Ferroelectric Nematic Liquid Crystals

非技术摘要：铁电向列相是本质上棒状分子的流体，其自发地组织成具有宏观极性顺序的域。最近发现的这种液晶相创造了一个机会，探测和了解自发极化的外观在广泛的软材料，包括聚合物，生物材料，液晶和胶体。铁电液晶的极性性质使其在许多新的应用中具有吸引力，包括电光和非线性光学器件，并将导致铁电液晶的科学和应用的新发现。该项目提供了优秀的机会，为本科生的研究参与和实习的少数民族高中students.Technical摘要：铁电晶体（FN）是一种新的和基本上未开发的流体状态下发生的常规液晶的双相，结合取向顺序和自发极化的第一次在任何均匀的三维流体。估计的FN极化密度大于许多固态铁电体，其幅度意味着几乎完美的极性排列的双金属分子偶极子。 由于它们的大的自发极化，FN材料对施加的电场给出了简单、快速的取向响应，几乎给每一个微扰效应和应用一个新的维度。 一个基础广泛的，协调的努力，分子设计，合成和物理表征将追求的铁电体介电状态的特征，并逐步了解其纳米级的起源，新兴的介观性质，和潜在的应用。实验方法，包括电光研究，X射线散射，光学和SHG显微镜，和介电光谱将被用来表征FN分子组织，宏观结构和场响应动力学。 连续介质模型将被开发来描述一个新的区域的非线性弹性流体力学，其中极化空间电荷稳定成为主导因素。材料研究部（DMR）的这一资助支持研究，以了解铁电液晶与凝聚态物理学（CMP）的资金。该奖项反映了NSF的法定使命，并被认为是值得通过使用基金会的学术价值和更广泛的影响审查标准。

Nontechnical Abstract:Ferroelectric nematics are fluids of essentially rod-shaped molecules that spontaneously organize into domains with macroscopic polar order. The recent discovery of this liquid crystal phase has created an opportunity to probe and understand the appearance of spontaneous polarization in a broad range of soft materials, including polymers, biomaterials, liquid crystals and colloids. The polar nature of the ferroelectric nematic makes it attractive for a host of novel applications, including electrooptical and non-linear optical devices, and will lead to new discoveries in the science and applications of nematic liquid crystals. This project offers excellent opportunities for undergraduate research participation and internships for minority high school students.Technical Abstract:The ferroelectric nematic (FN) is a new and essentially unexplored fluid state that occurs below the conventional nematic phase of liquid crystals, combining orientational order and spontaneous polarization for the first time in any homogeneous three-dimensional fluid. The estimated FN polarization density is larger than many solid state ferroelectrics, its magnitude implying almost perfect polar alignment of the nematic molecular dipoles. Because of their large spontaneous polarization, FN materials give a facile, rapid orientational response to applied electric fields, giving virtually every nematic effect and application a new dimension. A broad-based, coordinated effort of molecular design, synthesis, and physical characterization will be pursued to characterize the ferroelectric nematic state and to evolve an understanding of its nanoscale origins, emergent mesoscopic properties, and potential applications. Experimental methods including electro-optic studies, x-ray scattering, optical and SHG microscopy, and dielectric spectroscopy will be used to characterize FN molecular organization, macroscopic structure, and field response dynamics. Continuum modeling will be developed to describe a new regime of nematic elasto-hydrodynamics where polarization space charge stabilization becomes a dominant player.This Division of Materials Research (DMR) grant supports research to understand ferroelectric nematic liquid crystals with funding from the Condensed Matter Physics (CMP) program in DMR of the Mathematical and Physical Sciences Directorate.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.