Authors Ripoll L, Bordes C, Etheve S, Elaissari A, Fessi H
A cosmetotextile is a textile containing a cosmetic preparation mainly for dermatology applications such as moisturizing, slimming or anti stretch mark. This specific textiles functionalization is based on the physical immobilization or impregnation of textile fibers by nano-objects containing active molecules. The preparation of such active nano-objects is generally based on the encapsulation of active molecules by a spherical polymer matrix (particles or capsules) fixed on the fiber. The release of the active molecule is due to the physical degradation of the polymer matrix or shell or, in some cases, via molecule diffusion processes. According to the definition of the Textile Industry and Clothing Standards Agency (BNITH), a cosmetotextile is “a textile item containing a substance or mixture that releases active molecules when in contact with the human body (i.e. on the epidermis, hair, and external sexual organs, with the exclusive or primary intention of cleaning, perfuming, changing aspect, protecting, and helping to maintain or correct body odors). Skin’ Up patented a fabric treatment process using a drug encapsulated in nanoparticles. According to the author, nanoparticle can be titanium or zinc dioxide, fullerenes, nanocrystals, nano emulsions, nano capsules, nanospheres, as well as spherulites. The fabrics are first impregnated with particles by exhaustion bath or spraying. Then fibers are coated with a protective filmogenic polymer to increase washing resistance and prolonged drug release kinetics. In parallel, the authors developed a technique to track drug release according to the number of washings by using a label impregnated by a coloring agent. The concentration of the coloring solution is adjusted as a function of the release kinetics of the drug. Washing depletes the particles present on the fiber and fades the coloring agent on the tag. Thus when the label becomes white the textile no longer contains particles, meaning that reloading is necessary. However, this system does not take into account the release of the drug when the clothes are worn. Therefore the label can still retain its color although there is no more or insufficient active molecules present on the fiber Particular attention has been focused on the elaboration of phase change materials (PCM). The properties of such materials are related to their ability to change their physical state (solid-liquid) as a function of temperature. PCM was first developed in the 1980s in order to protect astronauts against the high temperature fluctuations. Today such materials are used in textile to provide thermal control. There are different ways to obtain PCM, but the most investigated ones are based on the encapsulation of phase change material in microparticle. Then such microparticles are immobilized on textile or included into the fiber. Some years ago cosmetotextiles resisted only several washes. Currently, this resistance is being improved by the development of new particles and new fixing methods. The industry has also developed reload systems that increase cosmetotextile life. These systems allow reloading fibers with particles and drugs when the latter have been exhausted. Reloading consists of spraying or the addition of a mono-dose to the last washing step. cosmetotextiles could be used in a wide range of applications : functional fabric of all types (girdles, socks, trousers, underwear) and for all purposes (slimming, antibacterial, anti-odor, hydration), Prilling. This process makes use of polymer fusion properties. The drug is dispersed in a hot polymer solution remaining in liquid state. The solution is then pulverized in a liquid at low temperature; the polymer solution is cooled and driven to solidification. Size distribution is very narrow and depends directly on the size of the spraying nozzle. Particle size generally ranges from 200 to 800 ?m. Spray coating Spray coating allows solid drug coating. In the case of liquid drugs, they must first be adsorbed on a solid support. This technique has 3 steps: drug fluidization, pulverization of the coating material, drying of the coating film. Spray coating is sometime used on nano or microparticles to perform double -encapsulation. The size of the particles depends on the form of the initial solid as well as on the thickness of the coating layer. Size generally ranges from several micrometers to 20 ?m and must be thick enough to perfectly cover the surface. Spray-drying is very useful in the agrochemical and pharmaceutical industries to obtain solid particles from a liquid formulation. The liquid formulation contains drug and coating material. The process consists in placing nebulized liquid in contact with a controlled temperature air flux to ensure quick drying and the formation of solid particles. The particles are microspheres whose size ranges from 1 to 50 ?m. As seen above, cosmetotextiles include cosmetic preparations (drug, essential oils, etc.). Generally, cosmetotextiles are produced in two stages: Particle preparation (according to the different methods described above) Particle deposition on fabric. Sometimes particles form physical links directly with the fiber so they adhere to the support. Most often, they are not able to bind directly to the fiber, so they are linked by a binder that fixes the particles on the fiber through other interactions (Van Der Waals, hydrogenates).A second method to functionalize fibers is the preparation of polymeric film that can be fixed on the surface of fibers. The film can, for example, have intrinsic antimicrobic properties or include drug, cyclodextrins, calixarenes or dendrimers. functionalized substrates (fiber, glass, silica) by using a polymeric film formed from the polymerization between cyclodextrine and a crosslinking agent (hydroxyls, isocyanate, polycarboxylic acid, halogen, divinylsulfones). Temperature and kinetics reaction depends on the choice of crosslinked agent. For example, the polymerization reaction with polyisocyanate takes 20 min at 130-140″C.In these two modes of preparation, the adhesion between particles and fibers is achieved physically. There are several methods for depositing particles or film on fabric surfaces. Microencapsulation for Functional Textile Coatings with Emphasis on BiodegradabilityA Systematic Review. Bojana Boh Podgornik *,Stipana andri?ORCID andMateja Kert Keywords indexed to the article: Microencapsulation, a technique that allows liquid or solid agents, such as drugs, proteins, cosmetics, dyes, and fragrance, to be encapsulated by a suitable barrier wall, is being used in the textile industry for functional finishes, which in turn helps in competition, gaining added values and increasing market share. microencapsulation for functional textile coatings. Methods for the preparation of microcapsules in textiles include in situ and interfacial polymerization, simple and complex coacervation, molecular inclusion and solvent evaporation from emulsions. Binders play a crucial role in coating formulations. Acrylic and polyurethane binders are commonly used in textile finishing, while organic acids and catalysts can be used for chemical grafting as crosslinkers between microcapsules and cotton fibers. Most of the conventional coating processes can be used for microcapsule-containing coatings, provided that the properties of the microcapsules are appropriate. There are standardized test methods available to evaluate the characteristics and wash fastness of coated textiles. Among the functional textiles, the field of environmentally friendly biodegradable textiles with microcapsules is still at an early stage of development. So far, some physicochemical and physical microencapsulation methods using natural polymers or biodegradable synthetic polymers have been applied to produce environmentally friendly antimicrobial, anti-inflammatory or fragranced textiles. Standardized test methods for evaluating the biodegradability of textile materials are available. The stability of biodegradable microcapsules and the durability of coatings during the use and care of textiles still present several challenges that offer many opportunities for further research. functional textile coatings based on microcapsules, with a particular focus on the biodegradability of microcapsules and textile products. One of the initial microencapsulation applications to achieve innovative effects in textile processing have been microencapsulated dyes and pigments for special textile printing and dyeing. Varieties of these include microencapsulated colorants for permanent dyeing and printing of textiles, as well as colour changing textiles based on thermochromic microcapsules, photochromic dyes, and electrochromic textiles containing microencapsulated liquid crystals. To achieve durable flame-resistance of textiles, organic or inorganic fire retardants have been microencapsulated and applied to textile substrates. Microencapsulation has been used to prevent exudation or sublimation of fire-retardant chemicals, to avoid reactions with textile polymers, and/or to overcome the hydrophilicity of the substances. Products include firefighting and military protective clothing, as well as textiles for automotive and domestic interiors. One of the flourishing applications of microencapsulation is functional textiles for active thermoregulation, used in insulating textiles, technical clothing, and sportswear. Most textiles for thermal regulation use phase change materials (PCMs), in which a dynamic heat exchange process occurs at the melting point temperature. To overcome the practical problems of solidliquid phase transitions, PCMs must be microencapsulated and converted into solid formulations. When a PCM undergoes a solid-to-liquid phase transition, energy is stored in the form of latent heat at a constant temperature. The accumulated latent heat energy is released when the PCM re-solidifies, and the transition process is reversible. Typical organic PCMs are paraffin hydrocarbons or lipids with a melting point close to body temperature. In addition to classical PCMs, photothermal energy conversion materials also perform similar functionalities. By absorbing light and converting it into thermal energy, they are used in light-absorbing thermoregulatory textiles. To prevent UV-induced skin problems, some authors have incorporated microencapsulated synthetic or natural UV-absorbing compounds into functional UV-protective fabrics.In other technical textiles, microencapsulation has been used to achieve specific functionalities, such as improved sound absorption, super hydrophobicity, antifouling and enzymatic bio-sensing. Microencapsulated insecticides, acaricides, insect repellents and combined bioinsecticide-insect repellent compounds have been used in textiles to reduce volatility, prolong release and decrease wash fastness of active compounds from textile substrates. Fragranced textiles often contain essential oils, perfumes, or aromas in microencapsulated form to either gradually release the active ingredients through permeable shells, or to protect the cores inside the impermeable microcapsules until they are released by mechanical pressure or rubbing during product use. Modifications of the shell materials and binding formulations play an essential role in achieving better washing resistance over multiple washing cycles and in prolonging olfactory sensations. Some aromatic compounds, such as essential oils and their components, not only provide a pleasant fragrance effect but also offer antimicrobial protection. Being liquid, volatile and susceptible to oxidation, microencapsulation is required for their protection and conversion to solid state. The release mechanisms vary from slow diffusion through the permeable shell to instantaneous release triggered by pressure or melting. Antimicrobial textile products include hygiene masks, footwear, sportswear, medical garments and bio functional materials. Bioactive healthcare textiles have similar functionalities. Microcapsules must be composed of natural and biocompatible materials and approved for direct skin contact. Examples of medical textiles include microencapsulated antibiotics, methyl salicylate, cannabidiol, ozonated vegetable oils, lime oil and chitosan. Microcapsules for cosmetotextiles contain skin-caring active ingredients, such as essential oils and vitamins. Functional textiles initially focused only on individual value-adding properties. However, recent research has targeted combinations of multiple properties and effects, leading to new multifunctional smart textiles with three or more functionalities in one product, such as simultaneous aromatic, antimicrobial, UV-protective and superhydrophobic effects.
