Black wattle (Acacia mearnsii De Wild.) barks are residues produced by tannin industries in huge quantities, which are normally discharged on environmental or used for energy production. Therefore, this study aimed to evaluate the use of black wattle bark residues as a raw material on obtaining of a rich-cellulose material by alkaline (MET1), acetosolv (MET2), and organosolv (MET3) procedures. The results obtained indicated that the alkaline methodology, followed by a bleaching step (MET1), promoted klason lignin and hemicellulose removals more efficiently. It was possible to observe that better results were achieved using NaOH concentration of 6% (wt%), at 65 °C for 2.5 h, presenting a yield of 63.24 ± 1.25%, and a reduction on klason lignin content of almost 90.45%. Regarding the bleaching step, it was possible to obtain a material free of non-cellulosic compounds with a yield of 78.28 ± 1.48%. Thermogravimetric analysis indicated the removal of lignin and hemicellulose as well as an increase in cellulose degradation temperature, due to changes in crystalline phases. According to X-ray diffraction (XRD), the procedures employed have led to an increase in crystallinity from 66.27 to 91.78% due to the removal of non-cellulosic compounds. Scanning electron microscopy (SEM) showed morphological alterations in accordance with the removal of non-cellulosic compounds.
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http://dx.doi.org/10.1007/s11356-023-30254-9 | DOI Listing |
ACS Sustain Chem Eng
December 2024
Department of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University, P.O. Box 16300, Aalto FIN-00076 Espoo, Finland.
Tannins from (black wattle) are one of the few industrially available sources of nonlignin polyphenols. The intrinsic chemical heterogeneity and high dispersity of industrial tannins complicate their use in applications where the reactivity or colloidal interactions need to be precisely controlled. Here, we employ a solubility-centered sequential fractionation to obtain homogeneous tannin fractions with a dispersity index lower than 2.
View Article and Find Full Text PDFCurr Ther Res Clin Exp
October 2024
Faculty of Medicine, University of Khartoum, Khartoum, Sudan.
Background: The coronavirus disease 2019 (COVID-19) emerged in China in late 2019 with high rate of spread and transmission. As there was no recognized therapy many people worldwide used herbs in attempt to help their body overcome the disease.
Objective: This study aims to evaluate the use of herbs by patients with COVID-19 in Sudan and tries to identify a possible role in cure or lowering the severity of the illness.
Infect Control Hosp Epidemiol
November 2024
Department of Pediatrics, Duke University Medical Center, Durham, NC, USA.
J Colloid Interface Sci
February 2025
Sichuan Science and Technology Resources Sharing Service Platform of Special Agricultural Resources in Tuojiang River Basin, Neijiang 641112, China; Key Laboratory of Fruit Waste Treatment and Resource Recycling of the Provincial Higher Learning Institutes, Neijiang 641112, China.
Conductive hydrogels are regarded as ideal candidates for the application of flexible sensors owing to their excellent flexibility, portability and conductivity. However, it is still challenging and meaningful to prepare multifunctional (self-healing, adhesion, anti-freezing, biocompatibility, antibacterial and conductivity properties) and multi-mode sensing hydrogel-based sensors. Herein, we developed an environmentally stable and multi-functional conductive organogel via dynamic crosslinks based on biomass materials gelatin, black wattle bark tannin and PVA in the propylene glycol/water binary solvent system.
View Article and Find Full Text PDFChemistry
December 2024
BMI Center for Biomass Materials and Nanointerfaces, College of Biomass Science and Engineering, Sichuan University, Chengdu, Sichuan, 610065, China.
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