  Well Shaped Mn(3)O(4) Nano-octahedra with Anomalous Magnetic Behavior and Enhanced Photodecomposition Properties; ; et al in Small : Nano Micro (2011), 7(4), 475-483 Very uniform and well shaped Mn(3)O(4) nano-octahedra are synthesized using a simple hydrothermal method under the help of polyethylene glycol (PEG200) as a reductant and shape-directing agent. The nano ... [more ▼] Very uniform and well shaped Mn(3)O(4) nano-octahedra are synthesized using a simple hydrothermal method under the help of polyethylene glycol (PEG200) as a reductant and shape-directing agent. The nano-octahedra formation mechanism is monitored. The shape and crystal orientation of the nanoparticles is reconstructed by scanning electron microscopy and electron tomography, which reveals that the nano-octahedra only selectively expose {101} facets at the external surfaces. The magnetic testing demonstrates that the Mn(3)O(4) nano-octahedra exhibit anomalous magnetic properties: the Mn(3)O(4) nano-octahedra around 150 nm show a similar Curie temperature and blocking temperature to Mn(3)O(4) nanoparticles with 10 nm size because of the vertical axis of [001] plane and the exposed {101} facets. With these Mn(3)O(4) nano-octahedra as a catalyst, the photodecomposition of rhodamine B is evaluated and it is found that the photodecomposition activity of Mn(3)O(4) nano-octahedra is much superior to that of commercial Mn(3)O(4) powders. The anomalous magnetic properties and high superior photodecomposition activity of well shaped Mn(3)O(4) nano-octahedra should be related to the special shape of the nanoparticles and the abundantly exposed {101} facets at the external surfaces. Therefore, the shape preference can largely broaden the application of the Mn(3)O(4) nano-octahedra. [less ▲] Detailed reference viewed: 28 (7 ULg)From polyester grafting onto POSS nanocage by ring-opening polymerization to high performance polyester/POSS nanocomposites; ; et al in Journal of Materials Chemistry (2010), 20 Polyester-grafted polyhedral oligomeric silsesquioxane (POSS) nanohybrids selectively produced by ring-opening polymerization of epsilon-caprolactone and L,L-lactide (A.-L. Goffin, E. Duquesne, S. Moins ... [more ▼] Polyester-grafted polyhedral oligomeric silsesquioxane (POSS) nanohybrids selectively produced by ring-opening polymerization of epsilon-caprolactone and L,L-lactide (A.-L. Goffin, E. Duquesne, S. Moins, M. Alexandre, Ph. Dubois, Eur. Polym. Journal, 2007, 43, 4103) were studied as ‘‘masterbatches’’ by melt-blending within their corresponding commercial polymeric matrices, i.e., poly(epsilon-caprolactone) (PCL) and poly(L,L-lactide) (PLA). For the sake of comparison, neat POSS nanoparticles were also dispersed in PCL and PLA. The objective was to prepare aliphatic polyester-based nanocomposites with enhanced crystallization behavior, and therefore, enhanced thermo-mechanical properties. Wide-angle X-ray scattering and transmission electron microscopy attested for the dispersion of individualized POSS nanoparticles in the resulting nanocomposite materials only when the polyester-grafted POSS nanohybrid was used as a masterbatch. The large impact of such finely dispersed (grafted) nanoparticles on the crystallization behavior for the corresponding polyester matrices was noticed, as evidenced by differential scanning calorimetry analysis. Indeed, well-dispersed POSS nanoparticles acted as efficient nucleating sites, significantly increasing the crystallinity degree of both PCL and PLA matrices. As a result, a positive impact on thermo-mechanical properties was highlighted by dynamic mechanical thermal analysis. [less ▲] Detailed reference viewed: 8 (0 ULg) |
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