The Research Of Self-Assembly Of Block Copolymers Melt

In recent years, many researchers have found that block copolymers are arguably the most ideal class of molecules for examining phenomena related to molecular self-assembly. It is well demonstrated by the progress achieved in understanding the phase behavior of the classical coil-rod diblock copolymer. Consequently, we gradually research the self-assembly characteristics of the melt systems of ABA coil-rod-coil triblock copolymers, at the same time, we also have compared the self-assembly of the melt systems that consist of AB coil-rod diblock copolymers with that of the melt systems which consist of ABA coil-rod-coil triblock copolymers respectively. Then we have present some results for accounting for the characteristics that copolymers composed of many blocks have to further exploit multiblock copolymers. We could present some theorical arguments for other fields .Because of the special framework of the coil-rod block copolymers, it makes the self-assembly of the meltsystems of coil-rod block copolymers present many new characteristics. Now more and more people think that the self-assembly of the melt systems that consist of coil-rod diblock copolymers or coil-rod-coil triblock copolymers may realistically have significant applications.In this work, we theoretically research the self-assembly of melt systems that consist of coil-rod diblock copolymers and coil-rod-coil triblock copolymers, respectively. In the following contents, we will qualitatively present some results.After simulating the self-assembly behavior of the melts composed of AB coil-rod diblock copolymers, we find stable micelle phase structure, hexagonal-packed strip phase structure, gyriod phase structure and lamella phase structure for this system. We also find two meta-stable phase structures. One is zigzag phase structure, the other is perforated lamellar structure. Then we also simulate the self-assembly of the melts composed of ABA coil-rod-coil triblock copolymers. We find three stable phase structures,i.e., micelle phase structure, strip phase structure, and gyriod phase structure.First, in contrast to the framework of coil-rod diblock copolymer, it is more flexible for the framework of ABA coil-rod-coil triblock copolymer. The characteristic make the melt systems of ABA coil-rod-coil triblock copolymers present more regular stable phases. In other words, the self-assembly of the melt systems composed of coil-rod-coil triblock copolymers is more complicated.Secondly, even if the proportion of this two kind of segments is fixed , and the position of the rigid block in the chain is also fixed, in contrast to the melt systems consisted of coil-rod diblock copolymers, the self-assembly of the melt systems of coil-rod-coil triblock copolymers may presents two kind of stable phase structures .Finally, what we want to say is that when the proportion of the two kind of segments (A and B) is fixed, because of the structure difference of AB coil-rod diblock copolymers and ABA coil-rod-coil triblock copolymers, it makes theself-assembly of the melt systems that consist of ABA coil-rod-coil triblock copolymers have more different phase separation points than that of the melt systems which consist of AB coil-rod diblock copolymers.