Block copolymers

Polymers and especially Block Copolymers (BCs) are an excellent tool for the preparation of nanostructured materials and more specifically for the controlled fabrication of functional nanocomposite materials. BCs may be defined as two or more chemically homogeneous polymeric fragments, i.e. homopolymeric chains, joined together by covalent bonds to form diverse and complex linear and non-linear architectures. In the frequent case of immiscibility among the constituent polymers, the competing thermodynamic effects give rise to different types of self-assembled morphologies depending on composition, segmental interaction and molecular weights, and having periodicity on length scales given by the polymer dimension itself. In the simplest case of amorphous diblock copolymers, the components may separate into regular arrays of lamellas, cylinders or spheres, while in solution spherical and cylindrical micelles or vesicles may be formed, therefore allowing to obtain in a simple manner and without any direct human intervention a large variety of highly regular mesostructures suitable for application in nanotechnology.

The potentiality of BCs for the preparation of nanomaterials have been widely recognized since the 90’s but only partially explored, and the investigations carried out within the group have the aim to give a contribute for a better comprehension and control of such systems.

In particular, our attention is actually focused on the following projects:

BC nanocomposites with special electro-optico-magnetic properties. Nanocomposites based on BCs as nanostructured matrices with metal or magnetic nanoparticles as fillers are very attractive materials mainly due to their potential applications in many sectors such as molecular electronics and photonics or to produce advanced sensoring systems, especially in the case of controlled spatial distribution of the nanoparticles into the matrix and collective behavior. This project has the aim of contributing to a better comprehension of such systems and tuning methods that use BC thin films (bidimensional, 2D) with well-ordered and oriented morphologies (superlattices) or tridimensional (3D) matrices with colloidal templates that can eventually be converted into porous materials which could offer particular properties even at low nanoparticle concentration.

BCs in solution as nanoreactors. A different way to utilize BCs in order to facilitate the formation of hybrid organic/inorganic materials concerns the possibility to use the BC micellar core as nanoreactor where inorganic precursors may be load and then reduced to produce NPs. Such BC/NP hybrids have peculiar magnetic, optic and catalytic properties, offering at the same time new opportunities due to the BC self-assembly which permits, as an example, the ordered deposition of metallic clusters into a BC micellar monolayer.