Role of Polymer Stabilization in Governing Oxytetracycline Adsorption on Graphene Oxide

محورهای موضوعی : Polymer

Farand Farzi ¹ , Karim Zare ² , Omid Moradi ³ , Kambiz Larijani ⁴

1 - Department of Chemistry, Science and Research Branch, Islamic Azad University, Tehran, Iran
2 - Department of Chemistry, Science and Research Branch, Islamic Azad University, Tehran, Iran
3 - Department of Chemistry, Shahr-e-Qods Branch, Islamic Azad University, Tehran, Iran
4 - Department of Chemistry, Science and Research Branch, Islamic Azad University, Tehran, Iran

تاریخ دریافت : 1404/08/21 تاریخ انتشار : 1404/10/30

کلید واژه: Graphene oxide, Polymer stabilization, Oxytetracycline, Adsorption behavior, Metal-free adsorbent,

چکیده مقاله :

Oxytetracycline (OTC) is a widely used antibiotic that can persist in aquatic environments and raise environmental concerns. In this work, a graphene oxide/methyl methacrylate (GO/MMA) nanocomposite was synthesized via radical polymerization to explore how polymer stabilization influences the adsorption behavior of OTC on graphene oxide. The presence of the polymer matrix contributed to improved structural stability of GO and affected its interaction with OTC molecules.Adsorption experiments were carried out under optimized conditions, including pH 7.5, an adsorbent dosage of 0.3 g per 100 mL, an initial OTC concentration of 40 mg L⁻¹, a contact time of 90 min, and a temperature of 25 °C. Kinetic analysis showed that the adsorption followed a pseudo-second-order model (R² = 0.995), while equilibrium data were best described by the Langmuir isotherm, yielding a maximum adsorption capacity of 96 mg g⁻¹ and indicating monolayer adsorption.Thermodynamic evaluation revealed that the adsorption process was spontaneous (ΔG° = –3.8 to –5.1 kJ mol⁻¹) and endothermic (ΔH° = +18.7 kJ mol⁻¹), accompanied by a positive entropy change (ΔS° = +52.3 J mol⁻¹ K⁻¹). The adsorption mechanism involved π–π interactions, hydrogen bonding, and electrostatic attractions between OTC and the polymer-stabilized GO surface. In addition, the GO/MMA nanocomposite retained approximately 85% of its initial adsorption capacity after five reuse cycles, demonstrating the beneficial role of polymer stabilization in developing stable, metal-free graphene based adsorbents for antibiotic removal from water.

چکیده انگلیسی:

Oxytetracycline (OTC) is a widely used antibiotic that can persist in aquatic environments and raise environmental concerns. In this work, a graphene oxide/methyl methacrylate (GO/MMA) nanocomposite was synthesized via radical polymerization to explore how polymer stabilization influences the adsorption behavior of OTC on graphene oxide. The presence of the polymer matrix contributed to improved structural stability of GO and affected its interaction with OTC molecules.Adsorption experiments were carried out under optimized conditions, including pH 7.5, an adsorbent dosage of 0.3 g per 100 mL, an initial OTC concentration of 40 mg L⁻¹, a contact time of 90 min, and a temperature of 25 °C. Kinetic analysis showed that the adsorption followed a pseudo-second-order model (R² = 0.995), while equilibrium data were best described by the Langmuir isotherm, yielding a maximum adsorption capacity of 96 mg g⁻¹ and indicating monolayer adsorption.Thermodynamic evaluation revealed that the adsorption process was spontaneous (ΔG° = –3.8 to –5.1 kJ mol⁻¹) and endothermic (ΔH° = +18.7 kJ mol⁻¹), accompanied by a positive entropy change (ΔS° = +52.3 J mol⁻¹ K⁻¹). The adsorption mechanism involved π–π interactions, hydrogen bonding, and electrostatic attractions between OTC and the polymer-stabilized GO surface. In addition, the GO/MMA nanocomposite retained approximately 85% of its initial adsorption capacity after five reuse cycles, demonstrating the beneficial role of polymer stabilization in developing stable, metal-free graphene based adsorbents for antibiotic removal from water.

منابع و مأخذ:

[1] Islam IU, Qurashi AN, Adnan A, Ali A, Malik S, Younas F, Akhtar HT, Farishta F, Janiad S, Ali F, Wang X. Bioremediation and adsorption: strategies for managing pharmaceutical pollution in aquatic environment. Water Air Soil Pollut. 2025 Sep;236(9):579.
[2] Zhou L, Zhang Y, Zhuge R, Wu L, Chu Z, Ma A, Gao P, Wong YK, Zhang J, Peng X, Wang P. Chemoproteomics unveils Sofalcone targeting ribosomal proteins to inhibit protein synthesis in Staphylococcus aureus. Mol Biomed. 2025 May 23;6(1):32.
[3] Singh A, Pratap SG, Raj A. Occurrence and dissemination of antibiotics and antibiotic resistance in aquatic environment and its ecological implications: a review. Environ Sci Pollut Res. 2024 Jul;31(35):47505–29.
[4] Satyam S, Patra S. Innovations and challenges in adsorption-based wastewater remediation: a comprehensive review. Heliyon. 2024 May 15;10(9):e00000.
[5] He X, Wang Z, Jin Z, Qiao L, Zhang H, Chen N. 2D carbon-based dual pioneers: graphene oxide and graphdiyne guiding solar evaporation through three-dimensional mastery. Nanoscale. 2025;17(33):18981–96.
[6] Jing L, Li P, Li Z, Ma D, Hu J. Influence of π–π interactions on organic photocatalytic materials and their performance. Chem Soc Rev. 2025;00(0):1–20.
[7] Nandanwar PM. Composite materials for dye capture: a comprehensive review. J Phys Conf Ser. 2025 Aug 1;3076(1):012017.
[8] Edo GI, Yousif E, Al-Mashhadani MH. Polymethyl methacrylate (PMMA): an overview of its biological activities, properties, polymerization, modifications, and dental and industrial applications. Regen Eng Transl Med. 2025 Sep 22;00:1–27.
[9] Selvam T, Rahman NM, Olivito F, Ilham Z, Ahmad R, Wan-Mohtar WA. Agricultural waste-derived biopolymers for sustainable food packaging: challenges and future prospects. Polymers (Basel). 2025 Jul 9;17(14):1897.

[10] Edo GI, Yousif E, Al-Mashhadani MH. Polymethyl methacrylate (PMMA): an overview of its biological activities, properties, polymerization, modifications, and dental and industrial applications. Regen Eng Transl Med. 2025 Sep 22;00:1–27.
[11] ] Mehralipour J, Bagheri S, Gholami M. Synthesis and characterization of rGO/FeO/Fe₃O₄/TiO₂ nanocomposite and application of photocatalytic process in the decomposition of penicillin G from aqueous solution. Heliyon. 2023 Jul 1;9(7):e00000.
[12] Fan Y, Su J, Xu L, Liu S, Hou C, Liu Y, Cao S. Removal of oxytetracycline from wastewater by biochar modified with biosynthesized iron oxide nanoparticles and carbon nanotubes: modification performance and adsorption mechanism. Environ Res. 2023 Aug 15;231:116307.
[13] Li Z, Tian W, Chu M, Zou M, Zhao J. Molecular imprinting functionalization of magnetic biochar to adsorb sulfamethoxazole: mechanism, regeneration and targeted adsorption. Process Saf Environ Prot. 2023 Mar 1;171:238–49.
[14] Dinarvand H, Moradi O. Sustainable approaches for pharmaceutical pollutant removal: advances in chitosan-based nanocomposite adsorbents. ChemistrySelect. 2025 Apr;10(13):e202405962.
[15] Montes ML, Taylor MA, Alonso RE. Sorption of the emerging pollutant oxytetracycline on eggshell. Experimental and theoretical approaches. Applied Surface Science. 2025 Feb 15;682:161781.

[16] Nishimura T, de Barros IR, Benincá C, Zanoelo EF. Inner-sphere adsorption of orthophosphates on amorphous aluminum hydroxide: the Laplace transform solution to a kinetic model involving first-order Taylor approximations to the Langmuir isotherm. Sep Purif Technol. 2025 Apr 18;133086.
[17] Petroli G, Brocardo de Leon V, Di Domenico M, Batista de Souza F, Zanini Brusamarello C. Application of artificial neural networks and Langmuir and Freundlich isotherm models to the removal of textile dye using biosorbents: a comparative study among methodologies. Can J Chem Eng. 2025 Mar;103(3):1169–82.
[18] Marković VL, Stamenković SN. Freundlich adsorption isotherm for description of gas–surface interaction. Vacuum. 2025 Apr 1;234:114092.
[19] Hansen SI, Sjo̷lin BH, Castelli IE, Vegge T, Jensen AD, Christensen JM. An adsorption isotherm that includes the interactions between adsorbates. J Phys Chem C. 2025 Mar 10;129(11):5393–407.
[20] Yuan G, Kapelewska J, Chu KH. Comparison of Dubinin–Radushkevich isotherm variants for types I and V adsorption of water contaminants. Chem Eng Commun. 2025 Apr 11;1–11.
[21] Fu T, Wu S, Zhao M, Zheng X, Wang Z, Jin Z, Fan C. Preparation and application of cattail residue-based magnetic cellulose composites for tetracycline antibiotics adsorption. Process Saf Environ Prot. 2024 Sep 1;189:598–611.
[22] Yang L, Chen Z, Tang Y, Wen Q. Evaluation of magnetic ion-exchange resin for oxytetracycline removal in secondary effluent: behavior, mechanisms and theoretical calculation. Sep Purif Technol. 2025 Jul 19;361:131333.
[23] Fu T, Wu S, Zhao M, Zheng X, Wang Z, Jin Z, Fan C. Preparation and application of cattail residue-based magnetic cellulose composites for tetracycline antibiotics adsorption. Process Saf Environ Prot. 2024 Sep 1;189:598–611.
[24] Jamiu W, Alu SO, Adekunle JA, Jaji BA, Adio O, Musa AO. Removal of oxytetracycline from aqueous solution using activated carbon derived from Eichhornia crassipes (water hyacinth): kinetics, isotherm, and thermodynamic studies. ChemClass J. 2025 Sep 11;9(3):80-103.
[25] Wen A, Chi K, Du Y, Yuan S, Yu H, Guo Y, Yao W. Impact of casein binding on thermal degradation of oxytetracycline: kinetics, products, and their toxicity. Food Chem. 2025 Jun 15;477:143534.
[26] Sun L, Xing Y, Liu C, Wang Z, Jiang Y, Song T. Water flow-driven N-CQDs/MoS₂ piezoelectric-photocatalytic percarbonate degradation of oxytetracycline: response surface modeling and mechanistic analysis. J Environ Chem Eng. 2025 Jun 12;117563.
[27] Sun L, Xing Y, Liu C, Wang Z, Jiang Y, Song T. Water flow-driven N-CQDs/MoS₂ piezoelectric-photocatalytic percarbonate degradation of oxytetracycline: response surface modeling and mechanistic analysis. J Environ Chem Eng. 2025 Jun 12;117563.
[28] Sun N, Meng Z, Zhen L, Qin Q, Liu W, Xue J, Sun Y, Tong P. Effect of GO on oxytetracycline and Cu²⁺ co-adsorption in a yellow–brown soil. Appl Surf Sci. 2025 Apr 24;163345.
[29] Zhou X, Ding Z, Li Z, Li X, Meng F, Lu L, Wang L. Adsorption characteristics of sludge-based composite biochar for norfloxacin and oxytetracycline in a binary system. Biochem Eng J. 2025 Sep 29;109949.
[30] Jiao Y, Yi Y, Fang Z, Tsang PE. Selective removal of oxytetracycline by molecularly imprinted magnetic biochar. Bioresour Technol. 2024;395:130394.

[31] Jiang W, Cai Y, Liu D, Yu X, Wang Q. Enhanced adsorption performance of oxytetracycline in aqueous solutions by Mg-Fe modified Suaeda-based magnetic biochar. Environ Res. 2024;241:117662.

[32] Jia W, et al. Adsorption of oxytetracycline hydrochloride by magnetic activated carbon: kinetics, mechanism and site energy distribution analysis. Front Mar Sci. 2025;12:1542584.

[33] Nguyen HN, Bui TP, Tran TTH, Nguyen THH, Le PT. Bamboo-derived biochar as an efficient adsorbent for oxytetracycline removal from water. Advances in Bamboo Science. 2025;11:100144.

[34] Yang X, Zhang Y, Xu X, et al. Adsorption performance of zero-valent iron-loaded biochar for tetracycline and oxytetracycline. RSC Adv. 2025;15(issue/page pending):ePub ahead of print.