Influence of Microwave Heating on Chemical Properties of Liquefied Lignocellulosic Residues

The chemical composition of liquid products obtained from liquefaction of several agro-industrial wastes was analyzed and the effects of microwave treatments were investigated, evaluating changes in chemical composition, structure, and physical properties, looking forward to exploring new utilization routes or processing paths for these liquid products. Gas chromatography–mass spectrometry (GC-MS) showed that the chemical components of liquefied products can be divided into several groups: furans, alcohols, and esters and acid derivatives. The microwave evaluation showed that irradiation at constant power levels affects the compositions of liquefied products. Fourier transform infrared (FT-IR) spectroscopic analysis showed increases in the absorption bands of carbonyl and CH groups, which suggests that microwaves induced more intensive oxidation of hydroxyl groups into carbonyl groups. Elemental analysis indicated higher carbon and lower oxygen contents and higher heat heating value (20 MJ/kg) in treated products with respect to untreated samples. The use of liquefied products as a new energy source has advantages such as their liquid state, convenient energy value, and renewability

Depolymerization of Different Organosolv Lignins in Supercritical Methanol, Ethanol, and Acetone To Produce Phenolic Monomers

Olive tree pruning was delignified by organosolv processes (acetosolv, formosolv, and acetosolv/formosolv) to extract different lignins. The obtained lignins (acetosolv lignin (AL), formosolv lignin (FL), and acetosolv/formosolv lignin (AFL)) were depolymerized using three different solvents (methanol, ethanol, and acetone) under supercritical conditions in a batch reactor to produce high value-added compounds. The recovered products (oil, char, and residual lignin) were analyzed in order to determine their composition and to know the influence of employed solvent and lignin. Lignin was successfully depolymerized in all cases, and the molecular weight of residual lignin was significantly reduced compared to raw lignin. The obtained oil had numerous phenolic monomers, with syringol and guaiacol being the main products in all studied cases. Depolymerization of AFL led to maximum yield of oil (38.04%), and acetone was the best solvent in terms of phenolic monomers production

Chitin Nanoforms Provide Mechanical and Topological Cues to Support Growth of Human Adipose Stem Cells in Chitosan Matrices

The precise role and value of incorporating nanoforms in biologically active matrices for medical applications is not known. In our current work, we incorporate two chitin nanoforms (i.e., nanocrystals or nanofibers) into Genipin-chitosan crosslinked matrices. These materials were studied as 2D films and 3D porous scaffolds to assess their potential as primary support and guidance for stem cells in tissue engineering and regenerative medicine applications. The incorporation of either nanoforms in these 2D and 3D materials reveals significantly better swelling properties and robust mechanical performance in contrast to nanoform-free chitosan matrices. Furthermore, our data shows that these materials, in particular, incorporation of low concentration chitin nanoforms provide specific topological cues to guide the survival, adhesion, and proliferation of human adipose-derived stem cells. These findings demonstrate the potential of Genipin-chitosan crosslinked matrices impregnated with chitin nanoforms as value added materials for stem cell-based biomedical applications