The inclusion of multiwalled carbon nanotubes in a conjugated polymer matrix results in extensive alterations in the polymer morphology. When the physical state of a substance is changed, heat is either absorbed or liberated but the temperature remains constant. The flexibility of chain molecules arises from rotation round the saturated chain bond moreover the potential energy barriers hindering this rotation. It is not surprising therefore that the flexibility of polymer chains is an important factor in determining their melting points and stability. If the substitution of carbon nanotube is random the primary effect is a decrease in the degree of crystallinity. These microstructures are governed by the balance of interactions between hydrodynamic forces (both viscous and elastic) and the forces working to retain the integrity of the disperse particles, such as interfacial tension or, in the case of solid filler and their mechanical strength. Carbon materials have long been shown to absorb as much as 60 wt% hydrogen due to their large surface areas as well as their high surface to volume ratios. In the present approach conducting polyaniline was doped with metal oxide, such as SnO 2 , as well as carbon nanotubes. The resulting carbon nanocomposite was made in both gel-and solid-state to study the effect of physical state on hydrogen adsorption and desorption by weight percentage. The morphology formation process and its impact on the rheological properties of complex polymer systems, i.e. polymer blends and composites are being studied. The materials are also compared with regard to their thermal stability using DSC, and further characterized using various techniques such as FTIR. Further experiments are in progress to better understand the nature of the hydrogen storage mechanism.
The development of light weight hydrogen storage systems with high volumetric and gravimetric hydrogen densities is indeed essential for the on-board fuel cell vehicular applications [1]. Among the different hydrogen storage systems designed and developed so far, Ti- doped sodium aluminum hydrides exhibit potential promise of reversible hydrogen storage capacity (4-5 wt.%) at moderate temperatures [2,3]. However, the poor cyclic stability of these hydrides due to the partial reversibility of the two step reactions necessitates the development of exotic materials or tailoring the known hydride systems. On the other hand, transition metal complex hydrides, TMHx(T = Mg; M = Fe, Co, Ni) have also been identified as potential candidates for hydrogen storage [4-6] and/or analogous to alanates [7]. These hydrides especially Mg2FeH6, have shown excellent cyclic capacities (more than 500 cycles) even without a catalyst [8]. Besides, Mg2FeH6possesses the highest volumetric and gravimetric hydrogen densities of 150 kg/m3and 5.6 wt.% respectively [9]. However, at low temperatures, the rate of release of hydrogen and the effective reversible hydrogen capacity seems poor. Recent reports declared that the enhancement in the cycling kinetics and reduction in the operating temperature is very much possible by using a distorted nano-scale Mg structure [10, 11], doping the host lattice with Ti- species and/or lattice substitution [12]. Keeping these facts in view, the present investigation aims to improve the sorption kinetics and thermodynamics of Mg2FeH6, by 1) preparing nano-scale Mg-Fe-H system using mechano-chemical synthesis process, 2) surface localized catalyst (Ti- species) doping and 3) cationic substitution of Na+/Li+for Mg2+by incorporating NaH/LiH. The synergistic behavior of the tailored nano-scale transition metal complex for hydrogen storage is outlined.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.