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Valorization of khat (Catha edulis) waste for the production of cellulose fibers and nanocrystals

Cellulose fibers (C(40) and C(80)) were extracted from khat (Catha edulis) waste (KW) with chlorine-free process using 40% formic acid/40% acetic acid (C(40)), and 80% formic acid/80% acetic acid (C(80)) at the pretreatment stage, followed by further delignification and bleaching stages. Cellulose n...

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Detalles Bibliográficos
Autores principales: Gabriel, Tesfaye, Wondu, Kebede, Dilebo, Jemal
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7872298/
https://www.ncbi.nlm.nih.gov/pubmed/33561156
http://dx.doi.org/10.1371/journal.pone.0246794
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author Gabriel, Tesfaye
Wondu, Kebede
Dilebo, Jemal
author_facet Gabriel, Tesfaye
Wondu, Kebede
Dilebo, Jemal
author_sort Gabriel, Tesfaye
collection PubMed
description Cellulose fibers (C(40) and C(80)) were extracted from khat (Catha edulis) waste (KW) with chlorine-free process using 40% formic acid/40% acetic acid (C(40)), and 80% formic acid/80% acetic acid (C(80)) at the pretreatment stage, followed by further delignification and bleaching stages. Cellulose nanocrystals (CNCs(40) and CNCs(80)) were then isolated from C(40) and C(80) with sulfuric acid hydrolysis, respectively. Thus, the current study aims to isolate cellulose fibers and CNCs from KW as alternative source. The KW, cellulose fibers, and CNCs were investigated for yield, chemical composition, functionality, crystallinity, morphology, and thermal stability. CNCs were also evaluated for colloidal stability, particle size, and their influence on in vitro diclofenac sodium release from gel formulations preliminarily. The FTIR spectra analysis showed the removal of most hemicellulose and lignin from the cellulose fibers. The XRD results indicated that chemical pretreatments and acid hydrolysis significantly increased the crystallinity of cellulose fibers and CNCs. The cellulose fibers and CNCs exhibited Cellulose I(β) crystalline lattice. TEM analysis revealed formation of needle-shaped nanoscale rods (length: 101.55–162.96 nm; aspect ratio: 12.84–22.73). The hydrodynamic size, polydispersity index, and zeta potential of the CNC(S) ranged from 222.8–362.8 nm; 0.297–0.461, and -45.7 to -75.3 mV, respectively. CNCs(40) exhibited superior properties to CNCs(80) in terms of aspect ratio, and colloidal and thermal stability. Gel formulations containing high proportion of CNCs sustained diclofenac sodium release (< 50%/cm(2)) over 12 h. This study suggests that cellulose fibers and nanocrystals can be successfully obtained from abundant and unexploited source, KW for value-added industrial applications.
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spelling pubmed-78722982021-02-19 Valorization of khat (Catha edulis) waste for the production of cellulose fibers and nanocrystals Gabriel, Tesfaye Wondu, Kebede Dilebo, Jemal PLoS One Research Article Cellulose fibers (C(40) and C(80)) were extracted from khat (Catha edulis) waste (KW) with chlorine-free process using 40% formic acid/40% acetic acid (C(40)), and 80% formic acid/80% acetic acid (C(80)) at the pretreatment stage, followed by further delignification and bleaching stages. Cellulose nanocrystals (CNCs(40) and CNCs(80)) were then isolated from C(40) and C(80) with sulfuric acid hydrolysis, respectively. Thus, the current study aims to isolate cellulose fibers and CNCs from KW as alternative source. The KW, cellulose fibers, and CNCs were investigated for yield, chemical composition, functionality, crystallinity, morphology, and thermal stability. CNCs were also evaluated for colloidal stability, particle size, and their influence on in vitro diclofenac sodium release from gel formulations preliminarily. The FTIR spectra analysis showed the removal of most hemicellulose and lignin from the cellulose fibers. The XRD results indicated that chemical pretreatments and acid hydrolysis significantly increased the crystallinity of cellulose fibers and CNCs. The cellulose fibers and CNCs exhibited Cellulose I(β) crystalline lattice. TEM analysis revealed formation of needle-shaped nanoscale rods (length: 101.55–162.96 nm; aspect ratio: 12.84–22.73). The hydrodynamic size, polydispersity index, and zeta potential of the CNC(S) ranged from 222.8–362.8 nm; 0.297–0.461, and -45.7 to -75.3 mV, respectively. CNCs(40) exhibited superior properties to CNCs(80) in terms of aspect ratio, and colloidal and thermal stability. Gel formulations containing high proportion of CNCs sustained diclofenac sodium release (< 50%/cm(2)) over 12 h. This study suggests that cellulose fibers and nanocrystals can be successfully obtained from abundant and unexploited source, KW for value-added industrial applications. Public Library of Science 2021-02-09 /pmc/articles/PMC7872298/ /pubmed/33561156 http://dx.doi.org/10.1371/journal.pone.0246794 Text en © 2021 Gabriel et al http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
spellingShingle Research Article
Gabriel, Tesfaye
Wondu, Kebede
Dilebo, Jemal
Valorization of khat (Catha edulis) waste for the production of cellulose fibers and nanocrystals
title Valorization of khat (Catha edulis) waste for the production of cellulose fibers and nanocrystals
title_full Valorization of khat (Catha edulis) waste for the production of cellulose fibers and nanocrystals
title_fullStr Valorization of khat (Catha edulis) waste for the production of cellulose fibers and nanocrystals
title_full_unstemmed Valorization of khat (Catha edulis) waste for the production of cellulose fibers and nanocrystals
title_short Valorization of khat (Catha edulis) waste for the production of cellulose fibers and nanocrystals
title_sort valorization of khat (catha edulis) waste for the production of cellulose fibers and nanocrystals
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7872298/
https://www.ncbi.nlm.nih.gov/pubmed/33561156
http://dx.doi.org/10.1371/journal.pone.0246794
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AT dilebojemal valorizationofkhatcathaeduliswastefortheproductionofcellulosefibersandnanocrystals