Directed self-assembly of block copolymer

Mikihito Takertaka received both the master s degree in engineering in 1988 and the doctor s degree in engineering in 1993 with Prof Takeji Hashimoto from Kyoto Urriversity. In 1997, he was appointed as an assistant professor of the Department of Polymer Chemistry in Kyoto University. He was promoted to associate professor in 2011. His research scope includes the dynamics of phase transitions of polymer alloys and the directed self-assembling of block copolymer thin films. 

H. Hu, M. Gopinadhan, C. O. Osuji, Directed Self-Assembly of Block Copolymers A Tutorial Review of Strategies for Enabling Nanotechnology with Soft Matter. Soft Matter 2014,10, 3867. 

Overall, reports on preparation of nanotubes from block copolymers have been rare, and there have been no reports on practical applications of such structures. For this, the emphasis of this chapter will be on the fundamental aspects of these materials. In Sect. 2, nanotube or tubular micelle formation from the direct self-assembly of block copolymers in block-selective solvents will be reviewed. Section 3 will be mainly on nanotubes derived from the chemical processing of cross-linked triblock copolymer nanofibers. Example nanotube preparations will be given, dilute solution properties of the nanotubes will be discussed, and the different reaction patterns of the nanotubes will be examined. Concluding remarks will be made in Sect. 4. 

Koo K, Ahn H, Kim S-W, Ryu DY, Russell TP (2013) Directed self-assembly of block copolymers in the extreme guiding microdomains from the small to the large. Soft Matter 9... 

Jeong S-J, Kim JY, Kim BH, Moon H-S, Kim SO (2013) Directed self-assembly of block copolymers for next generation nanolithography. Mater Today 16(12) 468-476 Katz JR (1925) Was sind die Ursachen der eigentiimlichen Dehnbarkeit des Kautschuks Kolloid-Zeitschrift 36(5) 300-307... 

Directed Self-Assembly of Block Copolymer Films... 

Tada, Y, Akasaka, S. etal. (2009) Density multiplication by directed self-assembly of block copolymer binary blends. 

Figure 1 Schematic illustration of the two major approaches of directed self-assembly of block copolymers, (a) Graphoepitaxy the self-assembly of block copolymers is guided by topography and possibly also surface chemistry, (b) Chemical epitaxy spatial variation of surface chemistry directs the self-assembly of block copolymers. In both cases, the hard mask or pinning region has high affinity to A domains, while neutral surface provides vertically oriented A and B domains. Such affinity drives the self-alignment of polymer domains to the topographical and chemical patterns.

Figure 10 Schematics of directed self-assembly of block copolymers with a natural period of Pbcp on chemical patterns, (a) Chemical epitaxy based on dense chemical patterns of alternating preferential wetting stripe with a pitch of patterned substrate (Ls) close to Lo. The affinity between chemical patterns and block copolymer domains drives the self-alignment of block copolymer, (b) Sparse chemical patterns composed of alternating pinning stripes (width = 0.5io) and neutral stripes (width = Lk = Ls Lo) with a pitch which is twice the pitch of block copolymers (Ls/Lo 2). The self-assembled block copolymer doubles the spatial frequency of the underlying guiding chemical patterns. One domain of the block copolymers is selectively removed to show the self-assembled line-space patterns.

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