Molecular Modeling of Polymeric Adsorbent Media: The Effects of Counter-Ions on Ligand Immobilization and Pore Structure


Molecular dynamics modeling and simulations are employed to study the immobilization of ligands on the surface of the pores of a base porous polymeric matrix. The results show the significant effects that the counter-ions have on the spatial distribution of the density of immobilized ligands as well as on the pore size and pore connectivity distributions of the porous adsorbent medium being constructed. The results for the systems studied in this work indicate that by using doubly charged counter-ions whose numbers during ligand immobilization are half to those of singly charged counter-ions, the ligand immobilization process proceeds faster and the magnitude of local nonelectroneutrality becomes smaller. More importantly, the pore structures of the adsorbent media resulting from the system using doubly charged counter-ions have porous structures that are characterized by more mid-sized pores and higher pore connectivity than the porous adsorbent structures generated by the system employing singly charged counter-ions and, furthermore, the density distribution of the immobilized ligands in the porous structures where doubly charged counter-ions are employed tends to be more uniform laterally and the ligands are surrounded by fewer counter-ions. These characteristics affected by the use of doubly charged counter-ions could provide important advantages with respect to the transport and adsorption of adsorbate biomolecules of interest. Furthermore, the results of this work indicate that the type of counter-ions being used in the ligand immobilization process could represent an additional control variable for affecting the ligand density distribution as well as the pore size and pore connectivity distributions of the porous structure of the adsorbent medium being constructed.


Chemical and Biochemical Engineering

Keywords and Phrases

Additional Control; Counter-Ion Effects; Counterions; Density Distributions; Immobilized Ligands; Ligand Density; Ligand Immobilization; Molecular Dynamics Modeling; Polymeric Adsorbent; Polymeric Matrices; Pore Connectivity; Porous Adsorbent; Porous Structures; Adsorption; Computer Simulation; Ions; Molecular Dynamics; Polymers; Pore Size; Pore Structure; Ligands; Adsorbent; Chemical Procedures; Density; Ligand Immobilization; Molecular Model; Particle Size; Porosity; Ions; Ligands; Models, Chemical; Counter-Ion Effects on Ligand Immobilization; Counter-Ion Effects on Non-Electroneutrality; Counter-Ion Effects on Pore Structure; Polymeric Adsorbent Media; Pore Size Distribution

International Standard Serial Number (ISSN)

1615-9306; 1615-9314

Document Type

Article - Journal

Document Version


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© 2012 Wiley-Blackwell, All rights reserved.

Publication Date

01 Nov 2012

PubMed ID