An insulation medium invention includes a plurality of microspheres. Each microsphere comprises a porous core comprising a porous core material and having an exterior surface, a gas within the porous core, and a coating layer coating all of the exterior surface of the porous core. The coating layer comprises a coating material which transitions from a first state to a second state. In the first state, the coating material is permeable to the gas. In the second state the material is impermeable to the gas. The coating material in the second state is configured to encapsulate and maintain partial vacuum of the gas inside the porous core. In one embodiment, in the second state the coating is impermeable to air. Insulated structures, a method of making an insulation medium, a fluid storage media, and a method of delivering a fluid are also disclosed.