Morphology of microphase separation

Figure 1 Common morphologies of microphase-separated block copolymers body-centered cubic packed spheres (BCC), hexagonally ordered cylinders (HEX), g)Toid (Ia3d), hexagonaUy perforated layers (HPLs), modulated lamellae (MLAM), lamellae (LAM), cylindrical micelles (CYL), and spherical micelles (MIC). (Reproduced from Ref. 2. Wiley-VCH, 1998.)...

SAXS patterns yield additional quantitative results on the morphology of microphase-separated block copolymers. The interdomain distance D is the domain identity period in the case of lamellae, or the nearest neighbour distance between the microdomains for the cylinders and spheres. D can be determined on the basis of the Bragg spacing of the principal peak (Equation (21.1)), according to the following equations ... 

Microphase separation with three phases can be obtained for an ABC triblock copolymer. The morphology of an ABC triblock copolymer has been suggested by Riess et al. [40]. An interesting morphology of microphase separation with three phases has been reported for ABC triblock copolymers [41-43]. On the other hand, we reported microphase separation with three phases in the blend system of AB and AC diblock copolymer micelles [44]. In that blend, two B and C spherical microdomains were dispersed at random in an A matrix. 

We investigated controlling the morphology of microphase separation by blending the microsphere and block copolymer, which forms a spherical microdomain in a matrix on its own [46]. Figure 20 shows the TEM micrographs of diblock copolymer SI-100 and the blend film of SV500-M/SI-100. The mor-... 

The viscoelastic effects on the morphology and dynamics of microphase separation of diblock copolymers was simulated by Huo et al. [ 126] based on Tanaka s viscoelastic model [127] in the presence and absence of additional thermal noise. Their results indicate that for

bulk modulus of both blocks, the area fraction of the A-rich phase remains constant during the microphase separation process. For each block randomly oriented lamellae are preferred. 

Figure 10.7. Small-angle X-ray scattering curves of microphase-separated samples and drawings of the corresponding structure morphologies.

Dais membranes are reported to be much less expensive to produce than Nation they are also reported to exhibit a rich array of microphase-separated morphologies because of the ability to tailor the block length and composition of the unsulfonated starting polymer. The main drawback of employing hydrocarbon-based materials is their much... 

Visualization of Microphase Separated Morphology of Films of Polystyrene-b-polyisoprene-b-polystyrene... 

The amorphous segment of microphase-separated amorphous/liquid crystalline block copolymers may influence the ordering of the mesogens at the interface, as well as the size and discreteness of that interface. Living copolymerizations are therefore being used to determine the effect of the morphology and domain size on the thermotropic behavior of side-chain liquid crystalline block copolymers. 

Azo BCs are one fascinating class of soft materials, showing a rich variety of microphase-separated nanostructures in films because the strongly bonded azo segments and the non-azo blocks are thermodynamically incompatible. As shown in Fig. 12.1, the microphase-separated morphologies can be controlled to be spheres, cylinders, or lamellae, depending on the length, chemical nature, architecture, and number of repeated units in each block (e.g., Thomas and Lescanec, 1994). 

Figure 12.17. Magnetically induced alignment of microphase-separated nanostructures in PS-based azo LCBCs. All the PS nanocylinders were oriented along the magnetic field, which shows no effect on the lamellar morphologies. Source Reproduced with modifications from Tomikawa et al., 2005.

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