Pluronic L121 as innovative solvent for CO2 sorption under pressureAuthor(s): Guido Angelini and Carla Gasbarri
Poly(ethylene oxide)-poly(propylene oxide)-poly (ethylene oxide) triblock copolymers are high molecular weight non ionic surfactants, commercially available as Pluronic. Generally, polymeric micelles and vesicles represent highly biodegradable and biocompatible systems, involved in a large range of applications from drug delivery to nanostructured materials due to their thickness, mechanical stability, and chemical functionality. One of the most investigated Pluronic is L121 considered as an ideal copolymer for drug target because of the capability to aggregate into vesicles having strong solute retention. Recently, the critical aggregation concentration of L121 in some ionic liquids and in D2O has been spectroscopically determined (Angelini, G.; Gasbarri, C., Curr. Drug Targets 2015, 16, 1606-1611), while a dense three-dimensional network showing a viscoelastic gel-like behavior has been observed in the presence of single-walled carbon nanotubes above a critical percolation concentration (Gasbarri et al., Chem. Eur. J. 2016, 22, 546-549).
The aim of this work was to determine the efficacy of L121 as solvent for carbon dioxide sorption. Successful method to capture CO2 are based on polyethylene and polypropylene glycols under high pressure as demonstrated by the spectral changes of the polymer in the liquid state before and after the gas exposure. L121 shows the CO2 typical bands in the NIR region of the spectra from 15 to 40 °C according to a linear correlation. The effect induced by temperature on the swelling degree of L121 was also investigated and compared to the data obtained by using other viscous media, as Triton X-100 and BMIM BF4 (Angelini et al. J. Mol. Liquids 2018, 258, 85-88).