Permeability of cellulose pulp membranes with nanocellulose

In the quest to enhance filtration system performance and remove microscopic particles, researchers are increasingly interested in affordable materials made from renewable sources with low environmental impact. Cellulose stands out as one of the most promising materials due to its abundance in nature. In this study, we present a simple approach to manufacture cellulose foam with a microfibrillated cellulose (MFC) interface, intended to be used as a filter to capture airborne microparticles. Four different methods were employed to produce the membranes, aiming to analyze and compare the effectiveness of each process, including two distinct solvent exchange approaches and two solvent filtration techniques. Specifically, two membrane production methods were explored: (i) using water as a solvent, and (ii) employing acetone as a solvent. Regarding the solvent filtration process, two modalities were investigated: (i) natural filtration, and (ii) vacuum filtration. The MFC acted as reinforcement, promoting the formation of cross-links between the cellulose pulp fibers, thereby enhancing cellulose interfibrillar cohesion. An experimental system was utilized to assess pressure drop in a gas flow, and filter permeability was calculated. Overall, the membranes exhibited high permeability constants, emerging as a promising material for filtration processes.