Stimuli-Responsive Poly(dimethylaminoethyl methacrylate) Nanogels Templated by Cellulose Nanocrystal Pickering Emulsions for Nitrate Removal

محورهای موضوعی : Applied Nanomaterials and smart polymers

Mojtaba Azizi ¹ , Milad Aghazadeh-Bonab ² , Seyed Mahdi Saedi ³ , Zeynab Emdadi ⁴

1 - Department of Chemistry, Iran University of Science and Technology, P.O. Box 1684613114, Tehran, Iran
2 - Department of Polymer Engineering and Color Technology, Amirkabir University of Technology, P.O. Box 15875-4413, Tehran, Iran
3 - Faculty of Industrial Engineering, Sharif University of Technology, Tehran, Iran
4 - Department of Chemistry, Iran University of Science and Technology, P.O. Box 1684613114, Tehran, Iran

تاریخ دریافت : 1404/08/09 تاریخ انتشار : 1404/11/15

کلید واژه: Pickering emulsion polymerization, pH-responsive PDMAEMA nanohydrogels, Cellulose nanocrystals, Nitrate adsorption, Smart polymers,

چکیده مقاله :

Elevated nitrate in groundwater and surface waters calls for efficient, regenerable adsorbents with low surfactant loading. Herein, pH-responsive poly(dimethylaminoethyl methacrylate)(PDMAEMA) nanohydrogels, using RAFT, through Pickering emulsion polymerization stabilized with cellulose nanocrystals grafted with amphiphilic poly(butylacrylate)-b-poly(dimethylaminoethyl methacrylate)(PBA-b-PDMAEMA), are reported. FT-IR confirmed the successful grafting, and the amphiphile gave a low critical micelle concentration (0.083 mg mL⁻¹), supporting robust interfacial activity. Dynamic light scattering/ζ-potential revealed that pH-dependent changes in size and charge were reversible, becoming more compact and cationic under acidic conditions. Such changes are consistent with protonation of the PDMAEMA. Under batch conditions, such as 500 ppm NO₃⁻ at pH 4, UV-Vis tracking shows rapid, steadily increasing nitrate uptake, evidencing strong electrostatic sorption within the protonated network. All these results establish a structure-function coupling of polymer charge state with anion capture and illustrate a modular route to regenerable adsorbents that avoids conventional surfactants. A readily tunable platform via the block composition and crosslink density shows promise for use in water remediation in continuous flow for nitrate and other anions.

چکیده انگلیسی:

Elevated nitrate in groundwater and surface waters calls for efficient, regenerable adsorbents with low surfactant loading. Herein, pH-responsive poly(dimethylaminoethyl methacrylate)(PDMAEMA) nanohydrogels, using RAFT, through Pickering emulsion polymerization stabilized with cellulose nanocrystals grafted with amphiphilic poly(butylacrylate)-b-poly(dimethylaminoethyl methacrylate)(PBA-b-PDMAEMA), are reported. FT-IR confirmed the successful grafting, and the amphiphile gave a low critical micelle concentration (0.083 mg mL⁻¹), supporting robust interfacial activity. Dynamic light scattering/ζ-potential revealed that pH-dependent changes in size and charge were reversible, becoming more compact and cationic under acidic conditions. Such changes are consistent with protonation of the PDMAEMA. Under batch conditions, such as 500 ppm NO₃⁻ at pH 4, UV-Vis tracking shows rapid, steadily increasing nitrate uptake, evidencing strong electrostatic sorption within the protonated network. All these results establish a structure-function coupling of polymer charge state with anion capture and illustrate a modular route to regenerable adsorbents that avoids conventional surfactants. A readily tunable platform via the block composition and crosslink density shows promise for use in water remediation in continuous flow for nitrate and other anions.

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