IMPROVEMENT OF MICROCAPSULES ADHESION TO FABRICS ABSTRACTThe presence of microcapsules has increased in textile field. They have been applied as a possibility to introduce new products to textiles such as fragrances, antibiotic, skin hydrant, etc. This work studies the resin influence on the adhesion of microcapsules to cotton fabrics. To paste microcapsules to fabrics, they should be in contact with a bath which contains microcapsules resin and water. Different resin concentrations were applied to fragrances microcapsules bath by impregnation. The research was focused to determine the influence of resin quantity in the microcapsules resistance to go out from the fabrics while washing treatments. Two experimental techniques, Scanning Electron Microscopy (SEM) and Counter apparatus, are used in order to determinate this influence.We can conclude that with higher quantity of resin, more microcapsules remain on the fabric surface. It is shown than longer microcapsules go out from the fabric faster than the little ones. KEY WORDS Adhesion Resin Microcapsules FabricCotton

An essential oil is the volatile lipophilic component extracted from plants. Microencapsulation systems protect the essential oil from degradation and evaporation, and at the same time allow a sustained release. This work analyzed and characterized the rosemary essential oil microcapsules prepared by co-extrusion technique using alginate as wall material and calcium chloride as cross linker. Several instrumental techniques were used: optical microscopy, coulter counter, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), termogravimetric analysis (TGA), spectrophotometry, antimicrobial test and chromatography. Results show that rosemary oil has pesticidal properties, and its microencapsulation allows knowing that these properties remain inside the microcapsules.

Microcapsules are widely used, being one of the fields which has increased their consumption the textile one. They can be applied to textiles using different methods such as, padding, bath exhaustion, spraying and foaming. Although the most extended industrial application is by padding commercial brands also suggest bath exhaustion as a possible procedure. In the research reported herein, bath exhaustion treatments are compared to padding. XPS (Photoelectronic spectroscopy of X-Rays) technique showed it was a suitable method to detect microcapsules presence on fabric surface. Results reported that high concentrations were required to obtain similar behaviours to those of padding. Moreover, we suggested reusing bath exhaustion baths, in order to minimise the loss of so much product in wastewater. We concluded it was not possible because microcapsules deflate when get in touch with water for a period of time, and what is more interesting, microcapsules preparation must be done just immediately before they are going to be used, so as to avoid microcapsules deflation due to contact with water.

Bonet Aracil, MA.; Monllorpérez, P.; Capablanca Francés, L.; Gisbert Paya, J.; Díaz-García, P.; Montava Seguí, IJ. (2015). A comparison between padding and bath exhaustion to apply microcapsules onto cotton. Cellulose. 22(3)

An essential oil is the volatile lipophilic component extracted from plants. Microencapsulation systems protect the essential oil from degradation and evaporation, and, at the same time, allow a sustained release. This work analyses and characterizes the oregano and sage essential oil microcapsules prepared by interfacial polymerization technique, using polyurea as wall material. Several instrumental techniques are used: optical microscopy, size particle, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), Termo gravimetric analysis (TGA), spectrophotometry, antimicrobial test and chromatography. Results show that oregano and sage oil have antimicrobial properties, and their microencapsulation allows knowing that these properties remain inside the microcapsules.

Electrospinning makes it possible to obtain solid fibers, in addition to core-shell fibers, using coextrusion. However, an exhaustive control of parameters allows the core-shell fibers from emulsion electrospinning to be obtained. The solvent in the outer surface tends to evaporate and the polymer density increases, moving the emulsion drops towards the center, which in turn promotes coalescence, thus creating the core. The aim of this work was to avoid coalescence and obtain a net of nanofibers entrapping oil microcapsules. We obtained an emulsion oil in water (O/W), with polyvinyl alcohol (W) and two essential oils (O), sage and thyme. An electrospinning process was used to place the microcapsules of oil inside a net of nanofibers. The electrospun veil was characterized by organoleptic testing, SEM microscopy, FTIR spectroscopy, DSC thermal analysis, and pressure tests. Organoleptic testing, FTIR spectroscopy, and DSC thermal analysis demonstrated the presence of the oil, which was retained in the spheres observed by SEM microscopy, while pressure tests revealed that the oil remained in a liquid state. Furthermore, we demonstrated a strong relationship between the emulsion size and the final microcapsules created, which are slightly larger due to the shell formation. The size of the emulsion determines whether the spheres will be independent or embedded in the nanofibers. Furthermore, the nanofiber diameter was considerably reduced compared to the nanofibers without the oil.

The aim of this work was to develop a functional biodegradable nonwoven with antimicrobial microcapsules maintaining the stability and biodegradability of the nonwoven for use in agriculture applications. The nonwoven was obtained using hemp fibers by Wetlaid technology. Microcapsules were prepared by co-extrusion/gelling method with alginate as shell and oregano oil as core material. The microcapsules were developed to protect and control release of oregano oil. Microcapsules were incorporated on the nonwoven by coating method using a natural polymer as a graft material. After incorporating microcapsules, the nonwoven was subjected to several tests in order to determinate the microcapsules fixation and their functionality. The nonwovens were characterized for their antimicrobial activity against different kinds of bacteria and fungi. Nonwoven loaded with microcapsules was found to show good antimicrobial activity in comparison with nonwoven that was not loaded with microcapsules.

Natural dyes, obtained from plants, insects/animals, and minerals, are renewable and sustainable bioresource products with minimum environmental impact. However, there are still many issues to solve related to natural dyes; consequently, synthetic dyes are still wildly used. Natural dyes have a low affinity towards the substrate cotton, so a solution had to be found: mordants. Mordants can also be harmful to the environment, which is why bio-mordants are used. The mordant used in this paper is chitosan. Cotton is pre-mordanted using the pad dyeing method. By using the exhaustion method, the fabric was coloured with red Camellia sinensis (tea) extracts. The colour, absorption of polyphenols and tannins, and ultraviolet protection (UPF) were tested. A comparison study was carried out between the cotton fabric and the cotton padded with chitosan at two different concentrations. The results are impressive. Cotton pre-mordanted with chitosan can absorb more polyphenols and tannins than cotton itself, and the colour fastness and UPF, once the fabric is laundered, demonstrate there is some kind of bonding between the fibre, quitosan, and active compounds from tea. The UPF was also doubled by using chitosan and the reddish colour obtained by Camellia sinensis extracts were darker on the cotton fabric. The increase in UPF protection on mordanted fabrics is higher than the gap obtained by colour difference, which means there are active compounds that do not confer colour, but enhance UPF protection.