Surface Nanostructures Fabricated by Polymerization-Induced Surface Self-Assembly

Abstract

Surface properties of materials are strongly dependent on surface chemistry and surface structures. The fabrication of hierarchical surface nanostructures will endow solid surfaces with new functionalities and properties. In this research, we propose the polymerization-induced surface self-assembly (PISSA) approach for surface reconstruction. In this approach, two macro-CTAs, one grafted on silica particles and the other molecularly dissolved in solution, were used in reversible addition–fragmentation chain transfer (RAFT) dispersion polymerization, and surface micelles (s-micelles) with different morphologies and sizes on silica particles were fabricated. Kinetics studies demonstrate that there are two critical points on a plot of ln­([M]0/[M] t ) vs polymerization time, corresponding to the onsets of surface assembly and the self-assembly of block copolymers. The morphology of s-micelles is dependent on the monomer conversion and the length of macro-CTA. For macro-CTA with short chain length, with an increase in monomer conversion the s-micelles experience a morphology change from spherical s-micelles to layered structures. For macro-CTA with long chain length, the average size of s-micelles increases with monomer conversion. In this research, we demonstrate PISSA can be used as a versatile method for surface modification.

Janus Surface Micelles on Silica Particles: Synthesis and Application in Enzyme Immobilization

“…In a previous publication, we reported the synthesis of surface micelles (s‐micelles) by polymerization‐induced surface self‐assembly (PISSA) approach. [ 39 ] In a typical PISSA process, two reversible addition‐fragmentation chain transfer (RAFT) agents, macro chain transfer agents (macro‐CTA) grafted on silica particles (SiO 2 ‐macro‐CTA) and macro‐CTA molecularly dissolved in solution, were employed in RAFT dispersion polymerization of styrene. After the polymerization, size‐tunable s‐micelles were formed on the silica particles.…”

“…The synthesis of py‐ss‐CTA was described previously. [ 39 ] Chemical structure and 1 H NMR spectrum of py‐ss‐CTA are shown in Figure S1 (Supporting Information). 1 H NMR spectrum of PDMAEMA‐CTA is presented in Figure S2 (Supporting Information), where the peaks corresponding to the protons on pyridyl groups, polymer chains and trithiocarbonates, can be observed.…”

“…[ 44 ] Thiol‐disulfide exchange reaction between SiO 2 ‐SH and pyridyl disulfides at the ends of PDMAEMA 114 ‐CTA, leads to the synthesis of PDMAEMA 114 ‐CTA brushes on silica particles, SiO 2 ‐PDMAEMA 114 ‐CTA. Based on the absorption of pyridine‐2‐thione, a by‐product produced in the exchange reaction, [ 39 ] the grafting density of PDMAEMA 114 ‐CTA brushes was calculated to be about 0.40 chains nm −2 . A standard curve of pyridine‐2‐thione in DMF and UV–vis absorption of pyridine‐2‐thione produced in the grafting reaction are shown in Figure S6 (Supporting Information).…”

Surface Nanostructures Based on Assemblies of Polymer Brushes

“…In these years, polymerization‐induced self‐assembly (PISA) method has been widely applied in the synthesis of BCP nanoparticles . The mechanism of PISSA has some similarities to PISA . In a typical PISSA process, PDMAEMA macro‐CTA was grafted to the silica nanoparticles and PDMAEMA‐CTA brushes were obtained (referred to as SiO 2 ‐PDMAEMA‐CTA, Figure a).…”

Light-intensity switch enabled nonsynchronous growth of fluorinated raspberry-like nanoparticles

“…7 While reversible-deactivation radical polymerization (RDRP) has enabled the generation of polymeric particles with various morphologies [8][9][10] ranging from spheres, worms, and vesicles to ordered inverse mesophases through the operationally simple polymerization induced self-assembly (PISA) pathway, [11][12][13][14][15] it still remains challenging to generate RB particles based on PISA. Conventionally, RB particles have been obtained via the combination of small corona and large core particles via physical or chemical interactions, 16,17 as well as emulsion polymerization. 18,19 However, these strategies oen suffer from complex operating processes or driving force of multiphase separation.…”