Thermal stability of silica-coated magnetite nanoparticles prepared by an electrochemical method

Fauziatul Fajaroh; Heru Setyawan; Adrian Nur; I. Wuled Lenggoro

doi:10.1016/j.apt.2012.09.008

Thermal stability of silica-coated magnetite nanoparticles prepared by an electrochemical method

Fauziatul Fajaroh, Heru Setyawan^*, Adrian Nur, I. Wuled Lenggoro

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

56 Citations (Scopus)

Abstract

Magnetite nanoparticles have been prepared by electrooxidation of iron in water. Surface modifications have been conducted by coating the nanoparticles with silica by a one-step synthesis in dilute sodium silicate solution. The mean size of particles was approximately 10-30 nm for the uncoated particles and 9-12 nm for the coated particles. The results obtained from thermal gravimetric/differential thermal analysis (TG/DTA) revealed that the silica layer formed by the electrochemical method was stable and could serve as a protective layer. Annealing the nanoparticles at 550°C for 30 min converts magnetite into maghemite for the silica-coated particles, and it further converts the uncoated particles into hematite. The conversions cause the saturation magnetization to decrease for all samples.

Original language	English
Pages (from-to)	507-511
Number of pages	5
Journal	Advanced Powder Technology
Volume	24
Issue number	2
DOIs	https://doi.org/10.1016/j.apt.2012.09.008
Publication status	Published - Mar 2013

Keywords

Electrochemical method
Magnetite nanoparticles
Silica-coated
Thermal stability

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10.1016/j.apt.2012.09.008

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title = "Thermal stability of silica-coated magnetite nanoparticles prepared by an electrochemical method",

abstract = "Magnetite nanoparticles have been prepared by electrooxidation of iron in water. Surface modifications have been conducted by coating the nanoparticles with silica by a one-step synthesis in dilute sodium silicate solution. The mean size of particles was approximately 10-30 nm for the uncoated particles and 9-12 nm for the coated particles. The results obtained from thermal gravimetric/differential thermal analysis (TG/DTA) revealed that the silica layer formed by the electrochemical method was stable and could serve as a protective layer. Annealing the nanoparticles at 550°C for 30 min converts magnetite into maghemite for the silica-coated particles, and it further converts the uncoated particles into hematite. The conversions cause the saturation magnetization to decrease for all samples.",

keywords = "Electrochemical method, Magnetite nanoparticles, Silica-coated, Thermal stability",

author = "Fauziatul Fajaroh and Heru Setyawan and Adrian Nur and Lenggoro, {I. Wuled}",

note = "Funding Information: We would like to thank the Directorate General of Higher Education (DGHE), the Ministry of Education and Culture, Indonesia, for funding and for the financial support for one of the authors (F.F.) to obtain a doctorate through BPPS and to visit the Tokyo University of Agriculture and Technology as a research fellow via a Sandwich-Like Program. We also thank Ms. Doris Nekesha for her assistance with the experiments.",

year = "2013",

month = mar,

doi = "10.1016/j.apt.2012.09.008",

language = "English",

volume = "24",

pages = "507--511",

journal = "Advanced Powder Technology",

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T1 - Thermal stability of silica-coated magnetite nanoparticles prepared by an electrochemical method

AU - Fajaroh, Fauziatul

AU - Setyawan, Heru

AU - Nur, Adrian

AU - Lenggoro, I. Wuled

N1 - Funding Information: We would like to thank the Directorate General of Higher Education (DGHE), the Ministry of Education and Culture, Indonesia, for funding and for the financial support for one of the authors (F.F.) to obtain a doctorate through BPPS and to visit the Tokyo University of Agriculture and Technology as a research fellow via a Sandwich-Like Program. We also thank Ms. Doris Nekesha for her assistance with the experiments.

PY - 2013/3

Y1 - 2013/3

N2 - Magnetite nanoparticles have been prepared by electrooxidation of iron in water. Surface modifications have been conducted by coating the nanoparticles with silica by a one-step synthesis in dilute sodium silicate solution. The mean size of particles was approximately 10-30 nm for the uncoated particles and 9-12 nm for the coated particles. The results obtained from thermal gravimetric/differential thermal analysis (TG/DTA) revealed that the silica layer formed by the electrochemical method was stable and could serve as a protective layer. Annealing the nanoparticles at 550°C for 30 min converts magnetite into maghemite for the silica-coated particles, and it further converts the uncoated particles into hematite. The conversions cause the saturation magnetization to decrease for all samples.

AB - Magnetite nanoparticles have been prepared by electrooxidation of iron in water. Surface modifications have been conducted by coating the nanoparticles with silica by a one-step synthesis in dilute sodium silicate solution. The mean size of particles was approximately 10-30 nm for the uncoated particles and 9-12 nm for the coated particles. The results obtained from thermal gravimetric/differential thermal analysis (TG/DTA) revealed that the silica layer formed by the electrochemical method was stable and could serve as a protective layer. Annealing the nanoparticles at 550°C for 30 min converts magnetite into maghemite for the silica-coated particles, and it further converts the uncoated particles into hematite. The conversions cause the saturation magnetization to decrease for all samples.

KW - Electrochemical method

KW - Magnetite nanoparticles

KW - Silica-coated

KW - Thermal stability

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DO - 10.1016/j.apt.2012.09.008

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VL - 24

SP - 507

EP - 511

JO - Advanced Powder Technology

JF - Advanced Powder Technology

IS - 2

ER -

Thermal stability of silica-coated magnetite nanoparticles prepared by an electrochemical method

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Keywords

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