A simple, scalable method for fabricating fouling-resistant ultrafiltration membranes is described. A self-doped, sulfonated form of polyaniline was blended into polysulfone (PSf) ultrafiltration (UF) membranes to enhance hydrophilicity and fouling resistance. Polyaniline in its base form was sulfonated with fuming sulfuric acid, yielding sulfonated polyaniline (SPANi) with a degree of sulfonation of ∼0.5 confirmed by XPS. The SPANi polymer was dedoped and dissolved in a solution of polysulfone in N-methylpyrollidone at varying concentrations. During phase inversion to form membranes, SPANi is redoped and precipitated within the PSf membrane films in a facile one-step process. Composite membranes containing increasing amounts of SPANi were compared to the pure PSf membranes to determine changes in performance, hydrophilicity, and antifouling characteristics. The composite membranes exhibit fluxes similar to those of the pure PSf membrane and maintain rejection properties similar to those of current UF membranes. Captive bubble contact angle measurements and atomic force microscopy suggest increasing membrane hydrophilicity with increasing SPANi content. During flux decline and recovery experiments, SPANi/PSf composite membranes exhibited higher flux recovery than a pure PSf membrane, with the best performing membrane regaining 95% of its original flux after being washed with deionized water, demonstrating a high resistance to irreversible fouling.

Supercapacitors are known for their rapid energy charge–discharge properties, often ten to a hundred times faster than batteries. However, there is still a demand for supercapacitors with even faster charge–discharge characteristics to fulfill the requirements of emerging technologies. The power and rate capabilities of supercapacitors are highly dependent on the morphology of their electrode materials. An electrically conductive 3D porous structure possessing a high surface area for ions to access is ideal. Using a flash of light, a method to produce highly interconnected 3D graphene architectures with high surface area and good conductivity is developed. The flash converted graphene is synthesized by reducing freeze‐dried graphene oxide using an ordinary camera flash as a photothermal source. The flash converted graphene is used in coin cell supercapacitors to investigate its electrode materials properties. The electrodes are fabricated using either a precoating flash conversion or a postcoating flash conversion of graphene oxide. Both techniques produce supercapacitors possessing ultra‐high power (5–7 × 105 W kg−1). Furthermore, optimized supercapacitors retain >50% of their capacitance when operated at an ultrahigh current density up to 220 A g−1.

Azide-functionalized graphene oxide (AGO) was covalently anchored onto commercial reverse osmosis (RO) membrane surfaces via azide photochemistry. Surface modification was carried out by coating the RO membrane with an aqueous dispersion of AGO followed by UV exposure under ambient conditions. This simple process produces a hydrophilic, smooth, antibacterial membrane with limited reduction in water permeability or salt selectivity. The GO-RO membrane exhibited a 17-fold reduction in biofouling after 24 h of Escherichia coli contact and almost 2 times reduced BSA fouling after a 1 week cross-flow test compared to its unmodified counterpart.

conditions to maintain the scale of medical device manufacturing; and 4) the treatment must not incorporate antibiotics to maintain global antimicrobial stewardship efforts. The zwitterionic polymer polysulfobetaine (PSB) was selected as the antifouling component of the surface modification to benefit from its biocompatibility, ultralow-fouling properties, and oxidative stability. By adsorbing water electrostatically, PSB coatings form a thin hydration barrier that prevents organic materials from adhering to surfaces. [22] Commonly used approaches to attach PSB coatings to surfaces, such as radical-initiated graft polymerizations of PSB-methacrylate necessitate the use of oxygen-free conditions, [23] preconditioning steps, [24] or long reaction times [25] that do not meet scalability requirements. To circumvent the use of air-free graft polymerizations, we employ perfluorophenylazide (PFPA) chemistry as a molecular anchor to link the PSB coatings onto the surfaces of polymeric materials under ambient conditions. When triggered with UV-light, PFPA moieties generate a highly reactive nitrene that forms covalent bonds with materials containing amines, CC double bonds, and CH bonds. [26,27] With this method, PSB is rapidly coated onto a broad range of substrates using UV light under ambient conditions with no preconditioning steps. Thus, many different medical devices may be quickly and conveniently treated on the manufacturing level.We first demonstrate the effect of the treatment on polydimethylsiloxane (PDMS) as an exemplary, extremely difficultto-modify model for a common elastomer used in implantable medical devices. [28] Commonly known as silicone, PDMS is widely used for its biocompatibility, good chemical stability, ease of fabrication using injection molding or extrusion, and low cost. [29][30][31] Many implantable device makers have moved away from classical medical elastomers and plastics such as latex and polyvinyl chloride due to allergens [32] or plasticizers [33] in these materials that leach out and often lead to irritation or complications. PDMS-based devices do not require plasticizers and have been shown to lead to fewer complications than latex and polyurethane-based devices. [34] Despite its ideal properties, the nonpolar nature of PDMS facilitates the adhesion of organic materials. Bacteria, platelets, proteins, and other biomolecules bind strongly to the hydrophobic surfaces of PDMS elastomers, leading to the colonization and proliferation of biofilms. [22] When common hydrophilic surface treatments are performed on PDMS, such as plasma oxidation, [35] UV-ozone, [36] or corona discharge, [37] the effects are short-term due to rapid hydrophobic recovery. The highly mobile chains of PDMS (glass transition temperature ≈ −120 °C) can reorient themselves to "hide" the surface modified elastomers, when exposed to air, within hours. [38] Other methods seeking long-lasting hydrophilic PDMS surfaces typically require preconditioning steps with silane [39][40][41] chemistry or radical polymerization. [...

Graphene oxide (GO) membranes have great potential for separation applications due to their low-friction water permeation combined with unique molecular sieving ability. However, the practical use of deposited GO membranes is limited by the inferior mechanical robustness of the membrane composite structure derived from conventional deposition methods. Here, we report a nanostructured GO membrane that possesses great permeability and mechanical robustness. This composite membrane consists of an ultrathin selective GO nanofilm (as low as 32 nm thick) and a postsynthesized macroporous support layer that exhibits excellent stability in water and under practical permeability testing. By utilizing thin-film lift off (T-FLO) to fabricate membranes with precise optimizations in both selective and support layers, unprecedented water permeability (47 L•m −2 •hr −1 • bar −1 ) and high retention (>98% of solutes with hydrated radii larger than 4.9 Å) were obtained.

For the past 30 years, thin-film membrane composites have been the state-of-the-art technology for reverse osmosis, nanofiltration, ultrafiltration, and gas separation. However, traditional membrane casting techniques, such as phase inversion and interfacial polymerization, limit the types of material that are used for the membrane separation layer. Here, we describe a novel thin-film liftoff (T-FLO) technique that enables the fabrication of thin-film composite membranes with new materials for desalination, organic solvent nanofiltration, and gas separation. The active layer is cast separately from the porous support layer, allowing for the tuning of the thickness and chemistry of the active layer. A fiber-reinforced, epoxy-based resin is then cured on top of the active layer to form a covalently bound support layer. Upon submersion in water, the cured membrane lifts off from the substrate to produce a robust, freestanding, asymmetric membrane composite. We demonstrate the fabrication of three novel T-FLO membranes for chlorine-tolerant reverse osmosis, organic solvent nanofiltration, and gas separation. The isolable nature of support and active-layer formation paves the way for the discovery of the transport and selectivity properties of new polymeric materials. This work introduces the foundation for T-FLO membranes and enables exciting new materials to be implemented as the active layers of thin-film membranes, including high-performance polymers, two-dimensional materials, and metal–organic frameworks.

We present a method to produce anti-fouling reverse osmosis (RO) membranes that maintains the process and scalability of current RO membrane manufacturing. Utilizing perfluorophenyl azide (PFPA) photochemistry, commercial reverse osmosis membranes were dipped into an aqueous solution containing PFPA-terminated poly(ethyleneglycol) species and then exposed to ultraviolet light under ambient conditions, a process that can easily be adapted to a roll-to-roll process. Successful covalent modification of commercial reverse osmosis membranes was confirmed with attenuated total reflectance infrared spectroscopy and contact angle measurements. By employing X-ray photoelectron spectroscopy, it was determined that PFPAs undergo UV-generated nitrene addition and bind to the membrane through an aziridine linkage. After modification with the PFPA-PEG derivatives, the reverse osmosis membranes exhibit high fouling-resistance.

n-PANi, an outstanding candidate for making chlorine tolerant antifouling ultrafiltration membranes.