Cooking oil lipids consist of long, unsaturated hydrocarbon chains. would you expect these molecules to form membranes spontaneously? why or why not?

I think the answer is No, because they have no polar end to interact with water. Instead these lipids would float on the surface of water or collect in droplets suspended in water, reducing their interaction with water to a minimum. Unsaturated hydrocarbons are those that contain ether double bonds or triple bonds along the carbon chains.