The Self-assembly Of Star Triblock Copolymer Within Cylindrical Nanotube

The self-assembly of copolymers has the fundamental significance in the theoretical research and fabrication novel morphologies in the experiment.For example,the microstructures of copolymers can be used as nanofibers,optical data storage,3D print matrials and biological drug delivery.Confinement is one of the effective methods of acquisition the longe-range order microstructures which are absent in bulk by simply changing the directions of the nanostructures.In the present studies,fewer discoveries are involved in the star triblock copolymer during to the complexed chain configurations.In this article,we will focus on the self-assembly of ABC star triblock copolymer within the cylindrical nanotube using the self-consistent mean field theory.First,we study the morphologies and triangle phase diagram of the star triblock copolymer confined in the fixed cylindrical tube.Thenanotubes are designed to possess homogenous and patterned surface.When the surface prefers A blocks,the distribution of the phases are sensitive to the volume fraction of A blocks.By contrast,when the tube surface attracts the other BC blocks,the morphoglogies are distributed in a center-face manner.In the case of Janus patterned surfaces,the discrete cylinders appear in the concentric of the phase diagram.However,the Janus cylinders occupy near the edge regions of the phase diagram.Moreover,in the double ring-type surface case,the mesh-ring,double-ring,triple-ring and net-ring microstructures arise in the phase diagram.Finally,the free energies,internal energies,entropic energies and segment distributions are discussed and analyzed to explore mechanical properties behind the phase transitions and chain configurations.Then,we consider about the assembly of an ABC star triblock copolymer melts in the small-,moderate-and larger-size nanocylinder tube with various adsorption strength.Many novel microstructures that are absent in bulk can be obtained with confinement and the selectivity.We change the interaction between the three different blocks and tube from neutral to preferential for one block and then to the other two blocks.The phase transformation occurs when increasing the size of the tube and the surface field energy,which is determined by free energy and analyzed by the internal energy and configuration entropy.Our results indicate thatthe morphologies can be controlled by adjusting the copolymer-surface interaction and the confinement in nonplanar templates.