Multiple dynamic regimes in colloid-polymer dispersions: New insight using X-ray photon correlation spectroscopy

Journal Article · Tue Dec 01 04:00:00 EST 2015 · Journal of Polymer Science. Part B, Polymer Physics

DOI:https://doi.org/10.1002/polb.23973· OSTI ID:1325247

Srivastava, Sunita ^[1]; Kishore, Suhasini ^[2]; Narayanan, Suresh ^[3]; Sandy, Alec R. ^[3]; Bhatia, Surita R. ^[4]

---

1. Department of Chemistry, Stony Brook University, Stony Brook New York; National Institute of Standards and Technology, Gaithersburg Maryland
2. Department of Chemistry, Stony Brook University, Stony Brook New York; Department of Chemical Engineering, University of Massachusetts Amherst, Amherst Massachusetts
3. Argonne National Laboratory, Advanced Photon Source, Argonne Illinois
4. Department of Chemistry, Stony Brook University, Stony Brook New York; Brookhaven National Laboratory, Center for Functional Nanomaterials, Upton New York

We present an X-ray photon correlation spectros- copy (XPCS) study of dynamic transitions in an anisotropic colloid-polymer dispersion with multiple arrested states. The results provide insight into the mechanism for formation of repulsive glasses, attractive glasses, and networked gels of col- loids with weakly adsorbing polymer chains. In the presence of adsorbing polymer chains, we observe three distinct regimes: a state with slow dynamics consisting of finite particles and clusters, for which interparticle interactions are predominantly repulsive; a second dynamic regime occurring above the satu- ration concentration of added polymer, in which small clusters of nanoparticles form via a short-range depletion attraction; and a third regime above the overlap concentration in which dynamics of clusters are independent of polymer chain length. The observed complex dynamic state diagram is primarily gov- erned by the structural reorganization of a nanoparticle cluster and polymer chains at the nanoparticle-polymer surface and in the concentrated medium, which in turn controls the dynamics of the dispersion

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); National Science Foundation (NSF)
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 1325247
• Journal Information: Journal of Polymer Science. Part B, Polymer Physics, Journal Name: Journal of Polymer Science. Part B, Polymer Physics Journal Issue: 7 Vol. 54; ISSN 0887-6266
• Publisher: Wiley
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
colloids
gels
nanoparticles