Device for diffusion of volatile substances

A device for diffusion of volatile substances, the device comprising:

• a container for containing volatile substances, the container having an aperture and a perimetric flange at the perimeter of said aperture of the container defining a sealing area;
• and
• a multilayer structure placed over said aperture and on said perimetric flange, said multilayer structure comprising:
• a microporous membrane positioned over said aperture, and the perimetric flange, and having a section configured to permit the volatile substances contained in the container to diffuse through the microporous membrane, the microporous membrane including a heterophasic layer over the perimetric flange that does not permit liquid transport,
• a removable barrier layer removably attached to the microporous membrane;
• and
• a sealing portion on the perimetric flange and made of a material that extends into the microporous membrane to seal pores in the microporous membrane to define the heterophasic layer.