Jump to main content
Jump to site search


Effect of the molecular weight distribution of the hydrophobic block on the formation of inverse cubic mesophases of block copolymers with a discrete branched hydrophilic block

Author affiliations

Abstract

The molecular weight distribution (MWD) of polymer blocks constituting block copolymers (BCPs) directly influences their self-assembly in the bulk and the resulting periodic nanostructures. However, the effect of the MWD of core-forming hydrophobic blocks on the structures of BCPs self-assembled in solution has rarely been studied in relation to the formation of highly ordered mesophases. Herein, we report the effects of core-forming hydrophobic block MWD on the formation of bicontinuous cubic mesophases of BCPs in solution. Specifically, a series of BCPs with tunable-MWD hydrophobic blocks is prepared by coupling a discrete (Đ = 1.0) branched poly(ethylene glycol) (bPEG) hydrophilic block with a hydrophobic polystyrene (PS) block with the desired MWD. The MWDs of PS blocks were adjusted by controlling the addition rate of the initiator for the atom-transfer radical polymerization of styrene, with the resulting Đ values ranging from 1.08 to 1.72. The solution self-assembly of the thus produced branched-linear BCPs (bPEG-PS) indicated that an increase of PS block Đ value from 1.09 to 1.72 resulted in a gradual deterioration of the internal order of bPEG-PS polymer cubosomes from a cubic crystalline phase to a disordered cubic and sponge phase. It was concluded that the MWD of the core-forming hydrophobic block is the major parameter determining the internal structure disorder of polymer cubosomes. In addition, when the Đ value of the core-forming hydrophobic PS block of bPEG-PS was increased at constant Mn, the dominant symmetry of self-assembled cubosomes changed from Pn[3 with combining macron]m to Im[3 with combining macron]m.

Graphical abstract: Effect of the molecular weight distribution of the hydrophobic block on the formation of inverse cubic mesophases of block copolymers with a discrete branched hydrophilic block

Back to tab navigation

Supplementary files

Publication details

The article was received on 12 Aug 2019, accepted on 09 Oct 2019 and first published on 09 Oct 2019


Article type: Paper
DOI: 10.1039/C9PY01211G
Polym. Chem., 2019, Advance Article

  •   Request permissions

    Effect of the molecular weight distribution of the hydrophobic block on the formation of inverse cubic mesophases of block copolymers with a discrete branched hydrophilic block

    S. Ha and K. T. Kim, Polym. Chem., 2019, Advance Article , DOI: 10.1039/C9PY01211G

Search articles by author

Spotlight

Advertisements