Fig. 5: Nanofibrils of mPCL undergo (reversible) dissociations at 60 °C.
a,b 1H NMR spectra of mPCL from CPMG experiments at 60 °C for different τ, where n has been varied so that texp is similar for all the spectra. The spectral regions containing the polymer backbone peaks (δ = 1–5 ppm) and the end-group peaks (δ = 6–12 ppm) are shown separately at different magnifications. c R2 for the peaks associated with j (gray squares) and NH2 + NH3 (blue squares). The dashed lines represent the plateaus in R2. The solid red curve represents the best fit of the Carver–Richards equation to the increase in R2 for the NH2 + NH3 peak, caused by the amide dynamics, with kd = 5170 ± 1910 s–1 and R2,0 = 0.10 ± 0.02 ms–1. A list of all the experiments, along with spectra for all the τ investigated and the corresponding exponential fits to the decay in the integrals of the NH2 + NH3 peaks, is provided in Materials and Methods and Supplementary Fig. S6. Error bars represent uncertainties from the fitting procedure, which exceeded the experimental error in all cases.
