Hexagonally packed cylindrical microdomains

An isothermal morphology diagram of poly(styrene-fe/oc -butadiene) is shown in Fig. 19 as a function of molecular weight and copolymer composition the classic morphologies include spherical microdomains (0< a<0.15) packed in a body-centered cubic lattice, hexagonally packed cylindrical microdomains (0.15 <( a-0-3), and alternating lamellae of approximately symmetric diblocks (0.3 <0 -0-5). Sever-... 

Figure 6-11. T smisston electron micrographs of gold partide preparation in hexagonal packed cylindrical microdomains of phase separated norbornenyl phosphine/gold complex copolymCTs a) before and b) after gold particle formation. (Bar = 100 nm in a) 50 nm in b) reproduced by permission from ref. [155J.)...

Figure 8.6 Phase diagrams of AB-type diblock copolymer in terms of xA versus /, which are based on self-consistent mean-field theory, in which S denotes spherical microdomains, C denotes hexagonally packed cylindrical microdomains, G denotes gyroids, and L denotes alternating layers of lamellae. (Reprinted from Matsen and Bates, Macromolecules 29 1091. Copyright 1996, with permission from the American Chemical Society.)...

Figure 8.55 Log G versus log G" plots for an SIS tiiblock copolymer (Vector 4211) at various temperatures C"C) (A) 160, ( ) 170, ( ) 180, (V) 190, (A) 200, ( ) 210, and (O) 220. The inset gives a TEM image of Vector 4211, showing hexagonally packed cylindrical microdomains. The plots indicate that the 7op.p of Vector 4211 is much higher than 220 °C, the highest experimental temperature employed.

An independent study with TEM has indicated that SI-L has hexagonally packed cylindrical microdomains [67], A broad scattering peak at = 0.77nm appearing in Fig. 16c is attributable to the form factor of isolated particles. Again, we have demonstrated that SAXS is very powerful to identify the microdomain structures of the three SI diblock copolymers. 

The existence of the disordered micelles in SIS-110 are easily detected by SAXS measurements, as shown in Fig. 24 [126]. The following observations are worth noting in Fig. 24. SIS-110 has hexagonally packed cylindrical microdomains at lower... 

The bulk properties of microphase-separated diblock copolymers are well understood. Studies show that the relative volume fraction of each component of a microphase separated copolymer essentially determines the structure that it exhibits,If the average volume fraction of one of the blocks of the copolymer chain is between 0.4 and 0.6 then the equilibrium structure is comprised of alternating lamellae of each component. When the volume fraction of the minor component is less than 0.2 it forms spherical microdomains, exhibiting a body-centered cubic structure, in a matrix of the major component. The minor component forms cylindrical microdomains which exhibit a hexagonal close-packed (hep) structure in the major component of its volume fraction is between 0.2 and 0.4. It has recently been shown that these cylindrically shaped microdomains form a structure which exhibits a double diamond-like symmetry when the volume fraction of the minor component lies in the narrow regime between those which predict the formation of the lamellar and the cylindrical microdomains arranged in a hep structure.The size of the microphase separated domains is determined by the total length of the copolymer chain. 

If the film thickness is inaeased beyond Lq, then, like with symmetric BCPs, the morphology of the film will be diaated by the interactions of the blocks with the srrbstrate, the surface energies of the blocks, and the cotnmensmability between the film thickness and charaaeristic periods of the hexagonal packing of the cylindrical microdomains. " Unlike the case of s)mmetric BCPs, there has been much less research done on the cylindrical miaodomain morphology where the cylinders... 

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