PROJECT OVERVIEW

Complex out-of-equilibrium soft matter systems, such as colloidal gels – a network of suspended, micron-sized particles showing arrested dynamics – form the cornerstone of technologies used in a wide range of applications from personal care and food products to batteries, fuel cells, and cementitious materials. To meet European sustainability goals, these products and the processes used to manufacture them must become more environmentally friendly and energy-efficient. This pressing need motivates the CoCoGel Industrial Doctoral Network (DN-ID). We will open new routes to control the microstructure and final properties of model and industrial colloidal gels utilizing innovative internal and external physical stimuli to meet this challenge.
Open Problem: The complexity in structure preparation implies that product development is still primarily based on trial and error, which is costly, wasteful, and limits new product development. It is, therefore, critical to develop the next generation of gel-based materials by rational rather than empirical design. However, this requires an in-depth understanding of how out-of-equilibrium microstructures are affected by external fields and internal stimuli.
Goal and Expertise: The CoCoGel project aims to unravel the underlying physical principles, which can be shared between multiple stimuli so that tunability will turn into controllability. Our team of academic and industrial partners is up to this task, as we are experts working at the forefront of advancing soft matter physics for gel systems,especially in the direction of material tuning. Over the past decade, we have laid the network and knowledge foundation that will enable us to successfully establish the transfer from academic insight to industrial practice.
Approach: We will examine the effect of processing conditions (shear and flow fields), as well as ultrasound stimuli, on the structure of gels comprising Brownian particles. Similarly,external electric and magnetic fields will be used on magnetic or electrically,responsive colloidal gels. We will also use non-Brownian inclusions (i.e. solid particles and deformable inclusions that are much larger than a micron) to restructure gels locally by subjecting them to such fields and ultrasound. This route for making local modifications to gels is essentially novel in an industrial context. Still it is very promising – based on common physical principles between industrial and academic suspensions – for modifying features of complex multi component materials. Critical to obtaining fundamental physical understanding is the co-development of new experimental characterization techniques and numerical methods for analyzing the underlying dynamics, which we will also undertake.
Core Concept: In brief, the physical properties (mechanical, thermal, electrical, magnetic, etc.) of agel-based system are dictated by its microstructure. The dynamics of the particles making up the structure is arrested, and thus gels are intrinsically out-of-equilibrium systems. Their formation is the result of a delicate balance of thermodynamic parameters, quenching kinetics (e.g., rates of temperature or pressure change), and processing conditions, such as shear or flow history. The central physics underlying the tunability of colloidal gel-based systems is the presence of different metastable sub-states in the sample. External and internal stimuli can be used to – in some cases reversibly – move between these long-lived out-of-equilibrium states of the energy landscape.
Transfer to Industry: Academic partners will investigate fundamental aspects in synergy with industrial partners, who will test the protocols on industrial samples. The latter will also address process-related issues and optimize a wide range of formulations relevant to personal care and food products, building materials, as well as energy and biomedical applications using the stimuli-based approaches that we devise. In the context of CoCoGel, the specific products and applications are:plant protein- based gels for food products and clay gels for personal care formulations, nanostructures for battery electrolytes and fuel cells, magnetic gel scaffolds for tissue engineering and magnetic hyperthermia tumor therapy,and lower carbon footprint 3D- printed concrete.
Network and Training: CoCoGel brings together Soft Matter scientists from academia and industry, with a background in experiment and simulation, who bridge physics and engineering. We will train 15 ESRs, who will focus on experimental and computational studies of how shear/flow, electric/magnetic external fields, ultrasound triggers changes in various colloidal gels with and without inclusions (solid or deformable).These are relevant to our research goals and transferable to wider industrial and academic settings. Thus, the training offered within CoCoGel, will open the way to create a range of new products and manufacturing methods, enhancing European competitiveness in the key areas of sustainability, energy, and health.