Figure 4: Time evolution of the polymer network properties for the H(AB)n sequences. | Nature Communications

Figure 4: Time evolution of the polymer network properties for the H(AB)n sequences.

From: Predictive modelling-based design and experiments for synthesis and spinning of bioinspired silk fibres

Figure 4

(a) Median number of ‘a’ beads per node as a measure of the aggregate size. (b) The total number of bridges as a measure of the connectivity. (c) The polymer network conductance as a measure of the degree of protein alignment. During both equilibration and shear flow, the median sizes of nodes do not vary a lot among all sequences (a), but longer copolymers have significantly more bridges (b). During shear flow, copolymers are stretched under shear flow and the cross-links are continuously broken and reformed until the steady state is reached for the simulated polymer properties in ac. Although the network connectivity is not increased (in fact, it drops by a little due to shearing-induced perturbation) during shear flow (b), the network conductance for the long sequences (n=8 and 12) are greatly enhanced due to the shearing-induced polymer alignment (c). The discontinuity between shear flow and tensile stretching periods in ac is due to the stress relaxation simulation (results not reported here) in between the two periods. Interestingly, the shorter sequences (n=2 and 4) form weak networks that are not able to maintain structural integrity due to the shearing-induced perturbation and, therefore, their network conductance drops to zero (c). (d) The distribution histograms of the numbers of connected nodes for H(AB)4 and H(AB)12 after shear flow. The H(AB)12 sequence has node connectivity distribution peaks at higher values (5) than H(AB)4 (2).

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