ABSTRACT

The biaxial nematic ($N_B$) phase bordered by two uniaxial nematic (discotic – $N_D$ and calamitic – $N_C$) phases and the one between $N_D$ phases are studied in potassium laurate (KL), decanol (DeOH) and $D_{2}O$ mixture using conoscopic images. The sequences of phases ($N_D\to N_B^{+}\to N_B^{-}\to N_C$ and $N_D\to N_B^{+}\to N_D$) were optically characterized, where $N_B^{+}$ and $N_B^{-}$ are the biaxial positive and biaxial negative nematic phases, respectively. A new sequence of phases ($N_D\to N_B^{+}\to N_B^{-}\to N_B^{+}\to N_D$) found in one line of the phase diagram positioned close to the interface with the $N_C$ phase was also optically confirmed through conoscopic images. The $N_B^{+}(N_B^{-})\to N_B^{-}(N_B^{+})$ transition point was determined by means of image processing. In this review work, we emphasize the relevance of the optical characterization of an $N_B^{-}$ phase inherent to the nature of this lyotropic material.

摘要

双轴向列 ($N_{乙}$) 相以两个单轴向列（圆盘状 - $N_D$ 和灾难性的—— $N_C$) 阶段和之间的一个 $N_D$在月桂酸钾 ( KL )、癸醇 ( DeOH ) 和$D_2哦$混合使用锥光图像。相序 ($N_D\to N_{乙}^{+}\to N_{乙}^{-}\to N_C$ 和 $N_D\to N_{乙}^{+}\to N_D$) 进行了光学表征，其中 $N_{乙}^{+}$ 和 $N_{乙}^{-}$分别是双轴正相和双轴负向列相。一个新的阶段序列（$N_D\to N_{乙}^{+}\to N_{乙}^{-}\to N_{乙}^{+}\to N_D$) 位于相图中靠近与 $N_C$相位也通过锥光图像进行了光学确认。这$N_{乙}^{+}(N_{乙}^{-})\to N_{乙}^{-}(N_{乙}^{+})$过渡点是通过图像处理确定的。在这项审查工作中，我们强调了光学表征的相关性$N_{乙}^{-}$ 这种溶致材料的性质所固有的相。