Phase Inversion Membranes from Amphiphilic Diblock Terpolymers

Abstract

Polymeric materials as building blocks represent the most important membrane materials as they are relatively simple to synthesize and flexible regarding manufacturing conditions. In this contribution, the synthesis of amphiphilic diblock terpolymers and their use for the preparation of integral asymmetric membranes via nonsolvent induced phase separation (NIPS) processes is presented. The diblock terpolymers consist of a hydrophobic poly(styrene‐co‐isoprene) block and a hydrophilic segment of poly(N,N‐dimethylaminoethyl methacrylate). The materials are synthesized either via nitroxide mediated polymerization or living anionic polymerization. The NIPS process is used for the fabrication of porous diblock terpolymer membranes where the membrane morphology can be influenced by several parameters such as the applied solvent mixture, open time, or relative humidity. The resulting anisotropic membranes are characterized by scanning electron microscopy and water flux measurements. Furthermore, the UV‐induced crosslinking of the isoprene part of the membrane matrix is demonstrated.

Towards sustainable ultrafast molecular-separation membranes: From conventional polymers to emerging materials

“…Block copolymers (BCP) are also potentially useful for the fabrication of UMS membranes. These polymers can form a high concentration of uniform regular pores in ultrathin films [21,[186][187][188][189][190][191][192][193][194][195]. Recent breakthroughs in polymer science show that the sub-10 nm pore sizes in self-assembled BCPs can be tuned with external stimuli, representing a significant advance relative to current research.…”

“…Based on membrane properties such as permeance, rejection, mechanical strength, membrane stability and cost, the possibility of using various cutting-edge materials to scale-up the production of UMS membranes is summarized and evaluated in Table 2. For instance, the high pore density and uniform pore size distribution of BCP membranes lead to ultrahigh permeability [21,[186][187][188][189][190][191][192][193][194][195]. However, it is hard to tailor the mean effective pore size below 5 nm [21,[186][187][188][189][190][191][192][193][194][195], and the significant cost of BCPs hampers the commercialization potential of these membranes.…”

“…Currently, only a few types of polymers and 2D materials are suitable for the fabrication of UMS membranes using the coatingetching method or phase inversion-coating method. Biomimetic materials, block-copolymers, liquid crystals and porous frameworks, such as MOFs, COFs, and PAFs, are alternative building blocks for UMS membranes [184][185][186][187][188][189][190][191][192][193]. Unfortunately, the costs of these materials remain high, inhibiting the scale-up production of low-cost UMS membranes.…”

Fabrication and Optical Modeling of Micro‐Porous Membranes Index‐Matched with Water for On‐Line Sensing Applications

“…[ 8,9 ] Most common characterization approaches include flow measurements, gas adsorption, scattering of x‐rays or light, and electron microscopy. [ 10–13 ] For membranes with micron‐scale structure, optical methods are particularly suitable and continuous technical improvements are proposed to obtain higher quality structural information. Optical investigation of membrane structures can be achieved by angle‐resolved [ 14 ] or polarization‐resolved [ 15 ] light scattering, by 3D optical reconstruction based on low coherence interferometry [ 16 ] or optical coherence tomography, [ 17 ] and by direct observation through confocal microscopy.…”

Pure hydrophilic block copolymer vesicles with redox- and pH-cleavable crosslinks

“…as drug delivery vehicles, 14,15 hybrid materials, 16 photoluminescent materials 17 or membranes. 18 In contrast to the self-assembly of amphiphilic block copolymers in aqueous solution, pure hydrophilic block copolymers, e.g. double hydrophilic block copolymers (DHBCs), can form self-assembled structures in aqueous solution as well.…”