10.1021/acssuschemeng.8b05427.s001 Kelechukwu N. Onwukamike Kelechukwu N. Onwukamike Laurine Lapuyade Laurine Lapuyade Laurence Maillé Laurence Maillé Stéphane Grelier Stéphane Grelier Etienne Grau Etienne Grau Henri Cramail Henri Cramail Michael A.R. Meier Michael A.R. Meier Sustainable Approach for Cellulose Aerogel Preparation from the DBU–CO<sub>2</sub> Switchable Solvent American Chemical Society 2019 morphology cellulose-based aerogels cellulose concentration coagulation approach chemical modification surface areas cellulose aerogels DBU preparation procedure XRD 4.5 μ m macroporous cellulose network processing conditions Cellulose Aerogel Preparation aerogel characteristics pore size 2θ diffraction peak SEM Sustainable Approach scanning electron microscopy superbase solubilization pore sizes crystal structure porosity values Density values BET equation N 2 adsorption processing parameters X-ray diffraction 2019-01-04 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Sustainable_Approach_for_Cellulose_Aerogel_Preparation_from_the_DBU_CO_sub_2_sub_Switchable_Solvent/7599761 We report a sustainable and easy approach for the preparation of cellulose-based aerogels from the DBU–CO<sub>2</sub> switchable solvent system via a solubilization and coagulation approach followed by freeze-drying. The easy, fast, and mild solubilization step (15 min at 30 °C) allows for a rapid preparation procedure. The effect of various processing parameters, such as cellulose concentration, coagulating solvent, and the superbase, on important aerogel characteristics including density, porosity, pore size, and morphology, were investigated. Density values obtained ranged between 0.05 and 0.12 g/cm<sup>3</sup>, with porosity values between 92% and 97%. The morphology of the obtained cellulose aerogels was studied using scanning electron microscopy (SEM) showing a random and open large macroporous cellulose network with pore sizes ranging between 1.1 and 4.5 μm, depending on the processing conditions. In addition, specific surface areas determined by N<sub>2</sub> adsorption applying the BET equation ranged between 19 and 26 m<sup>2</sup>/g. The effect of the coagulating solvent and superbase on the crystallinity was investigated using X-ray diffraction (XRD) showing an amorphous crystal structure with a broad 2θ diffraction peak at 20.6°. In addition, no chemical modification was observed in the prepared aerogels from infrared spectroscopy. Finally, the recovery and reuse of the solvent system was demonstrated, thus making the process more sustainable.