A novel method for dyeing human hair fibres using coloured silica nanoparticles of 206 nm has been developed. Diffusion of coloured silica nanoparticles into hair fibres has been investigated; silica nanoparticles do not penetrate at all, or do so only sparingly, into the structure of Caucasian virgin hair. However, coloured silica nanoparticles diffused readily into bleached hair fibres. Scanning electron microscopy showed that coloured silica nanoparticles were present mainly in the outer regions of the hair structure (the inner layers of the cuticle and the outer region of the cortex). It was found that the silica nanoparticles were physically entrapped in the hair fibres and results showed a good shampoo fastness to washing.

Purpose -The use of organic phase change materials microcapsules (mPCM) has been gaining ground in technical textiles and clothing as a temperature regulating medium and hence a means of keeping the body at a comfortable temperature when wearing impermeable protective clothes. However, for such applications as fire fighter's protective clothes, the standards require that all the material composing the material be fire resistant. The purpose of this paper is to produce a lining containing fire resistant microcapsules of PCM without using flammable binders. Design/methodology/approach -This work tests other ways of fixing mPCM to the fibres with a lot less binder present. Washfastness is evaluated in SEM photographs and by weight. The thermal effect is evaluated in a prototype plate calorimeter. Findings -This method is first tested for fixing mPCM but the non-woven still does not pass the test according to the standard EN532. Microcapsules are alternatively fixed with MF resin, non-flammable, and by applying flame retardant recipes it is possible for the samples to pass the test. Research limitations/implications -Since the amount of flame retardant necessary for the mPCM to stand the test, and the resin to thermo fix it is very high, the material becomes unacceptably stiff.Originality/value -Based on a new approach where reactive microcapsules without any binder are used, it is possible to use a lot less flame retardant and resin, and the material is resistant to the standard EN532. In this standard the material has to resist washing and still be flame retardant.

Exhaustion of a reactive dye for wool is studied in the presence of liposome-forming compounds (lecithin). Both analytical and commercial products are used as a source for the lecithin. Liposome formation is tested with different preparation procedures (ultrasound and mechanical agitation), and the stability is evaluated under different conditions of time, temperature, and the presence of a tensoactive product. The effect of these different conditions and the variation of liposome concentration on exhaustion and levelness is presented. A practical method for dyeing wool with reactive dyes using liposome-forming compounds is proposed based on the results.

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The objective of our work has been the microencapsulation of dyes with lecithin from soybean, with the formation of liposomes, as a substitute for synthetic auxiliaries so as to improve the quality of the effluent. Current scenarios promote the disintegration and leakage of the liposomes, such as, changes in temperature, pH and the use of surfactants. Since dyeing process is a mix of all these parameters, we pretended to study each one separately. Rhodamine 6G fluorescence is known to be concentration quenched through the formation of non-fluorescent dimmers and, additionally, through the energy transfer from rhodamine monomer to these dimmers (Baptista ALF, Coutinho PJG, Real Oliveira MECD, Gomes JINR. Proceedings of 13th International Symposium of Surfactants, SIS 2000, Gainesville, USA, 2000). The temperature, the surfactant and pH induce a release of the encapsulated dye resulting in rhodamine dilution and consequently alterations in the dimerization/binding equilibrium. The experimental spectra indicate that rhodamine binds almost completely to liposomes. The decomposition of the rhodamine fluorescence spectra allowed us to determine the percentage of released dye during a simulated dyeing process, and allowed us to conclude that the dimerization process occurs mainly at the inner interfaces. The amount of dye released induced by temperature changes was greater in the presence of surfactant.