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Interaction of Grafted Dextrin with a Hematite Surface: Effect of Functional Groups and Molecular Weight
Author(s) -
Saha Biswajit,
Patra Abhay S.,
Biswas Arijit,
Mukherjee Asim K.,
Paul Indrajit
Publication year - 2021
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.202102583
Subject(s) - dextrin , polyacrylic acid , density functional theory , hydrogen bond , chemistry , polymer , binding energy , adsorption , interaction energy , molecular orbital , computational chemistry , polymer chemistry , molecule , organic chemistry , physics , starch , nuclear physics
Abstract Reactive force field (ReaxFF) based molecular dynamics simulations were performed to study the interaction nature of grafted dextrin with hematite. Nature of interaction further explained by doing periodic density functional theory (DFT) calculations. It was observed that in presence of moisture, the polymer adsorbed on the hematite surface via hydrogen bond formation mediated by water. Upon heating, the interfacial water evaporated and boding interactions with the surface was were established. The oxygens present in the polymer backbone also took part in bonding interactions in addition to −COOH, −OH and −COOCH 3 functional groups. The binding energies were estimated as −35.8 (Dextrin), −42.6 (Dextrin grafted with polyacrylic acid) and −38.0 kcal/mol (Dextrin grafted with polyacrylic acid and poly (methyl acrylate)) which indicated chemisorption and effect of molecular weight. Grafted dextrin, having higher molecular weight exhibited stronger interaction and it is anticipated that it will have better thermal stability. Binding energy estimated from DFT calculations as −34.8 kcal/mol. DFT charge density difference calculation showed that the oxygen present in the ring polymer structure also interacted with Fe d‐orbitals.