Brodyck Royles, bom in Edinburgh (April 20,1965), received his Bachelors degree from Heriot-Watt University in 1987. He then moved to the University of Edinburgh where, under the guidance of Professor R. Ramage, he carried out research on the asymmetric synthesis of polyenoyltetramic acids which led to the award of his Ph.D. in 1991. In 1992 he was appointed to a post-doctoral research assistantship with Dr. D. M. Smith in the University of St. Andrews. For the first three years he was involved with the development of the "inverse electron-demand" Diels-Alder reaction as a potential novel route to poly(heteroaromatic) systems. He is currently (in conjunction with Drs. D. M. Smith and C. Glidewell) engaged in the synthesis of novel heterocyclic and polymeric systems that incorporate a ferrocenyl nucleus.

We describe a new one-pot, single-step route for the preparation of pH-responsive branched polymer nanoparticles. These polymers, which are based on the pH-responsive monomer 2-(diethylamino)ethyl methacrylate (DEA) and hydrophilic macromonomer poly(ethyleneglycol) methacrylate (PEGMA), are synthesised using a modified conventional free-radical polymerisation. Consequently, their preparation is generic, scaleable and tolerant of functionality. In aqueous solution the branched copolymers form core-shell structures at basic pH and on reducing the solution pH they become hydrated and swell, displaying similar characteristics to those of pH-responsive shell cross-linked micelles and microgels. We demonstrate good control over the hydrodynamic particle size, polymer chain-end, and the uptake and release of a model hydrophobe and also the ability to tune the apparent pK a of the DEA residues by varying the degree of branching. These results augur well for commercially viable tunable release applications.

Reaction of 3,6-bis(3,5-dimethylpyrazolyl)-1,2,4,5-tetrazine with mono-and di-amines gives rise to nucleophilic substitution of one or both of the pyrazolyl substituents, and reaction with diamines under appropriate conditions can lead to bis(3-amino-1,2,4,5-tetrazines), e.g. 12a, 12b and 13. The crystal structures of two of these (12a and 13) show electronic interaction between the tetrazine rings and the amino groups, but none between the tetrazine and pyrazole rings. In 12a there is an extensive network of N᎐H ؒ ؒ ؒ N hydrogen bonds.

Subtle changes in copolymer surfactant architecture and chain-end functionality can induce diverse behaviours in pH-responsive branched copolymer-stabilized emulsions.

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