Use of Limestone Sludge in the Preparation of ɩ-Carrageenan/Alginate-Based Films
The use of processed limestone sludge as a crosslinking agent for films based on Na–alginate and ɩ-carrageenan/Na-alginate blends was studied. Sorbitol was tested as a plasticizer. The produced gel formulations included alginate/sorbitol and carrageenan/alginate/sorbitol mixtures, with tested sorbit...
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| author | Pedro Adão Maria da Luz Calado Wilson Fernandes Luís G. Alves Leonor Côrte-Real Mafalda Guedes Ricardo Baptista Raul Bernardino Maria M. Gil Maria Jorge Campos Susana Bernardino |
| author_facet | Pedro Adão Maria da Luz Calado Wilson Fernandes Luís G. Alves Leonor Côrte-Real Mafalda Guedes Ricardo Baptista Raul Bernardino Maria M. Gil Maria Jorge Campos Susana Bernardino |
| author_sort | Pedro Adão |
| collection | DOAJ |
| description | The use of processed limestone sludge as a crosslinking agent for films based on Na–alginate and ɩ-carrageenan/Na-alginate blends was studied. Sorbitol was tested as a plasticizer. The produced gel formulations included alginate/sorbitol and carrageenan/alginate/sorbitol mixtures, with tested sorbitol concentrations of 0.0, 0.5 and 1.0 wt%. The limestone sludge waste obtained from the processing of quarried limestone was converted into an aqueous solution of Ca<sup>2+</sup> by dissolution with mineral acid. This solution was then diluted in water and used to induce gel crosslinking. The necessity of using sorbitol as a component of the crosslinking solution was also assessed. The resulting films were characterized regarding their dimensional stability, microstructure, chemical structure, mechanical performance and antifungal properties. Alginate/sorbitol films displayed poor dimensional stability and were deemed not viable. Carrageenan/alginate/sorbitol films exhibited higher dimensional stability and smooth and flat surfaces, especially in compositions with 0.5 wt% sorbitol. However, an increasing amount of plasticizer appears to result in severe surface cracking, the development of a segregation phenomenon affecting carrageenan and an overall decrease in films’ mechanical resistance. Although further studies regarding film composition—including plasticizer fraction, film optimal thickness and film/mold material interaction—are mandatory, the attained results show the potential of the reported ɩ-carrageenan/alginate/sorbitol films to be used towards the development of viable films derived from algal polysaccharides. |
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| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-04-24T10:40:05Z |
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| series | Materials |
| spelling | doaj.art-5b14b4dfbc04423da5b34ab1131a15472024-04-12T13:22:17ZengMDPI AGMaterials1996-19442024-04-01177166810.3390/ma17071668Use of Limestone Sludge in the Preparation of ɩ-Carrageenan/Alginate-Based FilmsPedro Adão0Maria da Luz Calado1Wilson Fernandes2Luís G. Alves3Leonor Côrte-Real4Mafalda Guedes5Ricardo Baptista6Raul Bernardino7Maria M. Gil8Maria Jorge Campos9Susana Bernardino10MARE-ARNET and Escola de Turismo e Tecnologias do Mar, Instituto Politécnico de Leiria, 2520-614 Peniche, PortugalMARE-ARNET and Escola de Turismo e Tecnologias do Mar, Instituto Politécnico de Leiria, 2520-614 Peniche, PortugalMARE-ARNET and Escola de Turismo e Tecnologias do Mar, Instituto Politécnico de Leiria, 2520-614 Peniche, PortugalCentro de Química Estrutural, Institute of Molecular Sciences, Department of Chemical Engineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais 1, 1049-001 Lisboa, PortugalCentro de Química Estrutural, Institute of Molecular Sciences, Department of Chemical Engineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais 1, 1049-001 Lisboa, PortugalUnIRE, ISEL, Instituto Politécnico de Lisboa, Av. Conselheiro Emídio Navarro 1, 1959-007 Lisboa, PortugalUnIRE, ISEL, Instituto Politécnico de Lisboa, Av. Conselheiro Emídio Navarro 1, 1959-007 Lisboa, PortugalMARE-ARNET and Escola de Turismo e Tecnologias do Mar, Instituto Politécnico de Leiria, 2520-614 Peniche, PortugalMARE-ARNET and Escola de Turismo e Tecnologias do Mar, Instituto Politécnico de Leiria, 2520-614 Peniche, PortugalMARE-ARNET and Escola de Turismo e Tecnologias do Mar, Instituto Politécnico de Leiria, 2520-614 Peniche, PortugalMARE-ARNET and Escola de Turismo e Tecnologias do Mar, Instituto Politécnico de Leiria, 2520-614 Peniche, PortugalThe use of processed limestone sludge as a crosslinking agent for films based on Na–alginate and ɩ-carrageenan/Na-alginate blends was studied. Sorbitol was tested as a plasticizer. The produced gel formulations included alginate/sorbitol and carrageenan/alginate/sorbitol mixtures, with tested sorbitol concentrations of 0.0, 0.5 and 1.0 wt%. The limestone sludge waste obtained from the processing of quarried limestone was converted into an aqueous solution of Ca<sup>2+</sup> by dissolution with mineral acid. This solution was then diluted in water and used to induce gel crosslinking. The necessity of using sorbitol as a component of the crosslinking solution was also assessed. The resulting films were characterized regarding their dimensional stability, microstructure, chemical structure, mechanical performance and antifungal properties. Alginate/sorbitol films displayed poor dimensional stability and were deemed not viable. Carrageenan/alginate/sorbitol films exhibited higher dimensional stability and smooth and flat surfaces, especially in compositions with 0.5 wt% sorbitol. However, an increasing amount of plasticizer appears to result in severe surface cracking, the development of a segregation phenomenon affecting carrageenan and an overall decrease in films’ mechanical resistance. Although further studies regarding film composition—including plasticizer fraction, film optimal thickness and film/mold material interaction—are mandatory, the attained results show the potential of the reported ɩ-carrageenan/alginate/sorbitol films to be used towards the development of viable films derived from algal polysaccharides.https://www.mdpi.com/1996-1944/17/7/1668limestone sludgeɩ-carrageenansodium alginatealgal polysaccharidespolysaccharide films |
| spellingShingle | Pedro Adão Maria da Luz Calado Wilson Fernandes Luís G. Alves Leonor Côrte-Real Mafalda Guedes Ricardo Baptista Raul Bernardino Maria M. Gil Maria Jorge Campos Susana Bernardino Use of Limestone Sludge in the Preparation of ɩ-Carrageenan/Alginate-Based Films Materials limestone sludge ɩ-carrageenan sodium alginate algal polysaccharides polysaccharide films |
| title | Use of Limestone Sludge in the Preparation of ɩ-Carrageenan/Alginate-Based Films |
| title_full | Use of Limestone Sludge in the Preparation of ɩ-Carrageenan/Alginate-Based Films |
| title_fullStr | Use of Limestone Sludge in the Preparation of ɩ-Carrageenan/Alginate-Based Films |
| title_full_unstemmed | Use of Limestone Sludge in the Preparation of ɩ-Carrageenan/Alginate-Based Films |
| title_short | Use of Limestone Sludge in the Preparation of ɩ-Carrageenan/Alginate-Based Films |
| title_sort | use of limestone sludge in the preparation of ɩ carrageenan alginate based films |
| topic | limestone sludge ɩ-carrageenan sodium alginate algal polysaccharides polysaccharide films |
| url | https://www.mdpi.com/1996-1944/17/7/1668 |
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