Cellulose derived from textile waste can represent a potentially renewable resource for several industries, but due to strong hydrogen bonds among the cellulosic chains, few solvents can solubilize it without degrading the polymeric chains first. In most cases, the solubilization requires expensive and/or toxic solvents as well as harsh reaction conditions. In this framework, deep eutectic solvents (DES), an emerging class of mild and cheaper solvents characterised by strong hydrogen bond networks and high compositional variability, are under development to be employed in the preparation of cellulose-based materials. In this work, two novel deep eutectic solvents were designed and prepared to treat cotton and textile waste: a mixture of zinc chloride formulated with lactic acid, and a calcium chloride formulated with tartaric acid. Considering the wide variety of chemical compounds that can be used to formulate deep eutectic solvents combined with various formulation conditions, a more fundamental study was carried out on these two new DES through comparison with the benchmark and more common choline chloride based DES, to gain an insight regarding their properties as solvents. Subsequently, they were tested on cellulose. DES chemical stability was monitored through 1H Nuclear Magnetic Resonance, while thermal properties were studied both with Thermogravimetric Analysis and with Differential Scanning Calorimetry. Infrared Spectroscopy was used to evidence hydrogen bond formation, while rheological tests were performed to monitor viscosity and atmospheric water intakes. The first DES formulated, based on zinc chloride, turned out to be chemically active towards cellulosic materials, showing the capability to act as a cellulosic gel cross-linking agent. The second DES, based on calcium chloride, was used to treat cellulose fibres and post-consumer denim waste, and nanocrystalline cellulose (NCC) was successfully obtained. Due to the high DES corrosivity, different formulations were tested, and the role of calcium chloride as the main corrosivity factor was proven. NCC derived from raw cotton fibres and post-consumer denim waste was characterized via Infrared Spectroscopy, X-Ray diffraction and Thermogravimetric Analysis techniques to outline possible changes in chemical structure, crystallinity, and thermal stability. Moreover, conversion from raw cotton to nano fibres was proved through morphological analysis by Transmission Electron Microscopy.

Cellulose derived from textile waste can represent a potentially renewable resource for several industries, but due to strong hydrogen bonds among the cellulosic chains, few solvents can solubilize it without degrading the polymeric chains first. In most cases, the solubilization requires expensive and/or toxic solvents as well as harsh reaction conditions. In this framework, deep eutectic solvents (DES), an emerging class of mild and cheaper solvents characterised by strong hydrogen bond networks and high compositional variability, are under development to be employed in the preparation of cellulose-based materials. In this work, two novel deep eutectic solvents were designed and prepared to treat cotton and textile waste: a mixture of zinc chloride formulated with lactic acid, and a calcium chloride formulated with tartaric acid. Considering the wide variety of chemical compounds that can be used to formulate deep eutectic solvents combined with various formulation conditions, a more fundamental study was carried out on these two new DES through comparison with the benchmark and more common choline chloride based DES, to gain an insight regarding their properties as solvents. Subsequently, they were tested on cellulose. DES chemical stability was monitored through 1H Nuclear Magnetic Resonance, while thermal properties were studied both with Thermogravimetric Analysis and with Differential Scanning Calorimetry. Infrared Spectroscopy was used to evidence hydrogen bond formation, while rheological tests were performed to monitor viscosity and atmospheric water intakes. The first DES formulated, based on zinc chloride, turned out to be chemically active towards cellulosic materials, showing the capability to act as a cellulosic gel cross-linking agent. The second DES, based on calcium chloride, was used to treat cellulose fibres and post-consumer denim waste, and nanocrystalline cellulose (NCC) was successfully obtained. Due to the high DES corrosivity, different formulations were tested, and the role of calcium chloride as the main corrosivity factor was proven. NCC derived from raw cotton fibres and post-consumer denim waste was characterized via Infrared Spectroscopy, X-Ray diffraction and Thermogravimetric Analysis techniques to outline possible changes in chemical structure, crystallinity, and thermal stability. Moreover, conversion from raw cotton to nano fibres was proved through morphological analysis by Transmission Electron Microscopy.

Deep Eutectic Solvents: Fundamental Understanding and Applications in Textile Waste Recovery

SMANIA, ZOE
2022/2023

Abstract

Cellulose derived from textile waste can represent a potentially renewable resource for several industries, but due to strong hydrogen bonds among the cellulosic chains, few solvents can solubilize it without degrading the polymeric chains first. In most cases, the solubilization requires expensive and/or toxic solvents as well as harsh reaction conditions. In this framework, deep eutectic solvents (DES), an emerging class of mild and cheaper solvents characterised by strong hydrogen bond networks and high compositional variability, are under development to be employed in the preparation of cellulose-based materials. In this work, two novel deep eutectic solvents were designed and prepared to treat cotton and textile waste: a mixture of zinc chloride formulated with lactic acid, and a calcium chloride formulated with tartaric acid. Considering the wide variety of chemical compounds that can be used to formulate deep eutectic solvents combined with various formulation conditions, a more fundamental study was carried out on these two new DES through comparison with the benchmark and more common choline chloride based DES, to gain an insight regarding their properties as solvents. Subsequently, they were tested on cellulose. DES chemical stability was monitored through 1H Nuclear Magnetic Resonance, while thermal properties were studied both with Thermogravimetric Analysis and with Differential Scanning Calorimetry. Infrared Spectroscopy was used to evidence hydrogen bond formation, while rheological tests were performed to monitor viscosity and atmospheric water intakes. The first DES formulated, based on zinc chloride, turned out to be chemically active towards cellulosic materials, showing the capability to act as a cellulosic gel cross-linking agent. The second DES, based on calcium chloride, was used to treat cellulose fibres and post-consumer denim waste, and nanocrystalline cellulose (NCC) was successfully obtained. Due to the high DES corrosivity, different formulations were tested, and the role of calcium chloride as the main corrosivity factor was proven. NCC derived from raw cotton fibres and post-consumer denim waste was characterized via Infrared Spectroscopy, X-Ray diffraction and Thermogravimetric Analysis techniques to outline possible changes in chemical structure, crystallinity, and thermal stability. Moreover, conversion from raw cotton to nano fibres was proved through morphological analysis by Transmission Electron Microscopy.
2022
Deep Eutectic Solvents: Fundamental Understanding and Applications in Textile Waste Recovery
Cellulose derived from textile waste can represent a potentially renewable resource for several industries, but due to strong hydrogen bonds among the cellulosic chains, few solvents can solubilize it without degrading the polymeric chains first. In most cases, the solubilization requires expensive and/or toxic solvents as well as harsh reaction conditions. In this framework, deep eutectic solvents (DES), an emerging class of mild and cheaper solvents characterised by strong hydrogen bond networks and high compositional variability, are under development to be employed in the preparation of cellulose-based materials. In this work, two novel deep eutectic solvents were designed and prepared to treat cotton and textile waste: a mixture of zinc chloride formulated with lactic acid, and a calcium chloride formulated with tartaric acid. Considering the wide variety of chemical compounds that can be used to formulate deep eutectic solvents combined with various formulation conditions, a more fundamental study was carried out on these two new DES through comparison with the benchmark and more common choline chloride based DES, to gain an insight regarding their properties as solvents. Subsequently, they were tested on cellulose. DES chemical stability was monitored through 1H Nuclear Magnetic Resonance, while thermal properties were studied both with Thermogravimetric Analysis and with Differential Scanning Calorimetry. Infrared Spectroscopy was used to evidence hydrogen bond formation, while rheological tests were performed to monitor viscosity and atmospheric water intakes. The first DES formulated, based on zinc chloride, turned out to be chemically active towards cellulosic materials, showing the capability to act as a cellulosic gel cross-linking agent. The second DES, based on calcium chloride, was used to treat cellulose fibres and post-consumer denim waste, and nanocrystalline cellulose (NCC) was successfully obtained. Due to the high DES corrosivity, different formulations were tested, and the role of calcium chloride as the main corrosivity factor was proven. NCC derived from raw cotton fibres and post-consumer denim waste was characterized via Infrared Spectroscopy, X-Ray diffraction and Thermogravimetric Analysis techniques to outline possible changes in chemical structure, crystallinity, and thermal stability. Moreover, conversion from raw cotton to nano fibres was proved through morphological analysis by Transmission Electron Microscopy.
Textile recovery
Deep Eutectic
Solvents
DES
Cellulose
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.12608/55412