Bicontinuous Gyroidic Morphologies in Ferrocenyldimethylsilane-b-Methyl Methacrylate Diblock Copolymer Blends

Abstract

Poly(1,1′-ferrocenyldimethylsilane)-b-poly(methyl methacrylate) (PFS-b-PMMA) diblock copolymers were blended with the corresponding homopolymers, PFS and PMMA. The obtained blends were investigated with respect to their microphase morphologies in the bulk. Special attention was paid to those compositions which are close to the transition from the cylindrical to the lamellar regime, i.e., where the overall PFS volume fractions in the blends were around φ PFS ≈ 0.40. This is because there the bicontinuous gyroidic morphology should arise. However, in samples prepared from high-molecular-weight diblock copolymers (Mn g 40 000 g/mol) and PFS homopolymers a direct transition of the cylindrical into the lamellar phase was found with increasing PFS content. Such a direct transition of two classic morphologies was also observed in blends of low-molecular-weight diblock copolymers (Mn ≈ 27 000 g/mol) and PMMA homopolymers where the PFS volume fraction was around φPFS ≈ 0.40sprovided the annealing temperature was rather low (165 °C). The same samples, on the other hand, show the formation of a gyroidic phase when the annealing temperature was raised to 190 or 220 °C. This result can be explained by the lower segregation tendency of the two constituents at higher temperatures, expressed by a lower Flory-Huggins interaction parameter χ.

Polyferrocenylsilane‐Based Polymer Systems

“…%) of a PMMA homopolymer (Figure 4). [135] The bulk microphase segregation of an asymmetric PFMS-b-PDMS copolymer (f PDMS = 0.20) was examined by SAXS, bright-field-mode TEM, high-resolution dark-mode scanning TEM, and electron-energy-loss spectroscopy. [136] The presence of iron in the PFS block complicates interpretation of the SAXS data as iron fluoresces upon absorption of the Cu Ka radiation.…”

Equilibrium Melting Temperature of Poly(ferrocenyl dimethylsilane) in Homopolymers and Lamellar Diblock Copolymers with Polystyrene

“…[1][2][3][4][5][6][7] Moreover, it counts among the very few metallopolymers accessible by living chain-growth protocols which give access not only to products of defined molar mass and narrow polydispersity but also to a broad variety of copolymer architectures: plenty of PFDMS block copolymers with, e.g., polystyrene (PS), [8][9][10][11] polyisoprene (PI), [12] poly(dimethyl siloxane) (PDMS), [8,12,13] poly(ethylene oxide) (PEO), [14] poly(methyl methacrylate) (PMMA), [15][16][17][18][19][20][21] and poly(2-vinylpyridine) [22] have been synthesized, and they have been shown to develop fascinating morphologies at the nanometer to micrometer scale. [2,7,23] Another important feature of PFDMS is its ability to crystallize.…”

Styrene–Ferrocenyldimethylsilane–Methyl Methacrylate Triblock Copolymers: Synthesis and Phase Morphology

“…[10] For blends of low-molecular-weight materials with the corresponding homopolymers, we were able to observe the bicontinuous gyroidic morphology as well. [11] Due to its co-continuous nature, the gyroidic phase should, in principle, combine in an ideal manner, the PMMA's mechanical properties with the special benefits of the functional PFS block. It might gain attention as, for example, antistatic coating, in (electro-)optical devices or in nanolithography.…”