title: Vast magnetic monolayer film with surfactant-stabilized Fe3O4 nanoparticles using Langmuir-Blodgett technique.
abstract: Although several methods (e.g., self-assembly, spin coating, etc.) have been explored for making a monolayer film of nanoparticles, the monolayer on a substrate is typically smaller than 1 micromx1 microm in certain regions. The approach is not ideally suitable for generating a highly ordered and close-packed homogeneous vast monolayer of nanoparticles, which is potentially important for applications. In this report, the preparation of the vast monolayer films of Fe3O4 nanoparticles with a wide range such as that over 3.25 micromx3.95 microm is reported. Their TEM images showed a two-dimensional assembly of Fe3O4 nanoparticles, demonstrating the uniformity of these nanoparticles. The formation of a Langmuir monolayer of the oleic acid-coated Fe3O4 nanoparticles mixed with stearic acid molecules at the air/water interface and its stability were studied with a pressure-area isotherm curve. TEM and BAM studies demonstrated that increasing surface pressure resulted in a transition from well-separated domains of nanoparticles complex to well-compressed, monoparticulate layers.
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: Don Keun
authors.initials: DK
authors.lastname: Lee
authors.forename: Young Hwan
authors.initials: YH
authors.lastname: Kim
authors.forename: Chang Woo
authors.initials: CW
authors.lastname: Kim
authors.forename: Hyun Gil
authors.initials: HG
authors.lastname: Cha
authors.forename: Young Soo
authors.initials: YS
authors.lastname: Kang
mesh_terms: D005290:Ferric Compounds / Q000737:chemistry*; D008280:Magnetics; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D046529:Microscopy, Electron, Transmission; D013501:Surface-Active Agents / Q000737:chemistry*; D013696:Temperature; D014961:X-Ray Diffraction
chemical_list: D005290:Ferric Compounds; D013501:Surface-Active Agents; C000499:ferric oxide