Surface tension between CO₂ gas and tetra-n-butylammonium bromide aqueous solution

This paper reports experimental values of the surface tension between CO₂ gas and tetra-n-butylammonium bromide (TBAB) aqueous solution measured by the pendant drop method. The experimental conditions were pressures from 1.00 MPa to 4.00 MPa, temperatures from 288.15 K to 303.15 K and w_TBAB from 0.10 to 0.40, where w_TBAB denotes the mass fraction of TBAB in the aqueous solution. These pressure-temperature-composition conditions partially fall into the stability zone of (CO₂ + TBAB) semiclathrate hydrate but all data were obtained without any hydrate in the system. Surface tension decreased with increasing w_TBAB and pressure but temperature dependency was not observed. Compared to the air-TBAB aqueous solution system and CO₂-water system, the values of the surface tension were smaller.