Analysis of porous structures of cellulose aerogel monoliths and microparticles

In this work, the porous structures of cellulose aerogel monoliths and microparticles are analyzed and the potential of cellulose aerogel microparticles in drug delivery is assessed. Cellulose dissolved in ionic liquid and N,N-dimethylformamide mixed solvents are regenerated into gels using antisolvent ethanol. The gels are then supercritically dried in carbon dioxide to obtain aerogels. Gel monoliths are cast inside a mold, while the gel microparticles of mean diameter 23–54 μm are obtained by emulsifying cellulose solutions in a surfactant-stabilized oil-in-oil emulsion system followed by regeneration in ethanol. Cellulose crystallinity, porosity and pore architecture, bulk density, and specific surface area of aerogel monoliths and microparticles are determined. In conjunction, the effects of water ingress on changes of pore architectures are assessed. These aerogel specimens show porosity as high as 99%, significant mesopores, and high specific surface area of 358 ± 13 m2/g and 426 ± 12 m2/g respectively for monoliths and microparticles. The porous architecture of the microparticles is responsible for slower release of the drug than when directly loaded into aqueous medium. [Display omitted] •The pore structures of cellulose aerogels are attractive for drug loading and release.•Cellulose aerogel microparticles slow down release of drug molecules.•Pore structures change due to water ingress and influence drug release.