Wettability of cellulose surfaces under the influence of an external electric field

Karna, Nabin Kumar; Jakob Wohlert; Anna Liden; Tuve Mattssson; Hans Theliander

Abstract

Hypothesis Interfacial tensions play an important role in dewatering of hydrophilic materials like nanofibrillated cellulose, and are affected by the molecular organization of water at the interface. Application of an electric field influences the orientation of water molecules along the field direction. Hence, it should be possible to alter the interfacial free energies to tune the wettability of cellulose surface though application of an external electric field thus, aiding the dewatering process. Simulations Molecular dynamics simulations of cellulose surface in contact with water under the influence of an external electric field have been conducted with GLYCAM-06 forcefields. The effect of variation in electric field intensity and directions on the spreading coefficient has been addressed via orientational preference of water molecules and interfacial free energy analyses. Findings The application of electric field influences the interfacial free energy difference at the cellulose-water interface. The spreading coefficient increases with the electric field directed parallel to the cellulose-water interface while it decreases in the perpendicular electric field. Variation in interfacial free energies seems to explain the change in contact angle adequately in presence of an electric field. The wettability of cellulose surface can be tuned by the application of an external electric field.

Más información

Título de la Revista: JOURNAL OF COLLOID AND INTERFACE SCIENCE
Editorial: Elsevier
Fecha de publicación: 2021
URL: https://www.sciencedirect.com/science/article/abs/pii/S0021979721000060