Dipartimento di Chimica Industriale "Toso Montanari" and INSTM, Università di Bologna, Viale Risorgimento 4, IT-40136 Bologna, Italy.
Soft Matter. 2018 Mar 28;14(12):2245-2253. doi: 10.1039/c8sm00067k. Epub 2018 Feb 27.
We have investigated the possibility of extending the stability range of the biaxial nematic phase by adding an off-centre dipole of various strengths and orientations to elongated biaxial Gay-Berne (GB) mesogens yielding a relatively narrow biaxial nematic (N) phase, and a smectic (S) phase when dipole-less. The effect of dipoles is not easy to predict, and our previous investigations have shown the limited benefits of having a central dipole. Here we show, employing molecular dynamics (MD) simulations, that a not too strong off-centre dipole positioned along the longest axis of the nematogen can extend the temperature range of stability of the biaxial nematic phase, also shifting it towards lower temperatures.
我们研究了通过向具有拉长双轴 Gay-Berne (GB) 介晶的各向异性双轴向列相添加不同强度和方向的非中心偶极子，将双轴向列相的稳定范围扩展的可能性，结果得到一个相对较窄的双轴向列相（N 相）和一个无偶极子时的向列相（S 相）。偶极子的影响不容易预测，我们之前的研究表明，具有中心偶极子的好处有限。在这里，我们通过分子动力学（MD）模拟表明，沿向列相最长轴放置的一个不太强的非中心偶极子可以扩展双轴向列相的稳定温度范围，同时也将其向低温方向移动。
