Aggregation Behaviors of PEO-PPO-ph-PPO-PEO and PPO-PEO-ph-PEO-PPO at an Air/Water Interface: Experimental Study and Molecular Dynamics Simulation

Abstract

The block polyethers PEO-PPO-ph-PPO-PEO (BPE) and PPO-PEO-ph-PEO-PPO (BEP) are synthesized by anionic polymerization using bisphenol A as initiator. Compared with Pluronic P123, the aggregation behaviors of BPE and BEP at an air/water interface are investigated by the surface tension and dilational viscoelasticity. The molecular construction can influence the efficiency and effectiveness of block polyethers in decreasing surface tension. BPE has the most efficient ability to decrease surface tension of water among the three block polyethers. The maximum surface excess concentration (Γ(max)) of BPE is larger than that of BEP or P123. Moreover, the dilational modulus of BPE is almost the same as that of P123, but much larger than that of BEP. The molecular dynamics simulation provides the conformational variations of block polyethers at the air/water interface.

Effects of Sodium Benzoate and Sodium Chloride on the Aggregation Behaviors of PEO‐PPO‐ph‐PPO‐PEO and PPO‐PEO‐ph‐PEO‐PPO at the Air/Water Interface

“…The surface activities of BPE and BEP solutions were investigated and the results show that BPE solution has a much lower surface tension than BEP when the concentration is lower than the critical micellization concentration (CMC), indicating that the presence of an aromatic ring can influence the efficiency and effectiveness of the block polyethers in lowering surface tension (Gong et al, ). Here, the effects of sodium benzoate on the aggregation behaviors of block polyethers BPE and BEP are investigated to determine if there are interactions between sodium benzoate and polyethers.…”

“…The block polyethers containing an aromatic ring (EO) 32 (PO) 36 -ph-(PO) 36 (EO) 32 (BPE) and (PO) 36 (EO) 40ph-(EO) 40 (PO) 36 (BEP) were synthesized in our laboratory (Gong et al, 2012). Their molecular structures are shown in Fig.…”

“…At the air/water interface, conformational transitions vary between the pancake, mushroom, and brush states of the hydrophilic backbone (Paeng et al, 2003). In our previous work, block polyethers were synthesized using bisphenol A as an initiator, and the aggregation behaviors at the air/water interface were investigated using surface tension and dilational viscoelasticity measurements (Gong et al, 2012). The results showed that the presence of alkylaryl groups can significantly enhance the adsorption capacity and reduce surface tension of the polyethers but also influences the dilational viscoelasticity due to the different microscopic conformations at the air/water interface.…”

The behavior of poly(amino acids) containing l‐cysteine and their block copolymers with poly(ethylene glycol) on gold surfaces

“…Equally, surfaces grafted with PEG will also exhibit biocompatibility . When exposed to an aqueous environment, PEG coordinates with water molecules, thereby preventing direct interactions between proteins and the PEGylated surface or other PEGylated conjugates …”

“…16 When exposed to an aqueous environment, PEG coordinates with water molecules, thereby preventing direct interactions between proteins and the PEGylated surface or other PEGylated conjugates. 17,18 When block copolymers are formed between PEG and p(L-Cys)-containing PAA's, the biocompatibility of the PEG is combined with the reactivity of p(L-Cys). Furthermore, copolymerizing L-Cys with other amino acid repeat units, as opposed to end-capping the polymer-chains with a single thiol group, generates multiple anchor sites along the copolymer chain that become available for the covalent attachment of the block copolymer to a surface.…”