## 3 Results
### In Situ FTIR
#### 3.1.2 Simultaneous FTIR and SANS on PEGDME in Solution
As observed in the FTIR spectra, a coexistence between an amorphous conformation of PEGDME, on one hand, and a slow increase in number density of crystallites by nucleation and growth, on the other hand, is observed, which explains the SANS pattern. The scattering data collected in the end state at 12 \({}^{\circ}\)C indicate the formation at mesoscale of a morphology made of crystalline lamellae alternating with amorphous interlamellar regions, as denoted by the peak-like feature which indicates an interlamellar domain spacing of D\({}^{\bullet}\) = 2\(\pi\)/Q\({}^{\bullet}\): where Q\({}^{\bullet}\) represents the peak position, and the steep increase of intensity towards low Q, due to association of the lamellar stacks in bundles and branches, which led to the formation of a large scale spherulite morphology. The scattering features characteristic of such morphology appear at much lower Q values than the range covered in pinhole mode with the KWS-2 [1] and in the current experiment only the high-Q asymptotic behavior of the scattering from the polymer spherulites could be observed (green symbols, Q\({}^{-4}\) power law behavior). A fit with the model combining the form factor of individual lamellar slabs with the paracrystalline structure factor describing the stacking effects over distances larger than the lamellar thickness [33] successfully described the experimental SANS data and delivered the interlamellar distance D\({}^{\bullet}\) = 110 A and its large smearing \(\sigma_{\text{D}^{\bullet}}\) = 30 A. A power law term with the exponent \(p\) = 4, as discussed above, was considered for a proper description of the data at low Q, which far exceeds the scattering from the polymer lamellae (depicted as a red dotted curve in Figure 6, based on the fitted parameters). A value for the lateral extension of lamellae  
Figure 7: FTIR spectra measured with polarized IR beam parallel (blue line) and perpendicular (red line) to the uniaxially deformation direction of the d-sPS co-crystalline film with hTol: whole spectra (**top**) and detail (**bottom**) are shown. (assumed as discs) much larger than their thickness was assumed as fixed parameter (R\({}_{\rm L}\) = 500 A), as long as this size level cannot be observed towards low Q, while a fixed lamellar thickness \(d\) = 45 A [17] was considered in the fitting procedure, since no scattering data were collected at high Q at 12 \({}^{\circ}\)C. The lateral extension of the lamellae does not affect the fitting of the D* and \(\sigma_{\rm D^{*}}\) parameters, as long as it is supposed to be much larger than the lateral size of the lamellar stacks. A more detailed model interpretation of the SANS data in terms of \"forward scattering\" and scattering length density parameters for different regions of the complex morphology [33] is beyond the goal of this report. The SANS results indicate that crystalline lamellar stacks, which form larger objects (spherulites), are the dominating morphology in the sample and are in very good agreement with the FTIR observations, which indicate that PEGDME chains are mainly in helical conformation, thus crystalline state, in these conditions.