Forming monolayer films

The water contains loosely bound Hydrogen nuclei in bonding with the OH radical. The molecules can have afinity to water depending on their polarity, if a molecule can contribute a positive charge, it would bond very well with OH negative radical. If it has negative polarity, it will be repelled from OH radicals. So any typical molecule will have either a crowding of OH -ve radicals around it or it has H+ ions around it. The situation is special when it comes to bipolar molecules, and if they are sufficiently long, they will attract both OH- or H+ at their ends. If the molecules are long, then they have sufficient space to accommodate different radicals on both ends. Surfactant molecules look like these:-

They are long chain molecules with a "head" that is water-loving :- water philic. the tails are water phobic, and hence in the given surface interface between water and air, they tend to stand upright as shown. Just like when you dip a plate in water, some water clings on the surface of plate, a metal can be dipped into a surfactant solution, and it will come out with a layer of the surfactant molecules. However this needs to be done very slowly. Here is a good article on this method of forming monolayers of one substance on another. Here are some good diagrams of the process.