settingsOrder Article Reprints Open AccessArticle Entrapment of Acridine Orange in Metakaolin-Based Geopolymer: A Feasibility Study by Antonio D’Angelo 1,2,Luigi Vertuccio 1,Cristina Leonelli 3ORCID,Mohammad I. M. Alzeer 4 andMichelina Catauro 1,*ORCID 1 Department of Engineering, University of Campania “Luigi Vanvitelli”, Via Roma n. 29, 81031 Aversa, Italy 2 Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, University of Campania “Luigi Vanvitelli”, Via Vivaldi 43, 81100 Caserta, Italy 3 Department of Engineering “Enzo Ferrari”, University of Modena and Reggio Emilia, Via P. Vivarelli 10, 41125 Modena, Italy 4 Fibre and Particle Engineering Research Unit, University of Oulu, Pentti Kaiteran Katu 1, 90014 Oulu, Finland * Author to whom correspondence should be addressed. Polymers 2023, 15(3), 675; https://doi.org/10.3390/polym15030675 Received: 1 January 2023 / Revised: 19 January 2023 / Accepted: 25 January 2023 / Published: 28 January 2023 (This article belongs to the Special Issue Recent Developments in Geopolymer Composites) Download Browse Figures Versions Notes Abstract Few studies have explored the immobilization of organic macromolecules within the geopolymer matrix, and some have found their chemical instability in the highly alkaline geopolymerization media. The present work reports on the feasibility of encapsulating the potentially toxic acridine orange (AO) dye in a metakaolin based geopolymer while maintaining its structural integrity. The proper structural, chemical, and mechanical stabilities of the final products were ascertained using Fourier-transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric (TGA/DTG), and mechanical analyses, whereas the dye integrity and its stability inside the geopolymer were investigated by the UV-Vis analysis. In addition, the antimicrobial activity was investigated. The FT-IR and XRD analyses confirmed the geopolymerization occurrence, whereas the TGA/DTG and mechanical (compressive and flexural) strength revealed that the addition of 0.31% (AO mg/ sodium silicate L) of AO to the fresh paste did not affect the thermal stability and the mechanical properties (above 6 MPa in flexural strength and above 20 MPa for compressive strength) of the hardened product. UV-Vis spectroscopy revealed that the dye did not undergo chemical degradation nor was it released from the geopolymer matrix. The results reported herein provide a useful approach for the safe removal of toxic macromolecules by means of encapsulation within the geopolymer matrix.
Entrapment of Acridine Orange in Metakaolin-Based Geopolymer: A Feasibility Study
Antonio D’Angelo;Luigi Vertuccio;Michelina Catauro
2023
Abstract
settingsOrder Article Reprints Open AccessArticle Entrapment of Acridine Orange in Metakaolin-Based Geopolymer: A Feasibility Study by Antonio D’Angelo 1,2,Luigi Vertuccio 1,Cristina Leonelli 3ORCID,Mohammad I. M. Alzeer 4 andMichelina Catauro 1,*ORCID 1 Department of Engineering, University of Campania “Luigi Vanvitelli”, Via Roma n. 29, 81031 Aversa, Italy 2 Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, University of Campania “Luigi Vanvitelli”, Via Vivaldi 43, 81100 Caserta, Italy 3 Department of Engineering “Enzo Ferrari”, University of Modena and Reggio Emilia, Via P. Vivarelli 10, 41125 Modena, Italy 4 Fibre and Particle Engineering Research Unit, University of Oulu, Pentti Kaiteran Katu 1, 90014 Oulu, Finland * Author to whom correspondence should be addressed. Polymers 2023, 15(3), 675; https://doi.org/10.3390/polym15030675 Received: 1 January 2023 / Revised: 19 January 2023 / Accepted: 25 January 2023 / Published: 28 January 2023 (This article belongs to the Special Issue Recent Developments in Geopolymer Composites) Download Browse Figures Versions Notes Abstract Few studies have explored the immobilization of organic macromolecules within the geopolymer matrix, and some have found their chemical instability in the highly alkaline geopolymerization media. The present work reports on the feasibility of encapsulating the potentially toxic acridine orange (AO) dye in a metakaolin based geopolymer while maintaining its structural integrity. The proper structural, chemical, and mechanical stabilities of the final products were ascertained using Fourier-transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric (TGA/DTG), and mechanical analyses, whereas the dye integrity and its stability inside the geopolymer were investigated by the UV-Vis analysis. In addition, the antimicrobial activity was investigated. The FT-IR and XRD analyses confirmed the geopolymerization occurrence, whereas the TGA/DTG and mechanical (compressive and flexural) strength revealed that the addition of 0.31% (AO mg/ sodium silicate L) of AO to the fresh paste did not affect the thermal stability and the mechanical properties (above 6 MPa in flexural strength and above 20 MPa for compressive strength) of the hardened product. UV-Vis spectroscopy revealed that the dye did not undergo chemical degradation nor was it released from the geopolymer matrix. The results reported herein provide a useful approach for the safe removal of toxic macromolecules by means of encapsulation within the geopolymer matrix.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
