TY - JOUR
T1 - Adsorption of Kinetic Hydrate Inhibitors on Growing Surfaces
T2 - A Molecular Dynamics Study
AU - Yagasaki, Takuma
AU - Matsumoto, Masakazu
AU - Tanaka, Hideki
N1 - Funding Information:
The present work was supported by JSPS KAKENHI Grant JP16K17857 and MEXT as “Priority Issue on Post-Kcomputer” (Development of new fundamental technologies for high-efficiency energy creation, conversion/storage and use) using computational resources of the K computer provided by the RIKEN Advanced Institute for Computational Science through the HPCI System Research project (Project hp170237). Calculations were also performed on the computers at Research Center for Computational Science, Okazaki, Japan.
Publisher Copyright:
© 2017 American Chemical Society.
PY - 2018/4/5
Y1 - 2018/4/5
N2 - We investigate the mechanism of a typical kinetic hydrate inhibitor (KHI), polyvinylcaprolactam (PVCap), which has been applied to prevent hydrate plugs from forming in gas pipe lines, using molecular dynamics simulations of crystal growth of ethylene oxide hydrate. Water-soluble ethylene oxide is chosen as a guest species to avoid problems associated with the presence of the gas phase in the simulation cell such as slow crystal growth. A PVCap dodecamer adsorbs irreversibly on the hydrate surface which grows at supercooling of 3 K when the hydrophobic part of two pendent groups are trapped in open cages at the surface. The amide hydrogen bonds make no contribution to the adsorption. PVCap can adsorb on various crystallographic planes of sI hydrate. This is in contrast to antifreeze proteins, each of which prefers a specific plane of ice. The trapped PVCap gives rise to necessarily the concave surface of the hydrate. The crystal growth rate decreases with increasing surface curvature, indicating that the inhibition by PVCap is explained by the Gibbs-Thomson effect.
AB - We investigate the mechanism of a typical kinetic hydrate inhibitor (KHI), polyvinylcaprolactam (PVCap), which has been applied to prevent hydrate plugs from forming in gas pipe lines, using molecular dynamics simulations of crystal growth of ethylene oxide hydrate. Water-soluble ethylene oxide is chosen as a guest species to avoid problems associated with the presence of the gas phase in the simulation cell such as slow crystal growth. A PVCap dodecamer adsorbs irreversibly on the hydrate surface which grows at supercooling of 3 K when the hydrophobic part of two pendent groups are trapped in open cages at the surface. The amide hydrogen bonds make no contribution to the adsorption. PVCap can adsorb on various crystallographic planes of sI hydrate. This is in contrast to antifreeze proteins, each of which prefers a specific plane of ice. The trapped PVCap gives rise to necessarily the concave surface of the hydrate. The crystal growth rate decreases with increasing surface curvature, indicating that the inhibition by PVCap is explained by the Gibbs-Thomson effect.
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U2 - 10.1021/acs.jpcb.7b10356
DO - 10.1021/acs.jpcb.7b10356
M3 - Article
C2 - 29278335
AN - SCOPUS:85044101414
VL - 122
SP - 3396
EP - 3406
JO - Journal of Physical Chemistry B
JF - Journal of Physical Chemistry B
SN - 1520-6106
IS - 13
ER -