Morphology cylindrical

Fig. 21 Schematic summary of thermodynamic phase behaviour for neat, composition-ally symmetric PI-fc-PS-fc-PDMS (ISD) and PS-fc-PI-fc-PDMS (SID) terpolymers. Heating PI-fc-PS-fc-PDMS or decreasing molecular weight causes transition from three-domain lamellae to hexagonally packed two-domain cylindrical morphologies, followed by disordering. PS-fc-PI-fc-PDMS disorders directly from three-domain lamellar state. From [88], Copyright 2002 American Chemical Society...

Fig. 60 Schematic illustration for formation of cylindrical morphology in a blend of slightly asymmetric lower molecular weight PS-b-PI (/3-chain) with large symmetric PS-fc-PI (a-chain). a Molecule of /S-chain with non-zero spontaneous curvature, b Cylindrical morphology formed by neat /3 chains shown in a. Here mean curvature of cylinder (solid line) is larger than spontaneous curvature of /3-chain (dashed lines). c Cylindrical morphology formed by binary blend of /3-chains shown in a and large symmetric copolymers (a-chain). In this case, mean curvature of cylinder closely fits to spontaneous curvature of /3-chain. From [180]. Copyright 2001 American Chemical Society...

Analysis of S-SEBS by SAXS has revealed the presence of cylindrical morphologies for a degree of sulfonation of <34%. Interestingly, different morphologies can also be observed when membranes are cast from different solvents. Membranes (27 mol% degree of sulfonation) cast from THE form lamellar morphologies, as seen in Figure 3.27, while those cast from MeOH/ THE (tetrahydrofuran) (20/80 v/v) exhibit a diffusive phase boundary with disorderly interconnections between domains. This is due to the differences... 

Note 2 Cylindrical morphologies can be observed, for example, in triblock copolymers. 

The cylindrical morphology occurs upon the phase separation of nonsym-metric diblock copolymers as well as ABA triblock copolymers. In thin films, the... 

An interesting dimension of metal-coordinated self-assembly that is often ignored, or at least not exploited to its fullest extent, occurs when the resulting coordination complex is a charged species and, as such, in need of a counterion. This counterion itself presents yet another subtle instance of ionic self-assembly, which often is overshadowed by its partner, the coordination complex. The second multi-functional side-chain supramolecular polymer system is based on this simple but important concept [14, 106-111]. In 2003, Ikkala and coworkers reported a study in which they exploited (1) a side-chain functionalized polymer, poly(vinyl-pyridine), (2) metal-coordination self-assembly via a tridentate Zn2+ complex and (3) ionic self-assembly through functionalized counterions, i.e. dodecylbenzene-sulfonate ions, to form multiple self-assembled complexes which adopted a cylindrical morphology (Fig. 7.23) [112]. 

The study of methane adsorption on activated carbon fibers has demonstrated, as was previously explained, that these carbonaceous materials, because of their cylindrical morphology and smaller diameter, have higher packing density than activated carbons with similar micropore volumes [191]. Subsequently, the higher adsorption capacity for the powdered activated carbons against the higher packing density for the fibers helps both kinds of materials reach similar, maximum adsorption values [191]. 

Five fundamental domain structures are possible for block copolymers consisting of two types of blocks. Generally lamellar structures will form at compositions with approximately equal proportions of the two components. As the proportion of one component increases at the expense of the other, cylindrical morphologies will result. The matrix phase will... 

Fig. 10 Schematic depiction of bridge chain and loop chain configurations in cylindrical morphology from the ABA triblock copolymer self-assembly...

Breiner U, Krappe U et al (1997) Cylindrical morphologies in asymmetric ABC triblock copolymers. Macromol ChemPhys 198 1051-1083... 

The concept where amphiphihc molecules are hydrogen bonded to one block of a block copolymer to form specific comb-shaped supramolecules allows the production of nanoporous materials in a straightforward way. The concept is illustrated in Fig. 24. The procedure was first applied to a polystyrene-bZocfc-poly(4-vinylpyridine) diblock copolymer with a stoichiometric amount of pentadecylphenol hydrogen bonded to the P4VP block. The relative block lengths were selected to render a lamellar-m-cylindrical morphology, where the P4VP(PDP) comb-shaped blocks form the cylinders... 

Only recently first reports appeared describing the potential of the nanostructured thin block copolymer films for lithographic etching. A thin film of polystyrene-block-polybutadiene with a hexagonal cylindrical morphology where the poly-(butadiene) cylinders were oriented perpendicular to the substrate was deposited on a silicon wafer and selectively decomposed by treatment with ozone or converted with osmium tetroxide. By a subsequent reactive ion etching process the pattern could be inscribed into the surface of the silicon wafer yielding small holes or islands with a lattice constant of 27 nm and hole/island sizes of 13 nm [305,312]. 

Figure 24 (a) Layered structures of AB diblock copolymers, (b) Vertical confinement causing the lateral orientation of block copolymer layers [304], (c) Cylindrical morphology (cylinder diameter = 13 nm) [305]. Reproduced with permission from [305]. 1996 American Institute of Physics... 

A detailed study of SB diblock copolymers and diblock/homopolymer blends was conducted in the range of composition in which the polybutadiene cylindrical morphology prevails Stress-strain experiments on a series of samples revealed dramatically varying behavior from essentially brittle response to substantial and attractive levels of toughness. Figures 2a to 2d provide representative stress-strain curves for the initial morphologies shown in Figs. 3a-3d. Table 1 provides the relevant molecular level information for these blends. 

Eig. 3a-d. Transmission electron micrographs of cylindrical morphologies (daric regions arc PB stained with OSO4). Materials cast from toluene a) SB2 b) SBS c) SB8 d) SBIO... 

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