This perspective is meant to provide some background and future directions for mixed matrix membranes. It is not meant to be a complete review but an initial description that allows the reader to find appropriate articles on various aspects of this topic and develop a better understanding so that they can pursue this topic with the information needed. A list of references that one can use to gain additional information is provided at the end of the article. (C) 2011 Elsevier B.V. All rights reserved.