Zid Maha, Cordoyiannis George, Kutnjak Zdravko, Kralj Samo
Condensed Matter Physics Department, Jožef Stefan Institute, 1000 Ljubljana, Slovenia.
Nanomaterials (Basel). 2024 Feb 5;14(3):320. doi: 10.3390/nano14030320.
We theoretically study the generic mechanisms that could establish critical behavior in nematic liquid crystals (NLCs). The corresponding free energy density terms should exhibit linear coupling with the nematic order parameter and, via this coupling, enhance the nematic order. We consider both temperature- and pressure-driven, order-disorder phase transitions. We derive a scaled effective free energy expression that describes how qualitatively different mechanisms enforce critical behavior. Our main focus is on the impact of nanoparticles (NPs) in homogeneous NP-NLC mixtures. We illustrate that in the case of pressure-driven phase changes, lower concentrations are needed to impose critical point conditions in comparison with pure temperature variations.
我们从理论上研究了可能在向列型液晶（NLCs）中建立临界行为的一般机制。相应的自由能密度项应与向列序参数呈现线性耦合，并通过这种耦合增强向列序。我们考虑了温度驱动和压力驱动的有序-无序相变。我们推导了一个标度化的有效自由能表达式，该表达式描述了性质不同的机制如何强制产生临界行为。我们主要关注均匀的纳米颗粒（NP）-NLC混合物中纳米颗粒（NPs）的影响。我们表明，在压力驱动相变的情况下，与纯温度变化相比，施加临界点条件所需的浓度更低。
