强熵效应与大分子体系的熵调控

Superentropy Effect and Macromolecular Entropy Control Strategy

在大分子体系中,以链的构象熵为主的熵效应对体系的微观结构和宏观性能都起着至关重要的作用.然而,熵的统计本质使其远不像焓作用那么直观,甚至会导致反直觉的现象出现.因此,探寻大分子体系中的熵效应,对于深入揭示此类体系纷繁复杂现象背后物理机制的重要性来说是不言而喻的,已成为高分子与软凝聚态物理学以及生命科学等多学科相交叉的重要前沿研究领域.如何在阐释熵效应的独特作用规律基础上,有效地调控熵以实现对体系微观结构的熵调控进而发展新型功能体系,是该领域一个亟需解决的重要科学问题.本文总结了我们在提出并发展熵调控策略方面的研究进展.首先,剖析了熵效应的一些基本作用规律,涵盖熵致有序和熵力等,并进一步提出了强熵效应的概念.其次,阐述了熵调控策略的必要性、基本原理以及调控途径.同时,举例介绍了熵调控策略在大分子体系中的应用,涵盖高分子纳米复合体系、凝胶网络、生命大分子体系以及大分子胶体体系等.最后,简明扼要地展望了该领域的未来发展趋势以及面临的关键问题,以期为其以后的发展提供些许有益的启迪.

Entropy,one of the elementary parameters in thermodynamics,is a central concept in statistical mechanics.In macromolecular systems,entropic effects,predominantly from the conformational entropy of a chain,play an essential role in both microstructural organization and macroscopic properties.In striking contrast to enthalpic interactions,entropic effects seem to be elusive and even lead to counterintuitive performance due to the statistical nature of entropy.Thus,exploring the entropic effects in macromolecular systems is of significant importance in elucidating the physical origin behind many complex phenomena,and has become one of the most important directions in the interdisciplinary fields covering polymer physics and soft matter physics.One particular aspect lies in how to manipulate entropic effects to tune the structural organization and thereby develop new functional systems,based on a fundamental understanding of the rules governing the ectopic effects.Here,we summarize our recent progress in proposing and developing entropic strategy in the structural control of macromolecular systems.Firstly,we elucidate the unique rules of the entropic effects,including entropic ordering and entropic forces,and propose the concept of superentropic effect.The significance,principles,and approaches regarding the entropic strategy are then described.Some applications of entropic strategy in various macromolecular systems,such as polymer nanocomposites,polymer gel networks,and biological macromolecules,are also presented.We finally seek to discuss future directions and identify open problems regarding the future progress of the entropic strategy.We hope that this article will promote further efforts toward fundamental research and the wide applications of entropic strategy in elucidating physical mechanisms,developing new types of functional materials,and beyond.