S. Bittolo Bon

Preparation of transparent and conductive cellulose nanocrystals/graphene nanoplatelets films

The manufacture of emerging products such as photovoltaic devices requires combinations of various novel materials to be leveraged into successful, scalable approach. In order to develop new electronic devices, it is necessary to find innovative solutions to the eco-sustainability problem of materials as substrates for circuits. We report on the demonstration of polymer solar cells fabricated on optically transparent and conductive graphene nanoplatelets (GNPs)–cellulose nanocrystals (CNC) film. The solar cells fabricated on the GNPs/CNC films display good rectification in the dark. Such GNPs–CNC functional films are expected to be attractive for eco-friendly electronics.

Graphene-Based Bionic Composites with Multifunctional and Repairing Properties

In this work, a novel bionic composite inspired by the concept of yeast fermentation has been proposed. It was observed that the addition of graphene nanoplatelets during the fermentation of extract of Saccharomyces cerevisiae fungi allows coupling of the graphene sheets to the yeast cell wall. This process resulted in the formation of a composite film with improved mechanical and electrical properties along with the capability of converting the light stimulus in the electrical signal. The mechanical properties of the prepared composites, namely, the fracture strength and Youngs modulus, were studied via numerical simulations and are related to the properties of the constituent phases via rules of mixture. Finally, it was observed that graphene nanoplatelets, added to the nutrient broth, were able to reassemble onto the stressed cell surface and repair the surface cracking, partially restoring the pristine electrical and mechanical properties. The method reported here may find potential application in the development of self-healable bioelectronic devices and microorganism-based strain and chemical biosensors.

Microorganism Nutrition Processes as a General Route for the Preparation of Bionic Nanocomposites Based on Intractable Polymers.

In this paper the fermentation process activated by living microorganisms of the bakers yeast is proposed as a facile assembly method of hybrid nanoparticles at liquid interface. Water dispersion of commercial bakers yeast extract used for bread production, graphene nanoplatelets (GNPs), and carbon nanotubes (CNTs) were added to oil/water interface; when the yeast is activated by adding sugar, the byproduct carbon dioxide bubbles migrate from the water phase to the oil/water interface generating a floating nanostructured film at liquid interface where it is trapped. Starting from this simple method, we propose a general approach for the stabilization of intractable poly(etheretherketone) polymeric particles with GNPs and CNTs at immiscible liquid interface. This process allowed the formation of sintered porous composites with improved mechanical properties. The porous structure of the composites gave rise to a low thermal conductivity making them good candidates for thermal insulating applications. Liquid absorption by these porous composites has been also reported. We believe that this new approach may have applications in the large scale fabrication of nanomaterials and is particularly suited for the preparation of nanocomposites starting from polymers that are intractable by solvent casting.

Graphene- and Carbon Nanotubes-Yeast Bionicomposites

Nature offers us an enormous amount of ready-to-use templates with various morphologies and functionalities, which can be successfully utilized in fabrication of biosensors, tissue engineering, and microelectronics. The directed combination of such natural templates with graphene or carbon nanotubes results in the development of a novel material which uses the features of both. We produced hybrid materials by giving to microorganisms the nutrient to grow together with graphene nanoplatelets and carbon nanotubes. Such hybrid materials can be considered as bionic because they have the benefits of both biological world which can self-organize and that of non-living materials, which couple functions such as self-healing and electronic transport.