Applications of Surfactants in Agrochemicals

Most agrochemicals are water-insoluble compounds with various physical properties, which have first to be determined to decide on the type of formulation. Accurate physical data on the compound is essential, such as its solubility, its lipophilic character and its chemical stability. One of the earliest types of formulations is wettable powders (WP), which are suitable for formulating solid water-insoluble compounds that can be produced in a powder form. The chemical (which may be micronised) is mixed with a filler, such as china clay and a solid surfactant, such as sodium alkyl or alkyl aryl sulphate or sulphonate, is added. When the 

Applied Surfactants Principles and plications. Tharwat F. Tadros Copyright 2005 WILEY-VCH Verlag GmbH Co. KGaA, Weinheim ISBN 3-S27-30629-3 

Mixtures of suspensions and emulsions, referred to as suspoemulsions, have been formulated to allow application of two active ingredients, one being solid and the other an immiscible liquid. Such multiphase systems are difficult to formulate due to the complex interaction between the suspension particles and emulsion droplets. Such complex formulations will be briefly described below. 

The above introduction illustrates the role of surfactants in various agrochemical formulations. It is necessary to know the physical properties of surfactants, their adsorption at various interfaces and their phase behaviour. These topics are dealt with in Chapters 2 to 5. The role of surfactants in stabilisation of emulsions and suspensions is been dealt with in detail in Chapters 6 and 7. 

In this chapter, I will concentrate on the application of surfactants in the various agrochemical formulations. The role of surfactants in enhancing biological efficacy will be dealt with in some detail. 

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