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DOE OSTI · 1923467

Lamellar and Hexagonal Assemblies of PEG-Grafted Silver Nanoparticles: Implications for Plasmonics and Photonics

Kim, Hyeong Jin·Wang, Wenjie·Bu, Wei·Mallapragada, Surya K.·Vaknin, David
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Abstract

Assembly of silver nanoparticles (AgNPs) grafted with thiolated poly(ethylene glycol) (PEG-SH) with various molecular weights is reported. Synchrotron-based X-ray surface-sensitive diffraction methods are used to determine the nature of two-dimensional (2D) assemblies at liquid/vapor interfaces, and small-angle X-ray scattering (SAXS) is used to monitor the three-dimensional (3D) assemblies in bulk suspensions. We find that assembly can be induced either by the addition of K 2 CO 3 or polyacrylic acid (PAA) to the PEG-AgNP aqueous suspensions. The addition of K 2 CO 3 induces a 2D hexagonal structure at the liquid/vapor interface and a 3D hexagonal columnar structure in solutions, where the columns consist of tethered PEG-AgNP chains. On the other hand, the addition of PAA leads to the formation of a 2D lamella-like distorted hexagonal sheet at the liquid/vapor interface and a 3D lamellar superstructure formed by stacked 2D sheets in the PEG-AgNP suspension. Effects of the core type of nanoparticles on the assembly can be used to control structures for potential applications in plasmonics and photonics.

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRYPEG-grafted silver nanoparticlegrazing-incidence small-angle x-ray scattering (GISAXS)lamellar structuresnanoparticle assemblysilver nanoparticlessmall-angle x-ray scattering (SAXS)x-ray reflectivity (XR)

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Kim, Hyeong Jin, Wang, Wenjie, Bu, Wei, Mallapragada, Surya K., Vaknin, David. 2022-11-29. Lamellar and Hexagonal Assemblies of PEG-Grafted Silver Nanoparticles: Implications for Plasmonics and Photonics. https://doi.org/10.1021/acsanm.2c03042

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