New methods for the study of physicochemical processes relevant to the agrochemicals industry

Abstract

This thesis concerns the application of modern analytical techniques for the study of a range of systems relevant to the agrochemicals industry, with a focus on adapting and further developing these technologies to the systems of study. The major systems involved include the study of bioadhesion relevant to plant root cells and their local environment, and the further study of the root cell surface. Evanescent wave cavity ring-down spectroscopy (EW-CRDS) is the first major technique employed. For these studies a range of mimetic surfaces are designed to represent the plant cell surface and soil environment. These studies are then used to study various chemical functionalities, in the form of functional groups on polymer molecules, for adsorption properties on such surfaces. Kinetic information on the adsorption rates is measured in the form of initial rate constants. These studies are the extended to examine the cell membrane via the use of supported lipid bilayer (SLB) membranes by the combination with an impinging jet flow cell. Confocal laser scanning microscopy (CLSM) is then used to measure microparticle adsorption rates to functionalised surfaces. These studies then employ two different delivery systems, resulting in the development of a microscale vertical flow cell on the scale of individual plant cells. Understanding of the characteristics of this flow system are enhanced by the use of finite element modelling to examine the movement of the particles and flow rates. Finally, a range of electrochemical scanned probe microscopy (ECSPM) techniques are used to study the root cell surface and local environment, with a focus on assessment of each for such applications. Scanning ion conductance microscopy (SICM) is found to be the most applicable and initial work on flux imaging is performed