title: Coating of magnetite with mercapto modified rice hull ash silica in a one-pot process.
abstract: In this research, mercapto-silica coated magnetite (Fe3O4-SiO2-SH) has been prepared in aqueous solution through a simple approach so called a one-pot process. The Fe3O4-SiO2-SH was prepared in nitrogen condition by mixing magnetite, 3-mercaptopropyltrimethoxysilane (MPTMS), and sodium silicate (Na2SiO3) solution extracted from rice hull ash, and adjusting the pH of 7.0 using hydrochloric acid. The residue was washed with deionized water, dried at 150°C and separated with an external magnetic field. In that work, the volume of MPTMS and Na2SiO3 was varied and the total amount of Si represented as silica was kept constant. Characters of the material including the functional group presence, the structure, the porosity, the morphology and stability toward various solvents were identified and evaluated. Results of characterization indicated that mercapto-silica has been coated magnetite particle with a simple one-pot process. Coating mercapto-silica on magnetite increases particle size, surface area, and chemical stability. Additionally, Fe3O4-SiO2-SH also shows high stability toward various organic solvents. The magnetic property of magnetite does not change after coating and the addition of nonmagnetic material still gives high value of maximum saturation magnetization. The presence of mercapto groups effective for interaction with heavy metal ions, the high chemical stability without removing the magnetic property promises the prospective application of Fe3O4-SiO2-SH in the future such as for separation and removal of heavy metal ions from aquatic environments.
authors.affiliation: Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada, Yogyakarta, 55281 Indonesia.
authors.forename: Nuryono
authors.initials: N
authors.lastname: Nuryono
authors.affiliation: Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada, Yogyakarta, 55281 Indonesia.
authors.forename: Nur
authors.initials: N
authors.lastname: Mutia Rosiati
authors.affiliation: Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada, Yogyakarta, 55281 Indonesia.
authors.forename: Bambang
authors.initials: B
authors.lastname: Rusdiarso
authors.affiliation: Division of Environmental Science Development, Graduate School of Environmental Earth Science, Hokkaido University, Hokkaido, Japan.
authors.forename: Satya Candra Wibawa
authors.initials: SC
authors.lastname: Sakti
authors.affiliation: Division of Environmental Science Development, Graduate School of Environmental Earth Science, Hokkaido University, Hokkaido, Japan ; Division of Environmental Material Science, Graduate School of Environmental Earth Science, Hokkaido University, Hokkaido, Japan.
authors.forename: Shunitz
authors.initials: S
authors.lastname: Tanaka
keywords: Coating; Magnetite; One-pot process; Rice; Silica