Production of nanocellulose gels and films from invasive tree species.
Int J Biol Macromol 2021;
188:1003-1011. [PMID:
34371043 DOI:
10.1016/j.ijbiomac.2021.08.015]
[Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 07/21/2021] [Accepted: 08/03/2021] [Indexed: 11/25/2022]
Abstract
Wood/wastes from invasive tree species Acacia dealbata and Ailanthus altissima were used to produce high-value added nanocellulose. Firstly, bleached pulps were produced from the wood of these tree species after kraft cooking. Afterwards, the resultant pulps were pre-treated by TEMPO-mediated oxidation (Acacia dealbata) or enzymatic hydrolysis (Ailanthus altissima) followed by high-pressure homogenization. Hydrogels were obtained and characterized for their main physical and chemical properties, including rheology and evaluation of the surface properties of the freeze-dried materials by inverse gas chromatography. Results showed that micro/nanofibrils could be obtained from the wood of these invasive species. Rheometry studies showed that Acacia-TEMPO cellulose nanofibrils form strong gels with high yield stress point and viscosities (reaching ca. 100,000 Pa·s). Additionally, the surfaces of the obtained nanocelluloses showed a dispersive component of the surface energy near 40 mJ/m2 and a prevalence of the Lewis acidic character over the basic one, as typical for cellulose-based materials. Finally, films with good mechanical and optical properties could be obtained from the cellulose hydrogels. Acacia-TEMPO film (produced by filtration/hot pressing) showed a tensile strength of 79 MPa, Young's modulus of 7.9 GPa, and a transparency of 88%. The water vapor barrier, however, was modest (permeability of 4.9 × 10-6 g/(Pa·day·m)).
Collapse