ABSTRACT
Red mud is a solid hazardous alumina industrial waste, which is rich in iron, titanium, aluminum, silicon, calcium, etc. The red mud contains 30-60% of hematite, which is suitable for shielding high energy X- and gamma rays. So, the iron rich red mud was converted into diagnostic X-ray shielding tiles through ceramic route by adding a certain weight percentage of BaSO4 and binders (kaolin clay or sodium hexametaphosphate) with it. The kaolin clay tile possess sufficient impact strength (failure point is 852â¯mm for 19â¯mm steel ball) and flexural strength of ~25â¯N/mm2, which is suitable for wall applications. The 10.3â¯mm and 14.7â¯mm thick red mud:BaSO4:kaolin clay tile possess the attenuation equivalent to 2â¯mm and 2.3â¯mm lead at 125 kVp and 140 kVp, respectively. No heavy elements were found to leach out except chromium and arsenic from the sintered tiles. However, the leaching of Cr (0.6 ppm) and As (0.015 ppm) was found to be well below the permissible limit. These tiles can be used in the X-ray diagnosis, CT scanner, bone densitometry, and cath labs instead of toxic lead sheet and thereby to protect the operating personnel, public, and environment from radiation hazards.
Subject(s)
Aluminum Oxide , Hazardous Waste , Ceramics , Industrial Waste/analysis , Iron , RadiographyABSTRACT
Copper oxide nanoparticles (CuO NPs)/multi-walled carbon nanotube (MWCNTs) nanocomposites were synthesized by a simple in-situ co-precipitation technique. MWCNTs networks acted as an ideal supporter for active material and permitted formation of free standing hybrid nanocomposite in the sheet form. Structural properties of CuONPs/MWCNTs nanocomposites were examined using X-ray diffraction (XRD), X-ray photon spectroscopy (XPS) and Transmission electron microscopy (TEM). By using three-electrode system, the electrochemical performance of the CuONPs/MWCNTs nanocomposite was investigated. The heat treated sample CuONPs/MWCNTs(H) yielded specific capacitance of 452.8 Fg-1 under 10 mV s-1 scan rate. Also, the nanocomposite exhibited good cyclic stability with 90% capacity retention over 500 charge-discharge cycles. This free-standing thin nanocomposite electrode can serve as a potential candidate as electrode for energy storage systems.
ABSTRACT
Flexible cotton fabric based electrodes were fabricated using multi-walled carbon nanotubes (MWCNTs) and manganese dioxide (MnO2) nanocomposite which was prepared using wet chemical synthesis. Characterization of CNT/MnO2 nanocomposite was done by Transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photon spectroscopy (XPS), Raman spectroscopy and BET analysis. Their electrochemical properties were investigated using three electrode systems. The high specific capacitance of 634.35 F/g was obtained for the nanocomposite coated cotton fabric prepared via dipping method. The high capacitance was attributed to its high specific surface area 678.9 m2/g. The electrode exhibited high cyclic performance showing retention of 84% of its initial capacity in 0.5 M sodium sulphate (Na2SO4) solution. The demonstrated high specific capacitance of CNT/MnO2 nanocomposite makes it a promising electrode material for energy storage applications due to its low cost and flexibility.
