Several new lactic acid derivatives containing the keto linkage group far from the chiral part and short alkyl chains have been synthesized and characterised by polarising optical microscopy, differential scanning calorimetry, as well as electro-optic and dielectric spectroscopy. The materials possess a self-assembling behaviour on the nanoscale level as they form polar smectic liquid crystalline mesophases, namely the orthogonal paraelectric SmA* and the tilted ferroelectric SmC* phases, in a broad temperature range down to room temperature. A short helical pitch (≈120–320 nm), relatively high spontaneous polarisation (≈150 nC/cm2) and reasonable tilt angle values have been determined within the temperature range of the tilted ferroelectric SmC* phase. The obtained results make the new materials useful for the advanced mixture design and for further utilisation in electro-optic devices based on the deformed helix ferroelectric effect.
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机译:通过偏光光学显微镜,差示扫描量热法以及电光和介电光谱法,已经合成并表征了几种新的含有远离手性部分的酮基连接基团和短烷基链的乳酸衍生物。这些材料在低至室温的宽温度范围内形成极性近晶液晶中间相,即正交顺电SmA *和倾斜铁电SmC *相,因此在纳米级具有自组装行为。在倾斜的铁电SmC *相的温度范围内,已确定出较短的螺旋螺距(≈120–320 nm),相对较高的自发极化(≈150nC / cm 2 sup>)和合理的倾斜角值。所得结果使新材料可用于先进的混合物设计,并可用于基于变形螺旋铁电效应的电光器件中。
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