Interface effects from moisture in nanocomposites of 2D graphene oxide in cellulose nanofiber (CNF) matrix – a molecular dynamics study

Molecular dynamics (MD) simulation is used to study effects from moisture at cellulose nanofibril (CNF)-graphene oxide (GO) interfaces adhering in the wet state. Two CNF models with different surface chemistry...

The Effect of Ionic Strength and pH on the Dewatering Rate of Cellulose Nanofibril Dispersions

Cellulose nanofibrils, CNFs, show a great potential in many application areas. One main aspect limiting the use of the material is the slow and energy demanding dewatering of CNF suspensions. Here we investigate the dewatering with a piston press process. Three different CNF qualities, two laboratory grades (high and low charge) and one industrial grade (low charge) were tested. The chemical conditions were varied by changing salt concentration (NaCl) and pH. For the original suspensions, the dewatering rate is substantially slower for the high charge CNFs. However, by changing the conditions it dewatered as fast as the two low charge CNFs, even though salt/acid additions also improved dewatering rate for these two CNFs. Finally, by tuning the conditions fast dewatering could be obtained with only minor effect on strength and barrier performance of films prepared from the CNFs.

Preparation and Characterization of Polybutylene Succinate Reinforced with Pure Cellulose Nanofibril and Lignocellulose Nanofibril Using Two-Step Process

This study reports the preparation of a polybutylene succinate (PBS) film reinforced with pure cellulose nanofibril (PCNF) and lignocellulose nanofibril (LCNF) by a two-step process that consists of solvent dispersion and twin-screw extrusion. Compared to the conventional one-step process, this method offered improved mechanical properties. The addition of 5% CNF increased the tensile properties up to 18.8%. Further, the effect of the lignin content was also studied by using LCNF as a reinforcement. The LCNF was prepared with and without a deep eutectic solvent (DES) pretreatment to gain LCNF with a lignin content that varied between 5, 19, and 30%. The mechanical properties results show that a 5% addition of LCNF to the PBS matrix increased its tensile strength and elastic modulus. Further, the morphological and thermal properties of the composites were also studied in detail.