Bidimensional lamellar assembly by coordination of peptidic homopolymers to platinum nanoparticles

Ghada Manai,Simon Tricard,Yannick Coppel,Colin Bonduelle,Bruno Chaudret,Alfonso Ibarra,Jérôme Esvan,Hend Houimel,Stéphanie Balor,Pierre Roblin,Angélique Gillet,Pier-Francesco Fazzini,Mathilde Rigoulet

doi:10.1038/s41467-020-15810-y

Abstract

A key challenge for designing hybrid materials is the development of chemical tools to control the organization of inorganic nanoobjects at low scales, from mesoscopic (~µm) to nanometric (~nm). So far, the most efficient strategy to align assemblies of nanoparticles consists in a bottom-up approach by decorating block copolymer lamellae with nanoobjects. This well accomplished procedure is nonetheless limited by the thermodynamic constraints that govern copolymer assembly, the entropy of mixing as described by the Flory–Huggins solution theory supplemented by the critical influence of the volume fraction of the block components. Here we show that a completely different approach can lead to tunable 2D lamellar organization of nanoparticles with homopolymers only, on condition that few elementary rules are respected: 1) the polymer spontaneously allows a structural preorganization, 2) the polymer owns functional groups that interact with the nanoparticle surface, 3) the nanoparticles show a surface accessible for coordination.

Highlights

A key challenge for designing hybrid materials is the development of chemical tools to control the organization of inorganic nanoobjects at low scales, from mesoscopic (~μm) to nanometric (~nm)
The NPs were synthesized by decomposition of Pt2(dba)[3] under a carbon monoxide (CO) atmosphere in THF, followed by complete elimination of the organic dba residue by washing with pentane[18]
Our results can be explained by the fact that PBLG adopt ordered secondary conformation, α-helices, which could spontaneously interact and align with each other following a nematic liquid crystal behavior[23]

Summary

Introduction

A key challenge for designing hybrid materials is the development of chemical tools to control the organization of inorganic nanoobjects at low scales, from mesoscopic (~μm) to nanometric (~nm). Structuring hybrid materials combining metallic nanoparticles (NPs) and polymers has stimulated a large effort to make new physical properties emerging: optical, electronic, or magnetic[1,2,3] Such composites have the potential of improving the functionality of devices ranging from memory storage to sensors or microelectronic systems[4,5]. Among a variety of possible structuring, disposing NPs in lines on substrates paves a way toward anisotropic ordering of matter at the nanoscale, which can be observed, manipulated, and connected To reach such a supraparticular organization, the most efficient strategy developed so far consists in decorating diblock copolymer lamellar assemblies by NPs, tuning the strength and the nature of weak interactions between the two components (essentially Van de Waals interactions)[5,6,7,8,9,10,11]. We choose poly(γ-benzyl-L-glutamate) (PBLG), a synthetic polypeptide that gives rise to a rigid rod-like α-helical conformation in organic solvents and that has often been employed as a model system to drive lamellar morphologies, when included in block copolymer structures[23]

Methods

Results

Conclusion