Effect of the organically modified vermiculite clay loading on the rheological and flammability properties of biopolyethylene/vermiculite clay biocomposites

In this work, the effect of the vermiculite (VMT) clay loading on the rheological properties and flammability of bio-based high-density polyethylene/organically modified VMT (BioHDPE/OVMT) clay biocomposites containing 0.5–10 phr of OVMT clay was investigated. X-ray diffraction patterns showed that the BioHDPE was intercalated between the OVMT clay galleries. BioHDPE/OVMT biocomposites containing 5 and 10 phr of OVMT clay exhibited a shear-thinning behavior and a better dispersion/distribution in the BioHDPE matrix. The biocomposite containing 10 phr of organoclay presented a percolated network structure. The elastic modulus increased with the increase in the OVMT loading whereas the tensile and impact strength remained almost unaffected. For the biocomposites containing the unmodified VMT clay, the burning rate decreased with the increase in the VMT loading. The opposite was observed for the biocomposites containing OVMT clay.

α-Fe2O3 Nanoparticles/Vermiculite Clay Material: Structural, Optical and Photocatalytic Properties

Photocatalysis is increasingly becoming a center of interest due to its wide use in environmental remediation. Hematite (α-Fe2O3) is one promising candidate for photocatalytic applications. Clay materials as vermiculite (Ver) can be used as a carrier to accommodate and stabilize photocatalysts. Two different temperatures (500 °C and 700 °C) were used for preparation of α-Fe2O3 nanoparticles/vermiculite clay materials. The experimental methods used for determination of structural, optical and photocatalytic properties were X-ray fluorescence (ED-XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray spectrometry (EDS), N2 adsorption method (BET), diffuse reflectance UV-Vis spectroscopy (DRS), photoluminescence spectroscopy (PL) and photocatalytic reduction of CO2, respectively. The data from XRD were confronted with molecular modeling of the material arrangement in the interlayer space of vermiculite structure and the possibility of anchoring the α-Fe2O3 nanoparticles to the surface and edge of vermiculite. Correlations between structural, textural, optical and electrical properties and photocatalytic activity have been studied in detail. The α-Fe2O3 and α-Fe2O3/Ver materials with higher specific surface areas, a smaller crystallite size and structural defects (oxygen vacancies) that a play crucial role in photocatalytic activity, were prepared at a lower calcination temperature of 500 °C.

Synergistic effect of vermiculite clay and ionizing irradiation on the physical and mechanical properties of polybutadiene rubber/ethylene propylene diene monomer nanocomposite

Blends of rubber-rubber have desired properties intermediated between two rubber matrices. On the other hand, polymer-clay nanocomposites have attracted the attention of many researchers and experimental results are presented in a large number of recent papers and patents because of the outstanding mechanical properties and low gas permeability that are achieved in many cases. Polymer-clay nanocomposites are a new class of mineral-field polymer that contain relatively small amounts (<10%) of nanometer-sized clay particles. In this study, new nanocomposite materials were produced from the blend of polybutadiene rubber (BR) and ethylene propylene diene monomer rubber (EPDM), BR/EPDM (50/50) as matrix and organically modified vermiculite clay (VMT) by quaternary alkylammonium in different contents (3, 6, 9 and 12 phr) as the filler by using rubber mill then, the rubber nanocomposite sheets were irradiated at doses of 25, 50, 75, 100 and 150 kGy using γ-radiation technique as a crosslinking tool. The prepared composites can be characterized by using various analytical techniques including X-ray diffractometer (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) as well as mechanical properties measurements.