Direct polymerization of surface‐tethered polyelectrolyte layers in aqueous solution via surface‐confined atom transfer radical polymerization

Abstract

The direct polymerization of deprotonated acidic monomers in aqueous solutions was achieved via surface-confined atom transfer radical polymerization (SC-ATRP) to produce surface-tethered polyelectrolyte brushes. Layers of poly(itaconic acid), poly(methacrylic acid), and sodium poly(styrene sulfonate) were grown by SC-ATRP from self-assembled initiator monolayers of [BrC(CH 3 ) 2 COO(CH 2 ) 11 S] 2 on gold substrates. The polymer layers were characterized with variable-angle ellipsometry and external-reflection Fourier transform infrared spectroscopy. Without intervention, atom transfer radical polymerization catalysts were deactivated by complexation with the deprotonated acidic monomers, disproportionation, and dissociation during the polymerization of these monomers in water; the result was the cessation of polymer growth. The addition of an alkali salt to the reaction media suppressed catalyst deactivation, allowing polymer layers to increase in thickness linearly for longer periods of time with respect to salt-free conditions. This result suggested an improved degree of polymerization control. V V C 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 566-575, 2007

Surface initiated ATRP of acrylic acid on dopamine‐functionalized AAO membranes

“…The relationship between the grafting yield and the monomer concentration is shown in Figure 6(b). An approximately linear increase in grafting yield of the PAAc chains on the AAO-Br membranes with the AAc monomer concentration, suggest that the growth of the PAAc chains was a controlled process, which is consisted with the results reported by Sankhe et al 24 Control experiments on the pristine AAO and AAO-DOPA membranes revealed that there was no increase in graft yield when they were subjected to the ''surface initiated'' ATRP of AAc under similar reaction conditions. All of these results are consistent with the successful graft polymerization of AAc on the AAO-Br membranes via surface-initiated ATRP.…”

“…The reaction solution comprised the monomer, acrylic acid (AAc, 2.88 g, 1.0 mol/L); catalyst, CuBr (2.97 mg), 2,2-Dipyridyl (4.68 mg); and 40 mL of deionized water as solvent. AAc was deprotonated by the addition of NaOH to reach a pH end point of 10.2, followed by the addition of NaCl (5.59 g), according to the protocol first proposed by Sankhe et al 24 The reaction mixture was purged with argon for 2 h in ice water bath to remove the dissolved oxygen. Polymerization was carried out at 50 C under argon atmosphere for the desired reaction time.…”

Swelling Behavior of Multiresponsive Poly(methacrylic acid)‐block‐‐poly(N‐isopropylacrylamide) Brushes Synthesized Using Surface‐Initiated Photoiniferter‐Mediated Photopolymerization

“…[31][32][33] Additionally, because light is the activating agent, SI-PMP is well suited for the direct synthesis of polyelectrolytes (PMAA, in this study), alleviating problems with, for example, catalyst complexation, dissociation, or disproportionation that occurs during ATRP of electrolytic monomers in protic media. [34][35][36][37][38] The response characteristics of the constituent materials used in this study are well known. Because of the weakly ionizable carboxylate groups along the backbone, the degree of dissociation of PMAA can be changed by adjusting the pH and/ or the ionic strength of the solution.…”

Heteroarm Star-Shaped Poly (N-isopropylacryamide-co-itaconic acid) Copolymer Prepared by Glucose Core as ATRP Initiator

“…This could help in designing copolymers with specific characteristics, which is a hot research field in both industrial and academic fields. In addition, this monomer as a hydrophilic monomer can shift the LCST to higher temperatures, which should be lower than the physiological temperature of 37 C for in vivo applications, and may determine the resiliency of a polymer under physiological conditions [25][26][27][28][29]. To our knowledge, no report could be found in the literature about the successful ATRP copolymerization of IA with NIPAAm [30].…”