Campus Units
Chemical and Biological Engineering, Materials Science and Engineering, Neuroscience, Ames Laboratory, Physics and Astronomy
Document Type
Article
Research Focus Area
Advanced and Nanostructured Materials
Publication Version
Accepted Manuscript
Publication Date
3-2021
Journal or Book Title
Journal of Colloid and Interface Science
Volume
585
First Page
312
Last Page
319
DOI
10.1016/j.jcis.2020.11.080
Abstract
Hypothesis
Grafting nanoparticles surfaces with water-soluble polymers modify interparticle interactions that are pivotal for assembling them into ordered phases. By manipulating salt concentrations of gold nanoparticles (AuNPs) that are grafted with poly(N-isopropylacrylamide) (PNIPAM-AuNPs), we hypothesize that various aggregated phases form at the suspension/vapor interface or in the bulk that depend on the molecular weight (MW) of PNIPAM and on salt concentrations.
Experiments
AuNPs are grafted with thiolated PNIPAM of molecular weights of 3 or 6 kDa, and grafting is confirmed by dynamic light scattering. Liquid-surfaces X-ray reflectivity and grazing incidence small-angle X-ray scattering are used to determine the density profiles of the suspension/vapor interface and their inplane structure as salt is added to the suspensions.
Findings
We find that surface enrichment is induced by adding NaCl to the suspensions, and that at low salt concentrations, the monoparticle layer formed is dispersed, and above a threshold salt concentration, depending on MW of PNIPAM, the PNIPAM-AuNPs order in a hexagonal structure. We show that the lattice constant of the two-dimensional hexagonal structure varies with salt concentration, and more significantly with MW of PNIPAM.
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Copyright Owner
Elsevier Inc.
Copyright Date
2020
Language
en
File Format
application/pdf
Recommended Citation
Minier, Samuel; Kim, Hyeong Jin; Zaugg, Jonathan; Mallapragada, Surya K.; Vaknin, David; and Wang, Wenjie, "Poly(N-isopropylacrylamide)-grafted gold nanoparticles at the vapor/water interface" (2021). Chemical and Biological Engineering Publications. 451.
https://lib.dr.iastate.edu/cbe_pubs/451
Included in
Chemical Engineering Commons, Materials Science and Engineering Commons, Nanoscience and Nanotechnology Commons, Physics Commons
Comments
This is a manuscript of an article published as Minier, Samuel, Hyeong Jin Kim, Jonathan Zaugg, Surya K. Mallapragada, David Vaknin, and Wenjie Wang. "Poly (N-isopropylacrylamide)-grafted Gold Nanoparticles at the Vapor/Water Interface." Journal of Colloid and Interface Science 585 (2021): 312-319. DOI: 10.1016/j.jcis.2020.11.080. Posted with permission.