Tga dsc thermogravimetric analyzer

TGA was carried out in a TGA/DSC thermogravimetric analyzer (Mettler-Toledo International Co., Ltd., Shanghai, China). The crust of fried BBFNs was peeled off with a stainless-steel knife and crushed by a QE-50 high speed crusher (Zhejiang Yili Industry and Trade Co., Ltd., Zhejiang, China). The crushed crust (5 g) was weighed into aluminum oxide pans and analyzed by first being heated from 20 °C to 700 °C at a heating rate of 10 °C/min, then cooled from 700 °C to 500 °C at a rate of 20 °C/min under a nitrogen flow rate of 60 mL/min. An empty aluminum oxide pan was used as the reference. The thermal weight (TG) spectrum, recorded using STARe evaluation software, was converted to derivative weight percentage to obtain the DTG curve of crust.

The OEO was loaded by SMV or RV by mechanical mixing with the OEO:vermiclulite ratio of 5:95. The FTIR spectra of OEO-loaded SMV and RV were characterized by a Thermo Scientific Smart iTR™ in the wavenumber range of 500–4000 nm⁻¹. The WA-XRD and SA-XRD patterns were recorded on a Rigaku X-ray powder diffractometer equipped with a Co source (40 kV, Kα 0.1790 nm). A TGA (TGA/DSC Thermogravimetric Analyzer, Mettler-Toledo Inc) was utilized to measure the weight loss of the OEO, OEO-loaded SMV and SMV, which were used to calculate the OEO loading amount. In a typical procedure, ~10–15 mg of a TGA sample was placed in an alumina pan and heated from 25 °C to 900 °C at a heating rate of 2 °C/min and an air flow rate of 20 mL/min. The isothermal release of OEO from the SMV was also evaluated by TGA at a constant temperature of 60 °C.