Microsphere-based insulating materials for use in vacuum insulated structures

A refrigerating appliance comprising:

• an inner liner and an outer wrapper that define an insulating cavity therebetween, wherein an at least partial vacuum is defined within the insulating cavity;
• a plurality of microsphere aggregates disposed within the insulating cavity, wherein interstitial spaces are defined between the microsphere aggregates, wherein each microsphere aggregate includes a size of from approximately 0.1 millimeters to approximately 4 millimeters, each microsphere aggregate comprising:
• at least one leached microsphere having a leached opening that extends through an outer wall and to an interior volume of each leached microsphere of the at least one leached microsphere;
• a binder that engages an outer surface of the outer wall, wherein the binder is disposed within a portion of the leached opening and at least partially defines the interior volume;
• wherein
• the interior volume of each leached microsphere defines an insulating space that is at least partially defined by the binder;
• the binder and the outer wall define a substantially air-tight seal around the insulating space.