No abstract

The textile fiber made of poly(trimethylene terephthalate) came onto the market a few years ago. This fiber has certain advantages over traditional polyester, especially its greater elasticity and the fact that it can be dyed at lower temperatures. Here we study the dyeing kinetics of this “new” fiber using an azo disperse dye, C.I. Disperse Red 82, observing that the dyeing rate increases with temperature and that dyebath exhaustions only reach acceptable levels at temperatures above 80 °C. In order to quantify and compare the experimental data obtained, three kinetics models have been chosen. To fit results with models, non-linear regression methods have been applied and, to differentiate between early and final stages, two levels of exhaustion have been checked. From results obtained with the Chrastil model, apparent diffusion coefficients and the activation energy of diffusion have been calculated.

Biofunctional textiles are materials with new properties and added value. In this work, emphasis was placed on the release capacity of the active principle (caffeine) from the formulation or from the biofunctional textile. In addition, a new in vitro methodology of percutaneous absorption was designed to demonstrate the delivery of encapsulated caffeine from the biofunctional textile to the different skin layers. In the first step, permeation studies through a nylon membrane were performed and the release capacity of caffeine present in the samples was quantified. In the second step, it was possible to detect the presence of caffeine in the different layers of the skin, while maintaining a close contact between the biofunctional textile and the skin by using pressure during the percutaneous absorption test. The new system is satisfactory for measuring the pass of the active principle from the biofunctional textile to the different skin layers.

In recent years, new technologies have led to the production of biofunctional textiles. These biofunctional textiles contain microscopic capsules of ingredients that break as the fabric rubs the skin, releasing the active agents.\ud Absorption and desorption behaviour of active agents embedded into the different biofunctional textiles should be taken into account when determining the amount of active agents incorporated into these textiles and when following the delivery mechanism as the fabric comes in contact with the skin. In this work, an encapsulated active agent (a sun filter, ethyl hexyl methoxycinnamate [EHMC] into microcapsules or liposomes) was applied by foulard onto different fabrics. The amount of capsules and active agents embedded into the fibres were quantified by (1) weight difference\ud between untreated and treated fabrics, (2) extraction with isopropanol in an ultrasound bath, or (3) extraction with isopropanol/water 50/50 in a soxhlet device. Sun filter detection of the extraction baths was followed by HPLC and by UV spectrophotometry. The results show that the real amount of the EHMC present in different textile substrates depends on the way that the active agent is trapped, the ionic character of the fibres and on the vehicles used.Peer ReviewedPostprint (published version

The antioxidant gallic acid (GA) has been incorporated into cotton (CO) and polyamide (PA) through two different vehicles, that is, liposomes and mixed micelles, and their respective absorption/desorption processes have been studied. Moreover, in vitro percutaneous absorption tests of different cosmetotextiles have been performed to demonstrate antioxidant penetration within the layers of the skin. When GA was embedded into the cosmetotextiles, it always promoted a reservoir effect that was much more marked than that observed for polyamide. Similar penetration was observed in the textiles treated with GA in mixed micelles or liposomes in such compartments of the skin as the stratum corneum, epidermis, and even the dermis. GA was detected in receptor fluid only when CO was treated with MM. This methodology may be useful in verifying how encapsulated substances incorporated into textile materials penetrate human skin. Indeed, such materials can be considered strategic delivery systems that release a given active compound into the skin at specific doses.