Low concentration alcohols produced by state-of-theart biological fermentation restrict subsequent purification processes for chemical, pharmaceutical, biofuel, and other applications. Herein, a rarely reported cucurbituril[n] (n = 6, 8) is employed to pattern the thin-film composite membranes with controllable and quantifiable nanostrand structures through a host−guest strategy. The resulting nanofiltration membrane with such morphology is the first report that exhibits excellent separation performance for isopropyl alcohol (IPA) and water, condensing the initial 0.5 wt % IPA aqueous solution to 9.0 wt %. This not only provides a novel strategy for patterning nanostructural morphology but also makes nanofiltration membranes promising for alcohol condensation in the biological fermentation industry that may reduce energy consumption and postprocessing costs.

This paper reveals the chemical, structural, and separation stability of stacked molybdenum disulfide (MoS2) membranes and establishes a low-cost and facile approach to developing stable, selective membranes for efficient molecular separation in an organic solvent. MoS2 nanoflakes that were dominant  by monolayer MoS2 sheets as prepared via direct chemical exfoliation (chem-MoS2) were found to be chemically and structurally instable, with a sharp decrease in the level of solute rejection within a few days. Few-layer MoS2 nanoflakes were then fabricated using a hydrothermal method (hydro-MoS2). A “supportive” drying process involving glycerol pretreatment and drying in an oven was established to allow realignment of nanoflakes and adjustment of interflake spacing. We have shown that the hydro-MoS2 membranes provide a mean interflake free spacing of ∼1 nm, which is ideal for the separation of a model solute (Rose Bengal, size of ∼1.45 nm) from the solvent isopropanol (size of 0.58 nm) with good long-term stability over a 7 day test.

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