Aloe vera rind cellulose nanofibers‐reinforced films

Abstract

Aloe vera (AV) gel has been widely used in various medical, cosmetic, and nutraceutical applications. However, AV rind, the tougher outer layer of AV leaves where the cell wall components exists, is currently treated as a fertilizer or waste. This study aimed to investigate the potential of the AV rind as a resource for the production of cellulose nanofibers. Since a detailed analysis of the AV rind has been lacking, chemical composition of rind was analyzed before processing it into nanofibers. The results showed that AV rind has a high proportion of α‐cellulose (57.72% ± 2.18%). AV rind nanofibers (AVRNF) were prepared using chemi‐mechanical process. The morphological analyses showed that most of the isolated fibers were individual fibers under 20 nm. Crystallinity and degree of polymerization of the obtained AVRNF, and mechanical properties of the nanofibrous film were evaluated and compared with the wood nanofibers. Tensile strength of AVRNF film (102 MPa) was comparatively lower than the wood fibers (132 MPa), which was consistent with the lower crystallinity of AVRNF [crystallinity index (CI) = 0.66] as well as the lower degree of polymerization (DP = 396), compared with wood fibers (CI = 0.90, DP = 1297). © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40592.

Preparation and Characterization of Polyvinyl Alcohol-Based Composite Reinforced with Nanocellulose and Nanosilica

“…The hydrogen bonding between the nanocellulose and PVA matrix resulted in a decrement in the elongation at break but gains in crystallinity. According to Cheng et al (2014), low deformability of composites under tensile loads is due to the high interfacial adhesion between the matrix and nanofillers. Since the nanocellulose and nanosilica were not as deformable as the matrix, the strong interactions between the nanoparticles and matrix molecules did not allow PVA to elongate.…”

Aloe Vera Rind Nanofibers: Effect of Isolation Process on the Tensile Properties of Nanofibre Films

“…1. The method used was similar to the previous study by the authors (Cheng et al 2014) except for the bleaching procedure. In the previous study, an acidified sodium chlorite bleaching method at 70 to 80 °C for 4 h was employed twice to remove the lignin.…”

“…The chemical compositions (ash, α-cellulose, hemicellulose, soluble lignin, and Klason lignin) of extractive-free AV rind powder without cuticle and AVRNF powder without cuticle were determined. The detailed procedures were described in previous work by the authors (Cheng et al 2014). In short, holocellulose was measured by treating with sodium chlorite and glacial acetic acid for 3 h at 70 °C.…”

“…Preparation of AV rind nanofibre films and evaluation of mechanical properties in terms of tensile strength and Young's modulus were performed according to the same procedures as detailed in the previous work (Cheng et al 2014). The AVRNF suspension was diluted with distilled water and mixed in a blender to obtain a uniform suspension.…”

“…A previous investigation by the authors on the analysis and utilization of AV rind as a resource for nanofibers revealed that AV rind has a high amount of α-cellulose (58%) (Cheng et al 2014), and the isolated nanofibers were found to have a diameter under 20 nm. However, the films prepared using the isolated nanofibers in the preliminary studies exhibited a lower tensile strength (102 MPa) and Young's modulus (5.3 GPa) compared to the nanofiber films using the nanofibers isolated from other resources such as wood, rice straw, potato tubes, etc.…”