核壳结构纳米复合材料是材料领域研究的热点。 一方面通过在核材料表面包覆性质较稳定的壳层可以防止核粒子发生物理化学变化, 提高核粒子的分散性、 稳定性等, 另一方面通过内核和壳层材料相互结合共同作用, 表现出优于单一纳米粒子的理化性能。 目前, 核壳结构纳米复合材料已经被应用于催化、 光化学、 电化学、 微电子学、 微波吸收及药物治疗等领域。 以氯化镍和水合肼为主要原料, 采用反胶束法制备了镍肼络合物(NHC), 并以NHC为核, 包覆间苯二酚-甲醛(RF)树脂和二氧化硅(SiO₂), 合成核壳结构NHC复合物(NHC@RF, NHC@SiO₂和NHC@RF@SiO₂)。 采用透射电子显微镜(TEM)、 X射线衍射仪(XRD)、 傅里叶变换红外光谱透射法(TR-FTIR)、 衰减全反射法(ATR-FTIR)和漫反射法(DRS-FTIR)等测试手段对所得材料进行表征和分析。 结果表明: NHC为纳米棒状结构, 分散性较好。 主要成分除了Ni(N₂H₄)₂Cl₂, 还含有少量Ni(NH₃)₆Cl₂。 三种红外测试方法各有特点, 都能检测出NHC样品中主要官能团的特征峰; 对于核壳结构镍肼复合物, TR-FTIR法采用KBr压片制样过程中可能会引起结构及表面性质的改变, 还可能同KBr发生离子交换; ATR-FTIR法制样简单、 无需对样品进行预处理, 不会对核壳结构样品造成损坏, ATR法侧重于核壳结构外壳表征, 可用于定性分析核壳结构包覆情况; DRS-FTIR法与ATR-FTIR一样可以做到无损测量, 一般仍需用KBr进行稀释, 检测深度及获取到的信号强度介于TR-FTIR与ATR-FTIR方法之间。 RF的包覆对NHC的红外特征峰影响不大, 但是SiO₂的包覆使N—H的伸缩振动峰红移而弯曲振动峰蓝移, 说明SiO₂与N—H键之间发生了相互作用。

The investigation on core@shell structured nanocomposites is a hotspot in material science. The dispersion and stability of core particles can be enhanced by coating with a stable shell layer to prevent the physical or chemical changes. Compared to single nanoparticles, improved performance can be achieved via the combined interactions of the cores and shells of the nanocomposites. Thus, core@shell nanocomposites are widely used in the fields of catalysis, photochemistry, electro chemistry, microelectronics, microwave absorption, drug therapy, and so on. In this study, nano-scale nickel-hydrazine complex(NHC)is fabricated by the reverse micelle approach in the oil phase with the nickel chloride and the hydrazine hydrate. Core@shell structured nickel-hydrazine composites (NHC@RF, NHC@SiO₂, NHC@RF@SiO₂) are synthesized by NHC coated with the resorcinol formaldehyde (RF) resin and silicon dioxide(SiO₂). The fabricated samples are characterized by transmission electron microscope (TEM), X-ray diffraction (XRD), transmission, attenuated total reflection and diffuse reflection Fourier transform of infrared spectroscopy (TR-FTIR, ATR-FTIR and DRS-FTIR). It is proved that the nano-rod structured NHC mainly includes Ni(N₂H₄)₂Cl₂ with a little Ni(NH₃)₆Cl₂. For TR-FTIR, the structure and surface properties might be changed by the potassium bromide though the possible ion exchange during the process of KBr tablet pressing. No sample pretreatment is needed for ATR-FTIR without any damage to the core@shell structured composites. ATR-FTIR focuses on the shell characterization of core@shell structure and can be used for the qualitative analysis of coating. Similar to ATR-FTIR, the nondestructive DRS-FTIR still requires the potassium bromide for dilution, and its detection depth and intensity are higher than that of ATR-FTIR and lower than that of TR-FTIR. The RF coating has little influence on the characteristics of NHC peak, while SiO₂ coating leads to red-shift of the stretching vibration and blue-shift of the bending vibration of N—H bonds, demonstrating the interaction between SiO₂ and N—H bonds.