MULTIFUNCTIONAL GRAPHENE-BASED POLYMER NANOCOMPOSITES FOR 3D PRINTING APPLICATIONS

Project leaders

Giovanna Giuliana Buonocore, Evgeni Ivanov

Agreement

BULGARIA - BAS - Bulgarian Academy of Sciences

Call

CNR/BAS triennio 2019-2021 2019-2021

Department

Chemical sciences and materials technology

Thematic area

Chemical sciences and materials technology

Status of the project

New

Research proposal

In the last few years, the dispersion of graphene (or its derivatives) nanoplatelets into polymer matrices has become the principal strategy for the development of multifunctional materials able to fulfill the demanding requests of societal challenges. The key issue for the mass production of innovative multifunctional materials is how to control the filler dispersion/distribution, interaction phenomena, and structure/morphology in order to transfer the excellent properties of graphene-based nanoplatelets from nano-scale to the macro-scale. This is very complex and up to now the graphene-based polymeric composites exhibit both mechanical and functional properties which are significantly lower than those expected on the base of pristine graphene filler. Recently it has been shown that the most promising graphene-based nanocomposites are designed by exploiting the concept of graphene segregation in spite of the random dispersion. Thus, the fine tailoring of filler spatial distribution represents alongside with the control of the interactions which establish between filler particles and between particle-polymer, the key factor to control for the optimization of the properties of graphene-based composites. Moreover, the advantages of graphene-polymer composites are still more prominent whether they are considered in the context of design and fabrication of 3D printed structures by rapid prototyping. This is because of this technology will allow to realize materials with a great complexity which may exhibit functional properties not obtainable on the base of technologies which traditionally are used for polymer processing. In this context, to further clarify the importance of the control of filler morphology on the balance between structural and functional properties, the proposed project aims to gain new scientific knowledge on the experimental mechanisms which allow the control of the spatial distribution of graphene as well as on the relationships between the nanoscale structural variables and macroscale properties of graphene-polymer nanocomposites. At the moment the availability of polymer-based materials for 3D printing technologies is very wide and continuously in expansion. However, as for the conductive composites containing graphene or more in general carbonaceous fillers, the product-benchmarks are only a few ones and often they are characterized by not-optimized balance between mechanical and functional properties and by processing properties which do not compile with the processing technology requirements. For these reasons, there is the need to further investigate the field of polymer-based composite filled with graphene or more in general with carbonaceous filler as raw materials for 3D printing technologies.
Relatively limited research has been conducted to understand the intrinsic structure-property relationship in graphene-polymer nanocomposites and even less have been devoted to the understanding of the structure-property relationship in 3D printed structures. Researchers emphasized that unless graphene sheets are separated and homogeneously dispersed within the polymer matrix, the full potential of graphene-based nanocomposites cannot be realized. However, at IPCB-CNR has been widely investigated the importance of graphene segregation as the best spatial distribution to allow the best balance between structural and functional properties of the resulting composites. In particular, a self-assembling approach to allow the deposition of graphene platelets on polymer latex was developed and promoted to enhance the barrier, electrical and thermal properties of rubber-based composites. Similar approaches have not yet proposed the field of materials for 3D printing technologies where only the simple compounding-molding is adopted to disperse, without any control, carbonaceous filler within thermoplastic polymers. Thus there is a lack of innovative approaches to produce materials with a tailored, repeatable and desirable structure and properties.
The project proposes a complete study addressed to identify new approaches to control the graphene distribution within the polymeric phase and investigate the main factors that govern a) the tailoring of the graphene morphology within the polymeric phase, b) the structure-property relations in the graphene-polymer composites for understanding, prediction and controlling of the improvement of their macroscopic properties (ie both structural and functional properties), c) the utilization of the graphene-based composites materials both as filament for FDM as well as powder for SLS, for the realization of complex printed structures. Wide range of experimental characterizations of rheological, structural, mechanical and thermal of the developed graphene-polymer nanocomposites will be performed. Finally, the printed structures will be validated for specific applications fields such as sensors, EMI shielding, Thermal dissipaters.

Research goals

The project is addressed to the development of innovative graphene-based polymer composites for the production of complex structures by using both FDM and SLS technologies. The main idea is to investigate how to prepare the raw materials for both selected 3D technologies in order to have a fine control of graphene morphology inside the composite and simultaneously enhance the mechanical and functional properties (ie electrical and thermal properties) of the printed structures. The main objectives of the project will be: a) to exploit experimental approaches/procedure such as self-assembling, solvent-assisted wrapping or melt compounding for controlling the carbonaceous filler morphology within the polymer matrix (ie PLA, HDPE, TPU, HAVOH), b) to determine the main factors that govern the intrinsic structure-property relationships of polymer nanocomposites for the understanding, prediction and controlling of the improvements of the macroscopic properties, while compiling with the processing specifications of FDM and SLS technologies, c) modelling of structure-property relationships of graphene-polymer nanocomposites related to the percolation concept by rheology, d) to further use these findings for the production of multifunctional graphene-polymer complex structures by 3D printing technologies, able to exhibit outstanding mechanical properties coupled with electrical and thermal properties to be used in the field of sensors, EMI shielding and thermal conductor systems.

Last update: 08/06/2025