Reactive Oxygen Species in Laundry Applications

Abstract

Chapter 1 is divided into two parts, the first gives a brief review of oxygen-based bleaching agents commonly used in powder laundry detergent with emphasis on the properties of hydrogen peroxide and peroxy acids. In the second part of the literature review, different methods of detection of Reactive Oxygen Species (ROS) are discussed.
Chapter 2 discusses analytical techniques used throughout this thesis, mainly focusing on the fluorescence and UV-Vis spectroscopy, as well as imaging techniques: Image Analysis and Diffuse Reflectance Spectroscopy. This chapter provides also detailed experimental procedures.
Chapter 3 includes the results and discussion part of the thesis. The process of the development of fluorescent probes for the most relevant ROS in laundry applications: hydrogen peroxide, peroxy acid, hydroxyl radicals and singlet oxygen is discussed. The established toolbox of molecular probes consists of: terephthalic acid, 9,10-anthracenediyl-bis(methylene)dimalonic acid and 2-naphthylboronic acid for detection of hydroxyl radicals, singlet oxygen and peroxides, respectively.
Chapter 4 reports the kinetic parameters of the ROS generated from genuine bleach source in simplified model system (alkaline solution) established with the developed toolbox of molecular probes.
Chapter 5 introduces four model dyes which represent genuine stains: curcumin, crocin, betanin and chlorophyllin. The impact of pH on the bleaching of the model dyes was investigated as well as bleaching kinetic parameters. The behaviour of peroxy acids generated from bleach sources in the presence of model dyes was determined with the toolbox of molecular probes developed
in Chapter 3.
Chapter 6 examines the bleaching performance of different ROS on genuine stains deposed on fabric: grass, tomato, curry, red wine and tea with Image Analysis technique and Diffuse Reflectance Spectroscopy. In the second part of the chapter the behaviour of the bleaching agents in the presence of stains was investigated.