Spatially Defined Chemical Functionalization of Ordered Block Copolymer Materials
Yuanzhi Li, Sarah A. Hesse, Wenlu Wang, Jörg G. WernerAbstract
The independent manipulation of chemical functionality over the equilibrium morphology in conventional block copolymer (BCP) self-assembly is intrinsically hindered due to the tight composition–structure coupling. Here, we report a synthesis strategy that breaks this constraint by employing self-assembled ABC triblock terpolymer base materials with a gyroid nanoarchitecture and one cross-linked end block as robust 3D templates for the spatially defined in-gel functionalization of the tethered non-cross-linked blocks. We demonstrate this generalizable concept with selective amine attachment in the C end block for selective metal ion coordination, uptake, and nanostructure-directed metal nanoparticle synthesis. Additionally, phase-confined sulfonation is achieved selectively on both the middle B and end C blocks, respectively, producing, to the best of our knowledge, the first monolithic gyroidal hydrogels exhibiting tunable swelling up to 600 vol % and nanoconfined hydration while maintaining structural integrity. Combined sequential and block-selective functionalization generates a nanostructured, pH-responsive polyampholyte material bearing blocked cationic and anionic polymer chains tethered to the continuous and cross-linked gyroidal network. The achieved decoupling of structural and chemical versatility in these cross-linked BCP gels provides a modular platform and design paradigm for studying nanoconfined synthesis, nanoarchitected ion-exchange membranes, and stimuli-responsive smart materials.