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

Abstract

This study aims to explore the use of cellulose nanocrystals (CNC) and cellulose nanofiber (CNF), obtained from unbleached fiber of oil palm empty fruit bunches (EFB), as raw materials in fabricating aerogel, using the facile technique without solvent displacement. The CNC was isolated from sulfuric acid hydrolysis, and the CNF was fibrillated using Ultra Turrax. The CNC and CNF were mixed by ultrasonication in different ratios to produce aerogel using slow freezing (−20 °C), followed by freeze-drying. The obtained aerogel was characterized as ultralightweight and highly porous material, at the density range of 0.0227 to 0.0364 g/cm3 and porosity of 98.027 to 98.667%. Interestingly, the ratio of CNC and CNF significantly affected the characteristics of the obtained aerogel. The mixed aerogel exhibited a higher specific surface area than pure CNC or CNF, with the highest value of 202.72 m2/g for the ratio of 1:3 (CNC/CNF). In addition, the crystallinity degree of obtained aerogel showed a higher value in the range of 76.49 to 69.02%, with the highest value being obtained for higher CNC content. This study is expected to provide insight into nanocellulose-based aerogel, with a promising potential for various applications.

Cross-Linking of Oxidized Hydroxypropyl Cellulose in Paper: Influence of Molecular Weight and Polymer Distribution on Paper Wet Strength Development

“…In first concepts, the focus of these initial studies was on understanding and controlling the oxidation kinetics in the preparation of keto-HPC as well as first conceptual investigations of the possibility to form polymer gel structures in bulk. The latter conceptually is similar to the formation of CNC/CNF aerogels described recently in the literature [ 26 ]. Our first experiments could also show the beneficial improvement of keto-HPC cross-linked with polyamines.…”

Isolation of Cellulose Nanocrystals from Banana Peel Using One-Pot Microwave and Mild Oxidative Hydrolysis System

“…Clear morphological changes were observed after the BP powder was subjected to pre-treatment and hydrolysis. The freeze-dried suspensions showed a sheet-like structure, which was commonly observed when cellulose suspension was subjected to a relatively slow freezing process (−20 • C) [64]. Closer observation on the surface of the sheet revealed randomly arranged nanosized cellulose fibers with a diameter ranging from 70-150 nm.…”

Natural polysaccharide-based aerogels and their applications in oil–water separations: a review

“…Characterization of aerogels: aerogels not only have mesopores but also have macropores, which will increase the oil absorption and storage capacity of the aerogels, and the maximum adsorption efficiency can reach 12 g g −1 . Burhani et al 198 prepared cellulose nanocrystals (CNC) and cellulose nanofibers (CNF) from unbleached fibers of oil palm empty fruit bunch (EFB) as the raw materials, and the ratio of CNCs and CNFs was controlled by a self-assembly method to prepare the aerogels; the aerogels exhibit a lamellar macroporous structure, light density (0.0225–0.364 g cm −1 ), high porosity (98.67–97.84%), and high specific surface area (117.86–202.72 m 2 g −1 ). The self-assembly method provided a good microstructure to the aerogels, which can endow it with better performance in the field of oil–water separation, and can also provide a basis for the preparation of multifunctional aerogels.…”