Abnormal transmittance of refractive-index-modified ZnO/organic hybrid films

The refractive index of ZnO/organic nanocomposite films was modified in the range from 1.44 to 1.55, while maintaining high visible transparency. The transparency of the nanocomposite films showed an abnormal behaviour as a function of the loading level of inorganic particles, because it did not decrease according to the Beer-Lambert law, but rather saturated to a near-constant value at high particle loading levels above 8 vol.-%. On the other hand, the refractive index of the film showed good agreement with the Bruggemann model, linearly increased as particle concentration increased. This result indicates the possibility of fabricating highly transparent nanocomposite films with controlled refractive indices.

Abnormally high optical transmittance of refractive-index modified ZnO / organic hybrid films

Hybrid films consisting of ZnO nanoparticles and organic matrices were fabricated at particle concentration levels of up to 60 wt%. The correlation between the refractive index and optical transmittance in the visible light region was investigated. The refractive index of the hybrid films was modified in a continuous manner in the range from 1.44 to 1.55. The refractive index increased linearly as a function of particle concentration. On the other hand, optical transmittance showed little change above the particle volume fraction of 0.08.

Mild and cost-effective synthesis of iron fluoride-graphene nanocomposites for high-rate Li-ion battery cathodes

Exploring high performance cathode materials is essential to realize the adoption of Li-ion batteries for application in electric vehicles and hybrid electric vehicles. FeF3, as a typical iron-based fluoride, has been attracting considerable interest due to both the high electromotive force value of 2.7 V and the high theoretical capacity of 237 mA h g_1 (1e_ transfer). In this study, we report a facile lowtemperature solution phase approach for synthesis of uniform iron fluoride nanocrystals on reduced graphene sheets stably suspended in ethanol solution. The resulting hybrid of iron fluoride nanocrystals and graphene sheets showed high specific capacity and high rate performance for iron fluoride type cathode materials. High stable specific capacity of about 210 mA h g_1 at a current density of 0.2 C was achieved, which is much higher than that of LiFePO4 cathode material. Notably, these iron fluoride/ nanocomposite cathode materials demonstrated superior rate capability, with discharge capacities of 176, 145 and 113 mA h g_1 at 1, 2 and 5 C, respectively.

Development of hybrid composites for automotive applications: effect of addition of SEBS on the morphology, mechanical, viscoelastic, crystallization and thermal degradation properties of PP/PS-xGnP composites

In this article, we report on a simple and cost effective approach for the development of light-weight, super-tough and stiff material for automotive applications. Nanocomposites based on PP/PS blend and exfoliated graphene nanoplatelets (xGnP) were prepared with and without SEBS. Mechanical, crystallization and thermal degradation properties were determined and correlated with phase morphology. The addition of xGnP to PP/PS blend increased the tensile modulus at the expense of toughness. The presence of xGnP increased the enthalpy of crystallization and enthalpy of fusion of PP in the blends, without affecting segmental mobility and thermal stability. Addition of polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene (SEBS) improved the toughness of PP/PS blends, but decreased the stiffness. The incorporation of xGnP into this ternary blend generated a super-tough material with improved stiffness and tensile elongation, suitable for automotive applications. It is observed that the presence of SEBS diminished the tendency of agglomeration of xGnP and their unfavorable interactions with thermoplastics, which in turn reduced the internal friction in the matrix.

Crystalline polymorph transition in poly(vinylidene fluoride) (PVDF)/acrylic rubber(ACM)/clay partially miscible hybrid

This study investigates the intercalation of nanoclay in partially miscible blends of poly(vinylidene fluoride) (PVDF) and acrylic rubber(ACM). Transmission electron microscopy and X-ray diffraction technique were used to investigate the formation of nanoscale polymer blend/clay hybrids. Using Infrared spectroscopy and X-ray analysis, the different polymorph formation in PVDF nanocomposite and conjugated phases of partially miscible nanocomposite was studied. Nanoclay was found to induce β and γ polymorphs while ACM tend to induce α phase in this polymer system. It was shown that PVDF chains in ACM-rich phase of partially miscible nanocomposites interact with ACM chains which in return form α polymorph in the presence of ACM. Further observations revealed that nanoclay in α polymorph is wrapped by ACM molecules.

The role of SEBS in tailoring the interface between the polymer matrix and exfoliated graphene nanoplatelets in hybrid composites

Nanocomposites of polypropylene (PP) and polypropylene/styrene-(ethylene-co-butylene)-styrene triblock copolymer (SEBS) blends with exfoliated graphene nanoplatelets (xGnP) were prepared by melt-mixing method. The incorporation of xGnP increased the stiffness and crystallinity of PP at the expense of toughness and the molecular mobility. The effect of addition of SEBS on the mechanical, viscoelastic, thermal degradation and crystallization properties of PP/xGnP composites was studied. The addition of SEBS into PP transformed the phase structure and distribution of xGnP in the PP matrix. SEM micrographs revealed that SEBS polymer chains formed a coating over the graphene nanoplatelets, which strengthened the interface between the filler and the matrix, and improved the dispersion and distribution of the filler throughout the matrix.