Effect of Additives on CO2 Adsorption of Polyethylene Polyamine-Loaded MCM-41.

Organic amine-modified mesoporous carriers are considered potential CO2 sorbents, in which the CO2 adsorption performance was limited by the agglomeration and volatility of liquid amines. In this study, four additives of ether compounds were separately coimpregnated with polyethylene polyamine (PEPA) into MCM-41 to prepare the composite chemisorbents for CO2 adsorption. The textural pore properties, surface functional groups and elemental contents of N for MCM-41 before and after functionalization were characterized; the effects of the type and amount of additives, adsorption temperature and influent velocity on CO2 adsorption were investigated; the amine efficiency was calculated; and the adsorption kinetics and regeneration for the optimized sorbent were studied. For 40 wt.% PEPA-loaded MCM-41, the CO2 adsorption capacity and amine efficiency at 60 °C were 1.34 mmol/g and 0.18 mol CO2/mol N, when the influent velocity of the simulated flue gas was 30 mL/min, which reached 1.81 mmol/g and 0.23 mol CO2/mol N after coimpregnating 10 wt.% of 2-propoxyethanol (1E). The maximum adsorption capacity of 2.16 mmol/g appeared when the influent velocity of the simulated flue gas was 20 mL/min. In addition, the additive of 1E improved the regeneration and kinetics of PEPA-loaded MCM-41, and the CO2 adsorption process showed multiple adsorption routes.

Fabrication of Fe-wings used for micro imprinting with a natural butterfly wing structure by in situ carbothermic reduction.

We demonstrate a simple and promising method for the preparation of large-area natural microstructured Fe-wings which combines biotemplating and biomimetic techniques using natural structures as templates. The replicas were robust and hydrophobic, and also possessed excellent magnetic properties. The micro-structures of the wing scales were accurately retained. Then these replicas were used as stamps to transcribe their micro-structures to the surface of polydimethylsiloxane (PDMS), and the stamps were subsequently separated from the PDMS with ease by a magnet. In this method, as the samples are not detached from the PDMS elastomer by mechanical means, the microstructure of PDMS is not destroyed, and levels of anti-counterfeiting can be improved distinctly by adjusting the imprinting parameters.