A novel silk-based segmented block copolymer containing GlyAlaGlyAla ?-sheets templated by phenoxathiin

Self-Assembly of β-Sheets into Nanostructures by Poly(alanine) Segments Incorporated in Multiblock Copolymers Inspired by Spider Silk

“…The overall morphology in Figure is in qualitative agreement with the Semenov model, and is very similar to that observed by Anderson et al for genetically engineered protein polymers based on the B. mori silk crystalline segment and the cell binding domains of extracellular matrix proteins coated on silicon wafers . We have also previously observed such superstructures in the morphology of B. mori silk-inspired multiblock copolymers containing (AlaGly) 2 8c. In addition, a nylon-6-based block copoly(ether amide) has been shown to exhibit the same morphology 18c…”

“…100−200 nm) are seen superimposed on the normal microphase-separated morphology with the polyether phase dispersed between them. We attribute these “superstructures” to agglomerated poly(alanine) nanostructures. 8c,18a,b These findings are consistent with self-assembly of the poly(alanine) blocks into separate domains composed of antiparallel β-sheets. Semenov has previously suggested the existence of superstructures in polydisperse multiblock copolymers. 18a,b He proposed that randomness in block lengths of polydisperse materials could result in two levels of organization: a microphase separation between regions with different block molecular weights superimposed on an ordinary microdomain separation.…”

“…20000−25000 and ca. 15000−20000, respectively, based upon similar measurements reported earlier. 8a-c

2

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Metallopolymer−Peptide Conjugates: Synthesis and Self-Assembly of Polyferrocenylsilane Graft and Block Copolymers Containing a β-Sheet Forming Gly-Ala-Gly-Ala Tetrapeptide Segment

“…The transition at 115 °C can be assigned to the T m of self-assembled peptide segments. 13 The individual observation of peptide and PFS thermal transitions in DSC thermograms supports our hypothesis of a phase separated structure. Scanning and transmission electron microscopies (SEM and TEM) were used in an attempt to visualize the phase separated structures, but it was unfortunately not possible to obtain thin films of PFS-g-AGAG.…”

Modulation of Phase Separation Between Spherical and Rodlike Molecules Using Geometric Surfactancy

“…This behavior is akin to that of a traditional surfactant promoting the formation of microemulsions on the basis of polar−nonpolar amphiphilicity . , Another analogy pertains to microemulsion formation induced by diblock copolymer as a macromolecular surfactant between two parent homopolymers through Flory−Huggins interaction . − That a single T g emerged from the thermally annealed 9:2:9 blend (see Figure ) is understandable with the reported lower limit of detectable phase separation, 20−50 nm, afforded by the conventional DSC instrument − employed in the present study. The results reported here represent the first demonstration of phase separation between a conjugated oligomer and a C 60 -derivative modulated by a dyad with geometric amphiphilicity.…”