Correlating inter-particle forces and particle shape to shear-induced aggregation/fragmentation and rheology for dilute anisotropic particle suspensions: A complementary study via capillary rheometry and in-situ small and ultra-small angle X-ray scattering.

Hypothesis: Understanding the stability and rheological behavior of suspensions composed of anisotropic particles is challenging due to the complex interplay of hydrodynamic and colloidal forces. We propose that orientationally-dependent interactions resulting from the anisotropic nature of non-spherical sub-units strongly influences shear-induced particle aggregation/fragmentation and suspension rheological behavior.

Experiments: Wide-, small-, and ultra-small-angle X-ray scattering experiments were used to simultaneously monitor changes in size and fractal dimensions of boehmite aggregates from 6 to 10,000 Å as the sample was recirculated through an in-situ capillary rheometer.

Development of an autonomous solvent extraction system to isolate astatine-211 from dissolved cyclotron bombarded bismuth targets.

Cyclotron-produced astatine-211 (At) shows tremendous promise in targeted alpha therapy (TAT) applications due to its attractive half-life and its 100% α-emission from nearly simultaneous branched alpha decay. Astatine-211 is produced by alpha beam bombardment of naturally monoisotopic bismuth metal (Bi) via the (α, 2n) reaction. In order to isolate the small mass of At (specific activity = 76 GBq·µg) from several grams of acid-dissolved Bi metal, a manual milliliter-scale solvent extraction process using diisopropyl ether (DIPE) is routinely performed at the University of Washington.

Al Pulsed Field Gradient, Diffusion-NMR Spectroscopy of Solvation Dynamics and Ion Pairing in Alkaline Aluminate Solutions.

Pulsed field gradient nuclear magnetic resonance (PFG-NMR) measurements were successfully applied to the Al ( I = 5/2) nucleus in concentrated electrolytes to investigate the diffusion of aluminate ions [Al(OH)] in simulant high-level nuclear waste (3 M NaOH) between 25 and 85 °C. The temperature-dependent diffusion coefficients obtained from H, Na, and Al PFG-NMR were well fit by a Vogel-Fulcher-Tammann model and a power law equation. Comparison of Al diffusion coefficients of 0.

An automated flow system incorporating in-line acid dissolution of bismuth metal from a cyclotron irradiated target assembly for use in the isolation of astatine-211.

Astatine-211 (At) is a promising cyclotron-produced radionuclide being investigated for use in targeted alpha therapy. The wet chemical isolation of trace quantities of At, produced within several grams of Bi metal deposited onto an aluminum cyclotron target assembly, involves a multi-step procedure. Because the At isolation method is labor-intensive and complex, automation of the method is being developed to facilitate routine processing at the University of Washington and to make it easier to transfer the process to other institutions.