Well-defined metal-polymer nanocomposites: The interplay of structure, thermoplasmonics, and elastic mechanical properties

Abstract

Metal-polymer nanocomposites are hybrid materials combining the superior plasmonic, electrical, and thermal properties of metals with the good elasticity and manufacturability of polymers. This renders metalpolymer nanocomposites promising candidates for conductive filler and coating applications, where mechanical properties are optothermally coupled. Here, we study the interplay of nanostructure, thermoplasmonics, and elastic mechanical properties of silver-polystyrene nanocomposites (AgPS) by transmission electron microscopy, small-angle x-ray scattering, Brillouin light scattering (BLS), and other supplemental techniques. We utilize the well-known particle-brush architecture to ensure a homogeneous and isotropic nanoparticle distribution throughout the hybrid material. The effective longitudinal modulus of the as-prepared samples is found to decrease from 5.7 to 4.8 GPa with increasing Ag content from 0 to 4.4 vol.%. Temperature-dependent BLS measurements reveal the unique contribution of local thermoplasmonic heating that depends on the Ag nanoparticle composition. This thermoplasmonic effect results in a lower apparent glass transition temperature (T g) and a stronger laser power dependence of the speed of sound. Exceeding moderate thermal annealing temperatures (>150 • C) leads to a strong structural rearrangement within the homogeneous nanocomposite material with a peculiar clustering-redispersion effect, which also translates into altered mechanical properties. The annealing-induced Ag nanoparticle aggregation results in an even stronger thermoplasmonic effect. We validate our experimental findings with complementary thermographic measurements and finite-element modeling. Overall, this work demonstrates the combined effects of composition and (reversible) aggregation on the mechanical and thermoplasmonic properties of metal-polymer nanocomposites. It not only deepens our understanding of the interaction between light, temperature, and mechanical properties in metal-polymer nanocomposites but also provides a guide for customizing AgPS nanocomposites for potential applications.

Optomechanic Coupling in Ag Polymer Nanocomposite Films

“…The synthesis and characterization of two PIB-grafted Ag NP samples with different Ag compositions (2.3 vol %, 15 vol %) and the same PIB molecular weight (2.6 kDa) and two PS-grafted Ag NP samples with PS molecular weight 2.6 kDa (9.5 vol %) and 18.9 kDa (1.4 vol %) were previously reported. 23 , 24 …”

Synthesis and modification of silica‐based epoxy nanocomposites with different sol–gel process enhanced thermal and mechanical properties

“…The reinforcement of polymers using different types of organic or inorganic fillers is common practice in the production of systems with improved mechanical, thermal, electrical, and other properties 6–10 . Minute nanoparticles are commonly used for the fortification of epoxy matrices to the inferior reduction on curing, thermal expansion coefficients, enhance thermal conduction and meet mechanical supplies 11–14 . The final properties of the polymer micro composites (PMC) are affected by several factors, such as the inherent properties of each component, the contact shape, and the dimension of fillers, and the nature of their interfaces 15,16 .…”

“…reduction on curing, thermal expansion coefficients, enhance thermal conduction and meet mechanical supplies. [11][12][13][14] The final properties of the polymer micro composites (PMC) are affected by several factors, such as the inherent properties of each component, the contact shape, and the dimension of fillers, and the nature of their interfaces. 15,16 In past decades, a wonderful amount has been conducted in the research of submicron inorganic particles, most important to the possibility of preparing composites with nanofillers, that is, nanocomposites.…”

Harnessing polymer grafting to control the shape of plasmonic nanoparticles

“…1,2 The hardsoft combination of the composites can lead to improved mechanical, electrical, and optical properties of materials. [3][4][5][6][7][8][9] Within the class of PNCs, [10][11][12][13][14][15][16][17] polymer shell/rigid core metal is of uprising interest as the polymer corona can provide uniformity, stability, and better dispersibility, and can even solubilize metallic nanoparticles (NPs). 17 Engineering PNCs for optical applications, as an example, requires high optical transparency at high filling ratios of nanoparticles.…”

“…17,21,22 Synthetic functional poly(isobutylenes) (SFPIBs) are chain-end functionalized transparent materials that can act as soft elastomeric templates tethering hard spheres (e.g., PIB-SH) for addressing novel physical properties related to the behavior of grafted plasmonic NPs in solution, 5,23,24 and their laser light-stimulated photoacoustic response in the solid state. [6][7][8][9]25 To explore a gap in the literature, where mainly the interaction of light with grafted glassy polymers has been tested, [4][5][6][7][8][9] or that of rubbery polymers attached onto silica NPs, 26 the structure/property interplay and optomechanical properties of rubbery, PIB-tethered metallic particles should be investigated.…”