Novel carbon molecular sieve membranes with high separation performance and stability in the presence of humidified streams were prepared from an optimized ionic liquid-regenerated cellulose precursor, in a single carbonization step. Membranes prepared at two different carbonization end temperatures (550°C and 600°C) were analyzed through scanning electron microscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy, carbon dioxide adsorption and permeation experiments. The prepared membranes exhibited uniform thickness of approximately 20 µm and a well-developed microporous structure. The permeation performance of these carbon molecular sieve membranes was above the Robeson upper bound curve for polymeric membranes. In particular, the membrane prepared at 550°C end temperature exhibited permeability to oxygen of 5.16 barrer and O 2 /N 2 ideal selectivity of 32.3 and permeability to helium of 126 barrer and He/N 2 ideal selectivity of 788; besides, permeation experiments performed in the presence of ca. 80% relative humidity showed that humidity does not originate pore blockage. These results open the door for the preparation of tailor made precursors that originate carbon molecular sieve membranes with extraordinary separation performances, mechanical resistance and stability. [21], poly(furfuryl alcohol) [22,23], phenolic resins [24-28], resorcinol-formaldehyde resin [29][30][31][32] and cellulose [16,[33][34][35]. Recently, our group applied for a patent of a process for obtaining, in a single carbonization step, CMSM that display no pore blockage effect in

For some time, carbon molecular sieve membranes (CMSMs) have been promoted as energy‐efficient candidates for gas separation due to their high selectivity, permeability, and stability in chemically aggressive environments. Nevertheless, these membranes have not yet been made into commercial products due to a significant decrease in performance when exposed to humidity and/or oxygen. Herein, disruptive CMSMs with extremely high separation performance and stability, even in the presence of humidity, are reported. The carbon membranes are prepared from a renewable, low‐cost precursor with a single carbonization step. Water vapor adsorption/desorption studies demonstrate that these membranes have a linear water vapor adsorption isotherm, characteristic of a homogeneous distribution of hydrophilic sites on the pore surfaces, allowing for water molecules to hop continuously between sites and avoiding the formation of pore‐blocking water clusters. These results are a breakthrough toward bringing this new type of membrane to a commercial level.

Polyesters made from 2,5-furandicarboxylic acid (FDCA) have been in the spotlight due to their renewable origins, together with the promising thermal, mechanical, and/or barrier properties. Following the same trend, (nano)composite materials based on FDCA could also generate similar interest, especially because novel materials with enhanced or refined properties could be obtained. This paper presents a case study on the use of furanoate-based polyesters and bacterial cellulose to prepare nanocomposites, namely acetylated bacterial cellulose/poly(butylene 2,5-furandicarboxylate) and acetylated bacterial cellulose/poly(butylene 2,5-furandicarboxylate)-co-(butylene diglycolate)s. The balance between flexibility, prompted by the furanoate-diglycolate polymeric matrix; and the high strength prompted by the bacterial cellulose fibres, enabled the preparation of a wide range of new nanocomposite materials. The new nanocomposites had a glass transition between −25-46 • C and a melting temperature of 61-174 • C; and they were thermally stable up to 239-324 • C. Furthermore, these materials were highly reinforced materials with an enhanced Young's modulus (up to 1239 MPa) compared to their neat copolyester counterparts. This was associated with both the reinforcing action of the cellulose fibres and the degree of crystallinity of the nanocomposites. In terms of elongation at break, the nanocomposites prepared from copolyesters with higher amounts of diglycolate moieties displayed higher elongations due to the soft nature of these segments.

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