BCMaterials Fortnightly Seminar #53: Roberto Fernández and Eduardo Fernandez

ROBERTO FERNANDEZ

(BCMATERIALS)

Composite AgVO₃@VO hydrogels and xerogels: Intrinsic properties and applications.

Hydrogels are self-entangled systems formed by non-covalent cross-linked nanoparticles or nanofibers… trapping even up to a 99% of its weight in water. In the specific case of Silver vanadium oxide (AgVO) hydrogels the AgVO₃ nanoribbons are self-entangled stabilizing the hydrogel. The modification of the synthetic conditions allows obtaining composite silver vanadium oxide + vanadium oxide (SVO@VO) hydrogels. The work presented in this seminar will be focused on the exploration of the intrinsic electronic properties of the synthesized hydrogels, studied by impedance spectroscopy. In addition, the local structure of different hydrogels and xerogels, and their formation, has been studied by means of X-ray absorption measurements. Giving a step beyond, the affinity of pure AgVO hydrogel and composite AgVO3@VO hydrogels for the adsorption of different positively, negatively and neutrally charged dyes have been studied. For some dyes, there is a selective adsorption induced by the vanadium oxide component of the hydrogels. As the vanadium cation can act as a catalyst centre, the catalytic performance of different hydrogels for the oxidation of aldehydes have been studied.

 

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EDUARDO FERNANDEZ

(BCMATERIALS)

Self-assembly copolymers

The self-assembly of block copolymer (BCP) thin films has become increasingly important as a method for nanoscale patterning as the resolution limits of optical lithography are approached. BCPs offer a bottom-up approach to nanolithography that is able to reach feature sizes of ∼5 nm and above, surpassing the resolution obtainable by conventional photolithography at lower cost than electron beam lithography. We will present a short description of all the applications of self-assembly copolymers published in the last ten years. Additionally, we will discuss advantages and disadvantages of self-assembly copolymers.