  Isoporous membranes made from diblock copolymers have numerous applications,
including water treatment and protein separation, and are successfully produced
at a laboratory scale under controlled conditions. However, achieving optimal
conditions for membrane preparation remains a challenge due to the complexity
of the involved phenomena. Experimental studies have shown that the
self-assembly of block copolymers in solution significantly affects the final
membrane structure. Despite extensive research, understanding the multiscale
phenomena leading to the characteristic morphology is still elusive. We address
this gap by using mesoscale computational simulations to investigate the
self-assembly of block copolymers in selective solvents, consistent with
isoporous membrane preparation. We focus on the interplay between entropic and
enthalpic interactions and their effects on the morphology of the micellar
aggregates in solution. Our computational results are consistent with
experimental evidence, revealing a morphological transition of the aggregates
as the polymer concentration and solvent affinity change. We propose different
phase parameters to characterize the emergence of monodisperse-spherical
micelles in solution and describe the order of crew-cut micelles using a
rigid-sphere approximation. Our study provides valuable insights into the
self-assembly of diblock copolymers to optimize the preparation of isoporous
membranes.
