From unavoidable food waste to advanced biomaterials: microfibrilated lignocellulose production by microwave-assisted hydrothermal treatment of cassava peel and almond hull

Abstract

Lignocellulose based nanomaterials are emerging green biosolids commonly obtained from wood pulp. Alternative feedstocks, such as as unavoidable food waste, are interesting resources for nano/microfibers. This research reports the production and characterization of microfibrillated lignocellulose (MFLC) from cassava peel (CP) and almond hull (AH) via acid-free microwave-assisted hydrothermal treatment (MHT) at different temperatures (120–220 °C). During processing, the structural changes were tracked by ATR-IR, TGA, XRD, 13C CPMAS NMR, zeta potential, HPLC, elemental analysis (CHN; carbon, hydrogen and nitrogen), TEM and SEM analyses. The microwave processing temperature and nature of feedstock exerted a significant influence on the yields and properties of the MFLCs produced. The MFLC yields from CP and AH shifted by 15–49% and 31–73%, respectively. Increasing the MHT temperature substantially affected the crystallinity index (13–66% for CP and 36–62% for AH) and thermal stability (300–374 °C for CP and 300–364 °C for AH) of the MFLCs produced. This suggested that the MFLC from CP is more fragile and brittle than that produced from AH. These phenomena influenced the gelation capabilities of the fibers. AH MFLC pretreated with ethanol at low temperature gave better film-forming capabilities, while untreated and heptane pretreated materials formed stable hydrogels at solid concentration (2% w/v). At high processing temperatures, the microfibrils were separated into elementary fibers, regardless of pretreatment or feedstock type. Given these data, this work demonstrates that the acid-free MHT processing of CP and AH is a facile method for producing MFLC with potential applications, including adsorption, packaging and the production of nanocomposites and personal care rheology modifiers. Graphic abstract

Adsorption Recycling and High-Value Reutilization of Heavy-Metal Ions from Wastewater: As a High-Performance Anode Lithium Battery

“…As shown in Figure S1f, the original stacked cellulose was separated, whereas the lignin particles were still attached to the cellulose. 18 According to the above analysis, the physical and chemical synergistic pretreatment of LC can effectively disperse and dissolve its components, improve solvent accessibility between its molecular chains, and expose more adsorption active sites.…”

Hydrothermal Treatment of Biomass Feedstocks for Sustainable Production of Chemicals, Fuels, and Materials: Progress and Perspectives

“…Microwave-assisted hydrothermal treatment is widely used for conversion of biomass into value-added products, namely biochemicals (e.g., furfural, sugars, and carboxylic acids), biofuels, and biomaterials (e.g., hydrochars) − (Table ).…”

Production of Hydrogels from Microwave-Assisted Hydrothermal Fractionation of Blackcurrant Pomace

“…By utilizing microwave energy, this process effectively and specifically eliminates hemicellulose, pectin, and amorphous cellulose from the biomass. This approach has been successfully applied to various biomass sources for production of pectineus and cellulosic materials [ 10 , 11 , 12 , 13 , 14 ].…”

“…Moreover, it has been found that cellulose recovered from MW extraction may lead to the formation of hydrogels. Several studies demonstrate that water and cellulose exhibit a strong affinity, allowing them to form gels [ 10 , 12 , 13 , 14 , 15 ]. The abundant hydroxyl groups present in cellulose play a vital role in creating a three-dimensional hydrogel by attracting and retaining water through hydrogen bonding [ 16 ].…”

“…It allows for the production of biop e.g., pectin and cellulose, that are free from chemical or biological additives and dergone defibrillation. By utilizing microwave energy, this process effectively an ically eliminates hemicellulose, pectin, and amorphous cellulose from the biom approach has been successfully applied to various biomass sources for productio tineus and cellulosic materials [10][11][12][13][14].…”