A device for diffusion of volatile substances that includes a container for containing volatile substances, including the container, an aperture defining a sealing area, and a multilayer structure placed on the aperture. The multilayer structure includes a microporous membrane through which the volatile substances are diffused and a barrier layer that is removed before a first use. The multilayer structure also includes a sealing portion in contact with the sealing area. A device with a microporous membrane where the porosity of the membrane at the portion of the sealing area has been substantially reduced or eliminated to stop liquid transportation.