Biobased System Composed of Electrospun sc-PLA/POSS/Cyclodextrin Fibers To Remove Water Pollutants

Abstract

In this work, a novel biobased system, characterized by specific features suitable for the removal of water pollutants, was developed. Indeed, the system consists of electrospun stereocomplex polylactide (sc-PLA)-based fibers, prepared from solutions containing equimolar amounts of high-molecular-weight poly(l-lactide) (PLLA) and poly(d-lactide) (PDLA), functionalized with an amino polyhedral oligomeric silsesquioxanes (POSS-NH2), which was added directly into the electrospinning solution. The sc-PLA/POSS-NH2 fibers, characterized by a submicrometric dispersion of the silsesquioxanes, underwent a grafting reaction with β-cyclodextrin molecules, activated to nucleophilic substitution via monotosylation (CD-O-Ts). The reaction was first investigated on neat POSS-NH2 and optimized conditions were then applied for sc-PLA/POSS-NH2 fibers. Indeed, IR and XPS measurements demonstrated the formation of a novel hybrid molecule, characterized by the linkage of the cyclodextrin to the silsesquioxane siliceous cage (POSS-NH-CD). Concerning the fibers, SEM measurements evidenced that the treated mats show a higher surface roughness than the neat ones, whereas by applying TGA analysis it was possible to evaluate the amount of the grafted cyclodextrin, which was found to be 3 wt %, that is a quantity correlated with the concentration of POSS-NH2 in the fibers (5 wt %). Moreover, the surface wettability of the fibers turned out to increase as a consequence of the surface grafting. Finally, UV measurements demonstrated the capacity of the novel synthesized hybrid molecule, based on POSS and cyclodextrin, to absorb water pollutants, by having chosen, as model compounds, alizarin red and 2-chlorophenol. Indeed, it was demonstrated that the grafting of CD on the surface of sc-PLA/POSS-NH2 fibers enhanced the absorption capacity of the system

Electrospun Environment Remediation Nanofibers Using Unspinnable Liquids as the Sheath Fluids: A Review

“…In traditional monolithic nanofibers, the active ingredients are homogeneously distributed all over the polymeric matrices, means that most of them are buried into the nanofibers and can't play their roles for removing the pollutants [66]. With the unspinnable solution as a sheath working fluid, a wide variety of functional ingredients (such as cyclodextrin) can be effectively distributed on the surface of polymeric nanofibers [67,68], and thus their functional performances on environmental remediation can be easily enhanced. Certainly, the modified coaxial electrospinning can further expand its capability of creating novel functional material through a combination with other spinning methods or numerous traditional physical and chemical manners [69,70].…”

Electrospun Fibers of Cyclodextrins and Poly(cyclodextrins)

“…Covalent bonding should avoid the leaching process, even when CD-functionalized mats are exposed over an extended period to pollutants-containing water [ 88 ]. Mixtures of PLA with amino polyhedral oligomeric silsesquioxanes (POSS-NH 2 ) as functional group have been electrospun followed by grafting reaction with βCD via monotosylation [ 98 ]. Click chemistry has been applied for the immobilization of azide-βCDs onto propargyl-terminated cellulose acetate fibers, showing enhanced affinity for phenantrene [ 99 ].…”

Poly (vinyl alcohol)/β-Cyclodextrin Composite Fiber with Good Flame Retardant and Super-Smoke Suppression Properties

“…However, little attention has been paid to the smoke suppression properties of CD, and there has been no CD-containing flame-retardant fiber reported to date. CDs have good spinnability, as demonstrated by Uyar's group and ourselves, who have developed CD and CD composite fibers using the electrospinning method and applied them in drug delivery, antibacterial, molecular entrapment and air filtration [23][24][25][26]. Furthermore, CDs are thermally stable (i.e., the degradation temperature of βCD is up to 300 • C), which may survive from the high post treatment temperatures of the fiber [27].…”