화학공학소재연구정보센터
Journal of Crystal Growth, Vol.508, 34-41, 2019
Nanorod morphology control of iron oxide nanoparticles induced by ionic surfactants and their solid - liquid interfacial adsorption
Morphology control is an important aspect of nanomaterials for their appropriate use in different applications. In this study, we report the morphology control of iron oxide nanoparticles (NPs) by using a variety of crystal growth controlling agents in a simple hydrothermal method. Sodium dodecyl sulfate (SDS) and cetyltrimethylammonium bromide (CTAB) ionic surfactants proved to be excellent shape directing agents to produce fine magnetic nanorods whereas non-ionic surfactants and other bioactive molecules were unable to do so. Different techniques were applied to understand the mechanism of nanorod formation. It was attributed to strong solid - liquid interfacial adsorption of ionic surfactant molecules on {1 0 0}/{1 1 0} crystal planes of cubic lattice of growing nucleating centres to produce nanorod morphologies. XRD analysis clearly identified the magnetite nature of nanorods while XPS analysis helped in evaluating the amount and chemical composition of surface adsorbed molecules that were further related to the magnetic behavior. A compact and larger surface adsorption impeded the magnetization of nanorods and an optimum concentration of about 12 mM of SDS and CTAB was considered to be the best option to achieve both shape controlled synthesis as well as retaining appropriate magnetism.