Equation ( ) can then be linearized by plotting ln[𝑞 𝐼(𝑞)] vs. 𝑞 2 in the region around the Guinier knee which yields a line of slope -𝑅 𝑔 2 ⁄ where in this particular case 𝑅 𝑔 is related to the physical radius 𝑅 by 𝑅 𝑔 2 = 𝑅 2 2 ⁄ . The cross-sectional Guinier plots for the knees at ~0.025 Å -1 and ~0.1 Å -1 are shown in Figure and E, respectively. Based on the extracted radius values we determine that the Guinier knees at ~0.025 Å -1 and ~0.1 Å -1 correspond to the cross-sections of fibrillar aggregates and individual polymer chains, respectively. We find that the fibril radius 𝑅 𝑓 is 6.4 nm in CB (diameter 𝐷 𝑓 = 12.8 nm) and 5.4 nm in Dec (𝐷 𝑓 = 10.8 nm) and that the polymer radius 𝑅 𝑝 is 14 Å in Dec (𝐷 𝑝 = 28 Å). The polymer diameter of 28 Å is in agreement with the lamellar stacking distance of ~25 Å in thin films with it being slightly larger likely due to increased disorder in solution and/or increased solvent swelling. The fibril diameters of ~10 nm are also consistent with imaging experiments as discussed below. This analysis indicates that while the conjugated polymers aggregate into fibrils, some population of the conjugated polymers remain dispersed or at least loosely interacting such that they are isolated enough to maintain their individual cross-section. We emphasize that these linearization based methods are not meant to provide precise measurements but are instead meant to illustrate the more evident structural features of our conjugated polymer system and provide a rationale for more complex modeling approaches discussed later in this paper where these cross-sectional parameters as well as other features are extracted. we can in fact unify all scattering profiles under this interpretation and further expand our understanding of the solution state. First, the most obvious difference between the low and high MW solutions is that the low 𝑞 slope for high MW PII-2T solutions is much steeper at -3.3.