gasencapsulated

Gas encapsulated, or gas-encapsulated, refers to systems in which gas molecules are confined within a host structure, forming discrete gas-filled entities that are protected from the surrounding environment. Encapsulation can occur in solids, liquids, or gels, and is used to store, deliver, or control the release of gases.

Common forms include gas hydrates or clathrates, where gas molecules are trapped within a lattice of water molecules at low temperature or high pressure; gas-filled microbubbles or microballoons surrounded by lipid or polymer shells used as contrast agents in ultrasound imaging; polymer- or lipid-shelled microcapsules that physically trap gas within a hollow core; and porous materials such as zeolites or metal-organic frameworks that hold gas in internal pores. In practice, encapsulation differs from adsorption, as the gas is enclosed by a discrete boundary rather than merely bound to surfaces.

Production and characterization: methods include emulsification and solvent evaporation to form gas-filled capsules, spray drying, phase separation, and pressure-driven gas infiltration into hollow particles or porous hosts. Release can be tuned by shell thickness, material properties, and external triggers such as temperature, pH, or ultrasound.

Applications and considerations: medical imaging and therapy rely on gas-filled microbubbles and oxygen carriers; food and beverage industries use inert gas packaging; environmental and energy sectors explore gas storage in hydrates or porous materials. Major challenges include long-term stability, leak resistance, biocompatibility, and cost.