Density, viscosity, surface tension and intermolecular interaction of triethylene glycol and 1,2-diaminopropane binary solution & its potential downstream usage for bioplastic production

Abstract

In this work, triethylene glycol (TEG) and 1,2-diaminopropane (DAP) binary mixture was proposed as a novel CO2 capturing solution. In order to understand the binary system better, the key physical and chemical properties of TEG and DAP binary solution including the density, viscosity and surface tension were determined and analyzed. The excess molar volume (VmE), viscosity deviation (Δη) and surface tension deviation (Δγ) of the solution were calculated and fitted by Redlich-Kister (R-K) equation to evaluate the factor and standard deviations between the experimental and calculated quantities. Meanwhile, the as-determined UV–Vis, FTIR, and Fluorescence spectra suggested that intermolecular hydrogen bonds were formed within the binary solution. In term of the excess molar volume, the intermolecular bonds were closely formed when the molar ratio of TEG to DAP was at 1: 1. This system showed strong CO2 capture capability, in which about 0.34 g CO2 was absorbed by per gram of DAP and TEG system. The resulting CO2-Storage Material (CO2SM) was further applied as potential carbon source for Poly-β-hydroxybutyrate (PHB, bioplastic) production by a photoautotrophic-cyanobacterium, and intracellular content of 12.92 wt% was achieved. This work used new biological methods to convert CO2, the fundamental, physical and chemical properties of the alcohol-amine system were studied, further, the basic data as the reference were provided for PHB downstream synthesis optimization.