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A clean solution

Michael Duncan, John Girkin and Tom McLeish describe how an unusual cross-disciplinary collaboration between Procter & Gamble and Durham University is generating benefits for both sides

fluorescence confocal microscopy image
Credit: Procter and Gamble/Durham University

For many physicists, the idea that physics should play a leading role in industrial research will come as a surprise. Naively, one might assume that such research – particularly the sort that goes into developing consumer products – would instead be dominated by chemistry and engineering. However, many of the effects that manufacturers want in their products result from very small changes in materials, and physics can help us to understand and quantify those changes.

A good case in point concerns an apparently mundane product: laundry detergent. Over the past five years, rising energy costs and a desire to limit environmental damage have spurred firms such as Procter & Gamble to develop washing materials that can get clothes clean at lower temperatures, while using smaller volumes of water. But accomplishing this goal represented a challenge to manufacturers, so Procter & Gamble asked scientists at Durham University in the UK for help.

In traditional academia-industry collaborations, firms essentially "hire out" a single group of researchers or department to work on a particular project. But the partnership between Durham and Procter & Gamble is different: we have a single collaboration agreement that enables Procter & Gamble to draw on all the skills the university has to offer – and that includes biophysics and astronomy as well as surface chemistry and engineering.

A butter battle
To understand how physicists can help solve a problem related to washing powder, suppose you just spilled butter on your favourite shirt, and you want to get the stain out. Washing powder removes stains by breaking the chemical bonds between the butter and the cloth, allowing other compounds to come in and break up the fat itself, so it can be washed away. Further compounds in the powder prevent the fat from re-depositing itself on other areas of cloth.

In "biological" washing products, the ingredients that break the bond between the butter and the cloth are enzymes known as lipases. Butter is more or less fluid at 30 °C, so in a warm wash, it is fairly easy for the lipase to move in under the nearly-liquid butter and perform its task. But at 15 °C – the temperature of a typical cold-water wash – butter is still solid, and the lipase's task is very much harder. How can you save energy and still salvage your shirt?

To find out, optical physicists at Durham led by one of us (JG) used optical microscopy to study the actions of the lipase in three spatial dimensions and real time. After we had labelled the butter, lipase and cloth with fluorescent "markers" and placed them in water baths that can be controlled to within 0.001 °C, we used a confocal microscope to observe the effects of tiny temperature changes on the lipase process (see pair of images above). We also studied how variations in the type of lipase, surfactants and anti-deposition compounds affected how efficiently the stain could be removed.

Soon, however, we ran into a problem: the quality of our imaging data was limited by the fact that fat acts as an optical element, typically as a series of converging lenses, distorting the images obtained via microscopy. To remove this distortion, we looked at introducing techniques from adaptive optics – which are more often used to remove atmospheric distortion from large astronomical telescopes – into the confocal microscopy process. The resulting datasets can then be analysed using advanced image-processing algorithms to give an insight into both the physics and the chemistry taking place in your washing machine. In the case of grease removal, we observed a new effect in the washing process, the importance of which had not been appreciated before. Procter & Gamble is currently using this information to develop a deeper understanding of removal mechanisms, which will guide the company when it selects approaches to washing-powder formulation.

Learning from each other
In establishing the partnership between Durham and Procter & Gamble, we made a joint decision to work on many projects simultaneously, building integrated teams from university and industry scientists and managing this portfolio together. There are now about 100 people involved in the relationship on both sides, and we are planning to set up 5–10-year research programmes to tackle Procter & Gamble's biggest technical challenges. The company has made a financial commitment of many millions of pounds, and Durham is using that investment to attract additional funding from government and other major businesses.

But to maintain that kind of long-term relationship, the scientists need more than just financial support from their industry partners: they also need projects that are scientifically interesting. Fortunately, we have found that the involvement of physics in the fast-moving consumer industry goes far deeper than one might first imagine. The challenges the industry sets are wide-ranging, and they frequently force physicists outside the comfort zones of their specialism, so that they have to use all their skills. Industrial research topics can be more complex than those an academic lab would usually tackle because business motives tend to push beyond academia's taste for "clean" systems.

Paradoxically, this has benefits for science. One example comes from the work one of us (TM) did on the temperature-induced phase separation of polymer mixtures. Historically, academic groups at Durham had studied systems of polymers in which the molecular weight of mixture components was kept in a narrow range. In the early 1990s, however, our work with a research team from ICI brought us face-to-face with the industrial world, where broad distributions in molecular chain length are common. We had no choice but to take this into account, and when we did, we discovered a wealth of rich behaviour that opened up fundamental issues other groups had missed.

On the other hand, sometimes groups will learn more, faster, about topics of greater relevance to industry if they move away from industrial materials for a while. In the ICI project, we would have had no chance of understanding a complex industrial blend of polymers if we had not previously done experiments on very well-defined materials synthesized in an academic lab. In effect, years of working on clean university-based materials taught us lessons that we could then apply in an industrial context. This is a far cry from a bilateral project in which a company simply gives an academic group a set of materials to characterize and learn from.

Making it work
The current economic crisis means that universities need to tap into business funding more than ever, and the UK government is strongly supporting this approach. As a result, we believe that interest in partnerships of the kind created by Procter & Gamble and Durham will grow, thanks to the rich rewards available for both sides.

Universities work best if they are given both tough technical challenges and, crucially, enough time to work on them. When a company like Procter & Gamble lays out its strategy over 5–10 years, this allows the university to develop the long-term capability needed to address the research challenge. In Durham's case, this has meant new equipment, a new building and ultimately whole new areas of research.

But successful partnerships like these require careful planning. Companies looking to work with academic institutions first need to be clear on what they want to achieve. They need to be committed to building a long-term relationship, and should invest in it up front. It is valuable to have a confidentiality agreement. This helps to create a culture of trust and openness in which both sides are able to appreciate the needs of their partners; and work in a way that brings benefits all round.

Michael Duncan is the global director for open innovation at Procter & Gamble, John Girkin is a biophysicist at Durham University, UK, and Tom McLeish is Durham's pro-vice-chancellor for research, email

This article appeared in the January 2013 issue of Physics World.

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