Structural Study of Microporous Xerogels Prepared by Polycondensation of Pyrogallol with Formaldehyde

Microporous xerogels were prepared by polycondensation of pyrogallol with formaldehyde catalyzed by perchloric acid in aqueous medium. The samples were characterized by FTIR absorption spectra. The micro-porosity and the specific surface area are characterized by nitrogen adsorption - desorption isotherms. The obtained characteristics depend on the conditions of polycondensation

Cellulosic Fibers from Lignocellulosic Biomass for Papermaking Applications

This chapter gives a brief overview of the cellulose extraction from Opuntia (Cactaceae) fibers. The suitability of this food waste for pulp and paper production was investigated by the determination of the chemical composition and testing two procedures of delignification: chemical and semichemical pulping processes. Chemical pulping procedure was carried out by using soda-anthraquinone (soda-AQ) mixture, and semichemical pulping process was performed by softening the raw material using soda-hydrogen peroxide (soda-HP) mixture; this operation was followed by mechanical grinding. The obtained fibrous suspensions were characterized by measuring their dimension parameters (fiber length, fiber width, and fine elements), polymerization degree, and their retention water capacity. The effect of pulping process on yield and fiber characteristics in each pulp was studied. The surface morphologies of the produced papers were studied using scanning electron microscope (SEM), and results show the good distribution and individuality of fibers. The structural and mechanical properties of the prepared paper were presented and discussed. Mechanical strength results show the good tenacity of papers made from soda-HP pulping process

Novel Trend in the Use of <em>Opuntia</em> (Cactaceae) Fibers as Potential Feedstock for Material Science Applications

Lignocellulosic fibers from Opuntia biomass, family Cactaceae, were mainly studied for their sustainability and cellulose content richness. This chapter highlights the current exploitation of Opuntia (Cactaceae) as potential feedstock for value-added applications such as reinforcement in composites and paper manufacturing. Cellulosic fibrous network fractions were isolated from different plant parts, and their fundamental properties, chemical and structural compositions, were analyzed, and the obtained results were discussed. The obtained fibrous networks were incorporated into two thermoplastic polymers; their enhancement properties and biodegradability have been studied. However, different recent methods of cellulose fiber extractions (pulping) and paper manufacturing have been investigated by testing two procedures of delignification: chemical and semi-chemical pulping process; these operations were followed by fibrous suspension characterizations and paper productions. The obtained results show the suitability of Opuntia (Cactaceae) for the new trend in ecological and green materials

Integral Valorization of Posidonia oceanica Balls: An Abundant and Potential Biomass

Posidonia oceanica balls (POB), a kind of seagrass, are a significant environmental issue since they are annually discharged onto beaches. Their current usefulness limits interest in their management and enhances the environmental problem. Therefore, in this research, the potential of this lignocellulosic biomass was studied from a holistic biorefinery point of view. To this end, an in-depth study was carried out to select the best pathway for the integral valorization of POBs. First, an autohydrolysis process was studied for the recovery of oligosaccharides. Then, a delignification stage was applied, where, in addition to studying different delignification methods, the influence of the autohydrolysis pre-treatment was also investigated. Finally, cellulose nanofibers (CNFs) were obtained through a chemo-mechanical treatment. The results showed that autohydrolysis not only improved the delignification process and its products, but also allowed the hemicelluloses to be valorized. Acetoformosolv delignification proved to be the most successful in terms of lignin and cellulose properties. However, alkaline delignification was able to extract the highest amount of lignin with low purity. CNFs were also successfully produced from bleached solids. Therefore, the potential of POB as a feedstock for a biorefinery was confirmed, and the pathway should be chosen according to the requirements of the desired end products.This research was funded by the Ministry of Higher Education and Scientific Research of Tunisia and Gobierno Vasco/Eusko Jaurlaritza grant number IT-1498-22

Thermodynamic Analysis of Moisture Adsorption of Taraxacum Officinale’ Powder

This work aims to model the adsorption isotherms and study the essential thermodynamic properties of Taraxacum Officinale’ powder during the moisture adsorption phenomenon at three temperatures 30, 40, and 50°C. The results have been determined by the application of the thermodynamics physical principles to the equilibrium data, which are experimentally measured. The estimated values of the isokinetic and harmonic temperatures and the Gibbs free energy change revealed that the sorption process is non-spontaneous and enthalpy driven