Full metadata record
DC FieldValueLanguage
dc.contributorInstitute of Textiles and Clothingen_US
dc.contributor.advisorFei, Bin (ITC)-
dc.contributor.advisorXin, John H. (ITC)-
dc.creatorNg, Pui Fai-
dc.identifier.urihttps://theses.lib.polyu.edu.hk/handle/200/9951-
dc.languageEnglishen_US
dc.publisherHong Kong Polytechnic University-
dc.rightsAll rights reserveden_US
dc.titleInvestigation on natural and man-made hollow fibres for functional applicationsen_US
dcterms.abstractNowadays, core-sheath fibres of which fascinating properties can be assembled into a single fibre are currently utilised in various fields. However, only few studies have focused on the preparation of functional textile fibres with core-sheath configurations. For this reason, this work lays down two approaches, by which natural textile materials, kapok fibre and silk fibroin, were converted into photoluminescence core-sheath fibres for advanced textile applications. Kapok fibre, a natural fibre possessing hollow tubular structure, has been selected to prepare luminous microtubes. A facile and general biomimetic mineralisation method was employed to introduce tungstate-based nano phosphors into kapok lumens. The hydrophobic nature of kapok fibre enables the formation of a uniform phosphor layer on the internal surface. Thorough characterisations of the crystal mineralisation and fibre properties were achieved by various characterisation methods. The resultant fibres achieved a high particle loading over 100 % of the kapok substrate. They exhibited stable red emission under UV irradiation, having potentials for applications in flexible optical devices and anti-counterfeit products. Silkworm silk, another natural textile fibre, was proposed to regenerate into core-sheath fibre by means of microfluidic spinning. Prior to fibre formation, a microfluidic device was prepared through template moulding technique using a highly stretchable gel material. The inherent characteristics of gel template supported replica moulding inside PDMS matrix with different architectures. The resultant microchannels exhibited high surface quality under SEM observation. The as-prepared microfluidic Y-junction device was subsequently used for regenerated silk fibre spinning. However, it was less applicable in preparing uniform filament with core-sheath structure due to fluid leakage at the spinneret-channel connection under high-pressure extrusion. Therefore, regenerated silk-based fibre, consisting of iota-carrageenan/polyacrylamide (τC/PAAm) gel core and silk fibroin/polyurethane (SF/PU) sheath, was prepared by commercial instrument - coaxial metal spinneret. These core-sheath fibres were characterised on morphology, secondary structure, and mechanical properties. Fibres fabricated at sheath concentration of 17 wt% showed the most uniform morphology with circular cross-section. Conformational changes of SF from random coil to ß-sheet structure were encouraged by fibre coagulation and post-drawing, as indicated in XRD analysis and Fourier transform infrared spectroscopy (FTIR). The resultant fibres with proper processing conditions displayed excellent mechanical properties, being suitable in preparing various functional textile materials. Moreover, the fabrication of continuous near-infrared-emitting fibres has been demonstrated by incorporating long-lasting phosphorescent phosphor and fluorescent Ag2S quantum dots (QDs) into the regenerated silk-based fibre. Green-emitting phosphor was introduced into the fibre core during spinning, while various layers of QDs emissive in NIR range were deposited on the fibre surface. Fluorescence spectrometry confirmed that the green emission of the embedded phosphors was absorbed by the surface Ag2S layer to give continuous NIR emission in dark. This modified silk-based fibre supported self-warming properties without using electric circuits, allowing its applications in thermal textile and wearable phototherapy device. Photoluminescence core-sheath fibres have successfully been fabricated herein. The findings could help explore the way forward for the preparation of functional textile materials from natural fibres, which offer benefit to the textile industry and wide consumers.en_US
dcterms.extentxxii, 201 pages : color illustrationsen_US
dcterms.isPartOfPolyU Electronic Thesesen_US
dcterms.issued2019en_US
dcterms.educationalLevelPh.D.en_US
dcterms.educationalLevelAll Doctorateen_US
dcterms.LCSHHong Kong Polytechnic University -- Dissertationsen_US
dcterms.LCSHPlant fibersen_US
dcterms.LCSHTextile fibersen_US
dcterms.accessRightsopen accessen_US

Files in This Item:
File Description SizeFormat 
991022210746503411.pdfFor All Users8.87 MBAdobe PDFView/Open


Copyright Undertaking

As a bona fide Library user, I declare that:

  1. I will abide by the rules and legal ordinances governing copyright regarding the use of the Database.
  2. I will use the Database for the purpose of my research or private study only and not for circulation or further reproduction or any other purpose.
  3. I agree to indemnify and hold the University harmless from and against any loss, damage, cost, liability or expenses arising from copyright infringement or unauthorized usage.

By downloading any item(s) listed above, you acknowledge that you have read and understood the copyright undertaking as stated above, and agree to be bound by all of its terms.

Show simple item record

Please use this identifier to cite or link to this item: https://theses.lib.polyu.edu.hk/handle/200/9951