Structural characterization and related properties of the stearate anions intercalated Ni–Al hydrotalcite-like compound prepared by the microwave crystallization

The stearate anions intercalated Ni–Al hydrotalcite-like compounds were prepared by a coprecipitation method coupled with the microwave-hydrothermal treatment. Their structures were characterized using FT-IR, XRD, contact angle, SEM, TEM and thermal analysis. The XRD results indicate that the interlayer anions of the microwave radiation samples have better order and stronger electrostatic interactions with hydroxyl layers than those of the conventional aging 12 h samples, the crystallinity of stearate anions intercalated Ni–Al hydrotalcite-like compounds can be rapidly enhanced in a short period of microwave treatment, and the stearate anions arrange in the form of a monolayer in the interlayer space for all samples. The morphology analysis results show that all samples consist of irregular and very thin platelets, while the crystals size of microwave treated samples was obviously smaller than that of the conventional aged samples. Based on the contact angle results, the surfaces of all samples show the hydrophobic property. This is due to the intercalation of stearate anions. The thermal analysis results point out that the sample obtained from microwave radiation 60 min possesses the best thermal stability. The rapid synthesis method explored in this paper is a promising method for studying other anionic surfactant intercalated HTLc.

Research highlights▶ The MWN60m with microwave radiation 60 min shows the best crystallinity. ▶ The interlayer anions of the microwave radiation samples have better order. ▶ The enhancement of crystallinity improves the thermal stability of the samples.