Sentence:  Related to micelle formation is the technologically important <WSD>ability</WSD> of detergent actives to congregate at oil water interfaces in such a manner that the polar ( or ionized ) end of the molecule is directed towards the aqueous phase and the hydrocarbon chain towards the oily phase . 
Meaning of the word marked with <WSD> tags:  the quality of being able to perform; a quality that permits or facilitates achievement or accomplishment