly adsorbs, while it does not when the surface is negatively charged, indicating the electrostatic nature of the PE adsorption. In the context of experimental limitations to investigate PE behavior on concave surfaces, this study shows that the TSPM is suitable to extract quantitative information and can be exploited to gain an understanding of the PE adsorption and desorption in a confined medium.
获取关于受限在带电纳米多孔材料中的聚电解质（PE）行为的定量信息仍然是一个巨大的实验挑战。在此，我们提出一种使用横向流动电势测量（TSPM）的原创方法，这是一种通过ζ电位测定提供纳米多孔材料电表面性质信息的有效技术。我们在由单个纳米通道组成的模型系统——填充有著名的聚电解质聚苯乙烯磺酸钠（NaPSS）的纳米多孔阳极氧化铝（AAO）膜——上，在薄双电层近似范围内进行TSPM。我们证明TSPM可以在不同实验条件下提供AAO的ζ电位，并监测带正电荷或负电荷表面的AAO中PE的渗透情况。在正表面上，PE不可逆吸附，而当表面带负电荷时则不会，这表明了PE吸附的静电性质。鉴于在研究PE在凹面上的行为时存在实验限制，本研究表明TSPM适用于提取定量信息，并且可用于了解受限介质中PE的吸附和解吸情况。
