UV-Induced Micropatterning of Complex Functional Surfaces by Photopolymerization Controlled by Alkoxyamines

Abstract

We report on the use of an alkoxyamine (AA) for fabrication of functional micropatterns with complex structures by UV mask lithography. The living character of the polymer surface and the vertical spatial control of the repolymerization reaction from few tens of nanometers to few micrometers were demonstrated. The impact of the main parameters governing the controlled polymerization and the reinitiation process activated by light or heat was investigated. Micropatterning is shown to be a powerful method to investigate the physicochemical molecular phenomena. It is possible to control the polymer microstructure thickness from few tens of nanometers to few micrometers. In the last section, some applications are provided showing the potential of the AA for generating covalently bonded hydrophilic/hydrophobic micropatterns or luminescent surfaces. This demonstrates the high versatility and interest of this route.

Photomediated controlled radical polymerization

“…The photoinduced NMP process was also proposed and developed for fabrication functional micropatterns with complex structures such as hydrophilic/hydrophobic or luminescent surfaces simply by using a mask ( Figure 42). [368] The self-healing process was reported in covalent polymer networks via the photodissociation of alkoxyamine junctions. [369] Insert Figure 42.…”

Surface Engineering with Polymer Brush Photolithography

“…[91] In the past 20 years, efforts have been made to develop light-mediated NMP: [92][93][94][95][96] in 2014, Telitel et al performed light-mediated NMP on a cross-linked polymer matrix surface and fabricated cross-linked micropatterns with trifunctional monomer, trimethylolpropane triacrylate (TMPTA). [97,98] More recently, Guselnikova et al reported a plasmon-induced NMP on gold surface to grow block copolymer brushes. [99] Both contributions suggested light-mediated SI-NMP to be a promising technique to fabricate patterned polymer brushes.…”

Recent Advances on Visible Light Metal-Based Photocatalysts for Polymerization under Low Light Intensity

“…Analyses of the chain length as well as the polydispersity of polymers can be thus performed. At present, only a low or moderate control of the polymer size is obtained by photopolymerization, high polydispersity indices being determined by size exclusion chromatography (SEC) [124,125]. This result is counterintuitive since, from a theoretical point of As often observed, the two-component systems Fe complex/Ph 2 I + (0.2%/2%, w/w) were less efficient than the three-component photoinitiating system Fe complex/Ph 2 I + /NVK (0.2%/2%/3%, w/w/w) for the FRP of TMPTA.…”

“…At present, only a low or moderate control of the polymer size is obtained by photopolymerization, high polydispersity indices being determined by size exclusion chromatography (SEC) [124,125]. This result is counterintuitive since, from a theoretical point of view, a higher control of the polymerization process should be obtained by using light, when the polymerization reaction is carried out at room temperature.…”

“…In these conditions, the competition between polymerization and side-reactions should be avoided [126][127][128][129][130][131][132][133][134][135][136]. However, the production of highly reactive radicals still limits the control of the polymerization process, even if some attempts have been made to introduce control agents, as exemplified with photoassisted nitroxide-mediated polymerization (NMP2) [124,125]. Another interesting feature is that dormant species which can only be activated by light can also be created, enabling a subsequent chemical modification of the initial polymer.…”