U.S. Department of Energy

Pacific Northwest National Laboratory

Correlation of colloidal interactions and macroscopic rheology in concentrated electrolyte solutions

Please join us on Tuesday, February 2, 2016, from 11:00 a.m. to Noon in the RPL Plutonium Room, when the NPSI will host a monthly Seminar Series featuring LDRD PI Jaehun Chun presenting on project Correlation of Colloidal Interactions and Macroscopic Rheology in Concentrated Electrolyte Solutions.

Research Team: Richard Daniel, Dongsheng Li, Xiao-Ying Yu, Carolyne Burns, Jeff Morris (CUNY), Sidhant Pednekar (CUNY), Arushi Prakash (UW) / Chris Mundy (PNNL), Hee Joon Jung (former PNNL post-doc) & Ning Wu (CSM)

Tuesday, February 2, 2016
Dr. Jaehun Chun
NPSI Project Manager
PNNL
This research is to understand unique particle interactions in tank waste relevant systems from chemical physics at solid-liquid interfaces, and to determine how those interactions influence long-range ordering (agglomeration) of colloidal waste particles and bulk suspension rheology. We will focus on boehmite as the target mineral phase of studies because it represents a major component and has been known as the most problematic solid component in Hanford tank waste sludges. Particle interactions will be measured directly using colloid probe atomic force microscopy and also will be modeled implementing the relevant water and dissolved ion structuring at the particle-liquid interface. The aggregate structure and its evolution will be investigated by different experimental tools such as in-situ SEM and TEM in order to couple particle forces with bulk rheology. The rheology of the model suspensions will be characterized using standard bench-top rheometers and/or a micro-rheometer based on System for Analysis at the Liquid Vacuum Interface (SALVI). As a complementary tool, colloidal scale simulations will be performed to link particle forces, aggregate structures, and bulk rheology. Computations will be cross-validated with experiments. The research couples physicochemical phenomena at different length scales involved in bulk rheology of colloidal suspensions, which can establish a unique platform to obtain physical insights for colloidal suspensions, applicable for many types of suspension-based processing including the WTP pretreatment facility, coal slurry processing, and suspension-based biomass processing.
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