Preface

Chapter 8 **The Potential Application of Selected Fungi Strains in Removal of Commercial Detergents and Biotechnology 233**

Eduardo Nicolás Schulz, Erica Patricia Schulz and Pablo Carlos

Chapter 10 **SAXS and SANS Techniques for Surfactant Characterization:**

**Application in Corrosion Science 287** Deepak Dwivedi and Kateřina Lepková

Violeta D. Jakovljević and Miroslav M. Vrvić

**Section 2 Characterization of Surfactants 259**

Chapter 9 **Electrochemistry of Surfactants 261**

Schulz

**VI** Contents

The surfactants are among the materials that have a significant importance in everyday life of human. These materials are the main effective ingredients in systems that are based on the emulsions or microemulsions, where stabilization or solubilization of two or more com‐ ponents with opposite polar characteristics in a uniform system is required. Even the rapid growth in science and technology has opened new horizons in a very wide range, in which the surfactants play a major and vital role. Hence, the increasing number of applications as well as arising environmental issues has made this relatively old topic still a hot research theme in the various professions, ranging from pure physical chemists to oil engineers, pharmacologists, and biologists. The synthesis of novel and specially designed surfactants for certain applications, efforts to reduce their environmental impacts, preparation of the en‐ vironmentally benign surfactants, or modifications of the methods to synthesize them from natural-based resources are still under the focus of many researchers. Furthermore, develop‐ ing new ways or methods to use old techniques for studying the performance of these mate‐ rials is of prime importance.

In the first section of this book, some of the applications of surfactants in various fields such as biology and petroleum industry, as well as their environmental effects, are described. The second section is devoted to the discussions on the experimental techniques used for charac‐ terization of the surfactants. In the first chapter, Dr. Kalak has described the environmental impacts of the use of some surfactants in the petroleum industry. Dr. Jurašin has summar‐ ized the recent progress in using mixtures of structurally different surfactants, especially catanionic surfactants and their various applications in nanotechnology and pharmaceutical formulations in Chapter 2. The use of hydrophobic polymers flooding in enhanced oil recov‐ ery (EOR) technologies is described by Dr. ElHoshoudy in Chapter 3. Gemini alkylammoni‐ um salts as Gemini surfactants that show unique surface and interfacial properties in aqueous solution and their applications in various fields is the subject of discussions made by Prof. Brycki in Chapter 4. Prof. Carmona in Chapter 5 has discussed dioctadecyldimethy‐ lammonium bromide as a quaternary ammonium surfactant with interesting properties and applications, with emphasis on its self-assembly in aqueous solutions to yield a wide range of novel uses in fields such as delivery of drugs, vaccines, etc. Steroidal and triterpenoid saponins are among the plant active compounds, which are traditionally used as natural de‐ tergents showing unique properties as foaming and emulsifying agents and can be used in many industrial applications, such as steroid hormones in the pharmaceutical industry to food additives. This issue is detailed by Prof. Kregiel in Chapter 6. Dr. Pinheiro has detailed in Chapter 7 the amino acid–based surfactants as surfactants prepared from natural resour‐ ces that can be used easily in biomedical applications like drug and gene delivery. Dr. Ja‐ kovljevic (in Chapter 8) has presented the experimental evaluation of the ability of fungi

species, isolated from municipal sewage and industrial wastewater, in removing of anionic surfactants from environment as well as their potential application in biotechnology. The application of several electrochemical techniques, such as cyclic voltammetry, chronoamper‐ ometry, chronocoulometry, and selective electrodes for studying the behavior of surfactants in solution as well as at the interfaces, has been discussed by Dr. Schulz in Chapter 9. The last chapter of the book is devoted to explain the use of SAXS and SANS techniques as pow‐ erful methods for studying surfactants and their behavior, by Dr. Lepkova.

Finally, I would like to express my gratitude to Ms. Martina Usljebrka, the publishing proc‐ ess manager, and InTech Open Access Publisher for their efforts in the publishing process. I would also like to thank my family and families of all other collaborators for their patience and acceptance of the lost evenings. I wish that this book can give an insight into the field.

> **Dr. Reza Najjar** Faculty of Chemistry University of Tabriz Tabriz, Iran
