Edinburgh Soft Matter and Statistical Physics Programme Grant Renewal

爱丁堡软物质和统计物理项目拨款续签

• 批准号: EP/E030173/1
• 负责人: Michael Cates
• 金额: $ 497.63万
• 依托单位: University of Edinburgh
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2007
• 资助国家: 英国
• 起止时间: 2007 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FE030173%2F1
• 关键词: Edinburgh; Soft; Matter; Statistical; Physics

The term 'soft matter' describes a group of materials that are assembled from components whose size scale is of order microns or nanometers -- much bigger than a typical molecule or atom. Examples include polymers (very long flexible molecules), colloids (small hard spheres), emulsions (droplets of one fluid in another), foams (gas bubbles in a fluid), detergent molecules (with a water-loving head and a water-hating tail -- these clump together into complex shapes), powders (small dry grains), and many analagous systems of biological origin. Familiar examples are respectively engine oil, paint, mayonnaise, shaving cream, shampoo, and talc; the biological analogues include mucus, slime moulds, saliva, and various components of the living cell.In many cases, the system's behaviour is controlled not by the chemical details of its components, but by their physical interactions, which are generic to each class of material. The softness of these materials, compared to (say) a piece of metal, arises from the fact that these interactions are generically weaker than those between atoms. This makes it easy to bend and shape the materials, and to subject them to extremes of flow (causing disruption to the structure) that cannot easily be achieved with metals or other forms of 'hard' condensed matter. The weakness of the interactions means that there is a lot of random motion (the motion we call heat) even at room temperature; the properties of soft materials are often closer to those found by maximising the entropy (randomness) of the system than to those found by minimizing its energy. Under these conditions, one must use the tools of 'statistical mechanics' to understand how the microscopic interactions, combined with entropy, come to determine the properties of the material.The Edinburgh Soft Matter and Statistical Physics Group has developed experimental and theoretical techniques for understanding how the ingredients of a soft material come to determine its properties -- particularly those properties related to how the material flows (the science of 'rheology'). Our work focusses on making detailed studies of a small number of model systems, each representative of a larger class: by understanding these in depth, we hope to find general principles that might not be obvious by collating more superficial results for a wider range of samples. We wish to continue our integrated programme in experiment and theory, to address new topics in soft condensed matter, increasingly those at the interface with biology. The five main projects are:1. Rheophysics -- to understand the behaviour of colloids and other soft materials under conditions of strong flow. Often, flow can totally alter the internal structure of such materials and we want to understand this.2. Physics of barriers in soft matter and biology -- to understand how soft and biological systems undergo 'rare events' taking them from one apparently stable state of organization to another. These include events that alter the way genes are expressed in a cell, and also the nucleation of one phase of matter within another.3. New soft materials -- building on our recent discoveries, we want to use physics to create new and interesting materials with properties potentially relevant to computer displays, drug delivery, catalysis and other fields.4. Physics of cellular motion -- we want to understand how bacteria (which, if they were dead, would be effectively colloids) behave when swimming, either individually, or collectively (in a swarm). At a smaller scale, within the cell there are various soft matter components which use a constant supply of chemical energy to maintain an 'active' (i.e. living) state. We want to understand these too.5. New statistical mechanics tools -- we want to develop new and better theories and simulation models that will, over the longer term, help us connect the microscopic components in soft materials to their macroscopic properties.

“软物质”一词描述的是一组由尺寸为微米或纳米级的组分组装而成的材料，比典型的分子或原子大得多。例子包括聚合物（非常长的柔性分子）、胶体（小的硬球）、乳液（一种流体在另一种流体中的液滴）、泡沫（流体中的气泡）、洗涤剂分子（有一个喜水的头和一个讨厌水的尾--这些分子聚集在一起形成复杂的形状）、粉末（小的干燥颗粒）和许多生物起源的类似系统。常见的例子分别是机油、油漆、蛋黄酱、剃须膏、洗发水和滑石粉;生物类似物包括粘液、黏菌、唾液和活细胞的各种成分。在许多情况下，系统的行为不是由其成分的化学细节控制的，而是由它们的物理相互作用控制的，这对每一类材料都是通用的。这些材料的柔软性，与（比如）一块金属相比，源于这些相互作用一般比原子之间的相互作用弱。这使得材料容易弯曲和成形，并使它们经受金属或其他形式的“硬”凝聚物质不容易实现的极端流动（导致结构破坏）。相互作用的弱意味着即使在室温下也有很多随机运动（我们称之为热的运动）;软材料的性质通常更接近于通过最大化系统的熵（随机性）而不是通过最小化其能量而发现的性质。在这种情况下，人们必须使用“统计力学”的工具来理解微观相互作用，结合熵，爱丁堡软物质和统计物理小组已经开发了实验和理论技术，用于了解软材料的成分如何决定其特性-特别是与材料如何流动有关的特性（“流变学”的科学）我们的工作重点是对少量的模型系统进行详细的研究，每个模型系统代表一个更大的类：通过深入理解这些模型系统，我们希望通过整理更广泛样本的更表面结果来找到可能不明显的一般原理。我们希望继续我们在实验和理论的综合方案，以解决软凝聚态物质的新课题，越来越多地在与生物学的接口。五个主要项目是：1。流变物理学-了解胶体和其他软材料在强流动条件下的行为。通常，流动可以完全改变这些材料的内部结构，我们想了解这一点。2.软物质和生物学中的障碍物理学-了解软和生物系统如何经历“罕见事件”，将它们从一个明显稳定的组织状态带到另一个。这些包括改变基因在细胞中表达方式的事件，以及一种物质在另一种物质中的成核作用。新的软材料--在我们最近发现的基础上，我们希望利用物理学来创造新的有趣的材料，这些材料的特性可能与计算机显示器、药物输送、催化和其他领域有关。细胞运动的物理学--我们想了解细菌（如果它们死了，实际上是胶体）在游泳时的行为，无论是单独的，还是集体的（在一个群体中）。在较小的尺度上，细胞内有各种软物质成分，它们使用恒定的化学能来维持“活性”（即活的）状态。我们也想了解这些。5.新的统计力学工具--我们希望开发新的、更好的理论和模拟模型，从长远来看，这些模型将帮助我们将软材料中的微观成分与其宏观特性联系起来。

项目成果

Quantum widening of a causal dynamical triangulations universe

因果动力三角测量宇宙的量子展宽

• DOI: 10.1103/physrevd.86.104015
• 发表时间: 2012
• 期刊: Physical Review D
• 影响因子: 5
• 作者: Bogacz L

The MOLDY short-range molecular dynamics package

• DOI: 10.1016/j.cpc.2011.07.014
• 发表时间: 2011-12-01
• 期刊: COMPUTER PHYSICS COMMUNICATIONS
• 影响因子: 6.3
• 作者: Ackland, G. J.;D'Mellow, K.;Stratford, K.
• 通讯作者: Stratford, K.

Cubic blue phases in electric fields

• DOI: 10.1209/0295-5075/81/66004
• 发表时间: 2008-03
• 期刊: EPL (Europhysics Letters)
• 作者: G. P. Alexander;D. Marenduzzo

The role of noise and advection in absorbing state phase transitions

噪声和平流在吸收态相变中的作用

• DOI: 10.1209/0295-5075/90/16003
• 发表时间: 2010
• 期刊: EPL (Europhysics Letters)
• 作者: Barrett-Freeman C

Nonequilibrium phase transition in the sedimentation of reproducing particles.

再生颗粒沉降中的非平衡相变。

• DOI: 10.1103/physrevlett.101.100602
• 发表时间: 2008
• 期刊: Physical review letters
• 影响因子: 8.6
• 作者: Barrett-Freeman C