Sentence:  Obviously hydrophobic ( oleophilic ) substances such as greases , oils , or particles having a greasy or oily surface are more at home in the center of a <WSD>micelle</WSD> than in the aqueous phase . 
Meaning of the word marked with <WSD> tags:  an electrically charged particle built up from polymeric molecules or ions and occurring in certain colloidal electrolytic solutions like soaps and detergents