•Addition of hindered amine increased thermal stability and viscosity of TTTM.•Addition of hindered amine improved the CO2 absorption performance of TTTM.•Good the CO2 absorption of recycled solvents after two regenerations.•Important role of amine group in CO2 absorption of TTTM confirmed by DFT analysis. Is it possible to improve CO2 solubility in potassium carbonate (K2CO3)-based transition temperature mixtures (TTMs)? To assess this possibility, a ternary transition-temperature mixture (TTTM) was prepared by using a hindered amine, 2-amino-2-methyl-1,3-propanediol (AMPD). Fourier transform infrared spectroscopy (FT-IR) was employed to detect the functional groups including hydroxyl, amine, carbonate ion, and aliphatic functional groups in the prepared solvents. From thermogravimetric analysis (TGA), it was found that the addition of AMPD to the binary mixture can increase the thermal stability of TTTM. The viscosity findings showed that TTTM has a higher viscosity than TTM while their difference was decreased by increasing temperature. In addition, Eyring’s absolute rate theory was used to compute the activation parameters (ΔG*, ΔH*, and ΔS*). The CO2 solubility in liquids was measured at a temperature of 303.15 K and pressures up to 1.8 MPa. The results disclosed that the CO2 solubility of TTTM was improved by the addition of AMPD. At the pressure of about 1.8 MPa, the CO2 mole fractions of TTM and TTTM were 0.1697 and 0.2022, respectively. To confirm the experimental data, density functional theory (DFT) was employed. From the DFT analysis, it was found that the TTTM+ CO2 system has higher interaction energy (|ΔE |) than the TTM+ CO2 system indicating the higher CO2 affinity of the former system. This study might help scientists to better understand and to improve CO2 solubility in these types of solvents by choosing a suitable amine as HBD and finding the best combination of HBA and HBD. 相似文献
Aluminum formate (AF), a degradable and non-corrosive coagulant, was synthesized from aluminum hydroxide and formic acid. Polyamidine (PA), as a coagulation aid, was combined with AF for dye wastewater treatment. AF was characterized by XPS, FT-IR, viscosity, zeta potential, mass spectrum and XRD, and the flocculation properties of the dual-coagulation system were characterized by FT-IR and SEM. The results showed that COOH, Al2O3-Al and O2-Al bonds were formed in the AF synthesis process, and AF had a higher molecular weight and higher charge neutralization ability than PAC. The hydrolysates of AF were determined to contain Al13 Al11 and Al2, and the components of AF were confirmed to comprise a mixture including aluminum formate (C3H3AlO6) and its hydrate. When the color removal efficiency reached 100% in jar tests, the optimized dosage of AF/PA was 18.91/0.71 mg/L, while the optimized dosage of PAC/PA was 21.19/0.91 mg/L. According to the variance analysis, the interaction between AF/PA and PAC/PA were insignificant in macroscopic view. FT-IR spectrum indicated AF captured pollutant by means of CCO bond, PAC captured pollutant by δ CH, CC and δ CH. Overall, although the coagulation mechanism of AF was different from that of PAC, AF/PA showed better coagulation efficiency than PAC/PA in dye wastewater treatment. 相似文献
As a preliminary step to preimplantation diagnosis of sickle cell disease in unfertilized eggs or 8-cell embryos of heterozygous parents, we established quality control for detection of the mutant and normal alleles of the beta-haemoglobin gene using single buccal cells. Efficient polymerase chain reaction (PCR) amplification of a 680 base pair sequence of the beta-globin gene spanning the site of the sickle cell mutation was obtained for 79 per cent of single heterozygous cells. In 71 per cent of cases, both alleles were detected. With this current efficiency, we predict that a clinical preimplantation diagnosis at the 8-cell embryo stage could be carried out safely and reliably for a couple at risk of transmitting sickle cell disease to their children. 相似文献