In preparing the second edition of this book, I have revised, updated and extended the original material, with particular attention to two areas of the book where there has been considerable publication of new material. The chapters on the use of surfactant theory and polymeric surfactants have been completely rewritten. Surfactant theory has seen considerable progress in the 1980s, but it is only in the last few years that it has been simplified such that it can be used in helping to formulate compositions containing surfactants in different applications. It must be admitted that even now most applications utilise empirical methods of formulation but the results in many cases can be better interpreted. Wetting and micro emulsions are now much better understood, but foams and defoamers still elude simplification. The use of theory in formulating compositions will probably very slowly be extended, but only if fairly simple rules, preferably non-mathematical, can be taught to industrial chemists. The concept of geometrical packing of surfactant molecules at an interface and the effect of the relative size of the head and tail has probably been the major advance in simplifying theory. This concept is now well recognised in the scientific literature but is not yet used widely by technologists using surfactants. I hope that this book will help in spreading the use of this simple concept."

The awareness and development of 'biodegradable' surfactants pre-dates current pressures by the environmental movement by nearly three decades, wherein a responsible industry mutually agreed to replace 'hard', non-biodegradable com ponents of household detergents by 'soft', biodegradable alternatives, without course to legislation. The only requirement at that time was for surfactants used in detergents to exhibit a 'primary biodegradability' in excess of 80%; this referring to the disap pearance or removal from solution of the intact surface active material as de tected by specified analytical techniques. This proved useful, as observed environmental impacts of surfactants, e.g. visible foam on rivers, are associated with the intact molecule. Test methods for 'primary biodegradability' were eventually enshrined in EU legislation for nonionic surfactants (Directive 821242/EEC, amended 73/404IEEC) and for anionic surfactants (Directive 8212431EEC, amended 73/405IEEC). No approved test methods and resultant legislation have been developed for cationic and amphoteric surfactants to date. The environmental classification of chemical substances, which of course includes surfactants, and associated risk assessment utilises a second criterion 'ready biodegradability'. This may be assessed by a number of methods which monitor oxygen uptake (BOD), carbon dioxide production or removal of dis solved organic carbon (DOC). Some surfactants which comply with the above Detergents Directive are borderline when it comes to 'ready biodegradability'."

The MR PORTER Guide To A Better Day covers all aspects of a man's daily life, from morning rituals, to flawless grooming to handy tips for taking the work out of your working and social life. Compiled by MR PORTER's Editors and featuring wisdom from Messrs Tom Ford, Laird Hamilton and more, this volume is packed with expert advice, helpful illustrations and full-colour photography that explores the habits and routines of the world's most stylish men. Of course, it's also got the wardrobe side of things covered: between each chapter, a dedicated section on 'How To Dress' offers a deep dive into the ins and outs of contemporary menswear, offering rules and guidelines on what to wear and how to wear it, whether you're heading out for a fancy dinner, or spending a weekend recovering from just such a thing. Drawing on MR PORTER's unparalleled experience of dressing discerning gentlemen across the globe, it is the definitive volume that every man of taste should have on his bookshelf this season.

The worldwide consumption of surfactants now exceeds several million tonnes per annum. Six ofthe major types represent approximately 80% of the volume consumed, whereas the remaining 20% is made up of approximately 40 different chemical types. Commercially produced surface active agents are not pure chemicals, and within each chemical type there can be tremendous variation. Technical staff who are not familiar with surfactants are frequently bewildered by the enormous variety of different products on the market and the vast body of literature which exists on the composition and properties of surfactants. The selection of the best surfactant for any given use therefore becomes a major problem. This volume arose from the clear need to have available a simple reference book summarising the different types of surfactants on the market and their properties. The concept and structure ofthe book evolved from early attempts to define chemical structure/property relationships of all the different types of surfactants commercially available, into a simple handbook providing essential background information for the surfactant user. It is realised that most users will be developing their own data bank of structure/end use property relationships and they will therefore be the experts on end use.

The awareness and development of 'biodegradable' surfactants pre-dates current pressures by the environmental movement by nearly three decades, wherein a responsible industry mutually agreed to replace 'hard', non-biodegradable com ponents of household detergents by 'soft', biodegradable alternatives, without course to legislation. The only requirement at that time was for surfactants used in detergents to exhibit a 'primary biodegradability' in excess of 80%; this referring to the disap pearance or removal from solution of the intact surface active material as de tected by specified analytical techniques. This proved useful, as observed environmental impacts of surfactants, e.g. visible foam on rivers, are associated with the intact molecule. Test methods for 'primary biodegradability' were eventually enshrined in EU legislation for nonionic surfactants (Directive 821242/EEC, amended 73/404IEEC) and for anionic surfactants (Directive 8212431EEC, amended 73/405IEEC). No approved test methods and resultant legislation have been developed for cationic and amphoteric surfactants to date. The environmental classification of chemical substances, which of course includes surfactants, and associated risk assessment utilises a second criterion 'ready biodegradability'. This may be assessed by a number of methods which monitor oxygen uptake (BOD), carbon dioxide production or removal of dis solved organic carbon (DOC). Some surfactants which comply with the above Detergents Directive are borderline when it comes to 'ready biodegradability'."

In preparing the second edition of this book, I have revised, updated and extended the original material, with particular attention to two areas of the book where there has been considerable publication of new material. The chapters on the use of surfactant theory and polymeric surfactants have been completely rewritten. Surfactant theory has seen considerable progress in the 1980s, but it is only in the last few years that it has been simplified such that it can be used in helping to formulate compositions containing surfactants in different applications. It must be admitted that even now most applications utilise empirical methods of formulation but the results in many cases can be better interpreted. Wetting and micro emulsions are now much better understood, but foams and defoamers still elude simplification. The use of theory in formulating compositions will probably very slowly be extended, but only if fairly simple rules, preferably non-mathematical, can be taught to industrial chemists. The concept of geometrical packing of surfactant molecules at an interface and the effect of the relative size of the head and tail has probably been the major advance in simplifying theory. This concept is now well recognised in the scientific literature but is not yet used widely by technologists using surfactants. I hope that this book will help in spreading the use of this simple concept."