Reusable and Recyclable pH-Responsive Hydrogel Particles for Acid/Base-Regulated Adsorption/Desorption Switching of Anionic Azo Dyes
- 1Osaka Institute of Technology (OIT) , , 5-16-1 Omiya, Asahi-ku , ,
- 2Widya Mandala Surabaya Catholic University , , Jalan Kalijudan 37 , ,
- 3Osaka Research Institute of Industrial Science and Technology (ORIST) , , 1-6-50 Morinomiya, Joto-ku , ,
Abstract
This study demonstrates the rational design of high-performance, pH-responsive hydrogel particle adsorbents synthesized via precipitation polymerization for advanced water remediation. An N,N-dimethylaminoethyl methacrylate unit was selected as the cationic functional group in the hydrogel particles for the removal of anionic azo dyes. The engineered three-dimensional polymeric network exhibited excellent adsorption efficiencies and rapidly reached adsorption equilibrium via electrostatic interactions on the adsorbent interface. Notably, mild acid/base stimuli of the hydrogel particles enabled switchable adsorption/desorption and recycling of the adsorbents with a removal efficiency of approximately 100%, which was maintained over 10 cycles. Increasing the molar composition of N,N-dimethylaminoethyl methacrylate from 20 to 60% increased the maximum adsorption capacity from 282 to 904 mg/g. The adsorption process for the anionic dyes fitted well to the pseudo-second-order kinetic model and the Langmuir isotherm model. The sorption behavior was predominantly driven by reversible, pH-dependent electrostatic associations with ion pairing between the adsorbent amino cation and adsorbate sulfonated anion. The rapid adsorption/desorption through acid/base stimuli based on pH switching provided high selectivity for anionic dyes in a mixed solution with cationic dyes. Furthermore, the adsorbents demonstrated superior removal efficiencies for various colored dyes in multicomponent contaminated solutions. These findings highlight the potential of acid/base-responsive hydrogel particles as robust, smart interfacial platforms for rapid, efficient, and selective separation processes.
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BibTeX
@article{takahashi2026reusable,
title = {{Reusable and Recyclable pH-Responsive Hydrogel Particles for Acid/Base-Regulated Adsorption/Desorption Switching of Anionic Azo Dyes}},
author = {Hyo Takahashi and Maria Yuliana and Felycia Edi Soetaredjo and Motohiro Shizuma and Masahiro Muraoka and Shintaro Kawano},
journal = {ACS Omega},
year = {2026},
month = oct,
doi = {10.1021/acsomega.6c06135},
url = {https://pubs.acs.org/acsodf/article/11/41/63110/5448179/Reusable-and-Recyclable-pH-Responsive-Hydrogel},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - JOUR
TI - Reusable and Recyclable pH-Responsive Hydrogel Particles for Acid/Base-Regulated Adsorption/Desorption Switching of Anionic Azo Dyes
AU - Hyo Takahashi
AU - Maria Yuliana
AU - Felycia Edi Soetaredjo
AU - Motohiro Shizuma
AU - Masahiro Muraoka
AU - Shintaro Kawano
PY - 2026
DA - 2026/10/09
JO - ACS Omega
DO - 10.1021/acsomega.6c06135
UR - https://pubs.acs.org/acsodf/article/11/41/63110/5448179/Reusable-and-Recyclable-pH-Responsive-Hydrogel
AB - This study demonstrates the rational design of high-performance, pH-responsive hydrogel particle adsorbents synthesized via precipitation polymerization for advanced water remediation. An N,N-dimethylaminoethyl methacrylate unit was selected as the cationic functional group in the hydrogel particles for the removal of anionic azo dyes. The engineered three-dimensional polymeric network exhibited excellent adsorption efficiencies and rapidly reached adsorption equilibrium via electrostatic interactions on the adsorbent interface. Notably, mild acid/base stimuli of the hydrogel particles enabled switchable adsorption/desorption and recycling of the adsorbents with a removal efficiency of approximately 100%, which was maintained over 10 cycles. Increasing the molar composition of N,N-dimethylaminoethyl methacrylate from 20 to 60% increased the maximum adsorption capacity from 282 to 904 mg/g. The adsorption process for the anionic dyes fitted well to the pseudo-second-order kinetic model and the Langmuir isotherm model. The sorption behavior was predominantly driven by reversible, pH-dependent electrostatic associations with ion pairing between the adsorbent amino cation and adsorbate sulfonated anion. The rapid adsorption/desorption through acid/base stimuli based on pH switching provided high selectivity for anionic dyes in a mixed solution with cationic dyes. Furthermore, the adsorbents demonstrated superior removal efficiencies for various colored dyes in multicomponent contaminated solutions. These findings highlight the potential of acid/base-responsive hydrogel particles as robust, smart interfacial platforms for rapid, efficient, and selective separation processes.
SN - 2470-1343
ER -