Publication: Complex interplay between the physicochemical properties of nanoscale zerovalent iron (nzvi).
| datacite.subject.fos | oecd::Engineering and technology::Chemical engineering | |
| dc.contributor.author | Ng, Wei Ming | |
| dc.date.accessioned | 2026-11-11T07:41:11Z | |
| dc.date.available | 2026-11-11T07:41:11Z | |
| dc.date.issued | 2025-03 | |
| dc.description.abstract | The complex interplay between surface functionalization, colloidal stability, chemical reactivity, magnetophoresis, and transport characteristics of nanoscale zerovalent iron (nZVI) introduces significant complexity to its practical applications, especially as it undergoes behavioral changes after reactions. Despite its importance, systematic studies on these post-reaction transformations remain limited. This study aims to bridge this gap by examining the interdependencies among these physicochemical properties, with a particular focus on the underexplored post-reaction transformations. To achieve this, surface-functionalized nZVI particles were prepared by simultaneous adsorption of polyelectrolytes, such as carboxymethyl cellulose (CMC) and polyethylene glycol (PEG), onto nanoparticles synthesized via the liquid phase reduction of ferric salt solution by sodium borohydride. A simple model reaction system involving the degradation of methyl orange (MO) dye by nZVI was employed to investigate the reactivity of the functionalized iron nanoparticles and the subsequent impacts on transport behavior. Later, (1) sedimentation, (2) low-gradient magnetophoresis and (3) sand column transport studies were conducted on both bare and functionalized nZVI particles before and after reaction to elucidate their behavioral changes. Results revealed that the presence of the adsorbed polymer layer significantly suppressed the reactivity of nZVI toward MO degradation. However, the consumption of metallic iron-content during the reaction led to a reduction in magnetic properties, thereby enhancing the colloidal stability of both bare and functionalized nZVI particles. Consequently, reacted particles exhibited slower sedimentation, reduced magnetophoretic velocity and improved mobility across the sand column, consistent with the predictions by the extended Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. Besides, quartz crystal microbalance with dissipation (QCM-D) measurements highlighted the significant contribution of viscoelasticity on the aggregates formed by both bare and functionalized nZVI particles after reaction, influencing their transport behavior across the sand column. This observation coincided with the changes in the surface properties of the reacted functionalized particles, potentially attributed to the entrapment of degraded products within the polymer adlayer. Notably, both bare and functionalized nZVI particles exhibited the formation of a thicker and softer adlayer on the silica surface after the reaction compared to their unreacted counterparts. Finally, the implementation of high gradient magnetic trap was proposed as a control strategy for nZVI application in both aqueous and soil environments. This study shed light on the complex interplay among the physicochemical properties of bare and surface functionalized nZVI particles, focusing on their behavioral changes after reacting with pollutant and developing a magnetophoretic-based solution for effectively controlling and confining nZVI within a targeted remediation site. | |
| dc.identifier.uri | https://erepo.usm.my/handle/123456789/25406 | |
| dc.language.iso | en | |
| dc.title | Complex interplay between the physicochemical properties of nanoscale zerovalent iron (nzvi). | |
| dc.type | Resource Types::text::thesis::doctoral thesis | |
| dspace.entity.type | Publication | |
| oairecerif.author.affiliation | Universiti Sains Malaysia |