Nanocellulose, a refined form of cellulose, can be further functionalized on surface-active sites, with a catalyst as a regenerative agent. Newly developed adsorbents are expected to have the characteristics of good and rapid adsorption performance and regeneration properties with flexible structure using 3D printing technology. In this work, the adsorption performance of 3D printed functionalized nanocellulose was investigated using batch and fixed-bed column adsorption. Kinetics adsorption studies were divided into different adsorption models, with the pseudo-second order model showing a better correlation coefficient than the pseudo-first order and intraparticle diffusion models. The Langmuir and Thomas models were used to calculate the adsorption performance of batch and fixed-bed columns. Given the catalytic activity of Fenton oxidation, the fixed-bed column was regenerated up to five adsorption-desorption cycles, suggesting satisfactory performance of the column, with a slightly reduced adsorption capacity.

This study explores the potential of using nanocellulose extracted from oil palm empty fruit bunch (OPEFB) as a biomaterial ink for 3D printing. The research focuses on using nanocellulose hydrogels for the controlled uptake and release of proteins, with the specific protein solution being Bovine Serum Albumin (BSA). To provide a suitable material for the bioprinting process, the study examines the characteristics and properties of the printed hydrogels through various analyses, such as morphology, functional group, crystallinity, and compression test. Several parameters, such as initial concentration, temperature, and the presence of calcium chloride as an additional crosslinker, affect the protein uptake and release capabilities of the hydrogel. The study is important for biomedicine as it explores the behavior of protein uptake and release using nanocellulose and 3D printing and can serve as a preliminary study for using hydrogels in biological materials or living cells.

Cellulose is a promising biomaterial ink for various applications, such as tissue engineering and soft robotics. Different cellulose derivatives have different advantages, depending on their surface area, fiber structures and rheological properties. In this work, the swelling capacity of carboxymethyl cellulose (CMC) was integrated with the stiffness of cellulose nanofibrils (CNF) to create multifunctional cellulose-based composites for additive manufacturing. CNF, CMC, and their composites show a higher storage modulus (G’) than loss modulus (G") in the rheological study. This is indicative of the materials’ ability to retain their printed structure post direct ink writing (DIW) 3D printing, thereby avoiding any structural collapse. Notably, the CNF at a concentration of 4.5 wt% demonstrates a higher storage and loss modulus, suggesting that CNF imparts the necessary rigidity to the CNF/CMC composite. Concurrently, CMC plays a pivotal role in water retention, which is a critical factor for the success of 4D printing processes. The CNF/CMC composite hydrogel can respond to stimuli and swell, which makes it suitable for biocompatible actuators. We demonstrated this by printing a prototype valve that can be reversibly closed and opened by dehydration/hydration cycles. The printed CNF/CMC composite structure has excellent mechanical properties, with tensile strength ranging from 55 MPa to 80 MPa, comparable with commercial PLA filament used in fused deposition modelling (FDM) 3D printing.