Formation of fibrillar aggregates in concentrated solutions of rigid-chain amphiphilic macromolecules with fixed torsion and bend angles

Effect of Induced Self-Organization in Mixtures of Amphiphilic Macromolecules with Different Stiffness

“…Actual number of macromolecules forming a cluster is determined by kinetics of aggregate formation and depends on local concentration of helical macromolecules. 20 Apparently the difference of the distribution over aggregation number is caused by difference in concentration of helical macromolecules: in fact the concentration of helical macromolecules in 1:1 mixtures is twice lower than that in homogeneous solution.…”

“…In concentrated solution with Ψ = 0.3 helical chains form clusters, identical to those formed in homogeneous concentrated solutions of helical macromolecules: 20,21 the average number of chains in aggregate cross-section is four; the length of aggregate could be several times higher than length of individual macromolecule, the aggregates oriented parallel to each other. A segment of one of the clusters is shown in Figure 6A.…”

“…where r c is the cutoff distance r c = 4, parameters ε ab (=ε HH , ε PP , ε HP ) define the strength of interactions between the beads of corresponding types, γ = 0.23 is the screening parameter. 20,21 The Langevin thermostat was employed to keep the reduced temperature at T = 1 (T = ε/k B , where k B is the Boltzmann constant).…”

“…In such case of gradual decrease of solvent quality the stiff amphiphilic macromolecules aggregate with each other and form braid fibrils of several intertwined macromolecules. 18,20,21 The number of chains forming the braid depends on chain stiffness and can vary along the braid.…”

“…Self-organization in concentrated solutions of macromolecules with hydrophobic backbone and hydrophilic side groups was investigated by means of molecular dynamics simulation. − The papers − study macromolecules with amphiphilic monomer units containing both hydrophobic and hydrophilic groups. The duality of the monomer units results in their simultaneous affinity and incompatibility with both polar and organic solvents.…”