Clathrate Hydrates. Группа авторов

noble gases, N₂, O₂, CO₂, and CH₄ to test some of the assumptions made regarding guest–cage interactions in using the van der Waals–Platteeuw approach. 1973–1983 Bertie and coworkers studied clathrate hydrates with infrared spectroscopy at low temperatures. 1974 Bily and Dick encountered gas hydrates below the permafrost in the Mackenzie Delta, Northwest Territories, Canada. 1974 Davidson, Garg, and Ripmeester reported broadline and pulsed NMR experiments on tetrahydrofuran (THF) hydrate from 4 to 270 K, showing regions of anisotropic and isotropic motions of the guest, relaxation minima for guest anisotropic rotation, water molecule reorientation, and diffusion. 1974 Davidson et al. showed that polar as well as non‐polar guests show reorientational guest motions that can be described by very broad distributions in reorientational correlation times at low temperatures. It led to a model for a guest–host potential determined by short range interactions between the guest and the disordered hydrogen atoms of the host water molecules. 1974 Dyadin was appointed to lead a research group that over some 40 years provided new information on structure, stoichiometry, and stability of clathrates and high‐pressure research on clathrate hydrates. 1975 Sloan and coworkers initiated work on two‐phase hydrate equilibria. 1976 Holder calculated that small guests are more likely to form sII (CS‐II) hydrate than sI (CS‐I). 1976–1987 Nakayama studied phase equilibria of salt hydrates. 1976 Peng and Robinson developed an accurate equation of state which is widely used to describe the vapor–liquid equilibria of hydrocarbons and small gases for hydrate equilibrium calculations. 1977 Ripmeester and Davidson reported 17 new clathrate guests mainly from NMR measurements. 1979–1993 Bishnoi and coworkers initiated a program of natural gas hydrate kinetic measurements and modeling and phase equilibrium modeling. 1981–1985 Cady measured hydrate compositions as a function of pressure, obtaining values which are in agreement with van der Waals–Platteeuw theory. 1981 Ross, Anderson, and Backström measured the anomalously low thermal conductivity of hydrates of clathrate hydrates. 1983 Tse, Klein, and coworkers initiated molecular dynamics simulations of clathrate hydrates. 1984 Handa prepared pure hydrocarbon hydrates under equilibrium conditions and obtained their thermodynamic properties from calorimetry. 1984 Davidson et al. experimentally showed very small guests form CS‐II rather than CS‐I. 1986 Davidson et al. provided the first laboratory analysis of recovered gas hydrate samples obtained from the Gulf of Mexico and identified both CS‐I and CS‐II hydrates. 1986 Davidson, Handa, and Ripmeester provided the first measurement of absolute cage occupancy of Xe hydrate. 1987 Ripmeester and coworkers discovered a new clathrate hydrate family, structure H (HS‐III). 1988 Whalley showed that octahedral melt figures are produced in THF clathrate hydrate crystals. 1988 Ripmeester and Ratcliffe introduced low‐temperature magic angle spinning ¹³C NMR spectroscopy to measure the relative occupancy of methane and methane/propane hydrate and used van der Waals–Platteeuw theory to obtain hydration numbers. 1988 Makogon and Kvenvolden independently provided estimates of the total volume of worldwide in situ hydrated natural gas at 10¹⁶ m³. Kvenvolden recognizes the decomposition of natural gas hydrates as potential contributor to global climate change. 1990 Collins, Ratcliffe, and Ripmeester used NMR spectral properties of several different nuclei, including ²H, ¹⁹F, ³¹P, and ⁷⁷Se to measure hydration numbers. 1990 Rodger studied hydrate stabilities with molecular dynamics simulations. 1990 Hallbrucker and Mayer formed clathrate hydrates by vapor deposition of amorphous solid water. 1990 Ripmeester and Ratcliffe discovered numerous new guests which form HS‐III and CS‐II using ¹²⁹Xe NMR of xenon co‐guest. 1991 Sloan proposed a molecular mechanism for hydrate formation with implications for inhibition. 1991 Handa et al. applied high pressure at 77 K to amorphize CS‐I and CS‐II clathrate hydrates, much as was observed for ice itself. Unlike, the amorphous ice phase, this amorphous phase recrystallized to the original hydrate phase when the applied pressure was reduced to ambient at 77 K. 1992 Handa and Stupin investigated hydrate phase equilibria in porous media. 1993 Inelastic incoherent neutron scattering (IINS) experiments on methane, Xe, and Kr hydrates were initiated at the NRC. 1993 Englezos and Hatzikiriakos used mathematical models to quantify how global temperature warming affects the stability of methane hydrates in the permafrost and in ocean sediments. 1993–2020 Tanaka and coworkers began a program of generalizing and improving on the assumptions of the van der Waals–Platteeuw theory. 1994 Edwards modeled winter flounder antifreeze peptide as a potential kinetic hydrate inhibitor. 1996 Sum measured clathrate hydration numbers with Raman spectroscopy. 1996 Koga and Tanaka studied the rearrangements of the water hydrogen bonding network in clathrate hydrates with polar guests using molecular dynamics simulation. 1997 Kuhs et al. reported double occupancy of large cages in CS‐II nitrogen hydrate. 1997 Udachin et al. reported HS‐III (sH) structure from single‐crystal X‐ray diffraction. 1997