International Letters of Chemistry, Physics and Astronomy Vol. 86

Abstract: This paper studies the classical restricted three-body problem of a carbon atom in the vicinity of two carbon 60 fullerenes (  fullerenes) at the nanoscale. The total molecular energy between the two fullerenes is determined analytically by approximating the pairwise potential energies between the carbon atoms on the fullerenes by a continuous approach. Using software MATHEMATICA, we compute the positions of the stationary points and their stability for a carbon atom at the nanosacle and it is observed that for each set of values, there exists at least one complex root with the positive real part and hence in the Lyapunov sense, the stationary points are unstable. Since only attractive Van der Waals forces contribute to the orbiting behavior, no orbiting phenomenon can be observed for , where the Van der Waals forces becomes repulsive. Although the  orbital is speculative in nature and also presents exciting possibilities, there are still many practical challenges that would need to be overcome before the  orbital might be realized. However, the present theoretical study is a necessary precursor to any of such developments.

Abstract: The prospective of maize cob powder (MCP) as an effective adsorbent for the removal of malachite green (MG) and congo red (CR) dyes from aqueous solution was investigated. The presence of functional groups and pores on maize cob powder were confirmed by FTIR and SEM analysis. Batch adsorption studies were conducted and various parameters such as contact time, adsorbent dosage, initial dye concentration, pH and temperature were examined to observe their effects in the dyes adsorption process. The optimum conditions for the adsorption of MG and CR onto the adsorbent (MCP) was found to be: contact time (60mins), pH (10.0) and temperature (303 K), adsorbent dose (1 g) for an initial MG dye concentration of 50 mg/L and contact time (80mins), pH (2.0) and temperature (343 K) for an initial CR dye concentration of 50 mg/L and adsorbent dose 1.0 g respectively. The experimental equilibrium adsorption data fitted best and well to the Freundlich isotherm model for CR dye adsorption and Langmuir Isotherm for MG adsorption. The maximum adsorption capacity was found to be 13.02 mg/g and 9.41 mg/g for the adsorption of MG and CR dyes respectively. The kinetic data conformed to the pseudo-second-order kinetic model. Thermodynamic quantities such as Gibbs free energy (ΔG⁰), enthalpy (ΔH⁰) and entropy (ΔS⁰) were evaluated and the negative values of ΔG⁰, ΔH⁰ and ΔS⁰ obtained indicated the spontaneous and exothermic nature of the MG adsorption process while positive enthalpy (ΔH⁰) indicated an endothermic nature of CR adsorption process.