Textile applications colour change

In this context, in which colour is displayed at the right time, as opposed to the context in which colour is a constant, prerequisites to building sensors have been satisfied, and assuming that these dyes are applicable to textile fibres and substrates, these sensors are the core of a smart textile. In-depth definition of the level of smartness reveals that, other than the visible colour change, no further action is taken from the sensor, which is why the technology is often referred to as passively smart (Bresky et al., 2008). 

Several technologies able to be used for the development of communicative textile devices have been presented. Some of them are already used for the development of textile displays. Their emission of reflective characteristics allow their use for different types of applications. Emissive devices such as luminescent stmctures or optical fibres are preferred for high-visibility outfits for personal safety, for art and fashion design or for advertising events. Reflective devices offer a softer, more discreet colour change, which could preferentially be used for everyday applications such as communicative clothes, home furnishings or fashion. 

Most colour-changing materials are sensitive to external influences such as sunlight, high temperatures, washing or ironing. Moreover, they often have a low fatigue resistance, ie, a short lifetime. For now, these drawbacks limit their applications on textile substrates. Ageing studies and optimization of their lifetime are very important perspectives that will allow the development of their use in many different applications. 

In smart polymer applications in textiles, PCMs and colour change polymers mostly take the form of microcapsules. A microcapsule is an intermediate state which is added to solutions, fibres, films and nonwovens to incorporated a smart function into the textile. These materials may be incorpated into textiles by printing, coating and dyeing. For printing and coating, the materials are microencapsulated first and then coated or printed onto the fabric surface by common methods such as the pad-dry-cure process. 

The Visible Invisibility project investigates contamination aware textile sur ces with applications within healthcare and aims to eventually develop printable ink that will change colour to indicate the presence of bacteria. 

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