Here, we report the mechanisms of chiral transfer at various length scales in the self-assembly of enantiomeric chiral block copolymers (BCPs*). We show the evolution of homochirality from molecular chirality into phase chirality in the self-assembly of the BCPs*. The chirality of the molecule in the BCP* is identified from circular dichroism (CD) spectra, while the handedness of the helical conformation in the BCP* is determined from a split-type Cotton effect in vibrational circular dichroism spectra. Microphase separation of the BCP* is exploited to form a helical (H*) phase, and the handedness of helical nanostructure in the BCP* is directly visualized from transmission electron microscopy tomography. As examined by CD and fluorescence experiments, significant induced CD signals and a bathochromic shift of fluorescence emission for the achiral perylene moiety as a chemical junction of the BCPs* can be found while the concentration of the BCPs* in toluene solution is higher than the critical micelle concentration, suggesting a twisting and shifting mechanism initiating from the microphase-separated interface of the BCPs* leading to formation of the H* phase from self-assembly.

We describe microstructural aspects of phase transitions between the lamellar (L), perforated layer (PL), and gyroid (G) morphologies in diblock copolymer melts. Using small-angle scattering, dynamic mechanical spectroscopy, and transmission electron microscopy, we show that these transformations proceed through the nucleation and growth of the final phase, in contrast to recent calculations that assume evolution from a thermodynamically unstable initial state. Direct L → G transitions are suppressed by the high surface tension associated with L−G grain boundaries; the formation of the metastable PL structure under such conditions reflects the ease with which the L → PL transition can occur, compared to L → G. Similar effects dominate the G → L transition. Mismatches in spacings between epitaxially related lattice planes also influence relaxation kinetics; the P → LG transition rate depends strongly on the relative spacings of the PL [10] and G [211] planes, and the considerable discrepancy between the G [211] and L [10] spacings at the L−G boundary may further retard that transformation. Similar factors have been shown to govern the evolution of amphiphilic systems, supporting geometrically inspired attempts to understand this phase behavior.

A series of semicrystalline block copolymers, poly(4-vinylpyridine)-block-poly(ε-caprolactone) (P4VP−PCL), with lamellar microstructure have been synthesized. Owing to the vitrified P4VP microdomains and strongly segregated microphase separation, the crystallization of the PCL blocks in P4VP−PCL was carried out within the nanoscale confinement. Simply by varying the molecular weight of the block copolymer, namely the confined size, polymeric crystallization can be tailored in the one-dimensional confinement. A distinct nucleation mechanism, altering from heterogeneous to homogeneous nucleation, was obtained once the confined size became smaller than a critical dimension, equivalent to the regular thickness of heterogeneously nucleated crystalline lamellae. Consequently, discrete crystalline granules were generated through homogeneous nucleation, namely a single nucleus within one granule. Also, crystal growth was altered from specific to random orientation with respect to the interface between the crystalline and amorphous domains in the copolymers. This system thus serves as a model to analyze the impact of confined size in 1D spatial confinement on the crystallization of polymers.