Figure 4
From: Contactless and spatially structured cooling by directing thermal radiation
Supercooling of hexadecane. (a) Schematic of the home-built microfluidic chip. (b) Photograph of the sample with hexadecane (HDC) in the solid phase in the five chambers. (c) Cooling curve of the central chamber (Pos 1). After 200 s the melting temperature of hexadecane at 18 °C is reached. A sharp increase in temperature is observed after 1150 s, which indicates a liquid–solid phase transition of hexadecane. The phase transition peak has a half-lifetime of 141.1 s until the sample has reached the same temperature as before freezing. Inset: Zoom-in showing a temperature increase from 12.3 to 14.6 °C between 1152 and 1154 s. IR images (scale bar as in b) show the temperature distribution on the sample surface for different time frames. The black circle in the first image indicates the area used to extract the temperature values over time (blue curve). (d) Cooling curve measured for Pos 2. The half-lifetime of the phase transition peak of t1/2 = 324.5 s is longer compared to t1/2 for Pos 1. Inset: Zoom-in showing the temperature increase from 12.3 to 14.6 °C between 1466 and 1468 s.
