Comparison of the Sorption of Trifluoromethane (R-23) on Zeolites and in an Ionic Liquid

In this study, trifluoromethane (R-23) has been adsorbed on three zeolites, namely 5A, LSX and 13X, and their adsorption isotherms have been measured at approximately 298 and 323 K using a gravimetric microbalance. All cases belong to the adsorption Type II (one of the six IUPAC classifications), and the adsorption (and desorption) processes are reversible. Three different adsorption models [original Langmuir, multi-site Langmuir and BET equations] have been adopted to analyze the data, with a particular interest in calculating the heat of adsorption (–ΔH), which was found to be about 10, 30 and 40 kJ·mol −1 for zeolite 5A, LSX and 13X, respectively. These values are within the range of typical physical adsorptions. Solubility of R-23 in ionic liquid 1-octyl-3-methylimidazolium 1,1,2,2-tetrafluoroethanesulfonate ([omim][TFES]) has been measured at approximately 298 and 323 K using the same gravimetric microbalance and the value was compared with the adsorption results. The solubility capacity of R-23 in ionic liquid reaches about 3 mol kg −1 around 2.5 MPa at 298 K, while the adsorption capacity on zeolites becomes around 3 mol kg −1 at around 0.25 MPa (ten times smaller). The adsorption on zeolites took more time than the absorption in the ionic liquid to reach thermodynamic equilibrium

The Synthesis of Silicon Carbide in Rhombohedral Form with Different Chemicals

This study describes the attempt at producing silicon carbide using a simpler and less costly method. Within the study, XRD, EDX, and FTIR analyses were performed to determine the structural properties of the product, and SEM analyses were used to identify its surface properties. The characteristics such as porosity and surface area were determined through BET analysis. The starting reagents were compared with the product using FTIR analysis, whereas the product was compared with a sample of SiC procured from a supplier who manufactures high-purity products through BET analysis. In EDX analysis, approximately 72 pct Si and 28 pct C were identified. The vibrational peaks of the synthesized product (characteristics Si-C bonds) were observed at around 1076 cm(-1) (FTIR analysis). At the same time, the outcomes were compared with major publications in the literature