Investigation of formation of silica-coated magnetite nanoparticles via sol–gel approach

Deng, Yonghui; Wang, Changchun; Hu, Jianhua; Yang, Wuli; Fu, Shoukuan

doi:10.1016/j.colsurfa.2005.04.009

Cited by 462 publications

(212 citation statements)

References 19 publications

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“…There are a number of methods reported for the removal of heavy metals, such as ion exchange (Deng et al 2005), filtration , precipitation (Chang and Chen 2005), membrane process, reverse osmosis (Xu et al 2012), sedimentation and electrochemical treatment (Kim et al 2001). Out of all the process, the membrane adsorption technique is the most preferable one for heavy metal ion removal.…”

Section: Introductionmentioning

confidence: 99%

Fabrication of chitosan–magnetite nanocomposite strip for chromium removal

et al. 2015

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Environmental pollution caused by heavy metals is a serious threat. In the present work, removal of chromium was carried out using chitosan-magnetite nanocomposite strip. Magnetite nanoparticles (Fe 3 O 4 ) were synthesized using chemical co-precipitation method at 80°C. The nanoparticles were characterized using UVvisible spectroscopy, fourier transform infrared spectroscopy, X-ray diffraction spectrometer, atomic force microscope, dynamic light scattering and vibrating sample magnetometer, which confirm the size, shape, crystalline nature and magnetic behaviour of nanoparticles. Atomic force microscope revealed that the particle size was 15-30 nm and spherical in shape. The magnetite nanoparticles were mixed with chitosan solution to form hybrid nanocomposite. Chitosan strip was casted with and without nanoparticle. The affinity of hybrid nanocomposite for chromium was studied using K 2 Cr 2 O 7 (potassium dichromate) solution as the heavy metal solution containing Cr(VI) ions. Adsorption tests were carried out using chitosan strip and hybrid nanocomposite strip at different time intervals. Amount of chromium adsorbed by chitosan strip and chitosan-magnetite nanocomposite strip from aqueous solution was evaluated using UV-visible spectroscopy. The results confirm that the heavy metal removal efficiency of chitosan-magnetite nanocomposite strip is 92.33 %, which is higher when compared to chitosan strip, which is 29.39 %.

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Section: Introductionmentioning

confidence: 99%

Fabrication of chitosan–magnetite nanocomposite strip for chromium removal

et al. 2015

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“…The systems may have magnetic cores with polymer or inorganic coating which can be functionalised, or may consist of porous polymers that contain magnetic nanoparticles precipitated within the pores [2][3][4].…”

Section: Introductionmentioning

confidence: 99%

Encapsulation of magnetic nanoparticles in a pH-sensitive poly(4-vinyl pyridine) polymer: a step forward to a multi-responsive system

Arizaga

Ibarz

Piñol

et al. 2012

Journal of Experimental Nanoscience

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A multiresponsive system that consists on pH-responsive polymer microspheres with encapsulated iron oxide magnetic nanoparticles that rendered the core magnetic to enable externally controlled actuation under magnetic induction has been developed. The inorganic nanoparticles were first prepared and, then, further encapsulated in a pH-sensitive poly(4-vinylpyridine). These spheres have been obtained by a modification of the simple, rapid and high-reproducible nanoprecipitation method. Magnetic measurements showed that the iron oxide nanoparticles are superparamagnetic and, therefore, able to undergo a local increase of the temperature when an oscillating magnetic field is applied. Magnetically triggered heating and pH sensitivity can be useful for biomedical applications.

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“…Fe 3 O 4 @SiO 2 NPs were prepared according to the Stöber method by applying some changes [10,21]. 50 ml of previously prepared magnetite liquid (1%) was dispersed ultrasonically and then added into a 500 ml three-necked flask which contained 40 ml distilled water, 120 ml ethanol, and 5 ml NH 4 OH (28%).…”

Section: Synthesis Of Nanoparticlesmentioning

confidence: 99%

“…Silica is the best known material to coat the surface of Fe 3 O 4 . Silica has a good mechanical and chemical stability and so silica coating provides Fe 3 O 4 NPs to stay stable and prevents to dissolve in acidic media [10]. Furthermore, silica is biocompatible and there are plenty of silane groups on the silica surface.…”

Section: Introductionmentioning

confidence: 99%

Synthesis, Characterization and Cr(VI) Adsorption Properties of Modified Magnetite Nanoparticles

2017

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In this study, magnetite (Fe3O4) nanoparticles were synthesized by chemical co-precipitation method, coated with silica, and then the surface of silica coated magnetite (Fe3O4@SiO2) nanoparticles was modified with (3-aminopropyl)triethoxysilane (APTES) at first. Secondly, attained nanoparticles were characterized by the Fourier transform infrared, X-ray diffraction, transmission electron microscopy, the Brunauer-Emmett-Teller, vibrating sample magnetometer, and zeta-sizer devices/methods. Finally, detailed adsorption experiments were performed to remove hexavalent chromium (Cr(VI)) from aqueous media by synthesized nanoparticles. Mean size and specific surface area of synthesized nanoparticles were about 15 nm and 89.5 m 2 /g, respectively. The highest adsorption capacity among used adsorbents (Fe3O4, Fe3O4@SiO2, Fe3O4@SiO2@L) was attained by Fe3O4 nanoparticles and it was determined that adsorption capacity of the other two adsorbents was too low when compared to the Fe3O4 nanoparticles. Optimum conditions for Cr(VI) adsorption by Fe3O4 nanoparticles were: pH, 3; temperature, 55• C; contact time, 90 min; adsorbent concentration, 0.5 g/l and initial Cr(VI) concentration 10 mg/l. Under these conditions, adsorption capacity and removal percentage of Cr(VI) were found to be 33.45 mg/g and 88%, respectively.

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Investigation of formation of silica-coated magnetite nanoparticles via sol–gel approach

Cited by 462 publications

References 19 publications

Fabrication of chitosan–magnetite nanocomposite strip for chromium removal

Fabrication of chitosan–magnetite nanocomposite strip for chromium removal

Encapsulation of magnetic nanoparticles in a pH-sensitive poly(4-vinyl pyridine) polymer: a step forward to a multi-responsive system

Synthesis, Characterization and Cr(VI) Adsorption Properties of Modified Magnetite Nanoparticles

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