The physics of glass-forming materials
Lead Research Organisation:
University of Leeds
Department Name: Physics and Astronomy
Abstract
Context of Research
Disordered non-equilibrium solids, such as glasses, are ubiquitous both in man-made materials and applications. The formation and behavior of glassy disordered non-equilibrium solids is one of the deepest unsolved fundamental questions in physics. Moreover, to better understand the physics of glassy materials it is important for a wide range of technologies, for battery and other energy materials, pharmaceuticals, foods, paints and for our understanding of biological matter such as proteins and cells. The fact that neither the microscopic mechanisms involved in glass formation nor the behaviour of the glassy state is well understood makes this a key problem both within the fundamental and applied sciences.
Despite this importance of glass-forming materials, we do not understand their behaviour, or the microscopic mechanisms responsible for their formation. Importantly, the dynamics of glass formation display generic features, suggesting that fluids with dramatically different chemistries can still be described within the same physical framework. For molecules of complex architectures such as polymers with varying side-chains topology or length, or for molecules with strong directional hydrogen bonding interactions, our understanding is presently poor. To be able to better design glass-forming materials we need to better understand the link between structure, interactions and relaxation dynamics. In this project, this will be achieved by systematic studies of glass-formers of varying structure, where the full relaxation dynamics and rheological response will be determined by advanced experimental techniques including calorimetry, dielectric relaxation spectroscopy, rheology, and scattering techniques.
Aims/Objectives
The aims of the project are to determine:
- how the relaxation dynamics and rheology in oligomeric or polymeric glass-formers depend on parameters including chain-length, chain flexibility, side-chain length and topology and how the relaxation behaviour contrasts that of non-polymeric molecular systems of varying molecular size.
- how hydrogen bonding in small molecule and oligomeric glass-formers affect the relaxation dynamics and glass transition behaviour.
Potential applications and benefits
Disordered out-of-equilibrium materials are common and important both in nature and in a truly wide range of technological applications. A better understanding would thus impact areas ranging from physics, engineering and materials science, to biology, medicine and food science and would also significantly affect our understanding of collective behaviour in a wide range of areas encompassing animal or human populations, traffic systems or granular packings. As stressed by the Nobel laureate Prof. Philip Anderson: "The deepest and most interesting unsolved problem in solid state theory is probably the theory of the nature of glass and the glass transition". To improve our understanding of glass-formation in polymers would lead to more efficient design of polymers, which is of particular importance due to the societal shift towards more sustainable, biodegradable polymer systems; the present lack of a predictive framework for polymer design is often a serious impediment to the efficient move towards more sustainable polymers.
Disordered non-equilibrium solids, such as glasses, are ubiquitous both in man-made materials and applications. The formation and behavior of glassy disordered non-equilibrium solids is one of the deepest unsolved fundamental questions in physics. Moreover, to better understand the physics of glassy materials it is important for a wide range of technologies, for battery and other energy materials, pharmaceuticals, foods, paints and for our understanding of biological matter such as proteins and cells. The fact that neither the microscopic mechanisms involved in glass formation nor the behaviour of the glassy state is well understood makes this a key problem both within the fundamental and applied sciences.
Despite this importance of glass-forming materials, we do not understand their behaviour, or the microscopic mechanisms responsible for their formation. Importantly, the dynamics of glass formation display generic features, suggesting that fluids with dramatically different chemistries can still be described within the same physical framework. For molecules of complex architectures such as polymers with varying side-chains topology or length, or for molecules with strong directional hydrogen bonding interactions, our understanding is presently poor. To be able to better design glass-forming materials we need to better understand the link between structure, interactions and relaxation dynamics. In this project, this will be achieved by systematic studies of glass-formers of varying structure, where the full relaxation dynamics and rheological response will be determined by advanced experimental techniques including calorimetry, dielectric relaxation spectroscopy, rheology, and scattering techniques.
Aims/Objectives
The aims of the project are to determine:
- how the relaxation dynamics and rheology in oligomeric or polymeric glass-formers depend on parameters including chain-length, chain flexibility, side-chain length and topology and how the relaxation behaviour contrasts that of non-polymeric molecular systems of varying molecular size.
- how hydrogen bonding in small molecule and oligomeric glass-formers affect the relaxation dynamics and glass transition behaviour.
Potential applications and benefits
Disordered out-of-equilibrium materials are common and important both in nature and in a truly wide range of technological applications. A better understanding would thus impact areas ranging from physics, engineering and materials science, to biology, medicine and food science and would also significantly affect our understanding of collective behaviour in a wide range of areas encompassing animal or human populations, traffic systems or granular packings. As stressed by the Nobel laureate Prof. Philip Anderson: "The deepest and most interesting unsolved problem in solid state theory is probably the theory of the nature of glass and the glass transition". To improve our understanding of glass-formation in polymers would lead to more efficient design of polymers, which is of particular importance due to the societal shift towards more sustainable, biodegradable polymer systems; the present lack of a predictive framework for polymer design is often a serious impediment to the efficient move towards more sustainable polymers.