SAXS measurements at fixed temperature, 298 K (25 • C), were conducted at beamline 12-ID-C 72 at the Advanced Photon Source (APS). Samples were loaded into a 2-mm-outer-diameter quartz capillary. Data was collected from a Pilatus 2M detector using a 2.133 m sample-todetector distance with an 18 keV incident energy. Scattering patterns were normalized to an absolute scale after empty capillary subtraction using scattering from pure water. All SAXS patterns were averaged over five one-second exposures. Variable temperature SAXS measurements were conducted at beamline 8-ID-I at the APS, with experimental details the same as those described by Sheyfer et al. Sample temperature was stepped in 0.2 K increments and monitored to 0.1 K accuracy with type K thermocouples.