In this work, we describe novel conducting chiral nematic composites prepared via in situ oxidative chemical polymerization of pyrrole onto modified chiral nematic cellulose nanocrystal (CNC) films. The surface of free-standing iridescent CNC films was modified by four different approaches including TEMPO-oxidation, acetylation, desulfation and cationization after the fabrication of sulfated CNC films by evaporation-induced self-assembly (EISA). Structural, thermal, optical and morphological features of the modified films were further evaluated. The modified CNC films show enhanced thermal stability of more than 95 °C relative to the acid form of the CNCs. The chiroptical properties could be customized to yield vibrant iridescent colors ranging from cyan-green to red by the surface treatments. Moreover, our experimental findings reveal that the surface modification approach allows the swelling behavior of the iridescent CNC films to be tailored, a property with potential for the fabrication of novel security devices. Conductive CNC/PPy composite films were prepared by in situ oxidative polymerization of pyrrole onto CNC surfaces using FeCl₃ and HCl as oxidizing agent and dopant, respectively. PPy was also polymerized onto chiral nematic mesoporous cellulose (CNMC) structures obtained through a concomitant assembly of CNCs and condensation of tetramethoxysilane (TMOS) to fabricate porous structures with enhanced specific charge capacity. Results reveal that the chiral nematic structure of CNCs could be replicated by the PPy coating. Furthermore, it was found that the electrochemical performance of CNC/PPy composites was improved after the development of mesoporous structures. These new, easily prepared materials are attractive candidates for environmentally friendly sensors and energy storage devices.

中文翻译：

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手性向列型介孔纤维素/聚吡咯复合膜的手性，形态和导电性能

在这项工作中，我们描述了通过原位制备的新型导电手性向列复合材料吡咯在改性手性向列型纤维素纳米晶体（CNC）膜上的氧化化学聚合。在通过蒸发诱导自组装（EISA）制造硫酸化CNC薄膜后，通过TEMPO氧化，乙酰化，脱硫和阳离子化四种不同的方法对自立式彩虹色CNC薄膜的表面进行了改性。进一步评估了改性膜的结构，热，光学和形态特征。相对于酸性形式的CNC，改性的CNC膜显示出超过95°C的增强的热稳定性。可以定制手性，以通过表面处理产生从青绿色到红色的充满活力的彩虹色。而且，我们的实验结果表明，表面改性方法可以定制彩虹色CNC膜的膨胀行为，这一特性具有制造新型安全装置的潜力。导电的CNC / PPy复合膜的制备方法是分别使用FeCl ₃和HCl作为氧化剂和掺杂剂，将吡咯在CNC表面上进行原位氧化聚合。PPy还聚合到手性向列型介孔纤维素（CNMC）结构上，该结构是通过CNC的伴随组装和四甲氧基硅烷（TMOS）的缩合获得的，以制造具有增强的比电荷容量的多孔结构。结果表明，PPy涂层可以复制CNCs的手性向列结构。此外，发现中孔结构发展后，CNC / PPy复合材料的电化学性能得到改善。这些新型，易于制备的材料是环保传感器和能量存储设备的有吸引力的候选材料。