Gold nanoparticles (AuNPs) have been studied extensively, while the particles with nanoscale size are easy to agglomerate. Spherical polyelectrolyte brush (SPB) has been used as nanoreactor to prepare and load nanoparticles, which makes the nanoparticles uniform disperse in the brush layer. However, the nanoparticles are easy to shed from the SPB during long-term application. Thus, studying interactions between SPB and AuNPs is critically important to improve their long-term stability. In this work, small angle X-ray scattering (SAXS) was employed to observe the adsorption and distribution of AuNPs in SPB. By fitting the scattering intensity curves, we can not only observe the internal structure of SPB, but also “see” the interaction between particles. Negatively charged poly(acrylic acid) brushes (PAA-SPB), positively charged poly(2-aminoethyl methacrylate hydrochloride) brushes (PAEMH-SPB), electroneutral poly(N-isopropylacrylamide) brushes (PNIPAM-SPB) were synthesized by photo-emulsion polymerization, respectively. Citrate-stabilized AuNPs were prepared and mixed with different SPB. SAXS results demonstrated that almost no AuNPs were absorbed in PAA-SPB, whereas the PAEMH-SPB showed obvious adsorption of AuNPs due to electrostatic interaction. After the adsorption, the size of PAEMH-SPB decreased slightly. It seems that SAXS is a powerful method to observe the interaction between SPB and AuNPs.

Interaction between spherical polyelectrolyte brushes and gold nanoparticles studied by small angle X-ray scattering

ACS Fall 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.