Cationization of Cellulose Nanofibers for the Removal of Sulfate Ions from Aqueous Solutions

Abstract

In this study, the adsorption properties of cationized cellulose nanofibers (c-CNF) were examined for the removal of sulfate (SO4 2–) ions from aqueous solutions under diverse experimental conditions. Nanofiber mats were fabricated through electrospinning and cationized with 3-chloro-2-hydroxypropyl trimethylammonium chloride (CHTAC). The resultant c-CNF with an ammonium content of 0.134 mmol/g showed the maximum adsorption capacity of 24.5 mg of SO4 2– per gram of sorbent using a Langmuir isotherm model. A pseudo-second-order (PSO) kinetic model was fitted to the adsorption rate data, showing a higher adsorption rate of 0.0022 mg g–1 min–1. Scanning electron microscopy (SEM) micrographs revealed the average fiber diameter to be 280 ± 10 nm, and a BET surface area of 5.04 m2/g was obtained with a BET surface area and porosity analyzer. Fourier transform infrared (FTIR) spectroscopy confirmed the conversion of cellulose acetate (CA) to cellulose and its subsequent cationization. Furthermore, the consequences of cationization were evaluated by zeta potential measurements and thermogravimetric analysis (TGA).

Cationic Lignocellulose Nanofibers from Agricultural Waste as High-Performing Adsorbents for the Removal of Dissolved and Colloidal Substances

“…The zeta-potential of CLCNF-3 was maximum at neutral pH, and a pH that is too high or too low will decrease the zeta-potential. This is similar to the phenomenon observed for another cationized cellulose nanofiber [ 42 ]. The state of the nanofiber surface charge will most likely affect its adsorption performance for anionic contaminants in water [ 41 , 45 ].…”

“…This was a fairly high value when compared with previous reports. In the literature, cationized CNF with an ammonium content of 0.134 mmol/g were obtained using 3-chloro-2-hydroxypropyl trimethylammonium chloride as the cationization agent [ 42 ]. Cationic CNF with a quaternary ammonium group content of 1.2 mmol/g were obtained from cellulose pulp etherified with a quaternary ammonium salt in water [ 15 ].…”

“…By fitting pseudo-first-order (PFO) and pseudo-second-order (PSO) kinetic models to the experimental data ( Figure 10 B,C), this allows further description and understanding of the adsorption process. The equations of these two models are as follows [ 42 ]:…”

Quaternary Ammonium Functionalized Lignosulfonate for Simultaneous Adsorption of Anionic/Cationic Dyes and Desinfection

“…As shown in Figure 2b, the characteristic adsorption peaks at around 3421 cm À 1 , 2943 cm À 1 are attributed to OÀ H stretching vibration peak of hydroxyl, CÀ H asymmetrical stretching vibrations peak of methylene, respectively. [19] Compared to the FT-IR spectra of LSP, the bending vibration peak of À CH 3 in À N + (CH 3 ) 3 at 1413 cm À 1 and the bending vibration peak of methylene group in CH 2 À N + (CH 3 ) 3 at 1474 cm À 1 were obvious in FT-IR spectra of Q-LSP [20,21] Moreover, the peak at 1327 cm À 1 attributed to CÀ N appeared. [22] These results of FT-IR spectra further confirm the successful introduction of quaternary ammonium group to LSP and synthesis of Q-LSP.…”

Recent Advances in the Fabrication and Environmental Science Applications of Cellulose Nanofibril-Based Functional Materials

“…To remove SO 4 2− ions, Gao et al fabricated cellulose derivative-based hybrid materials by combining carboxylate cellulose and ammonium-functionalized cellulose, which served as good biosorbents for the removal of Cu 2+ and SO 4 2− ions simultaneously [ 77 ]. In another case, Muqeet and co-workers reported the cationization of CNFs for the adsorption and removal of SO 4 2− ions from water [ 78 ]. As shown in Figure 6 b, CNF mats were prepared by electrospinning 17% cellulose acetate (CA), which were then cationized with 3-chloro-2-hydroxypropyl trimethylammonium chloride (CHTAC) to form cationized CNFs.…”