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As reported previously, novel ZnO nanostructures can be grown by oxidation of [MeZnO tBu]4 'building blocks' with O3 in ionic liquids (ILs). In this study, we have explored the role of the IL during ZnO formation by in-situ infrared reflection absorption spectroscopy (IRAS) in ultrahigh vacuum (UHV). [MeZnO tBu]4 and [C2C1Im][OTf] were (co-)deposited as thin films by physical vapor deposition (PVD) onto Au(111), separately or simultaneously. The IR spectrum of [MeZnO tBu]4 was analyzed between 300 and 4000 cm-1 based on calculated spectra from density-functional theory (DFT). Spectral changes in the IL-related bands during the thermal treatment of [MeZnO tBu]4 in [C2C1Im][OTf] indicate the loss of the precursor ligands and the interaction of the IL with the growing ZnO aggregates. The films were treated with ozone (10-6 mbar) in UHV and the spectral changes were monitored in-situ by IRAS. Slow ozonolysis of [C2C1Im][OTf] is observed. Spectroscopically we identify the primary ozonide formed by addition of O3 to [C2C1Im]+ and suggest a reaction mechanism, which leads to a biuret derivative. Upon ozone treatment of mixed [MeZnO tBu]4/[C2C1Im][OTf] films, ZnO aggregates are formed at the IL/vacuum interface. Ozonolysis of [C2C1Im][OTf] is suppressed. Upon annealing to 320 K, further ZnO aggregates are formed, leading to enclosure of [C2C1Im][OTf] in the ZnO film. At 380 K the IL is released from the mixed film. The pure [C2C1Im][OTf] desorbs at 420 K, leaving behind the ZnO phase. [ABSTRACT FROM AUTHOR]

Here we present novel CO2 sorbents based on chitosan ionogels. The powder sorbents called inverse supported ionic liquid phase (SILP) materials were prepared by dissolving chitosan in various ionic liquids (ILs) followed by encapsulation of the ionogel droplets with nanoporous fumed silica. CO2 absorption was determined at 40 °C in the range of 200 to 5500 mbar. At 1 bar, absorption capacities of these materials were 0.1-0.8 mol kg-1; at 5 bar, values of 0.2-1.5 mol kg-1 were reached. A comparison of inverse SILP materials with and without chitosan dissolved in the applied IL indicated that the presence of chitosan increased the CO2 absorption efficiency of the materials. The aim of the study was also to compare the CO2 absorption in pure chitosan and chitosan dissolved in ILs. It was found that dissolution increases the absorption capacity of chitosan about 10 times. [ABSTRACT FROM AUTHOR]