Wet milling of alginate alco‐ and hydrogel composites : a facile top‐down approach for continuous production of aerogel microparticles

Abstract

Moving toward high-throughput production of biopolymer aerogelmicroparticles, in this work, the wet milling process is applied to hydrogelsand alcogels. Alcogels are then converted into aerogels by well-establishedsupercritical drying. Alginate and hybrid alginate/silica gels are used as amodel system. As the Young’s moduli of hydrogels significantly change whenwater is exchanged by ethanol, it is possible to study the effect of the gelstiffness on macroscopic and microstructural properties of the resultingaerogels. Influence of process parameters (milling speed and gap size) is alsoinvestigated. Smallest particles sizes and minimal changes in microstructureare obtained for completely solvent exchanged gels. The wet milling is shownto be a versatile method to obtain aerogel particles with diameters in therange 50–300μm.