Numerical Study of the Interplay of Monomer-Surface Electrostatic and Non-electrostatic Interactions in the Adsorption of Weak Polyelectrolytes on Oppositely Charged Surfaces

• Published in: Chinese journal of polymer science Vol. 34; no. 5; pp. 552 - 562
• Main Authors: Li, Hai-ming, Chen, Yu-wei, Zhu, Yue-jin, Tong, Chao-hui
• Format: Journal Article
• Language: English
• Published: Beijing Chinese Chemical Society and Institute of Chemistry, CAS 01.04.2016
• Subjects: Adsorption; Bulk density; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Condensed Matter Physics; Density; Electrostatics; Industrial Chemistry/Chemical Engineering; Ionization; Polymer Sciences; Salt effect; Surface charge; Surface chemistry; 体表面; 数值研究; 相互作用强度; 相反电荷; 聚电解质; 表面吸附; 表面电荷密度; 静电相互作用; Non-electrostatic interaction; Self-consistent field theory; Polyelectrolyte adsorption
• ISSN: 0256-7679; 1439-6203
• DOI: 10.1007/s10118-016-1780-x

The adsorption of weak polybase on oppositely charged planar surfaces has been investigated numerically by using the self-consistent field theory（SCFT）. Particular attention was paid to the interplay of monomer-surface electrostatic and non-electrostatic interactions in the adsorption behaviors of weak polybase. In this study, the strength of monomer-surface non-electrostatic interactions was set to be no more than the thermal energy kBT. It was found from the numerical study that in the regime of low surface charge density of the substrate and low p H or high bulk degree of ionization, both the screeningenhanced and screening-reduced salt effects emerge. On the contrary, in the opposite regime, only the screening-reduced salt effect was observed. Moreover, the overall charge neutrality inside the adsorption layer was analyzed. The underlying mechanism governing the adsorption behaviors of weak polybase on oppositely charged surfaces was elucidated.