Highly Selective Vertically Aligned Nanopores in Sustainably Derived Polymer Membranes by Molecular Templating

Abstract

We describe a combination of molecular templating and directed self-assembly to realize highly selective vertically aligned nanopores in polymer membranes using sustainably derived materials. The approach exploits a structure-directing molecule to template the assembly of plant-derived fatty acids into highly ordered columnar mesophases. Directed self-assembly using physical confinement and magnetic fields provides vertical alignment of the columnar nanostructures in large area (several cm) thin films. Chemically cross-linking the mesophase with added conventional vinyl comonomers and removing the molecular template results in a mechanically robust polymer film with vertically aligned 1.2-1.5 nm diameter nanopores with a large specific surface area of ∼670 m/g. The nanoporous polymer films display exceptional size and charge selectivity as demonstrated by adsorption experiments using model penetrant molecules. These materials have significant potential to function as high-performance nanofiltration membranes and as nanoporous thin films for high-density lithographic pattern transfer. The scalability of the fabrication process suggests that practical applications can be reasonably anticipated.

Functional Liquid Crystals towards the Next Generation of Materials

“…[102] Forlyotropic columnar liquid crystals,alignment control of compound 20 using PDMS substrates or magnetic fields was reported by Osuji and co-workers (Figure 6a). [151][152][153] Fort he thinner films (< 5 mm), effects of the interface on the alignment of columnar structures are enough to form homeotropic aligned structures.F or the thicker films (> 5 mm), interaction between the aromatic rings and magnetic field control the orientation of columns.…”

Chemically Tailored Multifunctional Asymmetric Isoporous Triblock Terpolymer Membranes for Selective Transport

“…According to MM2 force field energy minimization model calculation (in vacuum), the lateral dimensions of MB+, RB0, and OR− are rather similar, i.e., 1.1, 1.0, and 1.3 nm, respectively. [27] The permeability and selectivity of membranes can be investigated via two methods: concentration-driven diffusion [1,2,[5][6][7]28] and pressure-driven flow. We determined the retention and selectivity of the model molecules from pressuredriven flow of aqueous solutions containing single solutes and mixed solutes as it is more relevant to a realistic application compared to a diffusion cell experiment.…”

Nanomaterial Preparation by Extrusion through Nanoporous Membranes

“…We are optimistic about the recent advances in nanoporous membrane fabrication technologies . For example, the utilization of self‐assembly block polymers has enabled us to prepare highly uniform and ordered nanoporous membrane with a pore size as small as 1 nm.…”

“…We are optimistic about the recent advances in nanoporous membrane fabrication technologies. [236][237][238][239][240][241][242][243] For example, the utilization of self-assembly block polymers has enabled us to prepare highly uniform and ordered nanoporous membrane with a pore size as small as 1 nm. These newly developed block polymer-based nanoporous membranes provide a narrower pore size distribution, higher porosity, tunable chemical and physical properties, with many other advanced functions, providing the field with new experimental tools and research opportunities in nanoporous membrane extrusion methods.…”