Warwick drives green growth with £13.6M EPSRC hub in plastics

From developing greener materials and processes to growing more sustainable supply chains, a new £13.6 million research hub, funded by the Engineering and Physical Sciences Research Council (EPSRC), will help researchers at the University of Warwick tackle some of the UK’s biggest manufacturing challenges. 

The new Manufacturing Research Hub in Sustainable Engineering Plastics (SEP) will be led by Professor of Polymer Processes, Ton Peijs, at WMG, and has Professor of Polymer and Colloid Chemical Engineering, Stefan Bon, at the Department of Chemistry as one of the co-investigators. 

Researchers from Warwick will work, over the next seven years, alongside the University of Manchester and UCL to improve the way durable plastics – commonly used in cars, buildings, and electronics – are created, reused, and recycled. Researchers aim to reduce waste, support greener manufacturing practices, and advance the circular economy, with support from over 60 industry partners, including JLR, Polestar, Siemens, BEKO, Bellway, and Biffa, to turn research into real-world solutions. 

By focusing on practical needs, the Hub will help move the UK toward a circular economy—where products are reused instead of thrown away. The work will support businesses in reducing waste and minimizing their environmental impact, while maintaining competitiveness. It will also strengthen local supply chains and help shape future policies that promote innovation and sustainability in the UK manufacturing sector. 

Professor Ton Peijs, Project Lead, of the EPSRC Manufacturing Research Hub in Sustainable Engineering Plastics, said: “We’re incredibly proud to lead this vital initiative. Until now, most sustainability efforts in plastics have focused on single-use items and packaging. Yet engineering plastics - essential to modern life - present equally complex sustainability challenges that have, until now, largely been overlooked. 

This Hub unites researchers, industry leaders, and policymakers to fundamentally rethink how engineering plastic parts are designed, reused, repaired and recycled. We’re focused on real-world impact: using greener materials, smarter manufacturing and recycling systems, and more sustainable supply chains. 

This grant underscores the urgent need for innovation in this space, and we’re excited to drive meaningful, lasting change.” 

Professor Stefan Bon, co-investigator, from the Department of Chemistry says: “We at Warwick, the University of Manchester, and UCL worked tremendously hard to get this initiative over the line. It is good to see that the UK government recognises the value of its polymer science and engineering capabilities. The next 7-8 years will be fantastic!”

The Hub is one of four, backed by a total of £44 million through the EPSRC the new Manufacturing Research Hubs for a Sustainable Future will bring together world-class researchers with over 180 industry and civic partners to drive practical, sustainable innovation across the UK. 

Each hub will focus on a different critical area of manufacturing, including creating net-zero supply chains and resilient production systems, as well as transforming waste and reducing our reliance on fossil fuels. 

Professor Charlotte Deane, Executive Chair of EPSRC, said: “These hubs will play a vital role in reshaping manufacturing to help the UK achieve green growth. By combining deep research expertise with real-world partnerships, they will develop the technologies, tools, and systems we need for clean, competitive, and resilient industries.” 

For more info see UKRI: https://www.ukri.org/news/new-research-hubs-to-cut-carbon-and-reshape-uk-manufacturing/

Replacing titanium dioxide as opacifier: consider a shape change

A fresh lick of paint breathes new life into a tired looking place. Ever wondered how a thin layer of paint is so effective in hiding what lies underneath from vision? Beside colour pigments, and a binder that makes it stick, paints contain microscopic particles that are great at scattering light and turning that thin layer of paint opaque. The golden standard for these opacifiers are small titanium dioxide particles, of dimensions considerably smaller than one micron. Their use is not without controversy, as they are a big environmental burden, with a large carbon footprint and a questionable impact on human health. The reason why titanium dioxide particles are great at scattering light is that they have a high refractive index compared to the other paint ingredients, so when distributed throughout the dried paint film their hiding power of the underlying surface is fantastic. When no coloured pigments are used, the coated surface appears then whiter than white.

Ideally though, titanium dioxide should be replaced, but the list of safe high refractive materials is very limited. This makes you wonder if there is another handle, beside refractive index? Can we design efficient scattering enhancers from materials of lower refractive index?. Inspiration came from the white Cyphochilus beetle, native to southeast Asia. The scales of the beetle are not made of high refractive index materials, but they thank their white appearance to an intricate anisotropic porous microstructure, resembling the bare branches of a dense bush.

We at BonLab formed a team where researchers dr. Brooke Longbottom and dr. Chris Parkins together with dr. Gianni Jacucci and prof. Silvia Vignolini at the University of Cambridge (UK) designed a simplified mimic in the form of tiny rodlike silica particles and compared their scattering performance with spherical silica particles.

Our work published in the Journal of Materials Chemistry C from the Royal Society of Chemistry is part of their HOT paper collection and shows that the anisotropic silica particle outperform their spherical counterparts, and show excellent scattering performances across the visible electromagnetic spectrum when casted as a film.

SEM images and optical characterization of white silica supraparticles. a) low magnification SEM image of supracolloidal balls, b) higher magnification image of single supracolloidal balls, c) supracolloidal ball assembled in the presence of 0.01 M calcium chloride. Scale bars: a) = 15μm b&c) = 10μm. d) Reflectance spectra comparing the scattering properties of supraparticles with films of silica rod particles of similar size (thickness of 25μm). Supraparticles show performance comparable to the corresponding films. Increasing the disorder reduces the scattering efficiency. The reflectance spectra for the supraparticles were measured using a microscope, while for the film they were retrieved from the total transmission data.

We did not stop there, and went a step further to develop a prototype of a new class of micron-sized hiding pigment. We took these rodlike silica particles and assembled and sintered them into stable porous supracolloidal microspheres, as can be seen in the image above.

Prof. dr. ir. Stefan Bon says: “This work has been a number of years in the making. It was an absolute pleasure to work with prof. Silvia Vignolini and her team. We are very happy with the end result. We hope that this new type of hiding pigment provides inspiration to those who wish to replace titanium dioxide. After all, there is more to opacifiers than refractive index.”

The paper can be accessed from here:

https://doi.org/10.1039/D1TC00072A

BonLab collaborates to produce bacteria containing biocoatings

We have a long history of making polymer dispersions to be used in waterborne coatings. The polymer colloids, or latex particles, are made by emulsion polymerization. Prof. Joe Keddie from the Physics Department at Surrey University contacted us if we were interested to help out on a bio-coatings project that needed some bespoke polymer latexes and colloidal formulations. With the term bio-coatings we mean here the coating formulation has the ability to entrap metabolically-active bacteria within the dried polymer film.

We loved the concept. In BonLab, PhD student Josh Booth optimized the synthesis of acrylic polymer latexes at approximately 40wt% solids with a monomodal particle size distributions. Important was to use bacteria-friendly surfactants in the semi-batch emulsion polymerization processes. Important was also to have a dry glass transition temperature of the polymer latex binder around 34 ℃, so that film formation could occur at temperatures which preserved viability of the bacteria.

The latexes were formulated as mixtures with halloysite nanoclay (hollow tubes) and E coli bacteria back at Surrey. The tubular clay was introduced to create porosity inside the polymer nanocomposite films. The overall composition of the waterborne formulation was optimized for mechanical and bacterial performance.

Prof. dr. ir. Stefan Bon says: “We are delighted to be part of this study, and are pleased with the outcomes. Credit goes to the teams at the University of Surrey for making it all a success. The concept of biocoatings fits well with the ethos of the BonLab to fabricate materials from colloidal building blocks. We hope to stay involved and work together on next generation advanced coatings, with a green twist”

The paper is published in the ACS Journal Biomacromolecules and shows that large free-standing films of bacteria containing biocoating composites can be made.

The work is a collaborative study with research teams at Surrey University: dr. Yuxiu Chen and prof. Joe Keddie (Soft Matter Group, dept. of Physics), and Simone Krings and dr. Suzanne Hingley-Wilson (dept. of Microbial Sciences).