The construction of organic-inorganic hybrid ferroelectric materials with larger, high-polarity guest molecules intercalated in kaolinite (K) faces difficulties in terms of synthesis and uncertainty of structure-property relationships. The purpose of the present study was to optimize the synthesis method and to determine the mechanism of ferroelectric behavior of kaolinite intercalated with p-aminobenzamide (PABA), with an eye to improving the design of intercalation methods and better utilization of clay-based ferroelectric materials. The K-PABA intercalation compound (chemical formula Al2Si2O5(OH)4∙(PABA)0.7) was synthesized in an autoclave and then characterized using X-ray diffraction (XRD), infrared spectroscopy (IR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The experimental results showed that PABA expanded the kaolinite interlayer from 7.2 Å to 14.5 Å, and the orientation of the PABA molecule was ~70° from the plane of the kaolinite layers. The amino group of the PABA molecule was close to the Si sheet. The presence of intermolecular hydrogen bonds between kaolinite and PABA and among PABA molecules caused macro polarization of K-PABA and dipole inversion under the external electric field, resulting in K-PABA ferroelectricity. Simulation calculations using the Cambridge Sequential Total Energy Package (CASTEP) and the ferroelectricity test revealed the optimized intercalation model and possible ferroelectric mechanism.

中文翻译：

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高岭石-对-氨基苯甲酰胺插层化合物的合成、结构和铁电性

在高岭石 (K) 中插入较大的高极性客体分子的有机-无机杂化铁电材料的构建在合成和结构-性质关系的不确定性方面面临困难。本研究的目的是优化合成方法并确定高岭石插层对氨基苯甲酰胺 (PABA) 的铁电行为机理，以期改进插层方法的设计和更好地利用粘土基铁电材料。 . 在高压釜中合成 K-PABA 插层化合物（化学式 Al2Si2O5(OH)4∙(PABA)0.7），然后使用 X 射线衍射 (XRD)、红外光谱 (IR)、热重分析 (TGA) 和扫描电子显微镜（SEM）。实验结果表明，PABA 将高岭石夹层从 7.2 Å 扩展到 14.5 Å，并且 PABA 分子的取向与高岭石层平面的距离约为 70°。PABA 分子的氨基靠近 Si 片。高岭石与PABA分子间以及PABA分子间氢键的存在引起K-PABA宏观极化和外电场作用下偶极子反转，从而产生K-PABA铁电性。使用剑桥顺序总能量包 (CASTEP) 和铁电测试的模拟计算揭示了优化的插层模型和可能的铁电机制。PABA 分子的氨基靠近 Si 片。高岭石与PABA之间以及PABA分子间存在分子间氢键，在外电场作用下引起K-PABA宏观极化和偶极子反转，从而产生K-PABA铁电性。使用剑桥顺序总能量包 (CASTEP) 和铁电测试的模拟计算揭示了优化的插层模型和可能的铁电机制。PABA 分子的氨基靠近 Si 片。高岭石与PABA之间以及PABA分子间存在分子间氢键，在外电场作用下引起K-PABA宏观极化和偶极子反转，从而产生K-PABA铁电性。使用剑桥顺序总能量包 (CASTEP) 和铁电测试的模拟计算揭示了优化的插层模型和可能的铁电机制。