Heat repellent behavior of cobalt‐based imidazole containing phosphate and meta‐phosphate complex mixtures

Abstract

Four different mixtures such as complex mixture A, [Co(H 2 O) 4 (HPO 4 )] (C 3 H 4 N 2 )(H 2 O) 2 Á 0.2 (C 3 H 4 N 2 ), complex mixture B, [Co(H 2 O) 6 ](H 2 PO 4 )(OH) (H 2 O) Á(C 3 H 4 N 2 ) 2 , mixture C, 0.34 Co(PO 3 ) 2 Á0.15(C 3 H 3 N 2 Na), and complex mixture D, 0.03Co(PO 3 ) 2 Á0.25(C 3 H 3 N 2 Na) Á0.1 [Co(H 2 O) 6 ]SO 4 .H 2 OÁ0.6 (C 3 H 4 N 2 ), were synthesized using ortho-phosphoric acid and meta-phosphoric acid with cobalt sulfate heptahydrate and imidazole in ambient conditions. These mixtures have been well characterized by different thermo-analytical techniques. Differential Scanning Calorimetry (DSC) has been carried out at different heating rates such as 5, 10, 20, and 30 K min −1 at atmospheric conditions. The specific heat capacity was measured at low temperatures up to 173 K for mixture C at a rate of 10 K min −1 . From the thermal analysis, it can be observed that the complex mixtures A and B prepared using phosphoric acid and mixture C prepared using meta-phosphoric acid behave as heat repellent material owing to their exothermic behavior at high temperature. The anomalous negative specific heat capacity exhibited by the mixtures is explained using partial molar quantities. Among all the four complex mixtures, the complex mixture A has been found to be the best heat repellent material.The complex mixture B can be used as heat storage material up to temperature $550 K due to its endothermic behavior. These phosphate materials can be used for longer period of time due to their stability and insolubility in aqueous media. The heat can be extracted from any system that is coated with these phosphate mixtures using high conductivity copper rod. K E Y W O R D SDSC, heat repellent material, negative heat capacity, partial molar quantities | INTRODUCTIONConsumption of energy has increased exponentially over the years in all aspects of human life. Because of this, the modern technological man is striving hard to explore all possible options to cater to the ever-increasing demand for energy. Conventional energy reserves, viz. coal and fossil fuels, have already been exploited to their maximum extent and their collateral impacts of environmental pollution and global warming leading to climate change. It is indeed essential to scout around various viable sources of renewable energy, such as extracting

Investigation on the Thermo-Oxidative Degradation of Polyethylene, Poly(vinyl chloride), and Polystyrene Using NiPIm1.5 and NiPIm2 Nanocomposites

“…18 The bands ascribed to the bending mode of P−O are in good accordance with the published literature by Rudrarapu and Aravind. 17,19 The stretching vibration of C  N is shifted from 1675 to 1584 cm −1 in NiPIm 1.5 and to 1586 cm −1 in NiPIm 2 . The stretching frequency of C−N is shifted from 1250 to 1178 cm −1 in NiPIm 1.5 and to 1180 cm −1 in NiPIm 2 .…”