Beta-cyclodextrines in textile industry

ß-Cyclodextrin (ß-CD) is an oligosaccharide composed of seven units of D-(+)-glucopyranose joined by a- 1,4 bonds, which is obtained from starch. Its singular trunk conical shape organization, with a well-defined cavity, provides an adequate environment for several types of molecules to be included. Complexation changes the properties of the guest molecules and can increase their stability and bioavailability, protecting against degradation, and reducing their volatility. Thanks to its versatility, biocompatibility, and biodegradability, ß-CD is widespread in many research and industrial applications. In this review, we summarize the role of ß-CD and its derivatives in the textile industry. First, we present some general physicochemical characteristics, followed by its application in the areas of dyeing, finishing, and wastewater treatment. The review covers the role of ß-CD as an auxiliary agent in dyeing, and as a matrix for dye adsorption until chemical modifications are applied as a finishing agent. Finally, new perspectives about its use in textiles, such as in smart materials for microbial control, are presentedPostprint (published version

Vector diseases treatment based on intermediate complexion using textile substrates

The most efficient insect repellents are DEET (N, N-diethhyl-meta-toluamide) from synthetic origin and citronella essential oil from natural origin. However, there are other products that can also be used as insect repellents from synthetic origin, such as: DEPA (N, N-Diethyl Phenylacetamide), Icaridin, IR3535 and Permethrin and, of natural origin: Carapa guianesis, Atemisia vulgaris, Ocimim., basilicum, Cinnamomum camphora, Corymbia citriodora, Eucalyptus sp, Cymbopogon, Mentha pulegium. All those products are the basis of most commercial repellents; however the action of these repellents is of short duration, due to the volatility of the chemical compounds of these products and, therefore they offer an uncontrolled release. The authors have shown that there would be an alternative to control their release based on the complexation of the active principle (the repellent oil). Thus, the repellent will have its prolonged effect and will protect the user longer. The active principle can be used in repellent products, applied to the skin via spray or can be used on textiles. According to Lis Arias et al. when used in textiles, these products become biofunctional, enabling the delivery of assets for cosmetotextiles applications. Due to its specific response, biofunctional textiles are especially useful when the textile comes into close contact with the skin. Thus, these products can be used as insect repellents, reducing the number of infections caused by these vectorsPostprint (published version

Barrier effects of cellulosic fibers with hybrid coating based on zirconium metal-organic framework

Metal-organic frameworks (MOFs) have great potential for the development of fire barriers for flammable materials. Accordingly, zirconium-based metal-organic framework (Zr-MOF), branched polyethyleneimine (BPEI), and vinyltriethoxysilane (VTES) were deposited to produce composites assembled on cellulosic fibers to investigate their barrier effects. The structure, morphology, and thermal properties of the cellulosic fibers were characterized using FTIR spectroscopy, SEM, and TGA. Compared with the untreated cotton sample, the temperature of the maximum rate of weight loss (Tmax) of C-Zr-MOF/BPEI/VTES increased from 479 to 523.3 °C and the maximum weight loss rate (Rmax) at Tmax decreased from 37.6 to 17.2 wt%/min. At 800 °C, the pristine cotton was burned out without residues whereas the residual char content of the C-Zr-MOF/BPEI/VTES sample was 7.2355 wt%. From the vertical burning tests, the results suggested that the C-Zr-MOF/BPEI/VTES sample had better barrier effects by reducing the flame-spread speed and generating more protective char layers.Peer ReviewedPostprint (published version

Study of microcapsules of essential oils: drug delivery and particle characterization

Essential Oils (EOs) are a substance composed of two phases. A liquid and volatile substance that has aromatic, antibacterial, antioxidant. The properties of EOs are not new to humanity. Indeed, these began to take a role from the first civilizations (Egyptian civilization). Where EOs used as preservatives and flavourings. Nowadays, the use of the EOs is the same. Avoid the growth of bacteria and viruses (theoretical) in food, the contact surface (chairs of the bus), tables, fabrics (clothes). During these last years, the industrial world took the relevance of the microencapsulation technique. This technique pretends to capture the EOs to reach two main objectives. First, contain all his active compounds into a microcapsule to prevent the degradation of the environment. Second, release control into the media, contact surface, or fabrics. Microencapsulation is a beneficial technology to improve fields of biomedicine and the food industry. Besides, the impregnation of these microcapsules on fabrics can develop a lot of new properties. Indeed, the antibacterial and antioxidant properties. The amount of these properties requires an accurate and meticulous methodology. The formation of the microcapsules is very complicated to explain from one point of view. Therefore, it is necessary to collect all the available data. Nevertheless, the research count with very sophisticated equipment, which can provide us with very accurate results. Nanosizer, Spectrophotometer, SEM. The meaning of this research is to make sure if it is possible to control either the diffusion of the EOs and his chemist properties (diameter and morphology). Simple coacervation of microcapsules of ß-cyclodextrin (B-CD) with lavender (L) is the technique that we will follow at the beginning of this research. These simple microcapsules will be impregnated in different fabrics: Polyester (PET), Cotton (COT), and Polyamide (PA). After his impregnation, we must wait until dry in the ambient and make the drug delivery. The complex coacervation is the principal object to study. In this part of the research, we will use Eco Tween 20 (TW) as a surfactant and some crosslinkers: Citric Acid (CA) and Tannic Acid (TA). Due to his addition, we will pay attention to his new chemist properties and behaviour in different fabrics. The drug delivery results will follow a mathematical procedure. This procedure, which will contrast with Korsmeyer-Peppas and Higuchi principles, will help us ascertain his diffusion behaviour.Peer ReviewedPostprint (published version

Evolution et principes fondamentaux des essais de solidité: lumière et intempérie

El objetivo del presente trabajo es mostrar la evolución y los fundamentos que sustentan los ensayos normalizados modernos de solidez a la luz y a la intemperie de los textiles, para comprender el porqué de los mismos y la validez de los métodos actualesThe aim of this paper is to show the evolution and fundamentals of modern standardized methods to measure colour fastness of textiles to light and weathering, to understand the reasons of their development and the validity of the current testsLe but de cet article est de montrer l'évolution et les bases des essais normalisés modernes de solidité à la lumière et aux intempéries de textiles, afin de comprendre les raisons et la validité des méthodes actuellesPeer Reviewe

Kinetics of dyeing in continuous circulation with direct dyes: tencel case

Due to the special characteristics of Tencel fibres, it is important to gather new data and information in order to improve our knowledge of their performance during dyeing. Kinetic equations are used to describe the behaviour of the heterogeneous dye-fibre system under isothermal conditions in order to determine the evolution of dye exhaustion versus dyeing time. Direct dyes are particularly suitable because they are physically absorbed and because they exhibit outstanding substantivity to cellulose. In addition, some of these dyes have a linear structure which ensures good correlation with structural differences in the fibres. The aim of this study is to quantify the kinetic behaviour of the Tencel-C.I. Direct Blue 1 system (one of the most common dyes in dyeing studies) by using three bi-parametric empirical dyeing-rate equations and a continuous-flow dyeing cell to obtain experimental data at six different temperatures: 30, 40, 50, 60, 70 and 80ºC. In order to check the level of adjustment of the equations we record the at three exhaustion levels: 50%, 80%, and final exhaustionPostprint (published version

Fire performance of cotton fabrics coated with 10-(2,5- Dihydroxyphenyl)-9,10-dihydro-9-xa-10-phosphaphenanthrene10-oxide (DOPO-HQ) Zr-based metal-organic fr

We investigated the performance of cotton fabrics coated with DOPO-HQ and Zr-based Metal–organic Frameworks when exposed to fire. The chemical structure of the cotton fabrics before and after the coating was characterized using FTIR spectroscopy, and the surface morphology of cotton and their combustion residues was probed via scanning electron microscopy. In our experiments, we used flammability tests and thermogravimetric methods to understand the burning behavior of the coated fibers, as well as their thermal stability. The cotton fabrics coated with DOPOHQ and Zr MOFs exhibited shorter combustion times, had better thermal degradation properties, promoted the creation of heat-insulating layers, and exhibited improved smoke suppression behaviorPostprint (published version

Recovery of cellulose from polyester/cotton fabrics making use of ionic liquids

This article refers to the chemical recovery of cellulose from fabrics composed of Cotton (CO)/Polyester (PES) achieved using Ionic Liquids (ILs). Initially, the effect of ionic liquids on the surface of the textile is analyzed, determining the influencing factors related to the entry of IL inside the textile and the chemical mechanism that controls the system. This work considers the influence of the time, ratio, and temperature variables on the system, with the aim of defining which of them has a greater influence on the process. The ability of ionic liquids, specifically 1-Allyl-3-Methylimidazolium Chloride (AmimCl), to dissolve cellulose and subsequently regenerate the material through a simulation of the wet spinning process is evaluated. The responsible for the fiber’s inflation, water or DMSO, has also been another factor of study, analyzing the influence of each solvent and the interactions when in contact with the ionic liquid. Finally, the regenerated substance is characterized by its surface structure using the Scanning Electron Microscope (SEM), its molecular structure by Infrared Spectroscopy Analysis (FTIR), and its thermal stability by Thermogravimetric Analysis (TGA)Objectius de Desenvolupament Sostenible::9 - Indústria, Innovació i InfraestructuraPostprint (published version

Nouveaux colorants disperses biodegradables

El desarrollo de nuevas estructuras químicas para colorantes, se dirige actualmente a la búsqueda de productos de menor impacto ecológico, manteniendo o incluso mejorando sus propiedades tintóreas y nivel de calidad. Recientemente han empezado a ser estudiadas estructuras anfifilicas, que respondiendo a las necesidades de la tecnología textil, manifiestan baja toxicidad y elevada biodegradabilidad. En este trabajo se han sintetizado colorantes dispersos conteniendo en su estructura, además del sistema cromofórico clásico de tipo azoico, substituyentes de tipo glucosídico, cuya naturaleza hidrofílica debe contribuir a una mayor biodegradabilidad. Con estos colorantes se ha analizado su comportamiento tintóreo y su solidez final, sobre fibra de poliéster y de diacetato de celulosa. Sobre poliéster se ha realizado el estudio de su cinética de tintura, en función de la temperatura, valorando la Energía de Activación, además del agotamiento y la solidez a la luz y a los tratamientos térmicos. Sobre diacetato de celulosa se ha valorado solamente el agotamiento al equilibrio, habiendo llegado a la conclusión de que la introducción de tales grupos glucosídicos en un sistema cromofórico de tipo azoico no necesariamente perjudica las propiedades tintóreas si bien según el balance hidrófilo-lipófilo de la estructura final dará lugar a colorantes dispersos más adecuados para una fibra hidrofóbica como el poliéster o más hidrofílica como el diacetato, pero en todo caso se disminuye su toxicidad y se aumenta la biodegradabilidad en los vertidos. Queda por ello abierto, a nuestro entender, un camino de investigación para definir las posibilidades y limitaciones de los colorantes con grupos glucosídicos.The development of new chemical structures for dyes is currently aimed at seeking products of lower ecological impact that conserve or even improve on the dying properties and level of quality. Recently, attention has been paid to amphiphilic structures that meet the needs of textile technology and show low toxicity and high biodegradability. In this work we synthesised disperse dyes that, in addition to the traditional azoic chromophoric system, contain glucosydic replacements in their structure whose hydrophilic nature should lead to greater biodegradability. The dyeing behaviour and final fastness of these dyes was analysed on polyester fibre and cellulose diacetate. The dyeing kinetics of polyester were studied as a function of the temperature. The activation energy, the exhaustion and the light and heat fastness were assessed. Only the exhaustion at equilibrium was assessed for cellulose diacetate. The conclusion had been reached that the introduction of such glycoside groups in an azoic chromophoric system did not necessarily affect the dying properties. According to the hydrophilic-lipophilic balance of the final structure it will give rise to disperse dyes that are more suitable for a hydrophobic fibre such as polyester or a more hydrophilic one such as diacetate, but in all cases the toxicity was reduced and the biodegradability of the waste increased. This therefore paves the way for research to define the possibilities and limitations of dyes with glycoside groups.Le développement de nouvelles structures chimiques pour colorants se tourne actuellement vers la recherche de produits plus respectueux de l’environnement, tout en conservant, voire en améliorant, leurs propriétés tinctoriales et leur niveau de qualité. Des études récentes se sont penchées sur des structures amphiphiles, qui répondent aux besoins de la technologie textile et font preuve en même temps d’une faible toxicité et d’une biodégradabilité intéressante. Dans cette étude, on a synthétisé des colorants dispersés dont la structure contient, outre le système chromophorique classique de type azoïque, des substituts de type glycosidique, dont la nature hydrophile doit contribuer à une meilleure biodégradabilité. Avec ces colorants, on a analysé le comportement tinctorial et la solidité finale sur la fibre de polyester et sur le di-acétate de cellulose. Sur le polyester, on a réalisé une étude de la cinétique de teinture, en fonction de la température, en évaluant l’énergie d’activation, en plus de l’épuisement et de la solidité à la lumière et aux traitements thermiques. Sur le di-acétate de cellulose, on a seulement évalué l’épuisement à l’équilibre, en arrivant à la conclusion que l’introduction de ces groupes glycosidiques dans un système chromophorique de type azoïque ne nuit pas nécessairement aux propriétés tinctoriales, même si, d’après le bilan hydrophile-lipophile de la structure finale, on obtiendra des colorants dispersés qui conviendront mieux aux fibres hydrophobes comme le polyester ou plus hydrophiles comme le di-acétate, mais, dans tous les cas, la toxicité diminue et la biodégradabilité des déversements augmente. Ces résultats ouvrent donc une voie de recherche pour définir les possibilités et les limitations des colorants avec des groupes glycosidiques

Caractérisation par spectrophotométrie FT-IR du PVC soumis à une dégradation thermochimique en milieu acide oxydant

El presente estudio pretende profundizar en los efectos que provoca la exposición con HNO3 sobre la estructura del PVC. A tal fin se han sometido una serie de probetas a exposición en medio HNO3 a distintas concentraciones (0, 6, 30 y 60 % en peso) durante un período de tiempo hasta 90 días a temperaturas comprendidas entre -15 y 60ºC. La técnica utilizada para medir los cambios químicos y microestructurales que han experimentado las probetas sometidas a estas condiciones de degradación es la espectrofotometría FT-IR.This work studies the effects caused by HNO3 exposition in PVC’s structure. The samples of PVC have been submitted to different concentration (0,6,30 y 60% in weight), temperatures (between –15 and 60ºC) and different periods of exposition. The extent of degradation was determined by evaluating the chemical changes and microestructural changes in PVC by means of FT-IR spectrophotometry.Ce travail vise à approfondir l’étude des effets de l’exposition au HNO3 sur la structure du PVC. Pour ce faire, plusieurs éprouvettes ont été exposées au HNO3 à différentes concentrations (0,6, 30 et 60% de poids) sur une période de 90 jours maximum, à des températures comprises entre –15 et 60 °C. La spectrophotométrie FT-IR a été la technique utilisée pour mesurer les modifications chimiques et micro-structurelles observées dans les éprouvettes soumises à ces conditions de dégradation