Tunable Magnetic Arrangement of Iron Oxide Nanoparticles in Situ Synthesized on the Solid Substrate from Diblock Copolymer Micelles

Abstract

Hexagonal arrangement of iron oxide nanoparticles was fabricated by utilizing a single-layered film of diblock copolymer micelles. The synthesis was directly performed on the solid substrate by oxygen plasma with preserving the dimensional order of micelles so that separate procedures for synthesis and deposition of nanoparticles were not necessary. Since the oxygen plasma treatment also eliminated polymers, pure patterns of iron oxide nanoparticles were obtained. Moreover, easy control over the size of nanoparticles enabled us to selectively create a ferrimagnetic or a superparamagnetic pattern of iron oxide nanoparticles without altering the fabrication process.

Large Scale Monodisperse Hexagonal Arrays of Superparamagnetic Iron Oxides Nanodots: A Facile Block Copolymer Inclusion Method

“…The magnetic properties are quantified and are commensurate with well‐isolated, size monodisperse nanodots exhibiting superparamagnetism. Whilst related preparation techniques are available using BCP micelle methodology which not only involves complex co‐ordination chemistry to create iron oxide arrays, but also the products have been seldom characterised in terms of their phases and magnetism 1, 2. Here we demonstrate a much simpler technique using readily available chemicals that provides materials of greater structural order and size uniformity than micelle based techniques, where the magnetic parameters have been shown to be consistent with isolated nanoparticle systems.…”

“…Alternatively, self‐assembly techniques such as diblock copolymer (DBCPs) microphase separation can be used 14, 15. Ordered patterns of iron oxide have fabricated by using DBCP micellar films and selective chemical co‐ordination of a metal precursors to one polymer blocks 1, 2. DBCPs which form cylindrical microdomains (one block hexagonally arranged in a matrix of the other block) are particularly interesting as selective removal of the minor component can produce a nanoporous template for generating an ordered array of inorganic nanoparticles 16, 17.…”

Self-assembled block copolymers: Bulk to thin film

“…By varying the concentration of metal ion loading in PS-PVP micelles, Yun et al showed the size tuning of iron oxide 2D nanoparticle arrays. [441][442][443] Recently, highly ordered arrays of Au nanoparticle in large areas were successfully fabricated from block copolymer micelles. 444 Ethirajan et al fabricated ordered 2-D arrays of magnetically attractive FePt nanoparticles on a silicon substrate by a micellar approach.…”

Controlling Orientation and Functionalization in Thin Films of Block Copolymers

“…Alternatively, phase‐selective chemistries can be used to generate nanocomposites where inorganic materials can be incorporated selectively in only one microdomain of the BCP 14. Polystyrene‐ block ‐poly(4‐vinyl pyridine) (PS‐ b ‐P4VP) has been used for this, since inorganic materials can easily be incorporated into the P4VP microdomains via a quarternization of the nitrogen in the pyridine ring 14–21…”