6 p.m.

7 Mar 2024

Wolfson lecture theatre

Abstract: What is the best way to create a receptor capable of molecular recognition and catalysis? Design is one approach, but it fails too often. So, inspired by nature, we developed Dynamic Combinatorial Chemistry in which a molecule can select and amplify its ideal partner from an equilibrating mixture. I will explain some of the background, and show some of the extraordinary unpredictable molecules and behaviours that we discovered.

6 p.m.

29 Feb 2024

Wolfson lecture theatre

Abstract: According to existing histories, theory drove chemistry's remarkable nineteenth-century development. This talk shows instead how novel experimental approaches combined with what I’ve called “laboratory reasoning” enabled chemists to bridge wet chemistry and abstract concepts and, in so doing, create the molecular world. Based on a series of new practice-based breakthroughs – including the “glassware revolution”, the “turn to synthesis”, and the “chemical identity crisis” – this historical reassessment reveals organic synthesis as the ground chemists stood upon to forge a new relationship between experiment and theory—with far-reaching consequences for chemistry as a discipline.

6 p.m.

22 Feb 2024

Wolfson lecture theatre

TBC

6 p.m.

15 Feb 2024

Wolfson lecture theatre

TBC

6 p.m.

6 Feb 2024

Wolfson lecture theatre

Abstract: Porous semiconducting nitrides are effectively a new class of semiconducting material, with properties distinct from the monolithic nitride layers from which devices from light emitting diodes (LEDs) to high electron mobility transistors are increasingly made. The introduction of porosity provides new opportunities to engineer a range of properties including refractive index, thermal and electrical conductivity, stiffness and piezoelectricity. Quantum structures may be created within porous architectures and novel composites may be created via the infiltration of other materials into porous nitride frameworks. A key example of the application of porous nitrides in photonics is the fabrication of high reflectivity distributed Bragg reflectors (DBRs) from alternating layers of porous and non-porous GaN. These reflectors are fabricated from epitaxial structures consisting of alternating doped and undoped layers, in which only the conductive, doped layers are electrochemically etched. Conventionally, trenches are formed using a dry-etching process, penetrating through the multilayer, and the electrochemical etch then proceeds laterally from the trench sidewalls. The need for these trenches then limits the device designs and manufacturing processes within which the resulting reflectors can be used. We have developed a novel alternative etching process, which removes the requirement for the dry-etched trenches, with etching proceeding vertically from the top surface through channels formed at naturally-occurring defects in the crystal structure of GaN. This etch process leaves an undoped top surface layer almost unaltered and suitable for further epitaxy. This new defect-based etching process provides great flexibility for the creation of a variety of sub-surface porous architectures on top of which a range of devices may be grown. Whilst DBR structures enable improved light extraction from LEDs and the formation of resonant cavities for lasers and single photon sources, recent development also suggest that thick, subs-surface porous layers may enable strain relaxation to help improve the efficiency of red microLEDs for augmented reality displays. Meanwhile, the option of filling pores in nitride layers with other materials provides new opportunities for the integration of nitrides with emerging photonic materials, such as the hybrid-perovskite semiconductors, with perovskites encapsulated in porous nitride layers demonstrating greatly improved robustness against environmental degradation.

6 p.m.

25 Jan 2024

Wolfson lecture theatre

Question: What do Henry VII’s tapestries at Hampton Court Palace, Athabaskan quillwork traded by the Hudson Bay company, Flora MacDonald’s wedding tartan, a Rembrandt painting, a purple Victorian silk boddice and a German catalogue of early synthetic textile dyestuffs have in common? Answer: They are all historical objects which have been analysed by the Hulme group. In doing so, we have answered important questions about where and how these objects were made, and how we can look after them for future generations. But to do so, we have had to develop new techniques for their analysis, transferring methods from other disciplines to the field of heritage science and overcoming the unique challenges associated with analysing such precious objects. This is chemistry in a real-world context as you have never seen it before.