Cyclodextrins are known to form noncovalent inclusion complexes with various fluorescent dye molecules in aqueous solution. This interaction can result in an increase in fluorescence of the compound that can modify the properties of the materials where they are applied.

In this study the effect of combined application of fluorescent whitening agents and hydroxypropyl-β-cyclodextrin to cotton fabrics was investigated. For this purpose, 4,4'-diamino-2,2'-stilbendissulfonic acid, an important precursor for the synthesis of fluorescent whitening agents and C.I. Fluorescent Brightener 252 dye, a derivative of stilbene dissulfonic acid widely used as optical brightener for textiles, were chosen as model compounds. All samples were characterized by infrared spectroscopy and differential scanning calorimetry.

The evaluation of fabric performance showed that addition of 0.75% hydroxypropyl-β-cyclodextrin increased the whitening effect by 15%, and caused a slight improvement in terms of light fastness. The washing fastness remained unchanged.

Introduction

βcyclodextrins, especially in their more water-soluble derivative forms, are versatile complexing agents. They have been used to functionalize textile substrates, operating as a controlled release agents for water-insoluble substances such as flavorings or natural extracts, and in cosmetic textiles production.


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"This article was originally presented at the 88th Textile Institute World Conference Shah Alam, Selangor, Malaysia, May, 2012".


About the Authors:


Morgane Le Fur and Graa M. B. Soares are associated with the University of Minho, Department of Textile Engineering, Portugal.