By spraying a mixture of 1.6% w/w enzymatic CNF, 0.4% w/w alginate and 10mM CaCl2 into flaxseed oil, small droplets were obtained. Everything was then frozen at -24°C and kept frozen for 18 hours. After thawing and oil removal by filtration, the formed particles were transferred to a beaker filled with 0.5 M CaCl2-solution to improve the physical cross-linking between the alginate polymer and possibly also the nanocellulose. The particles were then solvent exchanged to acetone via ethanol and allowed to dry at ambient conditions. The result was a coarse flaky powder with particle diameters ranging from 100-1000 µm and an approximate pore size diameter was estimated to be in the range between 2 and 15 μm, see figure 1. These pores will need time to be filled with water and this might also explain why the particles initially showed a floating behavior when dispersed in water. The water-stability of the formed particles was investigated by placing particles in water and stirring at 500 rpm for 4 hours. Image 1 shows the result of this process with photos taken at 0, 1 and 4 hours after stirring start and SEM images of corresponding dried powders. Even after 4 hours all particles are intact and the SEM images of a typical particle before and after stirring in water shows that they look qualitatively similar. (see figure 1). With this non-complicated procedure, it is hence possible to create rather well-defined submillimeter sized particles with a high water holding capacity and fine pores, and all this starting with a rather coarse CNF raw material. The particle dimensions and their internal structure are very interesting for a variety of applications, e.g. air and water filtration, catalyst support, controlled release of active components in biomedicine, just to mention a few examples. The enzymatic CNF is cost-efficient, which paves the way for an industrial up-scaling of these type of particles. 

Water-stable aerogel particles made of enzymatic CNF and alginate

Macromolecular Chemistry: The Second Century

[Author Benefits](https://scimeetings.acs.org/?utm_source=pubs_content_marketing&utm_medium=website&utm_campaign=0320_MCF_NPI_Launch_Spring_Homepage&ref=pubs_content_marketing)

[How to use SciMeetings](https://storage.googleapis.com/dl.morressier.com/acs/SciMeetings-ACSSpring2020-HowToGuide_M3020-Final.pdf)

[Frequently Asked Questions](https://storage.googleapis.com/dl.morressier.com/acs/SciMtng_ACSNMSp2020_FAQ_M3120_Final.pdf)

ACS Spring 2020 National Meeting & Expo

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.