Nanocellulose from Cotton Waste and Its Glycidyl Methacrylate Grafting and Allylation: Synthesis, Characterization and Adsorption Properties

Abstract

Nanocellulose (NC) is getting ahead as a renewable, biodegradable and biocompatible biomaterial. The NCs for this study were recovered from industrial cotton waste (CFT) by acid hydrolysis (HNC) and by 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) mediated oxidation (ONC). They were functionalized by radical based glycidyl methacrylate (GMA) grafting providing crystalline HNC-GMA and ONC-GMA, and by allylation (ALL) providing amorphous HNC-ALL and ONC-ALL. HNC, ONC and their derivatives were chemically and morphologically characterized. Crystalline NCs were found capable to adsorb, from diluted water solution (2 × 10−3 M), the antibiotics vancomycin (VC), ciprofloxacin (CP), amoxicillin (AM) and the disinfectant chlorhexidine (CHX), while amorphous NCs did not show any significant adsorption properties. Adsorption capability was quantified by measuring the concentration change in function of the contact time. The adsorption kinetics follow the pseudo-second order model and show complex adsorption mechanisms investigated by an intraparticle diffusion model and interpreted by structure-property relationships. ONC and ONC-GMA loaded with VC, and HNC and HNC-GMA loaded with CP were not colonized by Staphylococcus aureus and by Klebsiella pneumonia and suggested long lasting release capability. Our results can envisage developing CFT derived NCs for environmental applications (water remediation) and for biomedical applications (antibacterial NC). Among the future developments, it could also be of interest to take advantage of acidic, glycidyl and allyl groups’ reactivity to provide other NCs from the NC object of this study.

Suspended Multifunctional Nanocellulose as Additive for Mortars

“…The estimation of GMA and EGDMA molar substitution ratio ( MS ) was obtained with the method used in our previous works, see Equation (2), [ 25 , 26 , 28 ]: …”

“…A 0.5% suspension of ONC was used. The degree of oxidation ( DO ) is calculated as the ratio of the added moles of NaOH and the moles of the ONC in suspension [ 26 ].…”

“…The crystallinity index ( Cr. I %) of nanocellulosic materials was evaluated by means of the following equation used in our previous works, see Equation (3), [ 25 , 26 , 28 ]: where A corresponds to integrals of C4 peaks at 86–92 ppm (crystalline phase) and B to the integrals of C4 peaks at 80–86 ppm (other components). The signal components of C6 are evaluated by integrating from 69.0 to 64.5 ppm (crystalline phase) and from 64.5 to 59.3 ppm (other components).…”

“…Moreover, in a previous study focused on the biomedical field, other chemical modifications were obtained, such as grafting glycidylmethacrylate (GMA) and further cross-linking with ethylene glycol dimethacrylate (EGDMA). The observed increase in mechanical resistance with respect to the starting NC suggested that they can be preferred to BNC for tissue engineering scaffolds in the cases where resistance plays a crucial role [ 25 , 26 ]. For this reason, GMA and EGDMA modifications were also applied in this work, to investigate their potential in cement-based materials strengthening.…”

Synthesis and Biological Evaluation of a Novel Glycidyl Metharcylate/Phaytic Acid-Based on Bagasse Xylan Composite Derivative

“…BX was modified with GMA by a free radical polymerization technique [ 29 , 30 ]. In brief, BX (1.3 g) was scattered in double distilled water and transferred into a four-neck round-bottom flask, to which GMA (10 mL, 22%), OP-10 (0.5 mL, add OP-10 to disperse GMA in water), and potassium persulfate (10 mL, 5.26%) were added slowly.…”