Blendable peptide-polymer nanofibers to modulate mechanical properties of polymers

The self-assembly kinetics of a peptide-block-poly(n-butyl acrylate) copolymer (pnBA-(TV){5}{switch}nFGconjugate) in solution and the blend behavior of the resulting fibrillar nanoobjects are investigated. By using a switch peptide segment with temporarily suppressed aggregation behavior, the solution self-assembly of the peptide-polymer conjugate can be triggered via a small change in the pH(app.). This results in a controlled assembly of the peptide segments and thus the organization of the bioconjugate. The process was followed by time dependent determination of the dynamic viscosity of the aggregation solution and by AFM that allows visualization of the corresponding structures. The obtained anisotropic nanofibers are characterized in solution and in bulk by SAXS, showing a worm-like characteristic. Blend behavior is investigated, proving the homogeneous dispersibility of the nanofibers in poly(acrylate)s. It could be demonstrated that the nanofibers are modulating the mechanical properties of pnBA by mechanisms of molecular reinforcement, having a distinct stiffening effect.