A technique to solubilize fine magnetic inorganic particles in general organic solvents is proposed via surfaces modification by long-chain carboxylic acids. This organic modification should overcome the relatively weak van der Waals interactions between the nanoparticles, allowing the formation of ordered arrangements of the modified Fe3O4 and CoFe2O4 materials. Using nanodispersions of these organo-modified magnetic nanoparticles as "spreading solutions", Langmuir monolayers of these particles were formed. Multiparticle layered structures were constructed by the Langmuir-Blodgett (LB) technique. The fabrication of single- and multiparticle layers of organo-modified magnetic nanoparticles was investigated using surface pressure-area (π-A) isotherms, out-of-plane X-ray diffraction (XRD), in-plane XRD, and atomic force microscopy (AFM). The out-of-plane XRD profile of a single-particle layer of organo-modified Fe3O4 clearly showed a sharp peak which was attributed to the distance between Fe3O4 layers along the c-axis. The AFM image of single-particle layer of organo-modified CoFe2O4 revealed integrated particle organization with a uniform height; these aggregated particles formed large two-dimensional crystals. For both nanoparticle species, regular periodic structures along the c-axis and high-density single-particle layers were produced via the Langmuir and LB techniques.

No abstract

No abstract

A transparent and flexible crystalline polymer nanohybrid was fabricated, containing well-dispersed magnetic nanoparticles (MNPs) with organic chainmodified surfaces. The partially fluorinated copolymer matrix used is composed of switchboard-type lamellae. These become transparent owing to the creation of high-density amorphous regions on drawing the corresponding film at just below the polymer melting point. Although the creation of oleo-and hydrophobic fluorinated polymer/organo-modified MNP nanohybrids is generally difficult, formation via melt compounding was confirmed using wide-angle X-ray diffraction and thermal analysis. On organo-modification of the hydroxyl-terminated MNP surface with long-chain fatty acids, the resulting improvement in wettability aids the dispersion of the particles and hence maintains transparency. Nano-dispersion of the organo-filler was considered to result from surface modification-induced improvement of particle miscibility and melt compounding. These nanohybrids have enhanced thermal degradation temperatures and mechanical properties, derived from the nucleation effect caused by the adsorption of the terminal polymer chains onto the organic modifier. POLYM. COMPOS., 00:000-000, FIG. 2. (a) DSC thermogram of neat P(VDF-TeFE) and (b) TG curves of oMNPs with estimated values of surface-modification rate. [Color figure can be viewed at wileyonlinelibrary.com] FIG. 4. (a) Photographs of drawn (five times) and undrawn P(VDF-TeFE) nanohybrids containing 0.2 wt% oMNPs. (b) Schematic illustration of the changes in lamellae arrangement by the high-temperature drawing. [Color figure can be viewed at wileyonlinelibrary.com] 6 POLYMER COMPOSITES-2017 FIG. 5. (a) WAXD profiles of organo-Fe 3 O 4 (5 nm), neat P(VDF-TeFE), and P(VDF-TeFE) nanohybrids containing 0.2 and 0.5 wt% organo-Fe 3 O 4 (5 nm). (b) Schematic illustration of the layered structure of oMNPs, and their dispersion state in the matrix. [Color figure can be viewed at wileyonlinelibrary.com] FIG. 7. (a) The content of oMNPs in the polymer matrix versus crystallite size obtained with the Scherrer equation. (b) Schematic illustration of the changes in crystallite size along the ab-plane induced by oMNP addition. [Color figure can be viewed at wileyonlinelibrary.com]

No abstract