Inglés

Edwing Velasco,Camilo A Castro,Sonia A Giraldo

doi:10.18273/revion.v29n2-2016004

Abstract

AbstractTiO2-SiO2 coatings on fabric samples were obtained by immersion of 9cm2 of commercial polyester in a TiO2-SiO2 suspension. This suspension was prepared by adding TiO2 P25 to a silica matrix obtained from the hydrolysis of tetraethyl orthosilicate (TEOS). The aim of this work was to study the relationship between the immersion time of the fabric on the photocatalytic activity and stability of the coating against several cycles of use and washing. Obtained samples were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and infrared spectroscopy (FTIR-ATR). Evaluation of modified fabrics was performed by self-disinfection tests under 250W/m2 of simulated sunlight using E. coli as model bacteria. In general, all modified fabrics (except that obtained at 2h immersion time) inactivated bacteria in less than 120min and its regrowth was prevented for at least 24h after the disinfection tests.It was determined that low immersion time (3-4h) lead to active and stable fabrics to 3 cycles of use and washing, whereas higher immersion times (12h) lead to more active but unstable fabrics.

Highlights

A self-disinfecting fabric has the ability to inactivate pathogenic microorganisms such as E. coli because on its surface a photocatalyst such as TiO2 is fixed and ready to be activated in the presence of UV light, leading to the production of oxidative species that attack the cell wall, and cause lysis and death of the microorganism [1,2,3,4,5,6]
In 2008, Li et al [20] studied the interaction between silica and certain fabrics such as cotton, linen, nylon and polyester, and determined that the adhesion of the coatings of SiO2 in synthetic fabrics is mainly the result of thermodynamic affinities, dipole-dipole interactions and hydrogen bonds, while the adhesion over fabrics based on cellulose is produced by covalent bonds formed between the precursor groups of the silica and hydroxyl groups of the fabric
The c) and d) micrographs shows that TiO2-SiO2 coating is amorphous and porous. It was determined in the scanning electron microscopy (SEM)-energy dispersive spectroscopy (EDS) analysis that this coating is composed by a TiO2/Si mass ratio of 2.26 which is similar to that used in the synthesis of the coating

Summary

Introduction

A self-disinfecting fabric has the ability to inactivate pathogenic microorganisms such as E. coli because on its surface a photocatalyst such as TiO2 is fixed and ready to be activated in the presence of UV light, leading to the production of oxidative species that attack the cell wall, and cause lysis and death of the microorganism [1,2,3,4,5,6] The development of these fabrics, as a strategy to combat the spread of nosocomial infections [711], is still in the primary state due to difficulties to immobilize TiO2 on the fabric surface, so as to keep it active and stable for several cycles of use and washing [12,13,14]. The focus of this paper is to obtain self-disinfecting fabrics by immersion of polyester samples in TiO2-SiO2 suspensions and determine the influence of immersion time on the activity and stability during three cycles of use and washing

Objectives

Results

Conclusion