A divider assembly is provided for dividing a cooking cavity of a microwave oven into two cooking subcavities. The divider assembly includes a first tempered glass panel, a metal frame extending around the periphery of the first tempered glass panel to support the first tempered glass panel, a honeycomb core positioned above the first tempered glass panel, a second tempered glass panel positioned above the honeycomb core, and a gasket extending around the periphery of the metal frame for engaging metal walls of the microwave oven, wherein the gasket includes small-diameter, long-length carbon nano-tubes.