Nanolayered particulate of Zn-based layered double hydroxide (LDH) was prepared by a low temperature greener sol-gel method. X-ray diffraction (XRD) studies were performed on the particles annealed at different temperatures. Hexagonal crystal structure of the as-grown LDH particulates was observed. The crystal structure was modified to tetragonal structure of layered double oxide (LDO) on annealing at 250°C. Rietveld fittings showed a collapse of interlayer separation distance along the preferred orientation of the LDH particles as a result of heat treatment. Further, LDH particles were used as fillers of electrospun poly(vinyl alcohol) (PVA) fibers. Heat treatment of the polymer fibers was also performed at different temperatures, and thermal changes were studied by thermogravimetric analysis (TGA), Raman spectroscopy, and scanning electron microscopy (SEM) techniques. Improved interaction of fibers with LDH nanoparticles was observed and ascribed to LDH-related LDO phase transformation at higher temperature. Thermal mechanisms of the rapid weight loss in filled fibers were discussed in comparison to the pure PVA fiber losses. Experimental Raman frequencies of the composite fibers were compared with the calculated Raman modes of the enol and ZnO monomers. The molecular vibration frequencies were found to differ significantly due to heat treatment. Finally, the role filler in the faster and greener thermal decomposition of polymeric fibers was also discussed in the present work.

中文翻译：

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聚（乙烯醇）/层状双氢氧化物杂化纳米复合纤维的形貌和热学性质

Zn基层状双氢氧化物（LDH）的纳米层颗粒通过低温绿色溶胶-凝胶法制备。对在不同温度下退火的颗粒进行了X射线衍射（XRD）研究。观察到生长的LDH颗粒的六方晶体结构。在250℃下退火时，晶体结构被修改为层状双氧化物（LDO）的四方结构。Rietveld接头显示，由于进行了热处理，沿着LDH颗粒的首选方向的层间分隔距离崩溃了。此外，LDH颗粒用作静电纺丝聚乙烯醇（PVA）纤维的填料。还可以在不同温度下对聚合物纤维进行热处理，并通过热重分析（TGA），拉曼光谱，和扫描电子显微镜（SEM）技术。观察到纤维与LDH纳米颗粒的相互作用改善，并且归因于较高温度下LDH相关的LDO相转变。与纯PVA纤维损失相比，讨论了填充纤维快速失重的热机制。将复合纤维的实验拉曼频率与烯醇和ZnO单体的拉曼模态进行了比较。发现分子振动频率由于热处理而显着不同。最后，在本工作中还讨论了填料在更快，更环保的聚合物纤维热分解中的作用。与纯PVA纤维损失相比，讨论了填充纤维快速失重的热机制。将复合纤维的实验拉曼频率与烯醇和ZnO单体的拉曼模态进行了比较。发现分子振动频率由于热处理而显着不同。最后，在本工作中还讨论了填料在更快，更环保的聚合物纤维热分解中的作用。与纯PVA纤维损失相比，讨论了填充纤维快速失重的热机制。将复合纤维的实验拉曼频率与烯醇和ZnO单体的拉曼模态进行了比较。发现分子振动频率由于热处理而显着不同。最后，在本工作中还讨论了填料在更快，更环保的聚合物纤维热分解中的作用。