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Extractant impregnated polyethersulfone beads have been prepared by phase inversion method and investigated for yttrium recovery from aqueous medium. The effect of experimental parameters on yttrium sorption has been studied. Quantitative sorption of yttrium (> 90%) was attained after 8 hours of equilibration time in the case of D2EHPA impregnated composite beads. Analysis of sorption data by different kinetic and diffusion models suggested that the sorption of Y(III) followed the pseudo-second order model. Stability tests with polymeric composite beads by multiple cycles of sorption and desorption of Y(III) have established the feasibility of reusing the beads for sorption of metal ions.

The separation of entrained di-nonyl phenyl phosphoric acid (DNPPA) from merchant grade phosphoric acid (MGA) by adsorption on the coconut shell based activated charcoal has been carried out. The effect of various process parameters, such as DNPPA concentration in aqueous phase of MGA, equilibrium time, amount of activated charcoal and temperature upon adsorption capacity of activated charcoal has been studied. The results showed that the adsorption equilibrium was reached after 240 minutes. The adsorption phenomenon followed pseudo-second order kinetics. Adsorption of DNPPA increased with initial concentration of DNPPA in the range of 50 to 200 mg/L. The experimental data fitted well with the Freundlich isotherm model. Decrease in adsorption with increase in temperature suggests that the adsorption process is exothermic in nature. The value of enthalpy change (ΔH = −35.52 kJ/mol) indicated that DNPPA adsorption on activated charcoal is a physisorption phenomenon. Column operation was carried out to obtai...

Semiconducting carbon nanofibers (CNF) were prepared from three different sources, i.e., acetylene, ethanol, and cotton by the chemical vapor deposition (CVD) process at 850°C. CNF was then activated with KOH to attain high surface area. The characteristic study of the CNF was done to get information about the structure by SEM, TEM, and XRD. Activated CNF showed presence of more pores than non‐activated ones (in CNF from all 3 precursors), thus increasing the reactive surface area. Resistivity of activated CNFs was measured by the two‐probe method. An increase in hydrogen adsorption isotherm was recorded in activated CNF. The maximum hydrogen adsorption was noted in CNF obtained from cotton that showed the semiconducting nature; it was around 0.65 wt.% at 11 Kg/cm2 and 3 wt.% at 135 Kg/cm2. Whereas acetylene and alcohol‐derived CNF showed only 0.51 wt.% and 0.42 wt.% hydrogen adsorption respectively; maybe it was because they had less available surface area. Moreover, the negative TCR was lowest in cotton...

Carbon based materials and clusters can have various structures and properties. Apartfromcrystalline and ordered forms ofcarbon,a wide variety ofdisordered formsofcarbon are there.These disordered or amorphouscarbons are of importance in many applications as well as in basic research. Carbon black and glassy carbon are well known forms of disordered carbon and are widely used in industries. There is also a potential application for disordered carbon as a scatterer material in a low temperature thermal nuclear reactor. Depending on precursor materials and processing parameters, amorphous carbons can have different structures. Investigations from various researchers have revealed a variety ofstructural models fromthe turbostratic model to paracrystalline,schwartzite or quinoidal models. The bonding nature also varies from sp2 to sp3 or a mixture of both. Different techniques are used to characterise these disordered carbons depending on their uses. It includes diffraction studies, microscopy, spectr...