MULTI-FUNCTIONAL POLYMER SCAFFOLDS FOR CLEANING CATALYSIS

People share a common desire to wear clean clothes, regardless of their wealth or nationality. Current detergent formulations are a complex mixture of reagents, but in terms of their cleaning composition can broadly be considered to contain (i) surfactants to solubilise fabric-based stains; (ii) enzymes to digest stains and (iii) bleaches to degrade and increase the hydrophillicity of coloured stains. Typically, these formulations require non-ambient temperature water to be effective. There is a clear societal, economic and environmental benefit to developing cold water cleaning technology for example in the developed world the significant reduction in energy requirements will have economic benefit to users and the UK economy by reducing energy bills associated with heating water (UK government statistics suggest that the average UK washing machine is used for 270 wash cycles per year with each cycle using 16 L of water. The cost of heating that water (assuming 10 p/kWh and 2.4 M households) is estimated to be in the order of 184 million); this reduction in energy demand will also reduce greenhouse gas emissions from power generation. A significant problem associated with washing at lower temperatures is the solidification of fats and oils, often in crystallised forms below 35 oC, preventing their facile removal from fabrics. While the technological problems of cleaning in cold water are many-fold, ultimately it is the limited performance of the bleaching catalysts and enzymes at these temperatures that are major contributors to the problem.Several technical issues must be addressed to overcome these issues. A key element is the inefficient operation of enzymes and bleaching agents under these conditions. While there are several aspects to consider, the incompatibility of enzymes both with other enzymes and metal-based bleaching catalysts, the self-destruction of bleaching catalysts as well as the requirement to operate at high pH (that is in part driven of the need to activate bleaching compounds), limit the application and performance of the most aggressive formulations. The proposal will focus on the development of technology that enables these, currently incompatible technologies to be applied together under operating conditions that are more consistent with their efficient operation in a way that will prevent deleterious interactions.

There are many potential beneficiaries of this research. The most obvious outcomes of technology allowing cold water cleaning to be undertaken would be very significant societal, environmental and economic benefits. i) Societal benefit: A large proportion of the worlds population spend the majority of their lives cleaning clothes as they do not have access to the laundry facilities available to those in the developed world. A majority of this cleaning is performed by labour intensive, manual (hand-washing) processes. The successful prosecution of the technology outlined in this proposal would enable more facile cleaning to be achieved in low temperature water and hence allow the liberation of these people from such time consuming tasks, enabling them to devote their time to other pursuits e.g. employment and education that may lead to personal and societal benefits. This would lead to a profound shift in world dynamics. Additionally, current detergent formulations operate at high pH. While there are a variety of reasons for this, the effective operation of peroxide-based bleach activators is limiting with respect it to its reduction. The reduction of the operational pH of the cleaning systems would lead to health benefits by reducing the exposure of people to harsh chemicals. ii) Environmental benefit: Heating water above ambient temperature to effect cleaning requires a great deal of energy. The use of warm water cleaning in the UK alone is estimated to cost 184 million per anum; this of course requires the generation of power and hence, in general, consumption of limited fossil fuel resources and production of damaging 'greenhouse gases'. The removal of this requirement would provide a great environmental benefit with respect to both conservation of fossil fuel resources and reduction of greenhouse gas production hence helping to abate global warming. Furthermore, the basic waste effluent of the washing process is released into the environment. Removal of the peroxide-based bleaching systems could significantly reduce the environmental impact of laundry on the environment. Finally, the removal of stoichiometric bleach activators would result in space being freed up in the formulation so that other additives could be incorporated or it could lead to a further reduction in packaging, thus reducing the burden on transportation, storage, landfill and recycling facilities. iii) Economic benefit: Energy savings will lead to several economic benefits from the consumer to national level. Individual consumers in the developed world will benefit from lowered energy bills. In turn, these significant savings in energy costs would be invested in the economies of those countries benefiting the national economies, including that of the UK. The storage, manufacturing and transportation costs of a reduced volume detergent could also be significant. Most importantly P&G is ideally place within the project to transfer the technology to the commercial sector, benefiting the company and UK plc. Furthermore, the fundamental concept within this technology is highly likely to be applicable to several other product areas (i.e. other washing processes, cosmetics etc.) where the separation of incompatible technologies presents a major challenge.