Hydrothermal assisted synthesis of iron oxide-based magnetic silica spheres and their performance in magnetophoretic water purification

Abstract

h i g h l i g h t s g r a p h i c a l a b s t r a c t < Homogeneous and controlled size porous magnetic silica spheres were obtained. < Magnetophoretic removing of Ni 2þ processes was successfully preformed at HLGMF. < PMS show higher Ni 2þ removing capacity than spheres without hydrothermal treatment. < PMS can be used for the capturation of bio-species using metal adsorption mechanism.a b s t r a c t Porous Magnetic Silica (PMS) spheres of about 400 nm diameter were synthesised by one-pot process using the classical Stӧber method combined with hydrothermal treatment. Maghemite nanoparticles (g-Fe 2 O 3 ) were used as fillers and cetyltrimethylammonium bromide (CTAB) was used as templating agent. The application of the hydrothermal process (120 C during 48 h) before the calcination leads to the formation of homogeneous and narrow size distribution PMS spheres. X-ray diffraction patterns (XRD), Infrared measurements (FTIR) and Transmission Electron microscopy (TEM) methods were used to determine the composition and morphology of the obtained PMS spheres. The results show a homogeneous distribution of the g-Fe 2 O 3 nanoparticles in the silica matrix with a "hollow-like" morphology. Magnetophoresis measurements at 60 T m À1 show a total separation time of the PMS spheres suspension of about 16 min. By using this synthesis method, the limitation of the formation of silica spheres without incorporation of magnetic nanoparticles is overcome. These achievements make this procedure interesting for industrial up scaling. The obtained PMS spheres were evaluated as adsorbents for Ni 2þ in aqueous solution. Their adsorption capacity was compared with the adsorption capacity of magnetic silica spheres obtained without hydrothermal treatment before calcination process. PMS spheres show an increase of the adsorption capacity of about 15% of the initial dissolution of Ni 2þ without the need to functionalize the silica surface.

An introduction to nanoparticles and nanotechnology

“…Nanospheres and microspheres containing a magnetic core For more details about the preparation and characterization of these composites see [22,23].…”

Advances in steady-state continuous-flow purification by small-scale free-flow electrophoresis

“…Free-flow magnetophoresis separates particle analytes from a stream of sample, which is driven continuously through a magnetic field and typically orientated orthogonally to the flow. Magnetophoresis, in free-flow form, has been applied to the separation of cancer cells from normal cells [17,18], DNA purification [19], water purification [20,21], and nanoparticle (NP) purification [22].…”

Magnetic solid‐phase extraction for determination of sulpiride in human urine and blood using high‐performance liquid chromatography

“…The application of the proposed synthetic Fe 3 O 4 @SiO 2 MNPs to extract the sulpiride from human urine and blood for HPLC/DAD analysis was compared with Fe 3 O 4 MNPs and conventional HPLC/DAD analysis. Figure 7 (Li et al, 2010;Caparros et al, 2012). This approach prevents the agglomeration of particles as well as providing an environment for the transfer of hydrophobic iron oxide nano-particles into a hydrophilic system (Wang and Yao, 2010).…”