Recent Progress on Nanocellulose Aerogels: Preparation, Modification, Composite Fabrication, Applications

Abstract

The rapid development of modern industry and excessive consumption of petroleum‐based polymers have triggered a double crisis presenting a shortage of nonrenewable resources and environmental pollution. However, this has provided an opportunity to stimulate researchers to harness native biobased materials for novel advanced materials and applications. Nanocellulose‐based aerogels, using abundant and sustainable cellulose as raw material, present a third‐generation of aerogels that combine traditional aerogels with high porosity and large specific surface area, as well as the excellent properties of cellulose itself. Currently, nanocellulose aerogels provide a highly attention‐catching platform for a wide range of functional applications in various fields, e.g., adsorption, separation, energy storage, thermal insulation, electromagnetic interference shielding, and biomedical applications. Here, the preparation methods, modification strategies, composite fabrications, and further applications of nanocellulose aerogels are summarized, with additional discussions regarding the prospects and potential challenges in future development.

Self-Assembled Behavior of Ultralightweight Aerogel from a Mixture of CNC/CNF from Oil Palm Empty Fruit Bunches

“…Therefore, chemical crosslinking is often used to improve its structural integrity and stability [ 64 ]. Meanwhile, CNF with long fibrils can more easily establish the 3D network by the entanglement of the fibrils’ strong hydrogen bonding [ 65 ]. Figure 4 illustrates what might happen during the fabrication of aerogel.…”

“…Porous diameters of 300–400 µm were observed from all CNC/CNF mixtures aerogels. The macroporous structure might be formed due to the slow growth of ice crystals at the freezing stage (−20 °C) used in this study, resulting in many large pores after the freeze-drying process [ 65 ]. The pore size observed in the aerogels was not uniform, which might be caused by the irregular growth of ice crystals during the freeze-drying process [ 70 ].…”

Mechanical Performance of Binary and Ternary Hybrid MXene/Nanocellulose Hydro‐ and Aerogels – A Critical Review

“…Apart from the usage of MXenes, nanocellulose including cellulose nanofibers (CNFs), cellulose nanocrystals (CNCs) and bacterial cellulose (BC) has been used as a building block for the fabrication of hydro‐ and aerogels. [ 48 ] According to De France et al., [ 49 ] most “nanocellulose‐only” hydro‐ and aerogels possess fairly good strength and flexibility owing to the formation of relatively strong hydrogen between individual CNFs and CNCs as well as good mechanical properties (stiffness/flexibility balance). This mechanical performance enables the application of these nanocellulose‐based 3D porous structures for a range of flexible and stretchable sensing applications.…”

Recent Advances in the Fabrication and Environmental Science Applications of Cellulose Nanofibril-Based Functional Materials

“…Du and co-workers presented a review on the fabrication of cellulose nanocrystal- and CNF-based hydrogels for biomedical applications [ 18 ]. Very recently, the preparation, modification, fabrication, and applications of cellulose-based aerogels have been presented comprehensively [ 21 ]. In addition, recently, the fabrication of nanocellulose-based bioadsorbents for chemical contaminant remediation [ 22 ] and water purification [ 23 ] and environmental remediation [ 24 ] has been presented.…”