About this Research Topic
One of the major environmental problems faced today is the vast amount of water entering almost every industrial manufacturing process and civil wastewater treatment plant, and coming out polluted by chemical contaminants such as heavy metals, organic and inorganic compounds, and hazardous pathogens such as viruses and bacteria. For this reason, increasingly advanced technologies for water remediation are urgently needed, and at present, a large amount of scientific effort is being dedicated to achieving this. Here, we aim to address one specific topic: the application of macroscopic cellulose-functionalized fibers as absorbers of water pollutants. More specifically, we propose a Research Topic focusing on the chemistry involved in the variety of functionalization possibilities for cellulose fibers, as well as advanced techniques and methodologies to characterize the modified fiber surfaces, and finally on the efficiency of functionalized fibers in water remediation applications.
Cellulose fibers have been studied in the past to ascertain their potential use in water remediation. Macroscopic fibers with 5-10 micron diameters, and lengths in the order of several centimeters, could be very interesting in fabricating filters to absorb water pollutants, due to their high surface/weight ratio, high insolubility in water, easy final disposal, and the low-cost production from plants - growing all around the world. Cellulose fibers by themselves can only absorb pollutants that have a strong chemical affinity with hydrophilic surfaces. However, their absorbing or reacting ability can be greatly extended to other types of pollutants by introducing specific chemical groups by surface functionalization. Taking in consideration that careful choice of the polar/nonpolar balance, as well as the length of the macromolecular segments of the coupling agent, gives rise to a variety of interesting modified fibers which can be tested in various different applications. The aim of this Research Topic would be to promote knowledge about functionalized cellulose fibers for water remediation by presenting the most up-to-date research in this field.
Themes to be addressed may include, but are not limited to:
• Techniques for surface functionalization, chemical synthesis of functionalized fibers, and characterization of modified fiber surfaces
• Rational design of surface modifications yielding hydrophilic or hydrophobic and biodegradable substrates for specific pollutants absorption
• Exploitation of the reactivity of surface hydroxyl groups in cellulose to functionalize it in different ways, through nucleophilic substitution reactions with various electrophiles (carbonyls, alkyl halides, epoxides, etc.)
• Use of the acidity of hydrogen to make ion-exchange reactions or to interconvert the reactivity of hydroxyl groups, expanding the range of functionalization even with carbon nucleophiles
• Application of surface functionalized cellulose fibers for water remediation - from heavy metals, organic pollutants, and pharmaceutical products to bacteria and viruses
• Thermodynamic and kinetic mechanisms of absorbing processes
Topic Editor Prof. Giuseppe Chidichimo is the president of the University Spin-Off Company SIRIA S.r.l, and holds a patent in the field of heavy metal polluted water and soil remediation. The other Editors declare no conflicting interests.
Keywords: cellulose functionalized fibers, water remediation, filters, adsorption kinetics, adsorption thermodyanmics
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