A technique for the ultrasonic dispersion of larger quantities of cellulose nanocrystals with in-line validation

Cellulose nanocrystals (CNCs) can be used in a wide range of applications due to their unique properties. However, the dispersion required to achieve these properties in various media may be quite challenging, especially at larger scales. Starting from an optimized protocol to prepare small volumes (60 mL) of aqueous suspensions, a semicontinuous setup is developed in this work to disperse larger quantities (200 mL). Using this technique, a higher efficiency is achieved, consuming only 35 % of the energy needed with a comparable batch method. To follow the dispersion state, an in-line process rheometry technique is adapted and validated through finite element simulation. While this allows for fast and easy validation, a deeper analysis may also be carried out to extract additional information such as the process viscosity. This setup is further exploited for the CNC surface modification using polyethylenimine. Although it has been designed for CNCs, it may be adapted for other nanoparticle dispersion.