Surface functionalization of magnetite nanoparticle: A new approach using condensation of alkoxysilanes

Abstract

In this study we report on successful production of two samples (BR15 and BR16) comprising magnetite (Fe 3 O 4) nanoparticles (~10 nm) surface-functionalized via hydrolysis and condensation of alkoxysilane agents, namely 3-aminopropyl-trimethoxisilane (APTS) and N-propyl-trimethoxisilane (NPTS). The as-produced samples were characterized using transmission electron microscopy (TEM), x-ray diffraction (XRD), magnetization measurements (5 K and 300 K hysteresis cycles and zero field-cooled/field-cooled measurements), and Mössbauer spectroscopy (77 and 297 K). The Mössbauer data supported the model picture of a core-shell magnetite-based system. This material system shows shell properties influenced by the surface-coating design, either APTS-coated (BR15) or APTS+NPTS-coated (sample BR16). Analyses of the Mössbauer spectra indicates that the APTS-coated sample presents Fe(III)-rich core and Fe(II)-rich shell with strong hyperfine field; whereas, the APTS+NPTS-coated sample leads to a mixture of two main nanostructures, one essentially surfaceterminated with APTS whereas the other surface-terminated with NPTS, both presenting weak hyperfine fields compared with the single surface-coated sample. Magnetization measurements support the core-shell picture built from the analyses of the Mössbauer data. Our findings emphasize the capability of the Mössbauer spectroscopy in assessing subtle differences in surface-functionalized iron-based core-shell nanostructures.

Life Cycle Assessment of Functionalized Bionanocompounds with Ice Nucleation Protein for Freezing Applications

“…Several studies have shown that magnetite nanoparticles exhibit great potential for the development of new materials, mainly due to their magnetic properties and the possibility of functionalizing their surface with different agents such as enzymes [ 8 ], biopolymers [ 9 ], organic particles [ 10 ], chelating moieties [ 11 ], and alkoxysilanes [ 12 ]. Similarly, silica nanoparticles have drawn significant attention due to their stability, low toxicity, and ability to be functionalized with a range of molecules and polymers, which can form improved biomaterials from various hybrid nanomaterials [ 13 ].…”

NiS2@MoS2 Nanospheres Anchored on Reduced Graphene Oxide: A Novel Ternary Heterostructure with Enhanced Electromagnetic Absorption Property

“…As is well known, nanomaterials with core–shell and york–shell structures have high interfacial polarization due to the synergistic effects of both the cores and shells [ 8 , 22 , 23 , 24 , 25 ]. Therefore, a number of studies have explored nanomaterials with core–shell and york–shell structures to achieve high EM wave absorbing performances [ 26 , 27 ].…”