Influence of Chain Architecture on Nanopore Accessibility in Polyelectrolyte Block‐Co‐Oligomer Functionalized Mesopores. Issue 41 (25th August 2019)

• Record Type: Journal Article
• Authors: Brilmayer, Robert; Hess, Christian; Andrieu‐Brunsen, Annette
• Is Part Of: Small. Volume 15:Issue 41(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-08-25
• Subjects: confinement effects -- ionic permselectivity -- mesoporous silica -- multiresponsive gating -- polyelectrolyte block copolymers; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.201902710
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract: Functionalized ordered mesoporous silica materials are commonly investigated for applications such as drug release, sensing, and separation processes. Although, various homopolymer functionalized responsive mesopores are reported, little focus has been put on copolymers in mesopores. Mesoporous silica films are functionalized with responsive and orthogonally charged block‐co‐oligomers. Responsive 2‐dimethylamino)ethyl methacrylate)‐block‐2‐(methacryloyloxy)ethyl phosphate (DMAEMA‐ b ‐MEP) block‐co‐oligomers are introduced into mesoporous films using controlled photoiniferter initiated polymerization. This approach allows a very flexible charge composition design. The obtained block‐co‐oligomer functionalized mesopores show a complex gating behavior indicating a strong interplay between the different blocks emphasizing the strong influence of charge distribution inside mesopores on ionic pore accessibility. For example, in contrast to mesopores functionalized with zwitterionic polymers, DMAEMA‐ b ‐MEP block‐co‐oligomer functionalized mesopores, containing two oppositely charged blocks, do not show bipolar ion exclusion, demonstrating the influence of the chain architecture on mesopore accessibility. Furthermore, ligand binding–based selective gating is strongly influenced by this chain architecture as demonstrated by an expansion of pore accessibility states for block‐co‐oligomer functionalized mesopores as compared to the individual polyelectrolyte functionalization for calcium induced gating. Abstract : Multiresponsive polyelectrolyte block‐co‐oligomer (PDMAEMA‐b‐PMEP) filled mesopores ( d < 10 nm) with precise pore‐filling control and their chain‐architecture dependent transport characteristics are presented. Besides the confinement‐ induced pKa shifts, pH, and divalent ions, polymer chain architecture strongly controls mesopore accessibility. The precise pore filling and chain architecture design inside mesopores represents an important step toward future nanopore transport‐based technologies like water management and energy conversion.