Current Advances in Polymer Composite and Nanocomposite Membranes

In order to promote a scenario of sustainable growth, a more efficient use of natural resources is strongly recommended. Membranes, capable of facing the requirements of a circular economy by virtue of their intrinsic eco-friendly characteristics and low energy requirements, have a growing role to perform separation processes. For the membrane development, a single material, even if very valuable, could not fully express its potential if not combined to an adequate support. Thus, composite and nanocomposite membranes are the highest expression of this innovative technology, coupling high performance and low costs. They presuppose the most profitable combination of materials with a different nature and characteristics, taking advantage of the synergistic action that they can achieve during their use. Composite membranes are obtained as multiple overlapped thin layers, where the active one performs the "separative" tasks, while the others provide mechanical resistance to the structure. Extremely thin films can be practically applied only by using this approach, by separately optimizing the preparation of each layer. Nanocomposite membranes embrace nanofillers dispersed within polymeric matrices that offer the possibility to the former to express their superior properties. However, their effective development is not trivial, since different and arduous challenges must be addressed.