Directed Assembly of Bifunctional Silica–Iron Oxide Nanocomposite with Open Shell Structure

• Published in: ACS applied materials & interfaces 2014-10, Vol.6 (19), p.16508-16518
• Main Authors: Che, Hui Xin, Yeap, Swee Pin, Osman, Mohamed Syazwan, Ahmad, Abdul Latif, Lim, JitKang
• Format: Article
• Language: English
• Subjects: Amoxicillin - isolation & purification; Anti-Bacterial Agents - isolation & purification; Ferric Compounds - chemistry; Hydrodynamics; Light; Microscopy, Atomic Force; Molecular Weight; Nanocomposites - chemistry; Osmolar Concentration; Polyethylenes - chemistry; Quartz Crystal Microbalance Techniques; Quaternary Ammonium Compounds - chemistry; Scattering, Radiation; Silicon Dioxide - chemistry; Static Electricity
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/am5050949

The synthesis of nanocomposite with controlled surface morphology plays a key role for pollutant removal from aqueous environments. The influence of the molecular size of the polyelectrolyte in synthesizing silica–iron oxide core–shell nanocomposite with open shell structure was investigated by using dynamic light scattering, atomic force microscopy, and quartz crystal microbalance with dissipation (QCM-D). Here, poly­(diallydimethylammonium chloride) (PDDA) was used to promote the attachment of iron oxide nanoparticles (IONPs) onto the silica surface to assemble a nanocomposite with magnetic and catalytic bifunctionality. High molecular weight PDDA tended to adsorb on silica colloid, forming a more extended conformation layer than low molecular weight PDDA. Subsequent attachment of IONPs onto this extended PDDA layer was more randomly distributed, forming isolated islands with open space between them. By taking amoxicillin, an antibiotic commonly found in pharmaceutical waste, as the model system, better removal was observed for silica–iron oxide nanocomposite with a more extended open shell structure.