Many industrial formulations that form part of our daily lives are complex mixtures. These include food, hygiene and laundry products, paints, etc. In many of these systems small molecules migrating to and across interfaces (that are either exposed to atmosphere or buried in bulk) leads to undesired effects. These might include adhesive loss in hygiene products, poor flavour perception, and release of undesired chemicals to the atmosphere. This project is aimed at developing a software toolkit for understanding small molecule migration in complex fluid mixtures that have many ingredients. Our ambition is to go far beyond the very simple model systems for which molecular migration has previously been characterised, and to address the complexities that arise when migration occurs in products that have structure, or are evolving with time. This brings fascinating but subtle challenges which are not only stimulating fundamental problems, but underpin 'real world' issues such as shelf-life of detergent formulations, durability of coatings and even how our food tastes when we chew it. We have developed this proposal in close collaboration with 3 industrial partners (P&G, AkzoNobel and Mondelez) who represent three very different sectors of the consumer goods industry, yet have in common the need to control migration in structured products. Despite working on entirely different product ranges, scientists in these companies share a remarkable range of problems that can be addressed by answering 3 key questions: Q1. How does the depth profile of wetting layers and subsurface concentrations depend on bulk phase composition and molecular interactions? Q2. What is the surface structure resulting from lateral migration? Q3. What are the timescales and mechanisms associated with migration and formation of surface structures? We will tackle these questions for a variety of carefully defined model formulations to isolate influences of polarity, charge, hydrophobicity, elasticity and deformation, in a series of fundamental studies. The project will deliver fundamental science knowledge along with a predictive model toolkit, ready to be embedded in the research programmes of soft matter scientists and technologists. We will work with our industrial partners throughout the project to ensure successful implementation of these models to allow them to exploit this work in their R&D programmes, and make the deliverables available to wider downstream users through a supported software website and the National Formulation Centre. Solving these problems will pave the way to efficient formulations that offer reduced waste improved performance and stability in consumer goods.

This application requests funds to continue and develop the EngD in Formulation Engineering which has been supported by EPSRC since 2001. The EngD was developed in response to the needs of the modern process industries. Classical process engineering is concerned with processing materials, such as petrochemicals, which can be described in thermodynamic terms. However, modern process engineering is increasingly concerned with production of materials whose structure (micro- to nano- scale) and chemistry is complex and a function of the processing it has received. For optimal performance the process must be designed concurrently with the product, as to extract commercial value requires reliable and rapid scale-up. Examples include: foods, pharmaceuticals, paints, catalysts and fuel cell electrodes, structured ceramics, thin films, cosmetics, detergents and agrochemicals. In all of these, material formulation and microstructure controls the physical and chemical properties that are essential to its function. The Centre exploits the fact that the science within these industry sectors is common and built around designing processes to generate microstructure:(i) To optimise molecular delivery: for example, there is commonality between food, personal care and pharmaceuticals; in all of these sectors molecular delivery of actives is critical (in foods, to the stomach and GI tract, to the skin in personal care, throughout the body for the pharmaceutical industry);(ii) To control structure in-process: for example, fuel cell elements and catalysts require a structure which allows efficient passage of critical molecules over wide ranges of temperature and pressure; identical issues are faced in the manufacture of structured ceramics for investment casting;(iii) Using processes with appropriate scale and defined scale-up rules: the need is to create processes which can efficiently manufacture these products with minimal waste and changeover losses.The research issues that affect widely different industry sectors are thus the same: the need is to understand the processing that results in optimal nano- to microstructure and thus optimal effect. Products are either structured solids, soft solids or structured liquids, with properties that are highly process-dependent. To make these products efficiently requires combined understanding of their chemistry, processing and materials science. Research in this area has direct industrial benefits because of the sensitivity of the products to their processes of manufacture, and is of significant value to the UK as demonstrated by our current industry base, which includes a significant number of FMCG (Fast Moving Consumer Goods) companies in which product innovation is especially rapid and consumer focused. The need for, and the added value of, the EngD Centre is thus to bring together different industries and industry sectors to form a coherent underpinning research programme in Formulation Engineering. We have letters of support from 19 companies including (i) large companies who have already shown their support through multiple REs (including Unilever, P+G, Rolls Royce, Imerys, Johnson Matthey, Cadbury and Boots), (ii) companies new to the Centre who have been attracted by our research skills and industry base (including Bayer, Akzo Nobel, BASF, Fonterra (NZ), Bristol Myers Squibb and Pepsico).

Stories in the media about science continue to fire the imaginations of the general public. However, there is a significant proportion of the adult population whose scientific knowledge is insufficient to understand even the most basic aspects of these issues. The result is a section of the general public who are frustrated, or even intimidated, by science. The objective of this programme is to develop and present an extensive programme of events which illustrates the importance and pervasive nature of chemistry, and allows mature adults with only a rudimentary knowledge of science to learn about chemistry through presentations, demonstrations, debate, visits to laboratories and hands-on experience of practical chemistry. The programme has been designed to introduce the participants gently to a variety of aspects of fundamental and contemporary chemistry through taster events (presented by APTT, WEA and University of Newcastle). Other institutions (Centre for Lifelong Learning, University of Northumbria, Life Sciences Centre and The Open University) with an expertise and commitment to teaching adults are also collaborating on this project. Participants in the taster courses will receive guidance and encouragement to further their scientific knowledge by registering for the slightly more advanced course offered by these institutions. The more advanced courses range from those which stand alone, last only a few weeks and develop a particular aspect of chemistry in more detail, to those that lead to formal qualifications including degrees.

In designing new chemical manufacturing processes, the molecules or materials required (e.g., solvents or catalysts) are often chosen prior to optimising the topology or operating conditions of the product or process. This sequential decision-making process can lead to poor performance of the overall process because all these factors are intrinsically linked. For example, what is the best solvent for a reaction in a pharmaceutical manufacturing process depends on the temperature and pressure of the reactor, but also on what comes next in the process. If it is another reaction, it may be best to find a solvent which works reasonably well for both reactions, in order to avoid expensive additional processing steps such as swapping one solvent for another. By making decisions simultaneously, we can significantly improve the economics of a process and reduce its environmental impact through decreased material use and increased energy efficiency. Such an approach is referred to as integrated product and process design. There are three elements needed for integrated product and process design: predictive models that can relate changes in the materials and in the process to performance; optimisation formulations that capture mathematically the trade-offs inherent in such complex systems; reliable algorithms that can solve the resulting design problems efficiently. In recent years, we have developed predictive models that have opened up new possibilities in design. The aim of this proposal is therefore to propose new formulations and algorithms for integrated product and process design and to apply them to a series of design problems. The key challenge in problem formulation is to ensure that innovative (but unknown) solutions are embedded within the optimisation problem so that they can be uncovered. One way to do this is to allow the structure of the molecules or the materials to be part of the decision process by representing them through discrete decisions. Another complementary approach is to develop formulations that allow the identification of optimal mixtures. By mixing known molecules, one can tune the performance of the process. We will propose generic formulations for such problems. We will also tackle the simultaneous design of molecules/mixtures and processes. In the optimisation algorithms used to solve these design problems, the main issue is to identify the very best (global) solution reliably and in a reasonable amount of time. This is difficult due to the nature of the integrated product and process design problem: it is nonlinear and combinatorial, which means that many local solutions may exist. We will develop robust algorithms for such problems, tackling the different types of mathematics that may be encountered, such as differential equations and/or discrete variables. These generic algorithms will be applicable to large classes of problems and will therefore be useful to solve other optimisation problems. The findings of this research will be implemented and tested on a set of design case studies we have gathered in recent years through collaboration with industrial partners and other academic groups. Ongoing collaborations will ensure that our formulations and approaches are captured in software tools and suitable to tackle realistic design problems.

The proposed work involves an experimental and modelling investigation of vertically downwards gas-liquid annular flows. These are the key components in a wide variety of industrial applications, prime examples of which are, condensers and chemical reactors used in the production of detergents. In the latter case, a liquid feedstock is injected as a film onto the inside of a bundle of tubes and undergoes an exothermic sulphonation by contact with air containing SO3 which flows down the tubes co-currently with the films on the tube walls. To obtain the required quality of the product, the temperature of the reacting liquid must be rigidly controlled; otherwise, undesirable by-products are formed. Industry has made good progress in modelling these systems but such modelling is limited by the complexity of the underlying physics. First, a complex pattern of waves is formed on the interface and these affect the interaction between the gas and liquid and also the reaction and heat transfer processes. Secondly, liquid droplets are torn off the film and react with the SO3 in the gas in an uncontrolled way. Knowing which flow regime occurs under which conditions, and being able to predict the flow regimes in a systematic manner is crucial for the efficient and optimal operation of reactors that exploit downwards annular gas-liquid flows. Whereas vertically upwards annular flows have received considerable attention in the literature (see e.g. the work of Hewitt and Hall Taylor1a, Hewitt1b, Hewitt and Govan1c and Barbosa et al.1d), there has been very little work on vertically downwards annular flows. This is surprising given the early studies of Webb and Hewitt1e, whose work in this area has shown that the interactions between the turbulent gas core and the thin liquid film, particularly when both gravity and interfacial shear are significant, give rise to many complex phenomena and rich dynamics, which are not well-understood. The current state of modelling of downwards annular flows in general is insufficient. Hence, there is a need for a substantially improved understanding of the coupling between the liquid film and gas turbulence through the interfacial stress exerted by the gas onto the liquid which is responsible for wave formation and drop entrainment; achieving such an understanding is the aim of the proposed work. The project proposed here is a well-balanced synergistic approach adopting recent, advanced experimental methods, results of the detailed numerical and analytical studies conducted in other EPSRC-funded projects, EP/D031222 and EP/E021468, unavailable at the time of earlier studies, and advanced theoretical and modelling methodologies to develop efficient and accurate methods for the systematic prediction of flow interfacial behaviour and flow regimes in downwards annular flows.