Ereptiospiration

Abstract

Pure coconut oil, lanolin, and acetaminophen were vaporized at rates of 1-50 mg/min, using a porous network exhibiting a temperature gradient from 5000 to 5500 K/mm, without incurring noticeable chemical changes due to combustion, oxidation, or other thermally-induced chemical structural changes. The newly coined term "ereptiospiration" is used here to describe this combination of thermal transpiration at high temperature gradients since the process can force the creation of thermal aerosols by rapid heating in a localized zone. Experimental data were generated for these materials using two different supports for metering the materials to the battery powered coil: namely, a stainless steel fiber bundle and a 3-D printed steel cartridge. Heating coconut oil, lanolin, or acetaminophen in a beaker to lower temperatures than those achieved at the surface of the coil showed noticeable and rapid degradation in the samples, while visual and olfactory observations for ereptiospiration showed no noticeable degradation in lanolin and coconut oil while HPLC chromatograms along with visual observation confirm that within the limit of detection, acetaminophen remains chemically unaltered by ereptiospiration.

Keywords: Kanthal; Knudsen; Knudsen number; acetaminophen; coconut oil; lanolin; rapid vaporization; thermal degradation; thermal lability; thermal transpiration; vaporization.

Figure 1

(A) Image of the 3D printed cartridge for ereptiospiration testing; and (B) screen shot of the 3D drawing used to create the cartridge.

Figure 2

Fiber bundle and coil system shown loaded with lanolin. The fiber bundle is sandwiched between two glass slides and the capillary tubes are used to create a space between the slides in order to maintain a reservoir of lanolin. The coil and a section of the fiber bundle is maintained free from direct contact with the lanolin in order to minimize flow of material directly to the coil from outside of the fiber bundle pores.

Figure 3

HPLC data for methanol, acetaminophen, and acetaminophen collected after ereptiospiration. Image on the top (a) shows the chromatogram for the time period of 0–5 min, while the image on the bottom (b) shows the same chromatogram for the full run time of 0–10 min. Methanol (yellow trace) does not show a peak while the ereptiospirated acetaminophen and acetaminophen from the reagent container showing peaks with the same retention time and very similar peak shape and relative heights, indicated that no chemical change was detected [16]. Note that in reference [16] using similar HPLC conditions, increased peak width change is considered to be an especially good indicator of chemical changes.

Figure 4

Image of acetaminophen before (a) and after heating with a hot air gun at 300 °C for 2 s (b). Clear evidence of thermal degradation is noted in panel (b).