Rational Design of Smectic Liquid Crystals for Electro-Optical Applications

手征性是人类和几乎所有生物都具有的一种性质。手性对象以右手和左手形式存在（例如，手套、高尔夫球杆），并且在它们的镜像上是不可重叠的。手性在分子尺度上也很明显。(e.g.,氨基酸，碳水化合物）;这些手性结构单元自然组装形成较大的手性结构（例如，蛋白质、核酸），其本身形成具有手性形貌的晶体结构。这种分子手性在宏观水平上的表现，首先由巴斯德用酒石酸铵钠晶体认识到，在层状（近晶）液晶相中通过形式手性和自发极化来揭示。例如，手性近晶C（SmC*）相的特征在于螺旋结构，其中分子倾斜取向绕层法线旋进;它还表现出自发极化（

Chirality is a property that man-made and almost all living things possess. Chiral objects exist in right- and left-handed forms (e.g., gloves, golf clubs) and are non-superposable on their mirror images. Chirality is also manifest at the molecular scale. (e.g., amino acids, carbohydrates); these chiral building blocks are assembled by nature to form larger chiral structures (e.g., proteins, nucleic acids), which themselves form crystalline structures with chiral topographies. This manifestation of molecular chirality at the macroscopic level, which was first recognized by Pasteur with crystals of sodium ammonium tartrate, is revealed in lamellar (smectic) liquid crystal phases by form chirality and spontaneous polarization. For example, the chiral smectic C (SmC*) phase is characterized by a helical structure in which the molecular tilt orientation precesses about the layer normal; it also exhibits a spontaneous polarization (