Photo-regenerable liquid crystalline polymers for the adsorption of organic pollutants

Abstract

The increasing presence of organic pollutants such as herbicides and pesticides in water, soil and air requires efficient strategies for their removal and degradation in a reliable and environmentally sound manner. This work focuses on adsorbent materials for water remediation, also addressing pollutant degradation, a critical aspect allowing adsorbent re-use. A photo-regenerable adsorbent based on a liquid crystal network (LCN) is proposed, consisting of a highly ordered nanoporous material obtained through the polymerization of reactive mesogenic monomers. The addition of titanium dioxide nanoparticles in the LCN matrix as photocatalyst opens to its photoregeneration, allowing degradation of the pollutants and further cycles of adsorption. The LCN-TiO₂ composite was optimized using methylene blue (MB) as a model and then tested for a real pollutant. The adsorber proved its efficiency with a maximum pollutant uptake of 86 wt% and total photoregeneration achieved by irradiation with an ultraviolet source. The best tradeoff of adsorption capacity and photoregeneration efficacy was found for samples loaded with only 1 wt% of TiO₂ nanoparticles. This composite also exhibited a high pollutant adsorption capacity and fast and complete photo-regeneration toward the herbicide Diquat, opening the way for a new versatile strategy for water remediation from emerging organic pollutants.

Keywords

adsorption / liquid crystal networks / photocatalysis / regeneration / water remediation

References

[1] J. Lubchenco, Science 1998, 279, 491.

[2] M. Salgot, M. Folch, Curr. Opin. Environ. Sci. Health 2018, 2, 64.

[3] M. N. Rashed, in Organic Pollutants - Monitoring, Risk and Treatment (Ed: M. N. Rashed), IntechOpen, Rijeka 2013.

[4] J. F. J. R. Pesqueira, M. F. R. Pereira, A. M. T. Silva, J. Clean. Prod. 2020, 261, 121078.

[5] E. Eljarrat, D. Barceló, TrAC, Trends Anal. Chem. 2003, 22, 655.

[6] EU Commission, Circular Economy Action Plan, https://ec.europa.eu/environment/circular-economy/pdf/new_circular_economy_action_plan.pdf (accessed: September 2025).

[7] A. Castellano-Hinojosa, M. J. Gallardo-Altamirano, J. González-López, A. González-Martínez, J. Hazard. Mater. 2023, 447, 130818.

[8] S. Domingo-Echaburu, L. M. Dávalos, G. Orive, U. Lertxundi, Sci. Total Environ. 2021, 800, 149412.

[9] P. Wardrop, J. Shimeta, D. Nugegoda, P. D. Morrison, A. Miranda, M. Tang, B. O. Clarke, Environ. Sci. Technol. 2016, 50, 4037.

[10] S. Bertucci, P. Lova, Sol. RRL 2024, 8, 2400116.

[11] H. Kim, S. D. Kim, Sci. Total Environ. 2024, 946, 174388.

[12] D. Cheng, H. H. Ngo, W. Guo, S. W. Chang, D. D. Nguyen, Y. Liu, Q. Wei, D. Wei, J. Hazard. Mater. 2020, 387, 121682.

[13] T. Langenbach, in Applied Bioremediation - Active and Passive Approaches (Eds: Y. Patil, P. Rao), IntechOpen, Rijeka 2013.

[14] K. C. Khulbe, T. Matsuura, Appl. Water Sci. 2018, 8, 19.

[15] K. K. Yadav, M. M. S. Cabral-Pinto, A. Gacem, A. M. Fallatah, B. Ravindran, S. Rezania, J. S. Algethami, L. Bashier Eltayeb, M. Abbas, T. Hassan Al-shareef, V. Vinayak, C. Truong Son, M. Awjan Alreshidi, J. Manuel Rodríguez-Díaz, R. Z. Homod, Mater. Today Chem. 2024, 40, 102226.

[16] P. Vasudhevan, L. Shuhao, Z. Ruoyu, V. Manikandan, D. Yu, S. Devanesan, P. K. Sarangi, H. Ma, S. Dixit, S. Pu, J. Environ. Chem. Eng. 2025, 13, 115237.

[17] D. B. Tripathy, A. Gupta, Membranes 2023, 13, 713, https://www.mdpi.com/2077-0375/13/8/713 (accessed: October 2025).

[18] D. M. Stevens, J. Y. Shu, M. Reichert, A. Roy, Ind. Eng. Chem. Res. 2017, 56, 10526.

[19] R. Song, J.-A. Lv, Responsive Mater. 2025, 3, e70022.

[20] C.-Y. Lo, Y. Zhao, C. Kim, Y. Alsaid, R. Khodambashi, M. Peet, R. Fisher, H. Marvi, S. Berman, D. Aukes, X. He, Mater. Today 2021, 50, 35.

[21] S. Ma, P. Xue, C. Valenzuela, Y. Liu, Y. Chen, Y. Feng, R. Bi, X. Yang, Y. Yang, C. Sun, X. Xu, L. Wang, Adv. Mater. 2025, 37, 2505018.

[22] Y. Zhang, R. Liu, J. Chen, Responsive Mater. 2025, 3, e20250010.

[23] Y. Xu, X. Zhang, Z. Song, X. Chen, Y. Huang, J. Wang, B. Li, S. Huang, Q. Li, Angew. Chem. Int. Ed. 2024, 63, e202319698.

[24] Y. Xu, M. Jin, J. Wang, S. Huang, Q. Li, Responsive Mater. 2024, 2, e20240020.

[25] J. Gao, Y. Tang, D. Martella, J. Guo, D. S. Wiersma, Q. Li, Responsive Mater. 2023, 1, e20230008.

[26] H. K. Bisoyi, Q. Li, Chem. Rev. 2022, 122, 4887.

[27] Y. Chen, C. Valenzuela, Y. Liu, X. Yang, Y. Yang, X. Zhang, S. Ma, R. Bi, L. Wang, W. Feng, Matter 2025, 8, 101904.

[28] R. Lan, X.-G. Hu, J. Chen, X. Zeng, X. Chen, T. Du, X. Song, H. Yang, Responsive Mater. 2024, 2, e20230030.

[29] M. Abad, A. Martínez-Bueno, A. Concellón, Adv. Mater. Technol. 2025, n/a, e01236.

[30] H. P. C. van Kuringen, G. M. Eikelboom, I. K. Shishmanova, D. J. Broer, A. P. H. J. Schenning, Adv. Funct. Mater. 2014, 24, 5045.

[31] J. Kloos, N. Joosten, A. Schenning, K. Nijmeijer, J. Membr. Sci. 2021, 620, 118849.

[32] D. Devadiga, A. TN, Adv. Mater. Interfaces 2022, 9, 2101276.

[33] H. P. C. van Kuringen, Z. J. W. A. Leijten, A. H. Gelebart, D. J. Mulder, G. Portale, D. J. Broer, A. P. H. J. Schenning, Macromolecules 2015, 48, 4073.

[34] T. Liang, H. P. C. van Kuringen, D. J. Mulder, S. Tan, Y. Wu, Z. Borneman, K. Nijmeijer, A. P. H. J. Schenning, ACS Appl. Mater. Interfaces 2017, 9, 35218.

[35] S. Tian, S. J. D. Lugger, C.-S. Lee, M. G. Debije, A. P. H. J. Schenning, J. Am. Chem. Soc. 2023, 145, 19347.

[36] Y. Foelen, R. Puglisi, M. G. Debije, A. P. H. J. Schenning, ACS Appl. Opt. Mater. 2023, 1, 107.

[37] D. J. Mulder, L. M. W. Scheres, J. Dong, G. Portale, D. J. Broer, A. P. H. J. Schenning, Chem. Mater. 2017, 29, 6601.

[38] S. Suárez, I. Jansson, B. Ohtani, B. Sánchez, Catal. Today 2019, 326, 2.

[39] I. Jansson, S. Suárez, F. J. Garcia-Garcia, B. Sánchez, Appl. Catal., B 2015, 178, 100.

[40] W. Yu, L. Zhang, H. Xu, H. Wang, X. Peng, S. Wu, W. Yang, J. Zhou, Fuel 2021, 286, 119427.

[41] L. A. d. Silva, S. M. S. Borges, P. N. Paulino, M. A. Fraga, S. T. d. Oliva, S. G. Marchetti, M. d. C. Rangel, Catal. Today 2017, 289, 237.

[42] S. Mazzanti, G. Manfredi, A. J. Barker, M. Antonietti, A. Savateev, P. Giusto, ACS Catal. 2021, 11, 11109.

[43] B. Dauth, P. Giusto, B. König, R. M. Gschwind, Angew. Chem. Int. Ed. 2024, 63, e202412972.

[44] C. Karthikeyan, P. Arunachalam, K. Ramachandran, A. M. Al-Mayouf, S. Karuppuchamy, J. Alloys Compd. 2020, 828, 154281.

[45] M. Akkari, P. Aranda, H. Ben Rhaiem, A. Ben Haj Amara, E. Ruiz-Hitzky, Appl. Clay Sci. 2016, 131, 131.

[46] D. Wang, Y. Ying, L. Cai, H. Cheng, S. Giannakis, G. Moussavi, Z. He, S. Song, J. Ma, Chem. Eng. J. 2025, 516, 163890.

[47] A. Jamrah, H. Al-Jawaldeh, T. M. Al-Zghoul, A. Hamaideh, M. M. Darwish, E. Al-Karablieh, Water Conserv. Manage. 2024, 8, 415.

[48] N. Bashir, T. Sawaira, A. Jamil, M. Awais, A. Habib, A. Afzal, Mater. Today Sustain. 2024, 27, 100869.

[49] T. Zhou, G. Che, C. Liu, L. Ding, H. Teng, Arab. J. Chem. 2024, 17, 105808.

[50] R. S. Pedanekar, S. K. Shaikh, K. Y. Rajpure, Curr. Appl. Phys. 2020, 20, 931.

[51] G. Che, W. Yang, J. Luo, M. Li, X. Li, Q. Pan, Sep. Purif. Technol. 2024, 334, 126126.

[52] S. H. Yuen, J. E. Bagness, D. Myles, Analyst 1967, 92, 375.

[53] H.-Q. Chen, X.-Y. Wang, H. K. Bisoyi, L.-J. Chen, Q. Li, Langmuir 2021, 37, 3789.

[54] J. W. Goodby, G. W. Gray, in Handbook of Liquid Crystals (Eds: D. Demus, J. W. Goodby, G. W. Gray, H. W. Spiess, V. Vill), Vol. III, Wiley, NY, USA 1998.

[55] D. Dunmur, K. Toriyama, in Handbook of Liquid Crystals (Eds: D. Demus, J. W. Goodby, G. W. Gray, H. W. Spiess, V. Vill), Vol. III, Wiley, NY, USA 1998.

[56] M. J. Stephen, J. P. Straley, Rev. Mod. Phys. 1974, 46, 617.

[57] D. Martella, M. Mannelli, R. Squecco, R. Garella, E. Idrizaj, D. Antonioli, M. Laus, D. S. Wiersma, T. Gamberi, P. Paoli, C. Parmeggiani, T. Fiaschi, iScience 2021, 24, 103077.

[58] P. Simova, N. Kirov, M. P. Fontana, H. Ratajczak, Atlas of Vibrational Spectra of Liquid Crystals, World Scientific Publishing, Singapore 1988.

[59] H. Swenson, N. P. Stadie, Langmuir 2019, 35, 5409.

[60] S. P. Yadav, R. Manohar, S. Singh, Liq. Cryst. 2015, 42, 1095.

[61] S. Hao, Z. Jia, J. Wen, S. Li, W. Peng, R. Huang, X. Xu, Sep. Purif. Technol. 2021, 255, 117772.

[62] F. Yang, P. Yang, Macromol. Rapid Commun. 2022, 43, 2100669.

[63] A. Mills, J. Wang, J. Photochem. Photobiol., A 1999, 127, 123.

[64] D. P. DePuccio, P. Botella, B. O’Rourke, C. C. Landry, ACS Appl. Mater. Interfaces 2015, 7, 1987.

[65] X. Yan, T. Ohno, K. Nishijima, R. Abe, B. Ohtani, Chem. Phys. Lett. 2006, 429, 606.

[66] N. Serpone, J. Photochem. Photobiol., A 1997, 104, 1.

[67] H. H. Funderburk ., N. S. Negi, J. M. Lawrence, Weeds 1966, 14, 240.

[68] P. Slade, A. E. Smith, Nature 1967, 213, 919.

[69] M. Chen, Z. H. Farooqi, G. Bolognesi, G. T. Vladisavljević, Langmuir 2023, 39, 18784.

[70] F. Duran, C. Diaz-Uribe, W. Vallejo, A. Muñoz-Acevedo, E. Schott, X. Zarate, ACS Omega 2023, 8, 27284.

[71] L. Laysandra, M. W. M. K. Sari, F. E. Soetaredjo, K. Foe, J. N. Putro, A. Kurniawan, Y.-H. Ju, S. Ismadji, Heliyon 2017, 3, e00488.

[72] X. Jaramillo-Fierro, G. Cuenca, Int. J. Mol. Sci. 2024, 25, 4367.

[73] V. Rangel-Contreras, O. Reyes-Vallejo, V. Subramaniam, J. Mater. Sci. Mater. Electron. 2024, 35, 1301.

[74] F. Chen, Z. Liu, Y. Liu, P. Fang, Y. Dai, Chem. Eng. J. 2013, 221, 283.

[75] J. Li, J. Feng, W. Yan, Appl. Surf. Sci. 2013, 279, 400.

[76] H. Mittal, S. S. Ray, Int. J. Biol. Macromol. 2016, 88, 66.

[77] M. Turriani, N. Cosottini, N. Fuochi, D. S. Wiersma, D. Martella, C. Parmeggiani, Soft Matter 2025, 21, 1162.

[78] M. Náfrádi, T. Alapi, L. Farkas, G. Bencsik, G. Kozma, K. Hernádi, Materials 2022, 15, 49.

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2025 The Author(s). Responsive Materials published by John Wiley & Sons Australia, Ltd on behalf of Southeast University.