The LIVE/DEAD BacLight bacterial viability kit, containing propidium iodide (PI) and Syto 9, was obtained from Invitrogen (Molecular Probes, Carlsbad, CA). Unless specified, all chemicals were dissolved in deionized (DI) water obtained from a Milli-Q ultrapure water purification system (Millipore, Billerica, MA).Graphene oxide synthesis. Graphene oxide was produced by chemical exfoliation from graphite powder according to a method adapted from. 1 Briefly, 1.5 g of graphite was added to 200 mL of a 9:1 mixture of H 2 SO 4 :H 3 PO 4 and bath sonicated (26 W L -1 , FS60 Ultrasonic Cleaner, Fisher Scientific Co., Pittsburgh, PA) for 5 min. The reaction vessel was then placed in an ice bath and 9 g of KMnO 4 was added to the mixture under constant stirring. The solution was then slowly heated to 50 o C and stirred for 12 h. Special care was taken in this step to keep the temperature at 50 o C, since Mn 2 O 7 , formed when KMnO 4 is added to concentrated sulfuric acid, can detonate at temperatures higher than 55 o C. Next, the reaction was allowed to cool to room temperature overnight and poured on DI ice (~400 mL) with 3 mL of H 2 O 2 . The reaction was diluted with DI water to 2 L, passed through a 44 µm standard metal testing sieve (W.S. Tyler) and the solid fraction of the filtrate collected on a 5 µm PTFE filter by vacuum filtration. The solid material was then washed in succession with 100 mL of DI water (2x), 100 mL of 1:10 HCl (2x), 100 mL of DI water (2x) and 100 mL of ethanol (2x). For each washing step, the mixture was centrifuged (4000 g for 4 h) and the supernatant decanted away. Finally, the material was purified by dialysis for 72 h. The material was then filtered on a 0.45 µm PTFE filter and vacuum dried. Before use, graphene oxide was suspended in DI, probe-sonicated for 10 min (6.5

There is long-standing interest in developing membranes possessing uniform pores with dimensions in the range of 1 nm and physical continuity in the macroscopic transport direction to meet the needs of challenging small molecule and ionic separations. Here we report facile, scalabe fabrication of polymer membranes with vertically (i.e., along the through-plane direction) aligned 1 nm pores by magnetic-field alignment and subsequent cross-linking of a liquid crystalline mesophase. We utilize a wedge-shaped amphiphilic species as the building block of a thermotropic columnar mesophase with 1 nm ionic nanochannels, and leverage the magnetic anisotropy of the amphiphile to control the alignment of these pores with a magnetic field. In situ X-ray scattering and subsequent optical microscopy reveal the formation of highly ordered nanostructured mesophases and cross-linked polymer films with orientational order parameters of ca. 0.95. High-resolution transmission electron microscopy (TEM) imaging provides direct visualization of long-range persistence of vertically aligned, hexagonally packed nanopores in unprecedented detail, demonstrating high-fidelity retention of structure and alignment after photo-cross-linking. Ionic conductivity measurements on the aligned membranes show a remarkable 85-fold enhancement of conductivity over nonaligned samples. These results provide a path to achieving the large area control of morphology and related enhancement of properties required for high-performance membranes and other applications.

The effect of incorporating an organic linking group, 1,6-bis(trimethoxysilyl)hexane (BTMSH), into the underlying silica structure of a styrene cross-linked silica aerogel is examined. Vinyltrimethoxysilane (VTMS) is used to provide a reactive site on the silica backbone for styrene polymerization. Replacement of up to 88 mol % of the silicon from tetramethoxyorthosilicate with silicon derived from BTMSH and VTMS during the making of silica gels improves the elastic behavior in some formulations of the cross-linked aerogels, as evidenced by measurement of the recovered length after compression of samples to 25% strain. This is especially true for some higher density formulations, which recover nearly 100% of their length after compression to 25% strain twice. The compressive modulus of the more elastic monoliths ranged from 0.2 to 3 MPa. Although some of these monoliths had greatly reduced surface areas, changing the solvent used to produce the gels from methanol to ethanol increased the surface area in one instance from 6 to 220 m(2)/g with little affect on the modulus, elastic recovery, porosity, or density.

Membrane separations are critically important in areas ranging from health care and analytical chemistry to bioprocessing and water purification. An ideal nanoporous membrane would consist of a thin film with physically continuous and vertically aligned nanopores and would display a narrow distribution of pore sizes. However, the current state of the art departs considerably from this ideal and is beset by intrinsic trade-offs between permeability and selectivity. We demonstrate an effective and scalable method to fabricate polymer films with ideal membrane morphologies consisting of submicron thickness films with physically continuous and vertically aligned 1 nm pores. The approach is based on soft confinement to control the orientation of a cross-linkable mesophase in which the pores are produced by self-assembly. The scalability, exceptional ease of fabrication, and potential to create a new class of nanofiltration membranes stand out as compelling aspects.