My research career to date has been centred on the design, synthesis, and characterisation of nanostructured soft materials within particles and films. During my PhD research in Nottingham I conducted block copolymer synthesis by a novel route in a supercritical carbon dioxide (scCO2) dispersion using RAFT chemistry. The one-pot process was optimised for a wide range of monomers (methacrylates, styrenics, acrylamide), and proved versatile due to the universality of CO2 as a continuous phase for heterogeneous polymerisation. Using a range of chromatographic techniques, the process was found to produce relatively high blocking efficiency after optimisation (i.e. proportion of polymer chains that are block copolymer). Phase separation within the block copolymer particles synthesised in scCO2 (studied by SEM, TEM, AFM and SAXS analysis) revealed that CO2 acted as a selective solvent and influenced nanostructured morphology. Kinetically-trapped morphologies were formed in situ, and CO2 could be exploited to control particle internal morphology by tuning its concentration relative to polymer.
For my postdoctoral research I moved to the University of Wisconsin-Madison, to work on synthesising crosslinkable “gemini” surfactants and using their lyotropic liquid crystal phases as templates for nanoporous materials with the highly coveted double gyroid morphology. I also worked on a new class of synthetic lipids that mimic bacterial Lipid A, and studied their self-assembly behaviour under aqueous conditions using SAXS. The lamellar and cubic phases accessible to these lipids were prepared within dispersed particles (cubosomes), which can be loaded with antibacterial drugs and significantly inhibit the growth of bacterial colonies. I was also involved in projects exploiting RAFT polymerisation for the synthesis of “high χ/low N” block copolymers with small domain sizes, and to prepare novel copolymers containing azlactone and ester bonds, imparting both reactivity and degradability.
just accepted S. P. Bassett, N. A. Birkin, J. Jennings, E. Chapman, R. K. O’Reilly, S. M. Howdle, H. Willcock., One-pot synthesis of micron-sized polybetaine particles; innovative use of supercritical carbon dioxide
J. Jennings, S. P. Bassett, D. Hermida-Merino, G. Portale, W. Bras, L. Knight, J. J. Titman, T. Higuchi, H. Jinnai, S. M. Howdle, How Does Dense Phase CO2 Influence the Phase Behaviour of Block Copolymers Synthesised by Dispersion Polymerisation?
J. Jennings, G. He, S. M. Howdle, P. B. Zetterlund, Block copolymer synthesis by controlled/living radical polymerisation in heterogeneous systems
M. C. D. Carter, J. Jennings, V. Appadoo, D. M. Lynn, Synthesis and Characterization of Backbone Degradable Azlactone-Functionalized Polymers
M. C. D. Carter, J. Jennings, F. W. Speetjens, D. M. Lynn, M. K. Mahanthappa, A Reactive Platform Approach for the Rapid Synthesis and Discovery of High χ/Low N Block Polymers
M. C. D. Carter, D. Miller, J. Jennings, X. Wang, M. K. Mahanthappa, D. M. Lynn, N. L. Abbott, Synthetic Mimics of Bacterial Lipid A Trigger Optical Transitions in Liquid Crystal Droplets at Ultralow Picogram-per-Milliliter Concentrations
M. K. Mahanthappa and J. Jennings, Polymerizable Mixtures Containing Ionic Gemini Surfactants; and Lyotropic Liquid Crystals, Polymers, and Membranes Made Therefrom
D. Hermida-Merino, G. Portale, P. Fields, R. Wilson, S. P. Bassett, J. Jennings, M. Dellar, C. Gommes, S. M. Howdle, B. C. M. Vrolijk, W. Bras, A High Pressure Cell for Supercritical CO2 On-line Chemical Reactions Studied with X-ray Techniques
J. Jennings, M. Beija, J. T. Kennon, H. Willcock, R. K. O’Reilly, S. Rimmer, S. M. Howdle, Advantages of Block Copolymer synthesis in Supercritical CO2
J. Jennings, M. Beija, A. P. Richez, S. D. Cooper, P. E. Mignot, K. J. Thurecht, K. S. Jack, S. M. Howdle, One-Pot Synthesis of Block Copolymers in Supercritical Carbon Dioxide: A Simple Versatile Route to Nanostructured Microparticles
- University of Wisconsin-Madison postdoctoral seminar series (June 2016): “Exploiting Self-Assembly of Gemini Surfactants and Lipidoids for the Design of Functional Soft Materials”
- 249th ACS National Meeting & Exposition, Denver, Colorado, US (March 2015): “Nanoporous materials from crosslinked gemini surfactant lyotropic liquid crystal network phases”
- University of Wisconsin-Madison postdoctoral seminar series (August 2014): “Fabrication of nanofiltration membranes from gemini surfactant lyotropic liquid crystals”
- Macro Group UK Young Researchers Meeting, University of Cambridge (September 2012): “Synthesis and Phase Behaviour of Block Copolymers in Supercritical CO2”, prize awarded
- University of Nottingham Postgraduate Symposium (April 2012): “Block Copolymer Synthesis in Supercritical Carbon Dioxide- A Route to Nanostructured Microparticles”