Abstract
There is some disagreement in the literature on the phase transition temperatures of salt semi-clathrates, which melt incongruently due to the change of salt concentration in the liquid phase. By using differential scanning calorimetry (DSC), the phase transition temperatures of tetrabutylphosphonium bromide (TBPB) hydrates were investigated at 0.10<wTBPB<0.37 and atmospheric pressure. The freezing point of ice with the presence of NaCl was also studied as a reference. In this work, two DSC procedures were employed: dynamic and stepwise schemes, characterized by the maximum peak temperature Tpeak and inflection point temperature Tend, and final step temperature Tstep, respectively. The stepwise DSC scheme was validated by the measurement of the ice freezing point at wNaCl=0.10, 0.15 and 0.18. For the dynamic scheme, we developed and tested a method to estimate the melting temperature of TBPB hydrates. This method, though having a higher uncertainty, was more efficient than the stepwise scheme. The phase transition temperatures of TBPB hydrates are presented with the accuracy of 0.1K and compared with literature data.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.