TY - JOUR A1 - Hetti, M. A1 - Wei, Q. A1 - Casperson, Ralf A1 - Pohl, Rainer A1 - Bartusch, M. A1 - Neu, V. A1 - Pospiech, D. A1 - Voit, B. T1 - Magnetite core-shell nanoparticles in nondestructive flaw detection of polymeric materials N2 - Nondestructive flaw detection in polymeric materials is important but difficult to achieve. In this research, the application of magnetite nanoparticles (MNPs) in nondestructive flaw detection is studied and realized, to the best of our knowledge, for the first time. Superparamagnetic and highly magnetic (up to 63 emu/g) magnetite core-shell nanoparticles are prepared by grafting bromo-end group-functionalized poly(glycidyl methacrylate) (Br-PGMA) onto surface-modified Fe3O4 NPs. These Fe3O4-PGMA NPs are blended into bisphenol A diglycidylether (BADGE) based epoxy to form homogeneously distributed magnetic epoxy nanocomposites (MENCs) after curing. The core Fe3O4 of the Fe3O4-PGMA NPs endows the MENCs with magnetic property, which is crucial for nondestructive flaw detection of the materials, while the shell PGMA promotes colloidal stability and prevents NP aggregation during curing. The eddy current testing (ET) technique is firstly applied to detect flaws in the MENCs. Through the brightness contrast of the ET image, surficial and sub-surficial flaws in MENCs can be detected, even for MENCs with low content of Fe3O4-PGMA NPs (1 wt %). The incorporation of Fe3O4-PGMA NPs can be easily extended to other polymer and polymer-based composite systems and opens a new and very promising pathway toward MNP-based nondestructive flaw detection in polymeric materials. KW - Magnetite nanoparticles KW - Poly(glycidyl methacrylate) KW - Atom transfer radical polymerization KW - Magnetic nanocomposites KW - Nondestructive flaw detection PY - 2016 U6 - https://doi.org/10.1021/acsami.6b09934 SN - 1944-8244 SN - 1944-8252 VL - 8 IS - 41 SP - 28208 EP - 28215 PB - American Chemical Society CY - Washington, DC AN - OPUS4-38300 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tran, V. C. A1 - Nguyen, V. H. A1 - Tuma, Dirk A1 - Shim, J.-J. T1 - Ionic liquid mediated synthesis of poly(2-hydroxyethyl methacrylate-block-methyl methacrylate)/Fe3O4 core–shell structured nanocomposite by ATRP method N2 - A hybrid nanocomposite of magnetic nanoparticles (Fe3O4) and poly(2-hydroxyethyl methacrylate)-blockpoly(methyl methacrylate) (PHEMA-b-PMMA) was synthesized successfully by the atom transfer radical polymerization (ATRP) in an ionic liquid (IL), 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim]PF6). Fe3O4 nanoparticles were first surface-modified with the initiator, 2-bromoisobutyryl bromide (BiBBr), in dimethylformamide (DMF) solvent, which produced the macro-initiator, Fe3O4-BiB, to initiate the polymerization reactions for the synthesis of the block polymer, PHEMA-b-PMMA. After immobilizing the Initiator on the surface of Fe3O4, the block polymer chains were grafted successfully onto the Fe3O4 surface, causing the Formation of a core-shell nanostructure. The incorporation of Fe3O4 in the nanocomposite was confirmed by attenuated total reflectance-Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, thermogravimetric analysis, and X-ray photoelectron spectroscopy. The thermal stability and magnetic properties increased with increasing amount of Fe3O4 in the nanocomposite. KW - Nanocomposite KW - Block copolymer KW - Fe3O4 nanoparticles KW - Ionic liquid KW - Atom transfer radical polymerization PY - 2016 U6 - https://doi.org/10.1007/s00396-016-3835-5 SN - 1435-1536 SN - 0303-402X VL - 294 IS - 4 SP - 777 EP - 785 PB - Springer International Publishing AG CY - Berlin AN - OPUS4-35893 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -