We discuss instabilities exhibited by free surface nematic liquid crystal (NLC) films of nanoscale thickness deposited on solid substrates, with a focus on surface instabilities that lead to dewetting. Such instabilities have been discussed extensively; however, there is still no consensus regarding the interpretation of experimental results, appropriate modeling approaches, or instability mechanisms. Instabilities of thin NLC free surface films are related to a wider class of problems involving dewetting of non-Newtonian fluids. For nanoscale films, the substrate–film interaction, often modeled by a suitable disjoining pressure, becomes relevant. For NLCs, one can extend the formulation to include the elastic energy of the NLC film, leading to an ‘effective’ disjoining pressure, playing an important role in instability development. Focusing on thin film modeling within the framework of the long-wave asymptotic model, we discuss various instability mechanisms and outline problems where new research is needed.

我们讨论了沉积在固体基板上的纳米级厚度的自由表面向列液晶 (NLC) 膜表现出的不稳定性，重点是导致去湿的表面不稳定性。这种不稳定性已被广泛讨论。然而，关于实验结果的解释、适当的建模方法或不稳定性机制仍然没有达成共识。NLC 自由表面薄膜的不稳定性与更广泛的问题有关，包括非牛顿流体的去湿。对于纳米级薄膜，通常由合适的分离压力建模的基板 - 薄膜相互作用变得相关。对于 NLC，可以扩展公式以包含 NLC 薄膜的弹性能，从而产生“有效”分离压力，在不稳定性发展中发挥重要作用。