1. A method comprising: obtaining a roofing membrane, wherein the roofing membrane has a thickness of 1 mil to 100 mils; wherein the roofing membrane has a top surface and a bottom surface, obtaining a plasma-generating gas, wherein the plasma-generating gas comprises at least one of an oxygen, a nitrogen, a helium, an argon, a hydrogen, or any combination thereof; flowing the plasma-generating gas through a plasma-generation device so as to generate a plasma flow; subjecting the bottom surface of the roofing membrane to the plasma flow, wherein, after subjecting the bottom surface of the roofing membrane to the plasma flow to obtain a modified bottom surface of the roofing membrane, a surface roughness of the modified bottom surface of the roofing membrane is 12 microns to 40 microns as measured using stylus profilometry; and applying an adhesive material to the modified bottom surface of the roofing membrane, so as to form an adhesive layer on the roofing membrane, wherein the adhesive layer directly contacts the modified bottom surface of the roofing membrane; wherein, when installed on a roofing substrate, the adhesive layer directly contacts the roofing substrate; wherein, when installed on the roofing substrate, the top surface of the roofing membrane is exposed to an external environment.