RT Journal Article
T1 Cellulose-Based Nanofibers Processing Techniques and Methods Based on Bottom-Up Approach-A Review
A1 Kramar, Ana
A1 González Benito, Francisco Javier
AB In the past decades, cellulose (one of the most important natural polymers), in the form of nanofibers, has received special attention. The nanofibrous morphology may provide exceptionalproperties to materials due to the high aspect ratio and dimensions in the nanometer range of the nanofibers. The first feature may lead to important consequences in mechanical behavior if thereexists a particular orientation of fibers. On the other hand, nano-sizes provide a high surface-tovolume ratio, which can have important consequences on many properties, such as the wettability.There are two basic approaches for cellulose nanofibers preparation. The top-down approach implies the isolation/extraction of cellulose nanofibrils (CNFs) and nanocrystals (CNCs) from a varietyof natural resources, whereby dimensions of isolates are limited by the source of cellulose and extraction procedures. The bottom-up approach can be considered in this context as the productionof nanofibers using various spinning techniques, resulting in nonwoven mats or filaments. During the spinning, depending on the method and processing conditions, good control of the resultingnanofibers dimensions and, consequently, the properties of the produced materials, is possible. Pulp, cotton, and already isolated CNFs/CNCs may be used as precursors for spinning, alongside cellulosederivatives, namely esters and ethers. This review focuses on various spinning techniques to produce submicrometric fibers comprised of cellulose and cellulose derivatives. The spinning of celluloserequires the preparation of spinning solutions; therefore, an overview of various solvents is presented showing their influence on spinnability and resulting properties of nanofibers. In addition, it is shownhow bottom-up spinning techniques can be used for recycling cellulose waste into new materials with added value. The application of produced cellulose fibers in various fields is also highlighted,ranging from drug delivery systems, high-strength nonwovens and filaments, filtration membranes, to biomedical scaffolds.
PB MDPI AG
SN 2073-4360
YR 2022
FD 2022-01-11
LK https://hdl.handle.net/10016/35294
UL https://hdl.handle.net/10016/35294
LA eng
NO This research was funded by CONEX-Plus program of Universidad Carlos III de Madridand the European Commission through the Marie-Sklodowska Curie COFUND Action (Grant AgreementNo 801538). The authors also appreciate the financial support received from AEI (Ministerio deCiencia e Innovación of Spain, PID2020-112713RB-C22]; the Universidad Carlos III de Madrid due toFondos de Investigación of Fco. Javier González Benito [2012/00130/004] and the strategic Action inMultifunctional Nanocomposite Materials [Code: 2011/00287/003].
DS e-Archivo
RD 18 jul. 2024