Professor (Adjunct) Chemical and Environmental Sciences, University of Limerick
Core Competencies and Research Interests
The teaching duties of Dr. Hayes have involved the teaching of Organic Chemistry at all levels during his career in the University of Birmingham, and of Environmental Chemistry (The Chemistry of the Colloids in Soils and in Waters) during the period 1993-1998.
His core research interests have centered around 'Studies of the Compositions, Structures, and Interactions of the Organic and Inorganic Colloids in Soils and in Waters.
Achievements (with his students and colleagues), though only partially in chronological order, have included the development of techniques for the fractionation of polysaccharides from soils and elucidation of mechanisms of how these interact with clays; the development of techniques for the fractionation of bitumens and illustrating how these can be biodegraded; demonstration of the mechanisms by which a number of anthropogenic organic chemicals are sorbed (and inactivated) by some soil humic constituents; the development of techniques, based on solubility theories and fractionation principles, which allow humic substances to be isolatred in a systematic way from soils and sediments; the development, from fundamental organic mechanisms, and based on compounds identified in a variety of degradation digests, of approaches which indicate some of the types of molecules which can compose humic substances (the most abundant organic molecules of nature); the illustration of the mechanisms by which pyridinium and bipyridinium (such as paraquat) compounds are sorbed and inactivated by clays; the synthesis of organic polymeric molecules which are stable in solution even in high salt concentrations (this work had implications for drilling fluids, and for soil conditioning); the elucidation of the conformations which certain polymers adopt when sorbed by clays; the elucidation, using neutron scattering techniques, of the dynamics of two layer interlamellar water in expanding layer clays; the synthesis of organophilic pillared clays [his Group was first to synthesize an Fe-pillared caly with an (001) dimension of 25 Å], and the development of pillared clay -organic composites for the binding of organic and inorganic pollutants; the illustration that naturally occurring humic substances in solution do not enhance the solubilities of sparingly soluble anthropogenic organic chemicals; the illustration that humic substances in streams bear the characteristics of the humic materials in the watersheds, and these, when chlorinated give rise to different levels (depending on their origins) of mutagenic (and in some instances carcinogenic) compounds. The most recent work involving Dr. Hayes has shown, using advanced NMR techniques, that humic substances are essentially relatively small molecules (the popular definitions consider these to be macromolecules) which are associated with themselves and with other non-humic molecules in pseudomacromolecular structures. His current studies focus on humic structures and reactivities, and on their roles in the enhancement of plant growth.