Hierarchical Self-Assembled Structures from Diblock Copolymer Mixtures by Competitive Hydrogen Bonding Strength

Abstract

In this work we prepared poly(styrene–b–vinylphenol) (PS-b-PVPh) by sequential anionic living polymerization and poly(ethylene oxide-b-4-vinylpyridine) (PEO-b-P4VP) by reversible addition fragmentation chain transfer polymerization (RAFT) by using poly(ethylene oxide) 4-cyano-4-(phenylcarbonothioylthio)pentanoate (PEO-SC(S)Ph) as a macroinitiator with two hydrogen bonded acceptor groups. When blending with disordered PEO-b-P4VP diblock copolymer, we found the order-order self-assembled structure transition from lamellar structure for pure PS-b-PVPh to cylindrical, worm-like, and finally to PEO crystalline lamellar structures. Taking the advantage of the ΔK effect from competitive hydrogen bonding strengths between PVPh/P4VP and PVPh/PEO domains, it could form the hierarchical self-assembled morphologies such as core–shell cylindrical nanostructure.

Glass Transition Behaviors of Poly (Vinyl Pyridine)/Poly (Vinyl Phenol) Revisited

“…Specifically, glass transition temperatures, T g , of such blends become higher in some cases than the pure component T g due to the attractive interaction between the component polymers [15,16,17,18,19,20,21]. On top of that, studies about a new class of materials by combining the micro-phase separation and the H-bonding interaction have been reported [22,23,24,25,26,27].…”

CeFe-Based Bead Nanocomposites as Catalysts for Oxidation of Ethylbenzene Reaction

“…XRD patterns of the solids depict broadened diffraction peaks (Figure 3a), which confirm the existence of semi-crystalline structures. This is typical of nanocasted solids that possess the small crystallite sizes and internal strains [2,18,19] For CFN, the previously mentioned iron phases arise concomitantly with that of the CeO 2 and cubic NiO (Fm-3m space group, JCPDS card n • . 47-1049) as well.…”

“…XRD patterns of the solids depict broadened diffraction peaks (Figure 3a), which confirm the existence of semi-crystalline structures. This is typical of nanocasted solids that possess the small crystallite sizes and internal strains [2,18,19]. Accordingly, all solids exhibit weak diffraction patterns attributable to the cubic fluorite CeO2 structure at about 28.7, 34.6, 47.5 and 56.5°, which are indexed to the (111), (200), (220), and (311) planes, respectively (JCPDS card n°.…”

High-Molecular-Weight PLA-b-PEO-b-PLA Triblock Copolymer Templated Large Mesoporous Carbons for Supercapacitors and CO2 Capture

“…Using this approach, well-defined mesoporous structures can be obtained since the block copolymer could be self-assembled into different structures through microphase separation connected by covalent bond [18][19][20]. The concept of mediating the hydrogen bonding strength in block copolymer mixtures [21][22][23][24][25][26][27][28][29][30][31][32] to synthesize mesoporous materials has been widely discussed in our previous studies [18,19,[33][34][35]. Using a commercial pluronic-type poly(ethylene oxide-b-propylene oxide-b-ethylene oxide) triblock copolymer as the template is the most widely used approach to preparing mesoporous materials; however, because of the limitation presented by the molecular weight of this kind of triblock copolymer, it is difficult to prepare mesoporous phenolic or carbon with pore size >10 nm [36][37][38][39][40][41].…”