Comparative Study on Surface-Initiated ATRP and SI-ARGET ATRP of Oligo(Ethylene Glycol) Methacrylate on Gold

Abstract

Oligo(ethylene glycol) methacrylate (OEGMA) was polymerized from a polymerization initiator-presenting gold substrate by Activator ReGenerated by Electron Transfer Atom Transfer Radical Polymerization (ARGET ATRP) in water. Compared with the normal surface-initiated ATRP (SI-ATRP), SI-ARGET ATRP of OEGMA proceeded smoothly in the presence of air with L-ascorbic acid as a reducing agent and a CuBr2/2,2'-bipyridyl complex at the ppm level. In addition, SI-ARGET ATRP did not require the additional steps for removing a polymerization inhibitor from the OEGMA monomer and for deoxygenating the solvent. The ellipsometric measurements showed that the polymerized OEGMA (pOEGMA) films prepared by SI-ARGET ATRP were on average 10 times thicker than those prepared by normal SI-ATRP with the same monomer concentration and polymerization time.

Formation of Various Polymeric Films via Surface‐Initiated ARGET ATRP on Silicon Substrates

“…We have investigated the growth of polymer brushes over time from SiO 2 surfaces using various monomers such as neutral, zwitterionic, and anionic ones through this grafting‐from approach. The final concentrations of a monomer, CuBr 2 , bpy, and ascorbic acid were fixed as 620, 0.063, 0.38, and 3.1 mM, respectively, except that SI‐ARGET ATRP of OEGMA was performed with the reduced concentrations to avoid gelation of the reaction solution 26 …”

“…Except OEGMA, polymerization of other monomers was carried out with 620 mM monomer, 0.063 mM CuBr 2 , 0.38 mM bpy, and 3.1 mM ascorbic acid 25 . Polymerization of OEGMA (200 mM) was carried out with 0.1 mM CuBr 2 , 0.2 mM bpy, and 1 mM ascorbic acid 26 . A representative SI‐ARGET ATRP procedure is as follows: 313 μL of DMAEMA, 0.25 mL of a stock solution of a CuBr 2 /bpy complex (0.76 mM CuBr 2 , 4.5 mM bpy), and 2.187 mL of the co‐solvent were added into the vial containing the initiator‐immobilized substrate.…”

Anti‐Fouling Polymer or Peptide‐Modified Electrochemical Biosensors for Improved Biosensing in Complex Media

“…[ 79 ] In comparison with SI‐ATRP, ARGET‐ATRP is more cost‐effective and environmentally‐friendly while also enabling the fabrication of thicker polymeric films with higher grafting efficiency under ambient conditions. [ 80 ]…”

Antifouling Surface Coating Using Droplet-Based SI-ARGET ATRP of Carboxybetaine under Open-Air Conditions

“…This fact itself brings about inconvenience to users and narrows the scope of its applicability to small and flat surfaces, which allow deoxygenation to be managed under a isolated system. The recent development of activator regenerated by electron transfer (ARGET) ATRP has alleviated the air-tight issues of conventional ATRP. − In this case, excessive amount of reducing agent, represented by ascorbic acid, continuously regenerates an active Cu­(I) species from an inactive Cu­(II) species and allows polymerization under limited amount of air. This strategy has also been transformed in the version of surface-initiated polymerization to coated surfaces through the formation of a polymer brush, and their degassing-free condition itself enables the coating of large substrates, as well as the interfaces among nanoparticles, proteins, or living cells for their own application. − However, SI-ARGET ATRP is still regarded as an “air-tolerant” coating method, conceding that it is not fully compatible with an infinite amount of air.…”