权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Magnetic Resonance Investigation of Pattern Formation in the Belousov-Zhabotinsky Reaction Dispersed in an AOT Water-in-Oil Microemulsion.

磁共振研究分散在 AOT 油包水微乳液中 Belousov-Zhabotinsky 反应中图案形成的情况。

基本信息

批准号：
EP/D051851/1
负责人：
Melanie Britton
金额：
$ 16万
依托单位：
University of Birmingham
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2006
资助国家：
英国
起止时间：
2006 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FD051851%2F1
关键词：
Magnetic Resonance Investigation Pattern Formation

项目摘要

The proposed project is an experimental investigation of pattern formation in the Belousov-Zhabotinsky (BZ) reaction, dispersed in an AOT microemulsion medium: the BZ-AOT system. In the BZ reaction chemical waves and patterns are produced by coupling autocatalysis, a process whereby the rate of formation of key products accelerates, and diffusion, the process by which molecules move within a fluid. In a microemulsion medium the reactants of the BZ reaction predominantly reside within nanometre-sized water droplets, which are surrounded by surfactant (AOT) molecules, and are suspended in oil. The types of patterns produced can be tuned by controlling the concentration and size of water droplets within the oil. Amongst the rich variety of patterns exhibited, some previously unknown in other chemical systems, Turing structures are observed. This important type of pattern, where stationary waves are produced, has been proposed by Alan Turing in 1952 as the mechanism underpinning biological morphogenesis, the process by which organisms development form and structure. Other important patterns include dashed and segmented spiral waves, which mimic important biological patterns and have not been observed in other chemical systems. This project will use Magnetic Resonance Imaging (MRI) in this system, for the first time, to visualise patterns. This technique is based on Nuclear Magnetic Resonance (NMR), is non-invasive and can provide a wealth of chemical and physical information. The NMR signal is produced, by deflecting spinning nuclei (ie 1H) from their equilibrium positions, using radiofrequency pulses. Images are produce through application of magnetic field gradients, which can spatially locate nuclei by their spinning frequency, which is dependent on position. Image contrast is produced by differences in the density of nuclei or their relaxation time. It is the differences in relaxation time of the water molecules that will be exploited in imaging patterns in the BZ-AOT system.By using MRI, 3-dimensional (3D) patterns will be observed in the BZ-AOT system for the first time. Of significant importance, there is the opportunity to observe the first experimental example of 3D Turing patterns in a chemical system. MRI will also be used to probe the structure and dynamics of the microemulsion medium and better understand how it influences pattern formation and development. The diversity and complexity of patterns formed in this system is linked to differences in the diffusion co-efficients of key molecules in the BZ reaction. These will be measured using MRI experiments and relationships between pattern selection and development will be tested. Motivation for studying pattern formation in this system comes not only from the ability to better understand pattern formation in chemical systems, but also in its application to unravelling mechanisms underpinning biological wave and pattern formation.

该项目是对分散在AOT微乳液介质中的Belousov-Zhabotinsky(BZ)反应中图案形成的实验研究：BZ-AOT体系。在BZ反应中，化学波和图案是通过耦合自催化和扩散产生的，前者是一个关键产物的形成速度加快的过程，后者是分子在流体中运动的过程。在微乳液介质中，BZ反应的反应物主要存在于纳米尺寸的水滴中，水滴被表面活性剂(AOT)分子包围，悬浮在油中。通过控制油中水滴的浓度和大小，可以调整产生的图案的类型。在展示的丰富多样的图案中，观察到了图灵结构，其中一些以前在其他化学系统中是未知的。这种产生驻波的重要模式是由艾伦·图灵在1952年提出的，作为生物形态发生的机制，生物形态发生是生物体发育形式和结构的过程。其他重要的模式包括虚线和分段螺旋波，它模仿了重要的生物模式，在其他化学系统中没有观察到。该项目将首次在该系统中使用磁共振成像(MRI)来可视化图案。该技术以核磁共振为基础，具有非侵入性，可提供丰富的化学和物理信息。核磁共振信号是通过使用射频脉冲使自旋原子核(即1H)偏离其平衡位置而产生的。成像是通过施加磁场梯度来产生的，磁场梯度可以通过原子核的旋转频率在空间上定位原子核，而旋转频率与位置有关。图像对比度是由原子核密度或其弛豫时间的不同而产生的。水分子弛豫时间的差异将被用于BZ-AOT系统的成像模式中。通过使用磁共振成像，BZ-AOT系统将首次观察到三维(3D)模式。非常重要的是，有机会观察化学体系中3D图灵图案的第一个实验例子。核磁共振还将被用来探测微乳介质的结构和动力学，并更好地了解它如何影响图案的形成和发展。在这个系统中形成的图案的多样性和复杂性与BZ反应中关键分子的扩散系数的差异有关。这些将通过核磁共振实验进行测量，并将测试模式选择和开发之间的关系。在这个系统中研究模式形成的动机不仅来自于更好地理解化学体系中的模式形成的能力，而且还来自于它在揭开支撑生物波和模式形成的机制方面的应用。