Chemical functionalization of cellulose nanofibrils with 2-chloroethylamine hydrochloride

Cellulose nanofibrils (CNF) were chemically functionalized with ethylamine groups using a quick, one-pot, water-based approach. Elemental analysis (EA) indicated the effective grafting of amine groups, with degrees of substitution consistent with previously reported values for amine-functionalized nanocellulose. Fourier transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR) indicates that the chemical modification was successful. It was corroborated by Infrared nanospectroscopy (AFM-IR) demonstrating distinctive vibrations associated with methylene and amine groups at both bulk and nanoscale levels. Atomic force microscopy (AFM) revealed a reduction in nanofibril diameter after chemical modification. X-ray diffraction (XRD) revealed that cellulose Iβ crystalline structure remained intact after modification. However, the crystallinity index decreased slightly due to the addition of ethylamine moieties and swelling during reaction. Thermogravimetry (TG) revealed enhanced thermal stability for modified CNF, as shown by higher degradation onset and maximum temperatures. Overall, this study presents an efficient and environmentally friendly approach for tailoring the surface chemistry of CNF while preserving their structural integrity, allowing them to be used in applications such as nanocomposites, coatings, colloidal systems, and filter membranes.