Fig. 5. Equilibrium dynamics in supramolecular polymer systems.

a Raw transition matrix (centre) and transition probability sub-matrices (left and right, as in Fig. 2a), comparing the M system with ϵ = 40 kJ mol⁻¹ (top) and the BTA system at T = 340 K (bottom). b Same as (a), comparing the M system with ϵ = 50 kJ mol⁻¹ (top) and the BTA system at T = 300 K (bottom). c, d Illustrative schemes of the mechanisms of inter-assembly communication. When the interaction between the self-assembling units is weaker (lower ϵ, or higher T), the fibres preferably communicate with each other exchanging monomers or relatively small fragments. When the interaction between self-assembling units is stronger (higher ϵ, or lower T), the inter-assembly communication proceeds mostly via large fibre fragmentation and coalescence. The histograms indicate the incidence of the four communication mechanisms detailed in the text. The same colour coding of Fig. 3e is used. e Comparison with a model of water-soluble BTA supramolecular polymers (BTA_w: where the monomers are amphiphilic, and solvophobic effects are non-negligible). Left: structure of the BTA_w monomer: the monomer cores (blue beads) attract each other with interaction strength ϵ = 4 kJ mol⁻¹, to reproduce the solvophobic effect. Centre-left: snapshot of BTA_w fibres formed spontaneously after t_CG = 20 μs of CG-MD (starting from 500 dispersed BTA_w monomers, small inset). Centre-right: detail of the BTA_w fibres, highlighting the presence of defects all along the fibres backbone (the spheres represent the centres of the monomers, bulk defected domains are highlighted in green, defected domains akin to fibre tips are highlighted in red—see also Supplementary Fig. 32). Mechanism histogram, showing that the fibres preferably communicate with each other exchanging monomers or relatively small fragments.