Surface Grafting via Photo‐Induced Copper‐Mediated Radical Polymerization at Extremely Low Catalyst Concentrations

Abstract

Surface-initiated photo-induced copper-mediated radical polymerization is employed to graft a wide range of polyacrylate brushes from silicon substrates at extremely low catalyst concentrations. This is the first time that the controlled nature of the reported process is demonstrated via block copolymer formation and re-initiation experiments. In addition to unmatched copper catalyst concentrations in the range of few ppb, film thicknesses up to almost 1 μm are achieved within only 1 h.

Grafting of functional methacrylate polymer brushes by photoinduced SET-LRP

“…The possibility to perform the polymerization at ppblevel concentrations of catalyst brings this protocol even closer to applications. 41 The effect of the solvent was studied by comparing the kinetics in DMSO, DMSO/acetone 2 : 1, DMSO/2,2,2-trifluoroethanol (TFE) 3 : 1, and DMSO/water 2 : 1 while using 7.7 ppm of copper ( Fig. 2b).…”

“…[29][30][31][32][33][34] Typical for this approach are very fast polymer-ization kinetics at room temperature 29,35,36 and below 37,38 with very low catalyst concentrations. [39][40][41] SET-LRP is compatible with monomers containing various functional groups, 42 as well as with different solvents such as dimethyl sulfoxide (DMSO), 43,44 alcohols, fluorinated alcohols, 45,46 ionic liquids, water, and mixtures. 39,47,48 Moreover, it was recently extended to mixtures of non-disproportionating solvents with water.…”

Designing with Light: Advanced 2D, 3D, and 4D Materials

“…While there have been reports of SI‐ATRP performed under UV irradiation, including the use of a laser to facilitate the fabrication of smaller features, the growing trend in both general RDRP and SI‐RDRP is the use of longer wavelengths to mediate brush growth. Longer wavelengths provide synthetic flexibility due to their lower energy, allowing the inclusion of synthetic and biological species that may be susceptible to damage under exposure to shorter wavelength light.…”

Tuning Dispersity by Photoinduced Atom Transfer Radical Polymerisation: Monomodal Distributions with ppm Copper Concentration

“…One of the great benefits of aphotoinduced system is the possibility for "on/off" temporal control using intermittent light and dark exposure. [42][43][44][45] (Figure 6a and Figure S19). This is in agreement with previous reports where photoinduced ATRP in organic media suffers from poor temporal control.…”