With the technological progress of materials science, the palette of colours with which to print on textiles has expanded beyond those with previously known properties and expressions to a new generation, with more advanced functionality and expressive properties. This new range of colours is characterised by their ability when printed on textiles to change colour in relation to external factors and internal programmes; for example, leuco dye-based thermochromic inks generally change colour in response to temperature fluctuations. This research explores the design properties and potentials of leuco dye-based thermochromic inks printed on textiles, with regard to creating a wider range of colour-changing effects for textile applications. The significance of this for textile design is related to the development of a methodology for designing dynamic surface patterns. The research was conducted by creating a series of design experiments using leuco dye-based thermochromic inks, which resulted in different recipes and methods, along with a pedagogical tool. The results highlighted the diverse colour-changing properties of leuco dye-based thermochromic inks, which have the potential to create more complex patterns on textiles. The outcome of this research proposes a foundation for textile designers with which to approach new ways of thinking and designing.

A dynamic mathematical model was developed to simulate the response of polyacrylamide gel (PAG) dosimeters to a single spherical radioactive brachytherapy seed. Simulations were conducted for a high dose-rate (HDR) seed using 192Ir and a low dose-rate (LDR) seed using 125I. The model is able to predict the amount of polymer formed, the crosslink density, and the volume fraction of aqueous phase as a function of radial distance and time. Results show that PAG dosimeters can provide accurate HDR brachytherapy dosimetry at distances larger than 4 mm from the centre of the seed but will give poor results for LDR due to monomer diffusion. Experiments were conducted to evaluate the potential for using pentacosa-10,12-diynoic acid (PCDA) as the reporter molecule in micelle gel dosimeters for optical computed tomography (CT) readout. Several gels containing PCDA that was solubilized using sodium dodecyl sulfate (SDS) responded to radiation by changing from colourless to blue. Unfortunately, all phantoms that showed colour changes were turbid, making them unsuitable for optical CT scanning. Several techniques were used to produce transparent gels containing PCDA but none of these gels responded noticeably to radiation. Only turbid gels with precipitated PCDA responded, indicating that the colour change was due to oligomerization within PCDA crystals and that PCDA molecules solubilized in micelles did not undergo oligomerization. As a result, PCDA is not suitable for use in radiochromic micelle gel dosimeters. A new recipe for a radiochromic leuco crystal violet (LCV) micelle gel dosimeters with enhanced dose sensitivity was developed for optical CT readout. The recipe contains LCV, trichloro acetic acid (TCAA), Cetyl Trimethyl Ammonium Bromide (CTAB), 2,2,2-Trichloroethanol (TCE), and gelatin. Experiments were conducted to improve understanding about interactions between the different components of LCV micelle gel, highlighting the importance of pH on dose sensitivity and transparency. Results also showed the effectiveness of chlorinated compounds in improving dose sensitivity. Statistical techniques were used to build empirical models that were used to optimize the gel recipe. Additional testing in larger phantoms will be required to assess the effectiveness of the proposed gel for clinical dosimetry. / Thesis (Ph.D, Chemical Engineering) -- Queen's University, 2014-03-27 11:11:47.655