Recent efforts of bone repair focus on development of porous scaffolds for cell adhesion and proliferation. Collagen-nanohydroxyapatite (HA) scaffolds (70:30; 50:50; and 30:70 mass percentage) were produced by cryogelation technique using 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide hydrochloride/N-hydroxysuccinimide as crosslinking agents. A pure collagen scaffold was used as control. Morphology analysis revealed that all cryogels had highly porous structure with interconnective porosity and the nanoHA aggregates were randomly dispersed throughout the scaffold structure. Chemical analysis showed the presence of all major peaks related to collagen and HA in the biocomposites and indicated possible interaction between nanoHA aggregates and collagen molecules. Porosity analysis revealed an enhancement in the surface area as the nanoHA percentage increased in the collagen structure. The biocomposites showed improved mechanical properties as the nanoHA content increased in the scaffold. As expected, the swelling capacity decreased with the increase of nanoHA content. In vitro studies with osteoblasts cells showed that they were able to attach and spread in all cryogels surfaces. The presence of collagen-nanoHA biocomposites resulted in higher overall cellular proliferation compared to pure collagen scaffold. A statistically significant difference between collagen and collagen-nanoHA cryogels was observed after 21 day of cell culture. These innovative collagen-nanoHA cryogels could have potentially appealing application as scaffolds for bone regeneration.

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

Carbon molecular sieve membranes (CMSM) were prepared on α-alumina supports by carbonization of a resorcinol-formaldehyde resin loaded with boehmite. Two series of carbon membranes produced at 500 ºC and 550 ºC carbonization end temperatures were prepared. The influence of the carbonization end temperature on the structure, morphology and performance of the membranes was examined by scanning electron microscopy, thermogravimetric analysis, CO2 adsorption and permeation to N2, O2, He, H2 and CO2 at temperatures from 25 ºC to 120 ºC. SEM photographs showed carbon membranes with a thin and very uniform layer and a thickness of ca. 3 m. Carbon dioxide adsorption isotherms revealed that all the produced carbon membranes have a welldeveloped microporous structure. Nevertheless, the membranes carbonized at 550 ºC have more ultramicropores and a narrower pore size distribution. The permselectivity of CMSM prepared at this temperature surpasses the Robeson upper bound for polymeric membranes, especially regarding ideal selectivities of pairs O2/N2 (O2 permeation rate: 9.85 x10 -10 mol m -2 s -1 Pa -1 and ideal selectivity: >11.5), H2/N2 (H2 permeation rate: 5.04 x10 -8 mol m -2 s -1 Pa -1 and ideal selectivity: >586) and He/N2 (He permeation rate: 4.68x10 -8 mol m -2 s -1 Pa -1 and ideal selectivity: >544).

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.

Composite carbon molecular sieve membranes (c-CMSM) were prepared in a single dipping-drying-carbonization step from phenolic resin solutions (12.5-15 wt.%) loaded with boehmite nanoparticles (0.5-1.2 wt.%). A carbon matrix with well-dispersed Al2O3 nanowires was formed from the decomposition of the resin and dehydroxylation of boehmite. The effect of the carbon/Al2O3 ratio on the porous structure of the c-CMSM was accessed based on the pore size distribution and gas permeation toward N2, O2, CO2, He, H2, C3H6 and C3H8. c-CMSM with higher carbon/Al2O3 ratios had a more open porous structure, exhibiting higher permeabilities and lower permselectivities. c-CMSM performance was above the upper bound curves for polymeric membranes for several gas pairs, particularly for C3H6/C3H8 (permeability toward C3H6 of 420 barrer and permselectivity of 18.1 for a c-CMSM with carbon/Al2O3 ratio of 4.4).Unsupported films were also prepared (carbon/Al2O3 ratio 7.3) and crushed into small flakes. Equilibrium isotherms of H2, N2, O2, CO2, C3H8 and C3H6 at 293 K were determined on these flakes to obtain the kinetic and adsorption selectivities toward gas pairs of interest; obtained adsorption and diffusion coefficients accurately predicted the permeabilities of all studied gases except CO2 (experimental and predicted permeabilities of 1148 and 154 barrer, respectively).