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Edge‐Grafted Molecular Junctions between Graphene Nanoplatelets: Applied Chemistry to Enhance Heat Transfer in Nanomaterials
Author(s) -
Bernal Maria Mar,
Di Pierro Alessandro,
Novara Chiara,
Giorgis Fabrizio,
Mortazavi Bohayra,
Saracco Guido,
Fina Alberto
Publication year - 2018
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201706954
Subject(s) - materials science , graphene , surface modification , nanomaterials , covalent bond , nanoparticle , thermal conductivity , nanotechnology , conductance , chemical engineering , hybrid material , composite material , organic chemistry , chemistry , mathematics , combinatorics , engineering
The edge‐functionalization of graphene nanoplatelets (GnP) is carried out exploiting diazonium chemistry, aiming at the synthesis of edge decorated nanoparticles to be used as building blocks in the preparation of engineered nanostructured materials for enhanced heat transfer. Indeed, both phenol functionalized and dianiline‐bridged GnP (GnP‐OH and E‐GnP, respectively) are assembled in nanopapers exploiting the formation of non‐covalent and covalent molecular junctions, respectively. Molecular dynamics allow to estimate the thermal conductance for the two different types of molecular junctions, suggesting a factor 6 between conductance of covalent vs noncovalent junctions. Furthermore, the chemical functionalization is observed to drive the self‐organization of the nanoflakes into the nanopapers, leading to a 20% enhancement of the thermal conductivity for GnP‐OH and E‐GnP while the cross‐plane thermal conductivity is boosted by 190% in the case of E‐GnP. The application of chemical functionalization to the engineering of contact resistance in nanoparticles networks is therefore validated as a fascinating route for the enhancement of heat exchange efficiency on nanoparticle networks, with great potential impact in low‐temperature heat exchange and recovery applications.