软凝聚态物质物理学

THE PHYSICS OF SOFT CONDENSED MATTER

软物质是指其某种物理性质在小的外力作用下能产生很大变化的凝聚态物质 ,典型的例子包括液晶、高分子体系、胶体、微乳液等 .软物质的结构和性质主要不是由内能 ,而是由熵来决定 .文章较通俗地介绍了软物质的概念 ,仔细分析了熵在软物质中所起的作用 ,同时详细介绍了聚合物体系、胶体及生物膜等几种典型的软物质 .通过硫化橡胶和无管虹吸等十分有趣的例子 ,说明了聚合物对流变性质的影响 ;通过分析硬球胶体的相变及相分离等行为说明了熵力的概念 ;仔细分析了电稳定胶体的相互作用 ,并介绍了DLVO理论以及近年来发现的对这一理论的偏离 ,特别是约束条件下同号带电胶球的长程吸引相互作用及其对此现象的一些解释 ;对生物膜也作了初步介绍 .人们对软物质的研究和理解目前还处于一个非常原始的阶段 ,深入研究和理解软物质的各种性质必将促进人类对自然和人类自身的认识 .

The physics of soft matter is the study of materials which possess certain physical properties that respond strongly to small applied forces.Typical examples are liquid crystals,polymers,colloids,microemulsions,etc.Physically the structure and properties of such materials are determined mainly by entropy rather than by energy.We will review the basic concepts of soft matter,the role of entropy and give a detailed introduction to representative soft matters such as polymers,colloids and biological membranes.The effect of polymers on rheological properties is discussed from the interesting tube\|less siphon phenomenon;the entropic force is introduced through the phase transition and phase separation of hard sphere colloids.The interaction of charge stabilized colloids and DLVO theory are presented in some detail and accounts are also given of the newly found long\|range attraction between similarly charged colloid spheres.The study and understanding of soft matter is only in its preliminary stage;further research and a deep understanding of this kind of material will greatly enhance the understanding of the world around us in daily life and of mankind itself.