  Under both engineering and natural conditions on Earth and in the Universe,
some gas hydrates are found to be stabilised outside their window of
thermodynamic stability by the formation of an ice layer-a phenomenon termed
self-preservation. Low occupancy surface regions on type I CO2 clathrate
structures together with the self-preserving ice layer lead to an effective
buoyancy for these structures which restricts the size range of particles that
float in the ocean on Enceladus, Pluto and similar oceanic worlds. Our goal
here is to investigate the implications of Lifshitz forces and low occupancy
surface regions on clathrate structures for their self-preservation through ice
layer formation, presenting a plausible model based on multilayer interactions
through dispersion forces. We predict that the growth of an ice layer between
0.01 and 0.2 $\mu$m thick on CO2 clathrate surfaces depends on the presence of
surface regions in the gas hydrates with low occupancy. The effective particle
density is estimated delimiting a range of particles that would be buoyant in
different oceans. Over geological time, deposition of floating CO2 hydrates
could result in the accumulation of kilometre-thick hydrate layers above liquid
water reservoirs, and below the water ice crusts of their respective ocean
worlds. On Enceladus, destabilisation of near-surface hydrate deposits could
lead to increased gas pressures that both drive plumes and entrain stabilised
hydrates to be redeposited on the surface of Enceladus or ejected into the
E-ring of Saturn. On ocean worlds such as Enceladus and particularly Pluto, the
accumulation of thick CO2 hydrate deposits could insulate its ocean against
freezing. In preventing the freezing of liquid water reservoirs in ocean
worlds, the presence of CO2 hydrate layers could enhance the habitability of
ocean worlds in our solar systems and on the exoplanets and exomoons beyond.
