Research Activities

Scientist in charge: Dario Pisignano

According to the IIT scientific plan requirements, the ultra-high surface/weight ratio of polymer nanofibers (up to 10^3 m^2/g), which is practically the state-of-the-art for high-volume processable nanomaterials, will be exploited to achieve both effective absorption and eventually catalytic properties in nanofibers tissues. By capitalising on the know-how developed in the I.I.T. network, we will further implement the realization, deposition, characterization of nanofibers made by polymers for reinforced structural nanocomposite materials. In order to reduce the surface defects and to increase the reproducibility of the final product, both the experimental set-up and the process parameters will be implemented to control both the deposition and the orientation of the fibers.

Smart and functional surfaces

This research activity deals with fabrication of surfaces with tailored properties and switchable wettability. For the design of such dynamically modifiable surfaces we use plastic coating with organic molecules confined close or onto to their surface, that exploit reversible geometry and dipole moment changes due to conformational transitions upon externally applied stimuli, such as light irradiation, electrical potential, temperature, etc. Another approach for pronounced and switchable wettability changes is the use of nanocomposites with semiconductor oxides nanofillers, such as TiO2, ZnO, WO3, and V2O5, that exhibit increased hydrophilicity upon band-gap photoexcitation, due to photogeneration of holes that create oxygen vacancies at the semiconductor surface. These defects are then able to promote dissociative adsorption of atmospheric water, which leads to an increase in surface hydroxylation, and thus, to the hydrophilicity of the surfaces.

This research activity deals with the incorporation into polymeric matrices of fillers responsive to external stimuli, that affect reversibly specific properties of the matrices, or with the development of polymeric materials that by modulating their chains can become responsive to various stimuli. To create the smart composite materials the plastics are combined with responsive organic molecules or inorganic nanocrystals, that can transfer their reversible properties directly or indirectly to the host matrix.

This research activity deals with the in-situ preparation of polymeric nanocomposites or nanocomposite-patterns producing the nanofillers directly into the polymer matrix, or positioning the nanofillers at specific areas of the polymers.
One method used by our group for the in-situ formation of the nanocomposite materials is the laser-induced nanocrystal formation, using pulsed UV laser irradiation of polymer composite films containing metal precursors. The choice of the precursor, polymer, laser wavelength, irradiation fluence, and number of incident pulses determines the speed of formation and the size of the nanocrystals, aiming at the same time to keep the polymer matrix macroscopically/microscopically unaffected by the irradiation procedure.

This research activity deals with the preparation of polymer based nanocomposites incorporating chemically synthesized colloidal nanoparticles. We can change the chemical composition, shape, and size of the latter by inducing small variations in the synthetic process, and therefore, we manage to precisely tailor them according to the desired application. The control over the synthesis of the colloidal nanoparticles gives a great variety of possibilities in terms of properties (optical, thermal, mechanical, electronic, magnetic) that can be tuned over large ranges. The properties of nanocomposite materials depend not only on the properties of their individual components but also on their interfacial characteristics.