Particle Technology Established Career Fellowship Proposal: Characterisation and Evaluation of New Block Copolymer Nanoparticles

Particle Technology is an important discipline that underpins many industrial sectors, including biomedical applications, latex paints and coatings, engine oil additives, viscosity modifiers (thickeners) and emulsion stabilisation. The Principal Investigator, Prof. Steve Armes, is one of the UK's experts in particle science and technology, with more than thirty years of research experience in this field. In particular, he designs a wide range of microscopic polymer particles on the nano-scale (polymers are long-chain molecules that can be programmed to undergo in situ self-assembly during chain growth). He seeks a four-year EPSRC Particle Technology Established Career Fellowship to devote more time to such research activities, which will be conducted in close collaboration with four UK-based companies (GEO Specialty Chemicals, Scott Bader, Lubrizol & Syngenta), four UK academics and three overseas academics. This will enable him to integrate substantial academic and industrial expertise in order to tackle a range of important scientific problems that could not be addressed by a single researcher. Some of these problems are fundamental in nature, such as investigating the precise mechanism of particle formation during heterogeneous polymerisation or developing very fine particle-stabilised oil droplets that exhibit long-term stability towards droplet coalescence. Other aspects of the outlined research programme have obvious potential applications. These include: (i) the development of next-generation hydrogels for the long-term storage of human stem cells, which have the potential to transform regenerative medicine; (ii) the design of highly anisotropic worm-like particles to act as thickeners for a range of oils in cosmetics formulations; (iii) the elucidation of new high-temperature oil-thickening mechanisms for engine oils, which has the potential to improve fuel economy and hence improve air quality.

Prof. Armes is well-known for his synthetic expertise in particle design, but in the past five years he has gained substantial experience of particle characterisation studies. In particular, his research group now use a range of advanced instrumentation such as small-angle X-ray scattering for particle size analysis, assessing gel properties via oscillatory rheology and emulsion processing using a high-pressure microfluidiser. In this Fellowship, the focus will be on particle characterisation and evaluation, with underpinning particle syntheses being performed by the ten PhD students in the Armes group.

To oversee this ambitious research programme, Prof. Armes seeks 50% of his salary for four years. The four work packages will be undertaken by the four named highly-experienced post-doctoral scientists, who are all current members of the Armes group. A total of 13 post-doc (wo)man-years is requested, plus sufficient funds to access all the state-of-the-art equipment that will be required to rigorously characterise the size distributions and solution behaviour of these new polymer particles. In addition, funds are requested for travel, an outreach programme targeting local and regional primary schoolchildren, and to organise a two-day workshop.

Prof. Armes has worked closely with a wide range of companies and his research has already inspired the development of commercial products by BASF, Cabot and DSM. More recently, a UK SME (Diamond Dispersions) tripled its annual sales and doubled its workforce by implementing informal technical advice provided by Prof. Armes. In 2016 Lubrizol scaled-up his nanoparticle formulations from five grams to twenty kilos per batch and conducted an extensive in-house evaluation of their performance as additives for next-generation engine oils, with pilot plant trials now approved for 2017. Thus Prof. Armes has an excellent track record of commercially-relevant technical innovation that is of tangible value to UK plc. This augurs well for maximising the economic impact of this Fellowship.

Work Package 1 involves three named academic collaborators (Profs. M. Rivolta, N. Brown and E. Wang) and is focused on biomedical applications for new biocompatible nanoparticles. One important scientific objective is to identify the precise mechanism by which stasis is induced in human stem cell colonies when they are immersed in block copolymer worm hydrogels. If successful, such hydrogels could transform the global transportation of human stem cells, which are considered to be the key to regenerative medicine. The second scientific objective is to design new pH-responsive nanoparticles that mimic the Dengue virus and then evaluate their efficacy for the intracellular delivery of anti-cancer drugs. Thus this work has the potential to guide the development of next-generation cancer therapies. In both cases there is the opportunity to generate commercially valuable IP and our industrial collaborator (GEO) may also gain access to new markets for its pharmaceutical grade methacrylic monomers.

Work Package 2 involves two industrial collaborators. Scott Bader has expressed a strong interest in the design of new anisotropic particles to be used as thickeners for cosmetic oils. If the ideas outlined by Prof. Armes are successful, this could open up new markets for this UK-based polymer manufacturer. Lubrizol wishes to identify new high-temperature oil-thickening mechanisms for next-generation engine oils, which also offers considerable potential to generate commercially valuable IP. As part of the latter project, Prof. Armes will also establish an informal collaboration with Prof. R. Dwyer-Joyce, whose tribology expertise will enable in-house evaluation of the targeted nanoparticle-based lubricants.

Work Package 3 has three academic collaborators. Dr. O. O. Mykhaylyk will work closely with Prof. Armes to perform in situ SAXS experiments during PISA syntheses. Such fundamental studies are expected to greatly enhance our understanding of the evolution in particle morphology that occurs during such syntheses and hence have significant academic impact. In addition, GEO will benefit from its association with this work as the supplier of most of the methacrylic monomer building blocks. Prof. R. Tuinier's self-consistent mean field theory will provide a much better theoretical understanding of the remarkable self-assembly behaviour exhibited by a new thermoresponsive diblock copolymer recently designed by Prof. Armes that can form either spheres, worms or vesicles in water simply by varying the solution temperature. This system requires characterisation by TEM, NMR and SAXS and Prof. J. S. Pedersen's renowned expertise in the latter technique will be important for rigorous data analysis. All three academics will benefit from the resulting high-profile joint publications that are anticipated.

Work Package 4 is focused on designing new nanoparticles for the stabilisation of Pickering nanoemulsions and involves two industrial companies (GEO and Syngenta). GEO will provide the methacrylic monomer building blocks and benefit from the publicity generated by high-profile publications in this area. Syngenta has at least one Pickering emulsion-based agrochemical formulation, so in principle this company could benefit from the much higher interfacial area (and hence activity) offered by the target Pickering nanoemulsions.

Many additional academics across the world are working in the field of polymerisation-induced self-assembly (PISA) and hence are named as indirect beneficiaries in the Pathways to Impact section of this grant proposal. Selected academics, along with various industrial scientists, will be invited to the Particle Technology Showcase Workshop to be organised by Prof. Armes in Year 4 of this grant.

Finally, many primary school children in South Yorkshire will benefit from the inspirational schools outreach activities that are planned as part of this Fellowship.