Abstract
In this study, we prepared poly(acryloyl hydrazide) (PAH)-grafted cellulose nanocrystal (CNC-PAH) particles via the atom transfer radical polymerization method for application to Cr(VI) adsorption. The closely-packed PAH chains grafted on the cellulose nanocrystal (CNC) surface provide a high density of amine groups that can adsorb Cr(VI) through strong electrostatic, hydrogen bonding and chelating interactions. CNC-PAH exhibited the optimum Cr(VI) adsorption capacity at the solution pH = 3, where its electrostatic attraction with Cr(VI) was maximized. Cr(VI) was chemisorbed in CNC-PAH by following the Langmuir isotherm mechanism (homogeneous monolayer adsorption). The Cr(VI) adsorption kinetics of CNC-PAH was controlled predominantly by intra-particle diffusion resistance imparted by the PAH shell layer. Thermodynamic analysis revealed that Cr(VI) adsorption of CNC-PAH is a spontaneous and endothermic process. Importantly, CNC-PAH grafted with the higher Mw (∼50 kg mol−1) PAH exhibited a rapid Cr(VI) adsorption rate and remarkably high Cr(VI) adsorption capacity (∼457.6 mg g-1 at 298.15 K), exceeding those of previously reported adsorbents owing to its numerous Cr(VI)-adsorptive amine groups provided by the closely-packed grafted PAH polymers. Furthermore, CNC-PAH showed excellent reusability to maintain its high adsorption ability during repeated adsorption–desorption cycles owing to the covalently binding nature of the PAH polymers.
Original language | English |
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Article number | 122512 |
Journal | Journal of hazardous materials |
Volume | 394 |
DOIs | |
Publication status | Published - 2020 Jul 15 |
Bibliographical note
Funding Information:This research was supported by the National Institute of Forest Science (Grant No.: FP0400-2016-01 ) and the National Research Foundation of Korea (NRF) grant funded by the Korean government (Grant No.: 2019R1A2C1002333 , 2019M3E6A1064103 and 2018R1A4A1022194 ).
Publisher Copyright:
© 2020 Elsevier B.V.
Keywords
- Adsorbents
- Atom transfer radical polymerization
- Cellulose nanocrystal
- Cr(VI) removal
ASJC Scopus subject areas
- Environmental Engineering
- Environmental Chemistry
- Waste Management and Disposal
- Pollution
- Health, Toxicology and Mutagenesis