Novel photo-polymerizable chiral hydrogen-bonded self-assembled complexes: Preparation, characterization and the utilization as a thermal switching reflective color film
作者:Fengjin Chen、Jinbao Guo、Zhijian Qu、Jie Wei
DOI:10.1039/c0jm03810e
日期:——
In this study, novel photopolymerizable chiral hydrogen-bonded self-assembled complexes (PCHSCs) were fabricated, which were derived from photopolymerizable 4-(6-acryloyloxyhexyloxy) benzoic acid (AHBA, proton donor) and chiral pyridine derivatives (proton acceptor). Their structures were characterized by fourier transform infrared (FT-IR) and the proton nuclear magnetic resonance (1H-NMR) spectoscopy. The thermal stability, phase behaviors and helical twisted power (HTP) characteristics of the PCHSC were investigated by measuring the variable-temperature FT-IR spectrum, differential scanning calorimetry (DSC), polarizing optical microscopy (POM) and the Cano wedge. The results demonstrate that all the PCHSCs have good thermal stability within a temperature range, and the pitch length of all the cells containing the PCHSCs increases with increasing temperature, which is due to the fact that the HTP values of all the PCHSCs decrease with an increase of temperature. What's more, the introduction of AHBA leads to chiral enhancement of the PCHSCs. Based on the above results, a polymer stabilized cholesteric liquid crystals (PSCLCs) composite with the above PCHSCs was prepared and the thermal-optical characteristics of the PSCLCs film were investigated. The results confirm that the reflective wavelength of the PSCLCs film before and after irradiation can be thermally switched to reflect green and red color from the initial state reflecting a blue/green color with the temperature increasing from 30 °C to 75 °C. On the basis of this mechanism, the novel material in this study can be used as optical/photonic paper, optical sensors and LCs displays, etc.
本研究制备了新型可光聚合手性氢键自组装复合物(PCHSCs),它们来自可光聚合的 4-(6-丙烯酰氧基己氧基)苯甲酸(AHBA,质子供体)和手性吡啶衍生物(质子受体)。傅立叶变换红外光谱(FT-IR)和质子核磁共振光谱(1H-NMR)对它们的结构进行了表征。通过测量变温傅立叶变换红外光谱、差示扫描量热法(DSC)、偏振光学显微镜(POM)和卡诺楔仪,研究了 PCHSC 的热稳定性、相行为和螺旋扭曲力(HTP)特性。结果表明,所有 PCHSC 在一定温度范围内都具有良好的热稳定性,所有含有 PCHSC 的细胞的间距长度都随着温度的升高而增加,这是因为所有 PCHSC 的 HTP 值都随着温度的升高而降低。此外,AHBA 的引入还导致了 PCHSC 的手性增强。基于上述结果,制备了含有上述 PCHSCs 的聚合物稳定胆固醇液晶(PSCLCs)复合材料,并研究了 PSCLCs 薄膜的热光学特性。结果证实,随着温度从 30 °C 升高到 75 °C,PSCLCs 薄膜在辐照前后的反射波长可发生热转换,从最初的反射蓝/绿颜色转变为反射绿/红颜色。基于这一机理,本研究中的新型材料可用作光学/光子纸、光学传感器和液晶显示器等。