Synthesis of Nanoparticle Copolymer Brushes via Surface-Initiated seATRP

Abstract

Synthesis of densely grafted (co)­polymer brushes, including poly­(tert-butyl acrylate) (PtBA), poly­(tert-butyl acrylate)-b-poly­(styrene) (PtBA-b-PS), and poly­(tert-butyl acrylate)-b-poly­(butyl acrylate) (PtBA-b-PBA), from 15.8 nm silica nanoparticles (NPs) via a surface-initiated simplified electrochemically mediated atom transfer radical polymerization (SI-seATRP) under constant potential electrolysis conditions is reported for the first time. The rate of polymerization was enhanced by applying more negative potentials, which resulted in an increase in grafting density, up to 0.93 nm–2. Furthermore, temporal control over the polymerization was achieved by adjustment of the applied potential. The polymers showed narrow molecular weight distributions (Đ = 1.20–1.32), and polymer-grafted nanoparticles had excellent size uniformity. Dispersions in suitable solvents were stable without any nanoparticle aggregation. Microstructures observed in thin films of densely block copolymer tethered silica NPs suggested that the structure formation process is strongly influenced by the conformation of tethered chains. Hence, microstructure formation in thin films of block copolymer brush particles in which the first block is in the “stretched brush regime” was determined primarily by surface interactions rather than microphase separation.

The Counterion Effect of Imidazolium‐Type Poly(ionic liquid) Brushes on Carbon Dioxide Adsorption

“…With the presence of monomeric ionic liquids and catalysts, PIL chains could directly grow from the surface via initiation of ATRP by the surface-attached initiator monolayers, generating covalently-attached brush-like PIL monolayers. [17] To form PIL brushes with different anions, a simple ion exchange procedure was applied according to literature. [18] The advantage of surface-initiated ATRP process relies on the easy control of the architecture of grafted polymers including type, grafting density, and chain length of the attached polymers.…”

Miniemulsion switchable electrolysis under constant current conditions

“…Reversible deactivation radical polymerization techniques are currently one of the most influential solution in the preparation of precisely defined polymers with a predetermined structure and specialist purposes 26‐28 . It is compatible for modification of a wide range of substrates, ranging from naturally derived structures 27,29‐31 going to flat surfaces 32‐35 and nanoparticles, 36‐40 receiving functional hybrid nanomaterials. In this consideration, atom transfer radical polymerization approach (ATRP) technique combined with a “core‐first” approach is especially privileged in the preparation of the architecture polymers from polyphenol compound as naturally derived cores 15,41,42 .…”

Low Ppm Atom Transfer Radical Polymerization in (Mini)Emulsion Systems

“…ATRP techniques in dispersed media are especially beneficial for obtaining multifunctional polymers with narrow molecular weight distribution (MWD, M w /M n , Đ) and a predetermined molecular weight (MW), as segregation and compartmentalization decrease the rate of termination processes [47][48][49]. Polymerizations could be carried out in various media, including homogeneous systems (bulk or solution) or biphasic heterogeneous systems (suspension, emulsion, miniemulsion) [50].…”

“…Various polymer structures, including block [27,54], star [55][56][57] and brush [58][59][60], were synthesized in water-dispersed media (microemulsion [61][62][63], miniemulsion [64][65][66], and emulsion [67][68][69][70]). Emulsion and miniemulsion methods belong to a heterogeneous environment ATRP techniques in dispersed media are especially beneficial for obtaining multifunctional polymers with narrow molecular weight distribution (MWD, Mw/Mn, Đ) and a predetermined molecular weight (MW), as segregation and compartmentalization decrease the rate of termination processes [47][48][49]. Polymerizations could be carried out in various media, including homogeneous systems (bulk or solution) or biphasic heterogeneous systems (suspension, emulsion, miniemulsion) [50].…”