214 polyma differential scanning calorimeter

Sorbate ILs (SCILs) were synthesized by a salt metathesis reaction. In brief, sorbic acid and choline bicarbonate (molar ratio of 1:1) were weighed separately. Then, sorbic acid was dissolved in an appropriate amount of methanol. Choline bicarbonate was put into a 100 ml round‐bottom flask. The methanol solution of sorbic acid was added dropwise into choline bicarbonate. Reaction was kept under magnetic stirring until no bubbles overflow. Next, solvents of the resultant mixture were removed by rotary evaporation at 60°C for 30 min. Finally, the synthesized SCILs were placed in a vacuum oven and dried for 48 h to get rid of residual solvents.
The SCILs were characterized by ¹H‐nuclear magnetic resonance (¹H‐NMR) in DMSO‐d₆ with the residual solvent signals as the internal standard on a Bruker Ascend™ 600 MHz spectrometer (BRUKER AXS GmbH, Berne, Switzerland). The FTIR and differential scanning calorimetry (DSC) spectra of SCILs were recorded using a Nicolet FTIR spectrometer (Thermo Fisher Scientific Inc) and a 214 Polyma differential scanning calorimeter (NETZSCH Gerätebau GmbH, Selb, Germany), respectively.

Agilent 1260 high-performance liquid chromatography (HPLC) was purchased from Agilent (California, USA), HT7700 transmission electron microscopy (TEM) was purchased from Hitachi (Tokyo, Japan), 214 polyma differential scanning calorimeter (DSC) was purchased from Netzsch (Selbe, Germany), Nicolet 380 fourier transform infrared spectroscopy was purchased from Hitachi (Tokyo, Japan), Delsa Nano size analyzer was purchased from Beckman Coulter (Kraemer Boulevard Brea, USA), ZH-YLS-1A animal locomotor actimeter was purchased from Zhenghua Biologic Apparatus facilities company (Anhui, China).