【Gaofenzi.org前沿进展短讯】弹性是聚合物的一种重要性质，过去百年不断有科研人员试图探索出一套可以量化预测材料弹性的方法，但是聚合物内存在诸多缺陷和一些影响材料弹性的未知因素使得这项研究工作变得异常困难，但是最近MIT的科研人员取得了重大突破，以水凝胶网络聚合物为例，建立一种方法可以分析测量材料的内部缺陷，然后精确地计算出聚合物网络的弹性性能。首先科研人员计算了单个缺陷对材料弹性的影响，然后根据测量整个材料的缺陷获得材料整体缺陷对弹性的影响大小，而且理论计算与实际测试结果相符。通过试验不同材料后，研究人员将理论完善拓展至目前可以预测各种聚合物材料的弹性，对的，目前这套理论可以预测各种不同的聚合物材料的弹性性能，这是科研人员首次建立一种理论可以通过缺陷预测聚合物的弹性，这项研究成果意义重大，因为可以帮助研究人员更加精准地设计所需弹性性能的材料。这项研究成果发布在最新的《Science》杂志上。
参考文献：Quantifying the impact of molecular defects on polymer network elasticity；Mingjiang Zhong1,2,*, Rui Wang2,*, Ken Kawamoto1,*, Bradley D. Olsen2,†, Jeremiah A. Johnson1,†；Science 16 Sep 2016:Vol. 353, Issue 6305, pp. 1264-1268；DOI: 10.1126/science.aag0184
Abstract
Elasticity, one of the most important properties of a soft material, is difficult to quantify in polymer networks because of the presence of topological molecular defects in these materials. Furthermore, the impact of these defects on bulk elasticity is unknown. We used rheology, disassembly spectrometry, and simulations to measure the shear elastic modulus and count the numbers of topological “loop” defects of various order in a series of polymer hydrogels, and then used these data to evaluate the classical phantom and affine network theories of elasticity. The results led to a real elastic network theory (RENT) that describes how loop defects affect bulk elasticity. Given knowledge of the loop fractions, RENT provides predictions of the shear elastic modulus that are consistent with experimental observations.