| Abstract |
Femtosecond (fs) laser micromachining on polymeric materials is a single-step, and contactless manufacturing technology. Knowing the potential of poly(ionic liquid)s (PILs) and their derived composite materials incorporating ionic liquids (PIL-IL) to design membranes with improved CO2 separation, we here explore for the first time the creation of microchannels on the surface of PIL-IL materials by laser ablation using femtosecond laser radiation. PIL-IL membranes composed of pyrrolidinium-based PILs containing the [NTf2](-) and [C(CN)(3)](-) anions and different amounts of their corresponding ILs (40 and 60 wt\%) were prepared and micromachined using fs laser pulses varying the pulse repetition rate, scanning speed, and pulse energy. The morphology of the fs laser modified PIL-IL samples was investigated through scanning electron microscopy (SEM), while the influence of the fs laser processing on the membranes structure was analyzed by solid-state nuclear magnetic resonance (ssNMR), Fourier-transform infrared (FT-IR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). The CO2/N-2 and CO2/H-2 separation performances of the irradiated membranes were also evaluated and compared to those of the non-irradiated. Depending on the parameters used, fs laser processing was successful in modifying the surface of PIL-IL membranes through the formation of microchannels around 55-60 mu m deep. Significant improvements in CO2, N-2 and H-2 permeabilities were achieved for the irradiated PIL-IL membranes, maintaining their CO2/N-2 and CO2/H-2 permselectivities. |
