Cellulose aerogel particles: control of particle and textural properties in jet cutting process

Reported approach aims for the synthesis of spherical cellulose beads with high production rates (0.7-4.1 kg/h of hydrogel) via the so-called jet cutting method. To form particles, jets of aqueous cellulose/sodium hydroxide solutions were cut into pieces and collected in a gelation bath (30 wt% aqueous H2SO4, 20 degrees C). After solvent exchange with ethanol and subsequent supercritical drying, cellulose aerogel particles were obtained. The particles showed high specific surface areas (ca. 400 m(2)/g) and low bulk (untapped) densities (0.06-0.10 g/cm(3)). Variation of cellulose content (4-7 wt%) and jet cutting process parameters (cutting frequency, nozzle diameter, jet velocity) turned to be useful parameters for controlling the particles size and shape. Highly spherical particles with sphericity SPH >= 0.92 were obtained in a broad range of achievable particle sizes (0.4-1.0 mm), with an optimum of SPH at 6 wt% cellulose content.

Automated summary

The reported approach focuses on synthesizing spherical cellulose beads with high production rates using the jet cutting method. By varying cellulose content and jet cutting process parameters, control over particle size and shape was achieved, resulting in cellulose aerogel particles with high specific surface areas and low bulk densities. Highly spherical particles with high sphericity were obtained over a broad range of achievable sizes, with an optimum observed at 6 wt% cellulose content.