Processible Optically Transparent Block Copolymer Films Containing Superparamagnetic Iron Oxide Nanoclusters

Abstract

Free-standing block copolymer films containing magnetic iron oxide nanoclusters within the microdomains were produced by static casting. The thickness of the nanocomposite films was easily controlled to make optically transparent thin films. The size distribution of the nanoclusters was relatively narrow and the nanoclusters were uniformly distributed within the films. The spherical nanoclusters, ca. 5 nm in diameter, were identified as γ-Fe2O3 and had a well-defined crystalline structure. Magnetic measurements revealed that the nanocomposite films are superparamagnetic.

Synthesis and characterization of high molecular weight carboxylated polybutadiene

“…Such nanocomposites can possess superparamagnetic properties and optical transparency in the UV-visible range. 22,23 In this article, we report on the synthesis and characterization of high molecular weight (M n from 100 to 200 K) cPBDs by hydrocarboxylation of PBDs.…”

Selective preparation of novel fluoroalkyl end-capped co-oligomeric nanocomposite-encapsulated magnetites and magnetite-adsorbing co-oligomeric nanoparticles

“…So far, numerous synthetic and natural polymers have been used to obtain stable colloidal dispersions of magnetic nanoparticles by coating and encapsulating the particles. [22][23][24][25][26][27][28][29][30][31] It is well known that fluorinated surfactants have excellent surface characteristics, including oleophobicity and hydrophobicity, neither of which can be achieved with corresponding nonfluorinated polymers. 32 Thus, it is of particular interest to develop new, tailored magnetic fluorinated polymer colloids that possess not only good dispersibility in various solvents but also the unique active surface characteristics imparted by fluorine.…”

Transparent, Superparamagnetic K${{{\rm I}\hfill \atop x\hfill}}$Co${{{\rm II}\hfill \atop y\hfill}}$[FeIII(CN)6]–Silica Nanocomposites with Tunable Photomagnetism

“…[2,3] A parallel interest also exists in the development of nanocomposite structures containing nanoscale magnetic particles exhibiting single-domain magnetic behavior. [4][5][6] Investigations of magnetic nanocomposites is driven by their novel properties and their potential as new magnetic, optical, and electronic materials. With one exception, [7] however, the Prussian blue class of magnetic materials has not been produced as nanoparticles, and, to the best of our knowledge, there have been no reports of their incorporation into composite structures.…”

“…With one exception, [7] however, the Prussian blue class of magnetic materials has not been produced as nanoparticles, and, to the best of our knowledge, there have been no reports of their incorporation into composite structures. Herein we report the fabrication of a new nanocomposite material containing K x Co II y [Fe III (CN) 6 ] z , a ferromagnetic analogue of Prussian blue, in a porous silica matrix. This material is made by a controlled multicomponent sol-gel synthesis in which the precipitation of the Prussian blue analogue is arrested at nanoscale dimensions by gelation of the silica network.…”

“…To determine whether the magnetic behavior was singular, the magnetic susceptibility of these materials was measured as a function of temperature and field strength. [10] 6 ] z (M I = alkali-metal cation) shows ferromagnetic behavior in its field-cooled (FC) magnetization, with a Curie temperature of 14.0 K. [11,12] However, this complex, along with other first-row Prussian blue analogues, also shows blocking behavior in the zero-field-cooled (ZFC) magnetization, which has been attributed to spin-glass properties arising from defects in the lattice. [13,14] While it might be expected that a dilute dispersion 6 ] z in a xerogel would exhibit only simple paramagnetic behavior, the FC and ZFC magnetization as a function of temperature for a 0.03 mol % Co II /Fe III xerogel (Figure 2 a) indicates more complex behavior.…”