Gyroid Nanoporous Membranes with Tunable Permeability

Abstract

Understanding the relevant permeability properties of ultrafiltration membranes is facilitated by using materials and procedures that allow a high degree of control on morphology and chemical composition. Here we present the first study on diffusion permeability through gyroid nanoporous cross-linked 1,2-polybutadiene (1,2-PB) membranes with uniform pores that, if needed, can be rendered hydrophilic. The gyroid porosity has the advantage of isotropic percolation with no need for structure prealignment. Closed (skin) or opened (nonskin) outer surface can be simply realized by altering the interface energy in the process of membrane fabrication. The morphology of the membranes' outer surface was investigated by scanning electron microscopy, contact angle, and X-ray photoelectron spectroscopy. The effective diffusion coefficient of glucose decreases from nonskin, to one-sided skin to two-sided skin membranes, much faster than expected by a naive resistance-in-series model; the flux through the two-sided skin membranes even increases with the membrane thickness. We propose a model that captures the physics behind the observed phenomena, as confirmed by flow visualization experiments. The chemistry of 1,2-PB nanoporous membranes can be controlled, for example, by hydrophilic patterning of the originally hydrophobic membranes, which allows for different active porosity toward aqueous solutions and, therefore, different permeability. The membrane selectivity is evaluated by comparing the effective diffusion coefficients of a series of antibiotics, proteins, and other biomolecules; solute permeation is discussed in terms of hindered diffusion. The combination of uniform bulk morphology, isotropically percolating porosity, controlled surface chemistry, and tunable permeability is distinctive for the presented gyroid nanoporous membranes.

Nanoporous polymeric materials: A new class of materials with enhanced properties

“…The diffusion permeability of different solutes (antibiotics, proteins, and several biomolecules) across gyroid nanoporous 1,2-polybutadiene (1,2-PB) membranes was studied by Li et al [153] using Eq. (18).…”

Sodium Dodecyl Sulfate (SDS)-Loaded Nanoporous Polymer as Anti-Biofilm Surface Coating Material

“…The improvement provided by the S skin samples is particularly interesting. In a comparative study of glucose permeability through 1,2-PB nanoporous membranes [31], we have observed that the presence of skin layer diminishes the effective diffusion coefficient by a factor of 5.7 compared to the porous surface. This effect is correlated to decreased surface porosity due to the compact nature of the skin layer, irregularly interrupted by porous defects [31].…”

Block Copolymer‐Derived Monolithic Polymer Films and Membranes Comprising Self‐Organized Cylindrical Nanopores for Chemical Sensing and Separations

“…It should be noted that BCP-derived membranes with bicontinuous nanopore morphologies have also been examined as ultrafiltration membranes. [88,89] These membranes did not require domain alignment for fabrication and exhibited fairly sharp MWCOs, but showed fouling and lower flux owing to their large tortuosity. [89] …”