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Metal-organic frameworks have attracted a great deal of attention for future applications in numerous areas, including gas adsorption. However, in order for them to reach their full potential a substrate to provide an anchor may be needed. Ideally, this substrate should be environmentally friendly and renewable. Cellulose nanofibrils show potential in this area. Here we present a hybrid material created from the self-assembly of zeolitic imidazolate framework (ZIF-8) nanocrystals on cellulose nanofibrils (CNF) in aqueous medium. The CNF/ZIF-8 was freeze dried and formed free standing materials suitable for gas adsorption. A BET area of 1014 m2 g−1 was achieved for the CNF/ZIF-8 hybrid materials ZIF-8@cellulose which is comparable with reported values for free standing ZIF-8 materials, 1600 m2 g−1, considering the dilution with cellulose, and a considerable enhancement compared to CNF on its own, 32 m2 g−1.

To investigate the impact of process design factors such as number of passes, screw design and screw type, a poly(ethylene-co-acrylic acid) and a masterbatch containing 40 vol% nanocellulose were compounded using a twin-screw extruder with two different screw configurations. The 20 vol% composite pellets obtained, containing nanocellulose of different morphologies, cellulose nanofibrils and cellulose nanocrystals, were re-extruded several times to study the effect of re-extrusion. The compounded pellets were extruded into films using a singlescrew extruder. These films contained aggregates of the nanocellulose material, which was reduced in size upon re-extrusion leading to an improvement in properties of the composites. With the best combination of process factors, the Young's modulus and stress at break of the composites increased by factors of 10 and 1.6, respectively. The presence of a strong network of the cellulosic entities was observed qualitatively using melt rheology upon re-extrusion. Re-extrusion had a negligible effect on the crystallinity of the composites., INTRODUCTION Cellulose has been used as a reinforcement/filler in the plastics industry for decades and with the development and commercial availability of nanocellulose the possibilities of utilizing this material as [...]