In recent decades, researchers have focused on emulating nature by imparting functional properties to various materials, enabling them to exhibit specific functionalities. These advancements have found applications in diverse fields such as space, defence, automotive, clothing, biomedical, and electronics. Surface modifications using different chemical additives have been employed to enhance specific functional properties. However, minimising chemical consumption while preserving crucial functional characteristics remains a key challenge. This research aims to achieve multifunctionality in wool fabric through an in-situ, durable, and eco-friendly technique. Metal salts, combined with four distinct capping agents, were used as precursors for synthesising ZnO-modified woollen fabric. Trimethoxy methyl silane was utilised as a coupling agent, while wool was used as the reducing material. The formation of nanostructured particles was confirmed with the help of scanning electron microscopy (SEM), which revealed the surface morphology. Structural properties were investigated using Attenuated Total Reflection Fourier Transform Infrared spectroscopy (ATR-FTIR) and X-ray diffraction (XRD). The ATR-FTIR results revealed the formation of bonds among ZnO, silane, and wool, providing evidence of bridging between wool-silane and silane-ZnO in the treated samples. This was corroborated by the identification of distinct vibrations at peaks around 760, 930, and 1025 cm-1. EDX analysis also indicated the presence of relevant elements, while XRD analysis verified the presence of the characteristic peak corresponding to ZnO, signifying the existence of a wurtzite structure. Optical properties were further confirmed using UV-visible spectroscopy and dynamic light scattering (DLS) techniques. The formation of ZnO nanoparticles indicated the reduction ability of wool. To elucidate the intrinsic mechanism of reducing metal salts into ZnO, the complex structure of wool, comprising various amino acids with distinct polarities, was investigated. Select amino acids based on polarity were utilised in the synthesis of ZnO, and the formation was validated through the utilisation of transmission electron microscopy (TEM), XRD, ATR-FTIR, UV-vis- spectroscopy, and DLS. These analyses provided further evidence of wool's reduction potential. The research also explored the influences of different precursors. Furthermore, fire retardancy was evaluated using a cone calorimeter, Limiting Oxygen Index (LOI), and vertical flammability tests, confirming superior fire retardancy of the treated samples compared to the untreated ones. Enhanced hydrophobicity was assessed through contact angle measurements on the treated samples comparison to the untreated one. The improved UV ray protection ability of treated samples was demonstrated using a UPF (Ultraviolet Protection Factor) machine. Antimicrobial properties were tested according to AATCC standards. The treated samples exhibited significantly enhanced functional properties when compared to the control fabric, as confirmed by the aforementioned test methods. Additionally, the resilience of the optimised sample was also examined in this research till 25 wash cycles. In textile treatment, the wash resistance of the finishing agent relies on the compatibility and chemical adhesion between the agent and the textile material, ensuring long-lasting durability.
| Date of Award | 17 Apr 2024 |
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| Original language | English |
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| Supervisor | Parikshit Goswami (Main Supervisor) & Sohel Rana (Co-Supervisor) |
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