The SAXS profiles of PII-2T in CB and CB/DMF are shown in Figure . As discussed in our previous work , the scattering profiles can be described by a combination of scattering from fibril aggregates, dispersed polymer chains, and a lamellar structure factor peak. The profiles in CB and CB/DMF are nearly identical with similar features, such as the Guinier knee at = 0.02 Å -1 corresponding to the fibril radius. Additionally, both scattering profiles indicate the presence of aggregates by the power law region extending into low-as well as the broad lamellar structure factor peak at high-( ~ 0.22 Å -1 ). However, there are two key differences that the aggregation state exhibits in CB/DMF compared to pure CB. First is the presence of a sharper structure factor peak at 0.22 Å -1 which indicates a higher degree of lamellar order within the aggregates formed in CB/DMF compared to CB. The next key difference is the change in slope at low-in the region preceding the fibril cross-sectional Guinier knee at < 0.02 Å -1 which is affected by the persistence length of the fibril aggregate. For PII-2T in CB, the fibril aggregate has a slope of -1.6 while for PII-2T in CB/DMF the slope is -1.3 indicating a higher degree of rigidity. To quantitatively extract the features of the fibril aggregates we fit using the two semiflexible cylinder (2SFC) model as described in our previous work , with the addition of a second pseudo-Voigt peak for PII-2T in CB/DMF. As the scattering is largely insensitive to the polymer contour length and persistence length due to the overshadowing fibril contribution, we fix them to the values of 100 nm and 7.5 nm from our previous work. We also again find that the pseudo-Voigt peak Lorentzian fraction tended to 1 in both cases during fitting signifying paracrystalline disorder within the aggregates. The fitting results for PII-2T in CB match our previous results, indicating the presence of fibrillar aggregates with mean diameters of = 10 nm and persistence length = 17 nm, as well as an additional population of dispersed polymer chains which have diameters of = 32 Å, slightly larger than the lamellar stacking distance. The lamellar peak, fitted with the pseudo-Voigt contribution, is centered at = 0.21 Å -1 (d-spacing of 30 Å) and exhibits a FWHM of = 0.21 Å -1 , leading to a disorderassociated coherence length of = 3.0 nm. For PII-2T in CB/DMF, the fibril aggregates also have mean diameters of = 10 nm but are more rigid with a persistence length = 32 nm, in agreement with the shallower slope at < 0.02 Å -1 . The polymer chains have diameters of = 32 Å, matching the CB solution as expected since the cross-section of individual polymers chains in solution should not change much with solvent quality. Additionally, we found it necessary to use two pseudo-Voigt peaks to capture the high-region as it contains both a sharp peak and broad tails which cannot be captured by a single peak. This indicates that while there is highly ordered lamellar stacking, weak ordering still exists. The broad peak is centered at = 0.20 Å -1 with a FWHM of = 0.18 Å -1 ( = 3.5 nm). The sharp peak is centered at = 0.22 Å -1 with a FWHM of = 0.013 Å -1 , leading to a much larger lamellar coherence length of = 50 nm. The more rigid fibril aggregation in CB/DMF compared to that in CB is corroborated by the freeze-dried SEM imaging. Using the SAXS and imaging results, we then illustrate a scheme of the PII-2T solution state in both CB and CB/DMF in Figure .