Mc170 hd color camera

The microstructure of wax crystals was observed under normal and polarized light (PLM) using a Leica DM2500 microscope (Wetzlar, Germany) equipped with a Leica MC170 HD color camera. For cryo-scanning electron microscopy (cryo-SEM), deoiling of organogel samples was carried out using butanol to remove the surface liquid oil in order to visualize the wax crystals. Precisely, the deoiling was carried out in two different ways: (1) A known quantity of organogel was weighed in a glass vial followed by addition of butanol (at a gel:butanol ratio of 1:50 w/w approximately), which led to the collapse of the gel structure and resultant sedimentation of the crystalline fraction. After overnight storage, the supernatant liquid was decanted to collect the sediment, which was then placed on the sample holder. (2) The organogel sample was directly placed on a specialized stub (sample holder with grooves) followed by a dropwise addition of butanol to remove the liquid oil. The stub was left for overnight drying in inverted position to drain out all the solvent. The stub was then plunge-frozen in liquid nitrogen and transferred into the cryo-preparation chamber (PP3010T Cryo-SEM Preparation System, Quorum Technologies, UK), where it was freeze-fractured and subsequently sputter-coated with Pt and examined in a JEOL JSM 7100F SEM (JEOL Ltd., Tokyo, Japan).