Morphology-Controlled Mesopores with Hydrophilic Pore Walls from Triblock Copolymers

Abstract

We report a facile approach that can simultaneously control the morphology and surface chemistry of mesoporous materials from triblock copolymers. By doping phosphotungstic acid (PW), the self-assembled structures of polystyrene–poly­(ethylene oxide)–polylactide (PS–PEO–PLA, SEL) triblock copolymer can be tuned. Besides core–shell cylinders and lamellae, disordered bicontinuous structures can be achieved in SEL/PW composites. After etching with NaOH, PLA domains and PW additive are removed simultaneously, giving mesoporous PS monoliths with controlled morphologies and PEO-coated pores. Also, we demonstrated that the prepared porous PS monoliths can be used as templates to fabricate inorganic nanostructures. This work provides new insight into the fabrication of functional mesoporous materials.

Synthesis and applications of polymer cubosomes and hexosomes

“…52 After the co-assembly of BCPs and precursors (EISA and EIAA) or the infiltration of precursors into self-assembled BCP templates, crosslinking of the precursors and subsequent removal of the polymer template by calcination or solvent washing yield various networks. These networks include silica, 27,28,54,55,[57][58][59][60][61][62][63][64][65][66][67][68][69][70][71][72][73][74][75] silica composites, [53][54][55]76 calcite, 77 carbon, 14,56,70,71,[78][79][80][81][82][83][84][85][86][87][88] ceramic, 89 metals, [90][91][92][93]…”

“…After the co‐assembly of BCPs and precursors (EISA and EIAA) or the infiltration of precursors into self‐assembled BCP templates, crosslinking of the precursors and subsequent removal of the polymer template by calcination or solvent washing yield various networks. These networks include silica, 27,28,54,55,57–75 silica composites, 53–55,76 calcite, 77 carbon, 14,56,70,71,78–88 ceramic, 89 metals, 90–99 metal composites, 100–105 metal oxides such as aluminum oxide, 22 titania, 27,87,106–110 nickel oxide, 111 niobia, 103,112 vanadium oxide 113,114 tantalum oxide 115 and zinc oxide, 116 and polymers including PEDOT, 117 polypyrrole, 13,71,117,118 polydopamine, 13 poly‐ m ‐phenylenediamine, 13 and phenolic and epoxy resins 119…”

Stimuli-cleavable moiety enabled vinyl polymer degradation and emerging applications

“…18). 117 Upon etching with NaOH, the PLA segment can be removed, leading to the generation of PS monoliths and hydrophilic PEO-coated pores. Besides, the morphology of self-assembled nanostructure can be tuned by varying the amount of phosphotungstic acid (PW) additive due to its high affinity to PEO-block via electronic interaction, generating various morphologies, including core–shell cylinders, lamellae, and even disordered bicontinuous structures, which is highly desirable for not only mesoporous materials but also for solid electrolytes and catalysts.…”

Stability of Hierarchical Gyroid Structures in Frustrated ABC Triblock Copolymers

“…Block copolymer has been attracting abiding interest due to its unique ability of self-assembling into various ordered nanostructures that exhibit promising applications in a wide range of fields. − AB diblock copolymer, as the simplest block copolymer, has been intensively studied experimentally and theoretically, and thus its self-assembly behavior has been well understood . In particular, self-consistent field theory (SCFT), which can accurately calculate the free energy of each ordered phase and has been proven as one of the most powerful methods for the study of block copolymers, has verified that the AB diblock copolymer exhibits a phase sequence mainly consisting of lamella (L), hexagonally arranged cylinders (C 6 ), bicontinuous double-gyroid (G) network, and a body-centered cubic (BCC) lattice of spheres, as its volume fraction of one block changes from symmetric to asymmetric. − The appearance of the G phase has received extensive attention because its bicontinuous feature makes it become a promising candidate for the fabrication of many functional materials. − This transition sequence as well as the self-assembly mechanism of the AB diblock has laid the foundation for understanding the self-assembly behaviors of other block copolymers with more complex architectures.…”