Phase separation-induced microstructures

Phase separation is a physical process that occurs when a mixed, homogeneous mixture of substances separates in different phases, characterized by high density of one of the constituting substance, and with material interfaces among them. In particular, under appropriate conditions, (bio-)polymer mix-tures can undergo phase separation and form a microstructured solid scaffold from the solidification of the constituting polymer.

In the biomedical field, this process concerns various applications. For example, several soft implants, 2D substrates or 3D scaffolds for cells are realised by processes of phase-separating collagen mixtures. Likewise, electrospinning is used to manufacture ultra-thin network of nanoporous fibres, whose mi-crostructure results from the phase separation of the constituting (bio-)polymer from the solvent sys-tem. Electrospun networks find growing biomedical application as grafts or scaffolds in tissue engi-neering. Hence, the knowledge of the phenomenology of phase separation can lead to control the physical properties of the fabricated materials (e.g. mechanical stiffness), thus improving their ultimate functionality.