Adam Valentine Sheridan Parry

The study focuses on the development of a new family of layer-by-layer coatings comprising Nafion, lysozyme and chitosan to address challenges related to microbial contamination. Circular dichroism was employed to gain insights on the interactions of the building blocks at the molecular level. Quartz crystal microbalance tests were used to monitor in real time the build-up of multilayer coatings, while atomic force microscopy, contact angle and surface zeta potential measurements were performed to assess the surface characteristics of the multilayer assemblies. Remarkably, the nanocoated surfaces show almost 100% reduction in the population of both Escherichia coli and Staphylococcus aureus. The study suggests that Nafion based synergistic platforms can offer an effective line of defence against bacteria, facilitating antimicrobial mechanisms that go beyond the concept of exclusion zone.

This study presents preliminary experimental data suggesting that sodium 4-(pyrene-1-yl)butane-1-sulfonate (PBSA), 5, an analogue of sodium pyrene-1-sulfonate (PSA), 1, enhances the stability of aqueous reduced graphene oxide (RGO) graphene dispersions. We find that RGO and exfoliated graphene dispersions prepared in the presence of 5 are approximately double the concentration of those made with commercially available PSA, 1. Quantum mechanical and molecular dynamics simulations provide key insights into the behavior of these molecules on the graphene surface. The seemingly obvious introduction of a polar sulfonate head group linked via an appropriate alkyl spacer to the aromatic core results in both more efficient binding of 5 to the graphene surface and more efficient solvation of the polar head group by bulk solvent (water). Overall, this improves the stabilization of the graphene flakes by disfavoring dissociation of the stabilizer from the graphene surface and inhibiting reaggregation by electrostatic and steric repulsion. These insights are currently the subject of further investigations in an attempt to develop a rational approach to the design of more effective dispersing agents for rGO and graphene in aqueous solution.

Passive RFID sensors are capable of detecting a number of volatile organic compound vapors dependent upon the solubility parameters of the solvent and their vapor pressure.

The Scholl‐type reactions of 4,10‐disubstituted chrysene derivatives proceeded by variegated and unexpected oxidation/coupling pathways. These observations serve as a cautionary note when attempting to employ the Scholl reaction in target‐oriented materials synthesis.

Using an electrostatic-based super inkjet printer we report the high-resolution deposition of polyelectrolyte macroinitators and subsequent polymer brush growth using SI-ARGET-ATRP. We go on to demonstrate for the first time a sub-micron patterning phenomenon through the addition of either a like charged polyelectrolyte homopolymer or through careful control of ionic strength. As a result patterning of polymer brushes down to ca. 300 nm is reported. We present a possible mechanistic model and consider how this may be applied to other polyelectrolyte-based systems as a general method for sub-micron patterning.

The synthesis of a series of mono and di-fluorinated TIPS pentacene compounds for application as organic semiconductors is reported. Namely the novel 1-fluoro-6,13-bis[triisopropylsilyl-ethynyl]pentacene (1-fluoro-TIPS-pentacene), 2-fluoro-TIPS-pentacene and the recently reported 1 : 1 syn : anti isomeric mixtures of 1,(8 : 11)-difluoro-TIPS-pentacenes and 2,(9 : 10)-difluoro-TIPS-pentacenes. For the first time these materials have been subjected to a study of the relationship between molecular structure and thermal/photochemical stability. The changes in the pentacene HOMO via alteration of fluorine substitution is studied and related to environmental stability. As predicted, it was found that increasing the number of electron-withdrawing fluorine substituents increases stability to photodegradation. It was also observed that stability increases (and HOMO decreases) when fluorine is present on the 1- and 1,(8 : 11)-positions closer to the central rings rather than in the 2- and 2,(9 : 10)-positions. Comparative transistor measurements for the fluoro-derivatives demonstrated competitive device performance in comparison to underivatised TIPS-pentacene. Full characterisation and NMR assignment of these materials has been accomplished by comparison over the series for the first time.

A metal-free approach combining sulfoxide-directed metal-free C–H cross-couplings with tuneable heterocyclizations and dimerizations allows expedient access to important organic materials.

A generic approach to the regiospecific synthesis of halogenated polycyclic aromatics is made possible by the one‐ or two‐directional benzannulation reactions of readily available (ortho‐allylaryl)trichloroacetates (the “BHQ” reaction). Palladium‐catalysed cross‐coupling reactions of the so‐formed haloaromatics enable the synthesis of functionalised polycyclic aromatic hydrocarbons (PAHs) with surgical precision. Overall, this new methodology enables the facile mining of chemical space in search of new electronic functional materials.

Polytriarylamines with extended fused backbones are accessible by the coupling of anilines with dibromoarenes based on substituted indenofluorenes, diindenofluorenes, carbazoles and indolocarbazoles. The optical and electrochemical properties of these polymers show an increase in the HOMO energy levels and the onset of absorption on extending the length of the fused ring segment. The polymer derived from the indenofluorene unit shows the highest reported performance for a polytriarylamine in an OFET and this observation can be rationalized by DFT calculations of model oligomers that show higher calculated reorganization energies for the more extended diindenofluorene units.