Title

Effect of (poly)electrolytes on the interfacial assembly of PEG functionalized gold nanoparticles

Publication Date

1-10-2019

Department

Ames Laboratory; Chemical and Biological Engineering; Materials Science and Engineering; Physics and Astronomy; Neuroscience

Campus Units

Ames Laboratory, Chemical and Biological Engineering, Materials Science and Engineering, Physics and Astronomy, Neuroscience

OSTI ID+

1494940

Report Number

IS-J 9847

DOI

10.1021/acs.langmuir.8b03535

Journal Title

Langmuir

Volume Number

35

Issue Number

6

First Page

2251

Last Page

2260

Abstract

We report on the effect of interpolymer complexes (IPCs) of poly(acrylic acid) (PAA) with poly(ethylene glycol)-functionalized Au nanoparticles (PEG-AuNPs) as they assemble at the vapor–liquid interface, using surface-sensitive synchrotron X-ray scattering techniques. Depending on the suspension pH, PAA functions both as a weak polyelectrolyte and a hydrogen bond donor, and these two roles affect the interfacial assembly of PEG-AuNPs differently. Above its isoelectric point, we find that PAA leads to the formation of a PEG-AuNP monolayer at the interface with a hexagonal structure. In the presence of high concentration of HCl (i.e., below the isoelectric point), at which PAA forms IPCs with PEG, the hexagonal structure at the interface appears to deteriorate, concurrent with aggregation in the bulk. Thus, while the electrolytic behavior of PAA induces interfacial assembly, the hydrogen bonding behavior, as PAA becomes neutral, favors the formation of 3D assemblies. For comparison, we also report on the formation of PEG-AuNP monolayers (in the absence of PAA) with strong electrolytes such as HCl, H2SO4, and NaOH that lead to a high degree of crystallinity.

DOE Contract Number(s)

AC02-07CH11358

Language

en

Department of Energy Subject Categories

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY

Publisher

Iowa State University Digital Repository, Ames IA (United States)

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