2 research outputs found
sj-docx-1-soq-10.1177_14761270241231088 – Supplemental material for Epitomizing an emerging category: Effects of entrepreneurial firms and influential stakeholders on the entrepreneurial firms’ status attainment
Supplemental material, sj-docx-1-soq-10.1177_14761270241231088 for Epitomizing an emerging category: Effects of entrepreneurial firms and influential stakeholders on the entrepreneurial firms’ status attainment by Bo Kyung Kim, Donghoon Shin and Mooweon Rhee in Strategic Organization</p
Role of Salts in Phase Transformation of Clathrate Hydrates under Brine Environments
Although
ion exclusion is a naturally occurring and commonly observed
phenomenon in clathrate hydrates, an understanding for the effect
of salt ions on the stability of clathrate hydrates is still unclear.
Here we report the first observation of phase transformation of structure
I and structure II clathrate hydrates using solid-state <sup>13</sup>C, <sup>19</sup>F, and <sup>23</sup>Na magic-angle spinning nuclear
magnetic resonance (NMR) spectroscopy, combined with X-ray diffraction
and Raman spectroscopy. The phase transformation of clathrate hydrates
in salt environments is found to be closely associated with the quadruple
point of clathrate hydrate/hydrated salts and the eutectic point of
ice/hydrated salts. The formation of the quasi-brine layer (QBL) is
triggered at temperatures a little lower than the eutectic point,
where an increasing salinity and QBL does not affect the stability
of clathrate hydrates. However, at temperatures above the eutectic
point, all hydrated salts and the QBL melt completely to form brine
solutions, destabilizing the clathrate hydrate structures. Temperature-dependent
in situ NMR spectroscopy under pressure also allows us to directly
detect the quadruple point of clathrate hydrates in salt environments,
which has been determined only by visual observations