Preface

Surfactants or detergents, as they are often referred to, are vital ingredients in most formulated products that we use on a daily basis. These include food, medicines, cosmetics and laundry detergent. The use of surfactants is equally important in other industrial applications such as oil recovery from oil wells, lubricants, processing chemicals for textiles, adjuvants in agrochemicals, and so on.

 This book is a compilation of chapters from leading experts highlighting the use of specific surfactants and their functional properties in new and emerging areas of science and technology. Experts and novices alike will find the information contained herein to be of great value.

Chapter 1 discusses the fundamental aspects of surfactants and their surface active properties arising from their molecular structure and subsequent self-assembly at interfaces and in bulk. It also briefly covers emulsification of oils and their stability; the various mechanisms of cleaning, especially removal of tough oily soil from soft substrates like fabrics, skin and hair; and the importance and need of mild surfactants in baby and skin care products.

Chapter 2 provides an overview on the role of surfactants in the selective separation of specific minerals from their ores by the froth floatation process. The biggest challenge is choosing appropriate surfactants or their mixture that will selectively attach the particles of a specific mineral to the surface of air bubbles that forms the froth while allowing the other mineral ingredients of the ore to sink and get separated as sludge. The process of attachment of a particle to the bubble surface is complex in that it is a dynamic process involving several parameters like wettability of the surfaces, contact angle, hydrophilicity or hydrophobicity of the mineral particle and, more importantly, the rate of draining of the liquid in the film that forms the bubble wall. These features are discussed in some detail in Chapter 3.

Mixed surfactants and surfactant-polymer systems provide the flexibility of designing systems with tailored properties that have been extensively used in home and personal care, pharmaceuticals and food products. Systems with oppositely charged surfactants and polymers are complicated and continue to be an area of intense research. Chapter 4 investigates catanionic systems consisting of sodium dodecylsulphate (SDS) and cetyltrimethylammonium bromide (CTAB) and lysozymeperfluorononanoate and provides insight into the concentration-dependent interactions between the various ingredients in these systems.

In recent years there has been much interest in nanoparticles because of their interesting physico-chemical properties, which are different from the bulk properties of the same material. Tailor-made nanoparticles have been extensively used for numerous applications in semiconductor devices, sensors and light-emitting optical devices. Chapter 5 reviews various polymer-based nanoparticle systems in context to their microbial activities that may be utilized in the design of medical devices and biomedical screening systems.

Bio-surfactants or surfactants extracted from renewable biological substrates like fruits, roots, vegetables and micro-organisms are well known and encouragingly used in various applications because they are mild, natural and have low toxicity in contrast to their synthetic counterparts. However, their extraction from microorganisms present in the atmosphere has never been reported. Chapter 6 reports the extraction of bio-surfactants from atmospheric clouds for the very first time. This report is not the only one of its kind, but it opens up a totally new area of research in terms of an unexplored source of bio-surfactants. It also paves the way for understanding the role of these ingredients in the behavior of clouds and controlling such properties as precipitation from the clouds that the directly influences weather and environment.

I would like to thank all the authors for their efforts in writing the various chapters in this book. I would also like to thank IntechOpen's editorial and publishing staff for their cooperation and help at every juncture to make publication of this book possible.

Last but not least, I dedicate this book to the loving memory of my parents, and I thank my wife, Malabika, and my two children, Sourav and Siddharth, for their help and cooperation and for bearing with me in this endeavor.

> **Dr. Ashim Kumar Dutta** Vice President (R&D), India Glycols Limited, Uttarakhand, India

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**Chapter 1**

*Ashim Kumar Dutta*

**1. Introduction**

Introductory Chapter: Surfactants

Surfactants are ubiquitous and form a part of almost every essential household product we use on a daily basis and have become synonymous with detergents and cleaning agents. The global surfactant consumption is 18,000 kilotons per annum that had a market value of USD 43,655 million in 2017 and is projected to reach USD 66,408 million in 2025 with a compound annual growth rate (CAGR) of 5.4% [1]. Interestingly, the first detergent known to man was soap, the origin of which may be traced back to the Egyptian civilization in 2800 BC. Cylinders containing soap made from animal fats and ashes recovered from excavations in Babylon confirm that indeed soap was known to the Babylonians. The Ebers Papyrus (1550 BC) also mentions the use of soap for bathing and cleaning, and in the Bible, soap has been referred to as "Borith" meaning a cleaning agent made from wood and vegetable ashes. Paintings on the walls in the pyramids confirm that the Egyptians maintained a very high level of hygiene and both men and women used to be well-groomed. While the men folk especially the nobles sported a clean shaven head with a short braid, women kept their hair short [2]. The use of various oils (sesame, olive, and almonds) and herbs like lavender, myrrh, rosemary, rose, and cedar to make perfumes becomes evident from their extensive use in the embalming of Egyptian pharaohs. They also used various metallic oxides like ochre, malachite green, and antimony grounded to a very fine powder and mixed with an oil to color their lips and cheeks. Antimony ground to a fine powder and mixed with burnt almonds was used as kohl [2].

Before the nineteenth century, there was extreme poverty in Europe, and people lived in squalor and under very unhygienic conditions that is supposed to be one of the main reasons for the plague epidemics that recurred time and again. The deadly bacterial strain (Yersinia pestis) that was transmitted from rodents to man by fleas wiped out 25 million lives in Europe between 1347 and 1665. Mass realization that plague was related to the lack of cleanliness eventually led to a renaissance in hygiene. By 1525 at least two companies in Marseilles (France) had started producing and selling soap. In 1789, Andrew Pears made the first ever transparent soap, and almost a century later in 1886, the two brothers William and James Hesketh Lever made the first commercial soap manufacturing unit in Warrington which

In fact soap was the only detergent commercially available till the late 1950s when linear alcohol benzene sulfonic acids (LABSA) were synthesized from crude oil. Today almost all detergents contain LABSA [3] that form the heart of a multibil-

In this chapter, we review the basic properties of surfactants with specific focus

on their use as cleansers in household and personal care applications. As these

over the years evolved to become Unilever as we know it today.

lion detergent industry thriving worldwide.

in Household and Personal Care

Formulations - An Overview

### **Chapter 1**
