Synthesis of a bilayered SDS/ionic liquid stabilized ferrofluid and magnetic cubic mesoporous silica using a long chain ionic liquid

• Published in: New journal of chemistry 2022-12, Vol.47 (1), p.362-372
• Main Authors: Shen, Jing, Wang, Dongxiu, Yang, Li, Wang, Tongwen, Yang, Qianmo, Wang, Jun
• Format: Article
• Language: English
• Subjects: Decoloring; Ferrofluids; Ionic liquids; Ions; Iron oxides; Malachite green; Methylene blue; Nanoparticles; Nanostructured materials; Rhodamine; Silicon dioxide; Sodium dodecyl sulfate; Synthesis
• ISSN: 1144-0546; 1369-9261
• DOI: 10.1039/d2nj04958a

Bilayered sodium dodecyl sulfate (SDS)/ionic liquids (alkyl imidazolium type ionic liquid C n mim + , n = 10, 12, 14, and 16) were first employed to modify the surface of Fe 3 O 4 nanoparticles for the formation of stable aqueous ferrofluids. Subsequently, in the synthesized bilayered SDS/C 16 mim + -stabilized ferrofluid (Fe 3 O 4 /SDS/C 16 mim + ), magnetic mesoporous silica with a cubic ( Ia3d ) mesostructure (Fe 3 O 4 @MCM-48) has been synthesized using tetraethylorthosilicate as the silicon source and the long chain C 16 mim + as a template again. The research results showed that the combination of SDS and long chain C n mim + (such as C 16 mim + ) is superior to that of SDS and short chain C n mim + (such as C 10 mim + ) for the production of stable ferrofluids in water. Moreover, Fe 3 O 4 @MCM-48 (0.1 g) with Fe 3 O 4 particles embedded in the network of cubic mesoporous silica showed decolorization rates of up to ∼90% in 25 min for four dye (methylene blue, rhodamine B, malachite green, and methyl violet) solutions (50 mL, 100 mg L −1 ). In addition, the malachite green-adsorbed Fe 3 O 4 @MCM-48 can be separated and recovered under an external magnetic field. This method in which the long chain ionic liquid C 16 mim + can be manipulated in turn not only as the modifier but also as the mesoporous templating agent provides important guidelines for the multifunctional applications of C 16 mim + in the synthesis of various nanostructured materials. Magnetic cubic mesoporous silica can be synthesized using TEOS as a silicon source and ionic liquid C 16 mim + as a template.