Prof. Steven P. Armes

Biographical Sketch

Prof. Steve Armes obtained his BSc in Chemistry from the University of Bristol in 1983, which was followed by a PhD from the same institution in 1987. After a postdoctoral fellowship at Los Alamos National Laboratory in New Mexico (1987-89), he became a lecturer at Sussex University in 1989. After being promoted to Senior Lecturer, Reader and Professor in Polymer Chemistry, he moved to Sheffield in 2004 to become Professor in Polymer and Colloid Chemistry. He is currently Director of the Sheffield Polymer Centre and Farapack Polymers, a University spin-out company.

Awards

Royal Society/Wolfson Research Merit Award 2005-2009. RSC Macro Group Medal for Polymer Science (2007). RSC Peter Day Award for Soft Matter Research (2010).

Research Keywords

Water-soluble polymers, block copolymers, living radical polymerisation (e.g. RAFT and ATRP), polymerisation-induced self-assembly, dispersion polymerisation, micellar self-assembly, block copolymer vesicles, biocompatible polymers, colloidal nanocomposite particles, conducting polymers, stimulus-responsive microgels, polymer-based `Pickering´ emulsifiers.

Teaching Keywords

Polymer Chemistry, Colloid Chemistry, Chemistry and the World Around Us (Parts 1 and 2).

Selected Publications:

Correcting for a density distribution: particle size analysis of core-shell nanocomposite particles using disk centrifuge photosedimentometry, Lee A. Fielding, Oleksandr O. Mykhaylyk, Steven P. Armes, Patrick W. Fowler, Vikas Mittal and Stephen Fitzpatrick, Langmuir, 2012, 28, 2536-2544.
Polypyrrole Nanoparticles: A Potential Optical Coherence Tomography Contrast Agent for Cancer Imaging, K. M. Au, Z. H. Lu, S. J. Matcher and S. P. Armes, Adv. Mater. 2011, 23, 5792-5795.
Mechanistic Insights for Block Copolymer Morphologies: How Do Worms Form Vesicles?, A. Blanazs, J. Madsen, G. Battaglia, A. J. Ryan and S. P. Armes, J. Am. Chem. Soc. 2011, 133, 16581-16587.
Aqueous Dispersion Polymerization: A New Paradigm for in Situ Block Copolymer Self-Assembly in Concentrated Solution, Shinji Sugihara, Adam Blanazs, Steven P. Armes, Anthony J. Ryan and Andrew L. Lewis, J. Am. Chem. Soc. 2011, 133, 15707-15713.
An artificial biomineral formed by incorporation of copolymer micelles in calcite crystals, Yi-Yeoun Kim, Kathirvel Ganesan, Pengcheng Yang, Alexander N. Kulak, Shirly Borukhin, Sasha Pechook, Luis Ribeiro, Roland Kroeger, Stephen J. Eichhorn, Steven P. Armes, Boaz Pokroy and Fiona C. Meldrum, Nat Mater 2011, 10, 890-896.
Characterization of polymer-silica nanocomposite particles with core-shell morphologies using Monte Carlo simulations and small angle x-ray scattering. J.A. Balmer, O.O. Mykhaylyk, A. Schmid, S.P. Armes, J.P.A. Fairclough and A.J. Ryan, Langmuir, 2011, 27, 8075-8089.
Quantitative Evaluation of Mechanosensing of Cells on Dynamically Tunable Hydrogels, H. Y. Yoshikawa, F. F. Rossetti, S. Kaufmann, T. Kaindl, J. Madsen, U. Engel, A. L. Lewis, S. P. Armes and M. Tanaka, J. Am. Chem. Soc. 2011, 133, 1367-1374.
Unexpected Facile Redistribution of Adsorbed Silica Nanoparticles Between Latexes, J. A. Balmer, O. O. Mykhaylyk, J. P. A. Fairclough, A. J. Ryan, S. P. Armes, M. W. Murray, K. A. Murray and N. S. J. Williams, J. Am. Chem. Soc. 2010, 132, 2166-2168.
RAFT Synthesis of Sterically Stabilized Methacrylic Nanolatexes and Vesicles by Aqueous Dispersion Polymerization, Y. T. Li and S. P. Armes, Angew Chem Int Edit 2010, 49, 4042-4046.

Research Interests

Polymer Chemistry

We use living radical polymerisation techniques such as Reversible Addition-Fragmentation chain Transfer (RAFT) and Atom Transfer Radical Polymerisation (ATRP) to synthesise a wide range of controlled-structure, methacrylate-based water-soluble polymers. Block copolymers and their micellar self-assembly in aqueous solution are of particular interest: we are currently exploring the principles of polymerisation-induced self-assembly (PISA) to prepare a range of diblock copolymer-based ‘nano-objects’ in concentrated aqueous solution. Depending on the precise diblock copolymer curvature, such ‘nano-objects’ can possess either spherical, worm-like (see TEM image opposite) or vesicular morphologies. We now are establishing fundamental design rules for the rational design of such ‘nano-objects’ and we seek to exploit our enhanced understanding in order to generalise this powerful PISA approach to produce robust, reproducible formulations for both polar and non-polar solvents, as well as water.

Colloid Chemistry

We prepare a broad range of microscopic conducting polymer-based particles, including conducting polymer-coated latexes, conducting polymer-silica nanocomposite particles and sterically-stabilised conducting polymer particles. Such particles are proving to be useful synthetic mimics for carbonaceous and silicate-based micro-meteorites: we collaborate informally with space scientists based in the UK, Germany and the USA to aid their interpretation of data collected during various space missions (e.g. Cassini and Stardust). Polypyrrole particles also have potential biomedical applications as contrast agents in optical coherence tomography. We have pioneered the use of ultrafine aqueous silica sols in order to prepare a range of vinyl polymer-silica nanocomposite particles. Film-forming nanocomposite compositions can be prepared using acrylic monomers, which enable the production of tough, transparent, scratch-resistant coatings. Other recent examples include the synthesis of novel sterically-stabilised pH-responsive microgels, surface polymerisation of stimulus-responsive polymer brushes from planar surfaces and the evaluation of various latexes, microgels and nanocomposite particles as `Pickering´ emulsifiers for the production of both oil-in-water emulsions and also covalently cross-linked colloidosomes.

Teaching Section

Physical Chemistry

Undergraduate Courses Taught

CHM1506.5 "Paint Technology and Laundry Science"
The aim of this segment is to understand and appreciate the underlying chemistry and principles of paint technology and laundry formulations.
CHM1506.6 "Hair Products, Sunscreens and Cosmetics"
This course is designed to improve your scientific knowledge and understanding of: Various hair products (dyes, shampoos, conditioners etc); Sunscreen formulations; Skincare products; Assorted cosmetics (nail varnish, lipstick, mascara, perfume etc.).
CHM1507.5 "Chocolate" The aims of this segment are: (1) to gain a better understanding of the importance of processing in the industrial manufacture of ice cream chocolate and paper and (2) to appreciate some of the 'anomalous' properties of water.
CHM3301.1 "Fundamentals of Polymer Science"
This course forms an introduction to polymer science, including topics such as: nomenclature; molecular weight; solid-state properties; different types of polymerisation.
CHM3302.2 "Colloid Science" This course is an introduction to colloid science, covering topics such as: classification of colloids; particle size analysis; adsorption of amphiphilic molecules at the air/water interface; emulsions and microemulsions.
CHM4011.8: "Fundamentals of Polymer Science"

Postgraduate Courses Taught

CHM6106: "Fundamental Polymer Chemistry"

Tutorial & Workshop Support

First Year Workshops.
Second Year Physical Chemistry Tutorials.
Third Year Workshops (Colloid Science, Fundamentals of Polymer Science).
Third Year Literature Review.

Laboratory Teaching

Third Year Advanced Physical Chemistry
Fourth Year Research Project