Ismaili M, Anakkar A, Joly G, Isaert N, Nguyen HT
Laboratoire de Dynamique et Structure des Materiaux Moleculaires, UPRESA CNRS No. 8024, U.F.R. de Physique, Bainsertion marktiment P5, Universite des Sciences et Technologies de Lille, F59655 Villeneuve d'Ascq Cedex, France.
Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics. 2000 Jan;61(1):519-25. doi: 10.1103/physreve.61.519.
We report here the composition-temperature phase diagram of a mixture between n=9 and n=16 terms of a chiral tolans series shortly noted nF(2)BTFO1M7. This diagram constitutes an experimental illustration of one of the three theoretical phase diagrams predicted by the Renn and Lubensky's model. The pure compounds n=9 and n=16 exhibit, respectively, the phase sequences Cry-Sm-C*-Sm-A-TGB(A)-N*-BP-I and Cry-Sm-C*-N*-BP-I, where TGB refers to a twist grain boundary phase. Phases identification and transition temperatures, at atmospheric pressure, have been determined by both optical microscopy and photothermal methods. The experimental phase diagram shows the disappearance of Sm-A and TGB(A) mesophases and the appearance of a TGB(C) phase when the n=16 composition increases. Four of the five multicritical points theoretically anticipated by Renn and Lubensky are pointed out.
我们在此报告手性托兰斯系列中n = 9和n = 16项混合物的组成-温度相图，简称为nF(2)BTFO1M7。该相图是Renn和Lubensky模型预测的三个理论相图之一的实验例证。纯化合物n = 9和n = 16分别呈现出以下相序列：晶相-近晶相-C相-近晶相-A相-扭曲晶界相（TGB(A)）-向列相-蓝相-I和晶相-近晶相-C相-向列相-蓝相-I，其中TGB指扭曲晶界相。在大气压下，通过光学显微镜和光热方法确定了相的识别和转变温度。实验相图表明，当n = 16的组成增加时，近晶相-A相和扭曲晶界相（TGB(A)）消失，出现了扭曲晶界相（TGB(C)）。Renn和Lubensky理论预测的五个多临界点中的四个被指出。
