Developing SAXS Methodology for Solutions of Polystyrene Spheres

Attempts to study solutions of hydroxypropyl cellulose (HPC) microgels using small angle x-ray scattering (SAXS) were performed at Kent State University's AMLCI lab to expand on and verify previous results from static and dynamic light scattering. However, the results gathered from our initial methodology did not reflect the results previously gathered nor made sense within the context of SAXS. From these issues an entirely new methodology for running and analyzing SAXS results needed to be created by adjusting parts of the initial methodology. By deciding to use water-based solutions of polystyrene microspheres (PS) with the same size range we were able to utilize a sample with a known size and shape to self-teach SAXS and introduce corrections to our methodology. To improve we needed to eliminate masking, match detector and distance settings to sample sizes, determine scaling factors and ranges, improve calibration procedures, and determine a fitting procedure in SASVIEW that accounts for program sensitivities. By taking a meticulous step-by-step approach to every part of our process we were able to improve our methodology and create a process that yields much more accurate and consistent results for the sizes of probes than what was initially utilized. We now plan to apply this methodology to HPC microgels in hopes of deducing their internal structure