A highly satisfactory method of preparing graphite-loaded epoxy-based
coated wire and disc voltammetric electrodes has been developed. The novel
technique of multilayer coating and curing of coated surfaces in the
atmosphere above a 40% m/m hydrofluoric acid solution presents many
advantages: the possibility of obtaining very thin and smooth layers of
loaded-epoxy base has been demonstrated to be of great versatility and
convenience for the preparation of electrodes in various shapes and sizes.
The technique has been extended to the easy and inexpensive fabrication
of other types of voltammetric electrodes, namely coated plastic, coated
glass and coated fabric electrodes, and to the preparation of ionselective
electrodes. Three different types of sulphide ion-selective electrode have been
prepared and have been evaluated in standard solutions. The construction
adopted here could be a viable alternative to existing methods for the
fabrication of inexpensive home-made units. The advantages and versatility of the novel coating and hardening
technique in terms of thinness and smoothness of layers, the lack of
interference usually presented by common hardeners and catalysts and the
resistance shown by the hardened surfaces to common reagents and solventss
have been demonstrated. The possibility of polishing and prompt renewal
of dirty or damaged surfaces coated by the method presented here has been
one of the advantages of the system discussed in the present work.
A simple technique of saturating the surfaces of coated plastic
electrodes with graphite powder has been introduced. It has been shown
to be of great help in the fabrication of coated plastic electrodes and
other systems of comparatively low electrical resistance.
Doctoral Thesis. Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy of Loughborough University.