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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 °C). After solvent exchange with ethanol and subsequent supercritical drying, cellulose aerogel particles were obtained. The particles showed high specific surface areas (ca. 400 m2/g) and low bulk (untapped) densities (0.06–0.10 g/cm3). 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.

The temperature dependent redox decomposition rate constants of ascorbic acid (AsAc) in aqueous solutions were quantified in the presence of ammonium iron(III) sulfate dodecahydrate (Fe-cat) and tert-butylhydroperoxide (TBHP). Decomposition rates were determined in a temperature range from 35−75 °C with respect to the component ratios. First-order kinetics were observed up to specific conversions (∼20−80%) for AsAc decomposition. The application of a flexible Weibull model provided a good and comparable description (R 2 ≥ 0.992) of decomposition processes up to high AsAc conversions (96%) at all studied reaction conditions. The activation energy was determined as a function of AsAc and Fe-cat ratios (38−79 kJ mol −1 ). Statistical modeling facilitated the prediction of rate constants. Thus, it was possible to adjust the reaction rate of emulsion copolymerizations of vinyl acetate and Versa10 in a broad temperature range (10−70 °C) by variation of the Fe-cat content.

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