Experimental estimates of compression heating and decompression cooling in ethylene glycol

Abstract

The chemical shift difference, Δσ, between the methylene and hydroxyl protons in the high resolution 1 H nuclear magnetic resonance spectrum of ethylene glycol is shown to be pressure dependent. The equilibrium Δσ values for ethylene glycol are reported as a function of temperature and pressure between ambient conditions, 323 K and 2 kbar, respectively. This surface is used along with Δσ values measured in response to a rapid pressure increase to calculate a temperature rise that is used to infer a temperature change for water that is consistent with theoretical estimates. This work implies that compression heating and decompression cooling are not significant enough to interfere with pressure induced protein folding studies.

Regulating solvation and interface chemistry enables advanced aluminum-air batteries

“…20 The 1 H signal shifts to 4.72 ppm with the addition of 3 M MU, ascribed to the breakage of the H-bonds between water molecules and the decrease of the surrounding electronic density, which significantly enhances the H-bonds between MU and H 2 O. 21,22 Notably, both the chemical shift of 3 M MU and the hybrid electrolyte are almost identical, indicating that a little SnCl 2 does not affect the solvent structure. Moreover, no other impurity peaks were found in the Fourier transform infrared (FTIR) spectra (Fig.…”