Block Copolymer Membranes from Polystyrene-b-poly(solketal methacrylate) (PS-b-PSMA) and Amphiphilic Polystyrene-b-poly(glyceryl methacrylate) (PS-b-PGMA)

Abstract

Abstract:In this paper; we compare double hydrophobic polystyrene-b-poly(solketal methacrylate) (PS-b-PSMA) and amphiphilic polystyrene-b-poly(glyceryl methacrylate) (PS-b-PGMA) diblock copolymer membranes which are prepared by combining the block copolymer self-assembly in solution with a non-solvent induced phase separation (SNIPS). Diblock copolymers (i.e., PS-b-PSMA) were synthesized by sequential living anionic polymerization, whereas polystyrene-b-poly(glyceryl methacrylate) (PS-b-PGMA) were obtained by acid hydrolysis of the acetonide groups of the polysolketal methacrylate (PSMA) blocks into dihydroxyl groups (PGMA). Membrane structures and bulk morphologies were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM); respectively. The resulting PS-b-PGMA diblock copolymers produce an ordered hexagonal cylindrical pore structure during the SNIPS process, while membranes fabricated from the double hydrophobic (PS-b-PSMA) do not under similar experimental conditions. Membrane performance was evaluated by water flux and contact angle measurements.

Isoporous Membranes from Novel Polystyrene-b-poly(4-vinylpyridine)-b-poly(solketal methacrylate) (PS-b-P4VP-b-PSMA) Triblock Terpolymers and Their Post-Modification

“…Only if the P4VP block is large enough can it overcome the influence of the hydrophobic PSMA block and a membrane with highly oriented pores can be obtained. This is in agreement with our previous results for a PS-b-PSMA and the corresponding hydrolyzed PS-b-PGMA diblock copolymer, where only the latter one yielded isoporous membranes by applying SNIPS [48].…”

“…The membranes cast by SNIPS from the solution of the PS 71 -b-P4VP 17 -b-PSMA 12 91 (larger PSMA block) exhibited a dense structure even if the same composition of solvents was used (Supporting Information Figure S6a). Based on previous findings [41,48], this is probably due to the shorter hydrophilic P4VP block, which cannot compensate for the hydrophobic nature of the PSMA block. Apparently, the amphiphilic behavior plays a crucial role in the self-assembly and pore formation during the phase inversion process.…”

“…Recently, we reported a detailed comparison of double hydrophobic PS-b-PSMA and amphiphilic PS-b-PGMA diblock copolymer membranes, where the influence of the hydrophobic or hydrophilic nature of the second block was analyzed by water flux and contact angle measurements. In contrary to the present manuscript, the post-modification of PSMA was performed in the polymer solution [48]. Here we report for the first time the synthesis of a series of amphiphilic triblock terpolymers PS-b-P4VP-b-PSMA by living anionic polymerization, followed by the exploration of triblock terpolymer membrane formation in varying polymer concentrations, solvent compositions, and evaporation times.…”

Periodic Bicontinuous Structures Formed on the Top Surface of Asymmetric Triblock Terpolymer Thick Films

“…have used an elegant approach which combines the self-assembly of BCPs into an out-of-plane cylindrical nanostructure on the material top surface with the formation of a macroporous substructure generated by nonsolvent-induced phase separation (NIPS). However, a perfect control of the nanopore formation is challenging to achieve with the SNIPS method ( i .e., self-assembly + NIPS) due to the fact that, at best, a kinetically trapped morphology derived from a micellization process is formed on the material skin layer when appropriate manufacturing conditions can be defined. − Indeed, the complex exchange/migration of the nonsolvent occurring during the porosity formation allows isoporous membranes with pores extending over the top separation layer to be solely demonstrated for specific amphiphilic AB- and ABC-type BCP systems since the hydrophilic block plays a crucial role in creating pores during the precipitation process. − …”

Postfunctionalization of Nanoporous Block Copolymer Membranes via Click Reaction on Polydopamine for Liquid Phase Separation

“…In this, membranes were prepared not only from diblock − but also from triblock copolymers. − Furthermore, the effect of additives on the structure formation was investigated, , as well as the possibility to tune the pore size of the membrane by blending block copolymers of different molecular weights and compositions . For the variation of their properties, porous membranes were prepared from block copolymers with different chemical functionalities like hydroxyl- or amino-groups. − Nevertheless, the introduction of an alternative functional group (e.g., zwitterionic-group) also necessitates the time-consuming redetermination of the ideal membrane casting conditions. Postfunctionalization of membranes is a powerful toolbox to overcome this problem and allows adding functional groups on the membrane’s surface, pore walls, and substructure.…”