Janus Superiority of Membranes in Chemical Engineering and Beyond.

Janus configurations, characterized by their inherent asymmetry, enable directional mass transfer in membrane materials that drive novel and energy-efficient chemical processes. This Janus superiority spans applications from nanoscale molecular and ionic transport to macro-scale separation systems with asymmetric spatial architectures. This review provides an analysis of the material foundations including design principles, structure regulation, and scalability challenges underlying Janus membranes.

Optimization of Delignified Wood Rods for Interfacial Solar Evaporation.

Interfacial solar evaporation using three-dimensional evaporator materials has shown promise to achieve high evaporation rates exceeding the photothermal limit for water treatment and resource recovery processes. However, challenges remain in optimizing the material geometry to balance the vertical capillary uptake of water and the rate of evaporation to achieve both stable and high evaporation rates. Delignified wood can serve as a highly porous and hydrophilic substrate material to achieve high evaporation rates.

Pillared Laminar Vermiculite Membranes with Tunable Monovalent and Multivalent Ion Selectivity.

Effective membrane separation of Li from Na and Mg is crucial for lithium extraction from water yet challenging for conventional polymeric membranes. Two dimensional (2D) membranes with ordered laminar structures and tunable physicochemical properties offer distinctive ion-sieving capabilities promising for lithium extraction. Recently, phyllosilicates are introduced as abundant and cost-effective source materials for such membranes.

The brine of the times.

New processes directly extract lithium from dilute sources.

Thiol-Functionalized Adsorbents through Atomic Layer Deposition and Vapor-Phase Silanization for Heavy Metal Ion Removal.

The removal of toxic heavy metal ions from water resources is crucial for environmental protection and public health. In this study, we address this challenge by developing a surface functionalization technique for the selective adsorption of these contaminants. Our approach involves atomic layer deposition (ALD) followed by vapor-phase silanization of porous substrates.

Influence of the Dielectric Constant on the Ionic Current Rectification of Bipolar Nanopores.

In this paper, we investigate how the dielectric constant, ϵ, of an electrolyte solvent influences the current rectification characteristics of bipolar nanopores. It is well recognized that bipolar nanopores with two oppositely charged regions rectify current when exposed to an alternating electric potential difference. Here, we consider dilute electrolytes with NaCl only and with a mixture of NaCl and charged nanoparticles.

Chelation-directed interface engineering of in-place self-cleaning membranes.

Water-energy sustainability will depend upon the rapid development of advanced pressure-driven separation membranes. Although energy-efficient, water-treatment membranes are constrained by ubiquitous fouling, which may be alleviated by engineering self-cleaning membrane interfaces. In this study, a metal-polyphenol network was designed to direct the armorization of catalytic nanofilms (ca.

Protein-activated atomic layer deposition for robust crude-oil-repellent hierarchical nano-armored membranes.

Atomic layer deposition (ALD) offers unique capabilities to fabricate atomically engineered porous materials with precise pore tuning and multi-functionalization for diverse applications like advanced membrane separations towards sustainable energy-water systems. However, current ALD technique is inhibited on most non-polar polymeric membranes due to lack of accessible nucleation sites. Here, we report a facile method to efficiently promote ALD coating on hydrophobic surface of polymeric membranes via novel protein activation/sensitization.

Montmorillonite Membranes with Tunable Ion Transport by Controlling Interlayer Spacing.

Membranes incorporating two-dimensional (2D) materials have shown great potential for water purification and energy storage and conversion applications. Their ordered interlayer galleries can be modified for their tunable chemical and structural properties. Montmorillonite (MMT) is an earth-abundant phyllosilicate mineral that can be exfoliated into 2D flakes and reassembled into membranes.

Molecular interactions in short-chain perfluoroalkyl carboxylic acids and aqueous solutions.

The presence of short-chain per- and polyfluoroalkyl substances in water poses a major health and environmental challenge. Here, we have performed high-energy small- and wide-angle X-ray scattering measurements on CF[CF]COOH (where  = 1, 2, 3 represents the chain length) and their aqueous solutions at 10% mole concentrations to characterize their molecular interactions at the atomic and nanometer length scales. The experimental wide-angle structure factors have been modelled using Empirical Potential Structural Refinement.

Material Design Strategies for Recovery of Critical Resources from Water.

Population growth, urbanization, and decarbonization efforts are collectively straining the supply of limited resources that are necessary to produce batteries, electronics, chemicals, fertilizers, and other important products. Securing the supply chains of these critical resources via the development of separation technologies for their recovery represents a major global challenge to ensure stability and security. Surface water, groundwater, and wastewater are emerging as potential new sources to bolster these supply chains.

Nanofluidic computing makes a splash.

Ionic computing raises the possibility of devices that operate similarly to the human brain.

Tunable Ion Transport with Freestanding Vermiculite Membranes.

Membranes integrating two-dimensional (2D) materials have emerged as a category with unusual ion transport and potentially useful separation applications in both aqueous and nonaqueous systems. The interlayer galleries in these membranes drive separation and selectivity, with specific transport properties determined by the chemical and structural modifications within the inherently different interlayers. Here we report an approach to tuning interlayer spacing with a single source material─exfoliated and restacked vermiculite with alkanediamine cross-linkers─to both control the gallery height and enhance the membrane stability.

Ionic Transport in Electrostatic Janus Membranes. An Explicit Solvent Molecular Dynamic Simulation.

Janus, or two-sided, charged membranes offer promise as ionic current rectifiers. In such systems, pores consisting of two regions of opposite charge can be used to generate a current from a gradient in salinity. The efficiency of nanoscale Janus pores increases dramatically as their diameter becomes smaller.

Selectivity of Per- and Polyfluoroalkyl Substance Sensors and Sorbents in Water.

Per- and polyfluoroalkyl substances (PFAS) are a large group of engineered chemicals that have been widely used in industrial production. PFAS have drawn increasing attention due to their frequent occurrence in the aquatic environment and their toxicity to animals and humans. Developing effective and efficient detection and remediation methods for PFAS in aquatic systems is critical to mitigate ongoing exposure and promote water reuse.

Surface Zeta Potential of ALD-Grown Metal-Oxide Films.

Membranes are among the most promising technologies for energy-efficient and highly selective separations, and the surface-charge property of membranes plays a critical role in their broad applications. Atomic layer deposition (ALD) can deposit materials uniformly and with high precision and controllability on arbitrarily complex and large substrates, which renders it a promising method to tune the electrostatics of water/solid interfaces. However, a systematic study of surface-charge properties of ALD-grown films in aqueous environments is still lacking.

Suspended Membrane Evaporators Integrating Environmental and Solar Evaporation for Oily Wastewater Purification.

Solar-driven evaporation is promising in oily wastewater treatment, in particular for emulsions, but conventional evaporators suffer from pore blocking by residual oil or contamination by volatile oil compounds in the condensed water. In the current research, we develop a suspended membrane evaporator integrating solar evaporation with oil-in-water emulsion separation. The heating and evaporating interface is separated from the rejecting interface to avoid oil escape and improve heat management.

Sandwich-Structured Photothermal Wood for Durable Moisture Harvesting and Pumping.

Moisture capture coupled with photothermal regeneration provides an alternative and sustainable way to acquire fresh water. Composite moisture absorbents based on hygroscopic salts are environmentally friendly, economically feasible, and of high efficiency but suffer from the unavoidable desiccant leakage during absorption and evaporation-induced salt accumulation on material surfaces during desorption. In this study, we develop a superhydrophobic-hydrophilic-hydrophobic photothermal wood embedded with CaCl to promote the durability of the absorbents.

Advanced Materials for Energy-Water Systems: The Central Role of Water/Solid Interfaces in Adsorption, Reactivity, and Transport.

The structure, chemistry, and charge of interfaces between materials and aqueous fluids play a central role in determining properties and performance of numerous water systems. Sensors, membranes, sorbents, and heterogeneous catalysts almost uniformly rely on specific interactions between their surfaces and components dissolved or suspended in the water-and often the water molecules themselves-to detect and mitigate contaminants. Deleterious processes in these systems such as fouling, scaling (inorganic deposits), and corrosion are also governed by interfacial phenomena.

Drawing on Membrane Photocatalysis for Fouling Mitigation.

Photocatalysis is an effective and environmentally friendly approach for degrading organic pollutants, particularly in scenarios where sunlight can be utilized as the energy source. Opportunities are emerging to apply materials and methods from photocatalytic pollutant degradation to address the challenge of fouling. Membrane fouling, attributed to organic foulants, is a prevalent problem for all membrane-based technologies and represents a major deleterious impact on membrane performance.

Resolving the Atomic Structure of Sequential Infiltration Synthesis Derived Inorganic Clusters.

Sequential infiltration synthesis (SIS) is a route to the precision deposition of inorganic solids in analogy to atomic layer deposition but occurs within (vs upon) a soft material template. SIS has enabled exquisite nanoscale morphological complexity in various oxides through selective nucleation in block copolymers templates. However, the earliest stages of SIS growth remain unresolved, including the atomic structure of nuclei and the evolution of local coordination environments, before and after polymer template removal.

Sharpening Nanofiltration: Strategies for Enhanced Membrane Selectivity.

Nanofiltration plays an increasingly large role in many industrial applications, such as water treatment (e.g., desalination, water softening, and fluoride removal) and resource recovery (e.

Enrichment and Distribution of Pb Ions in Zwitterionic Poly(cysteine methacrylate) Brushes at the Solid-Liquid Interface.

Cysteine-based polyzwitterionic brushes have been prepared via a two-step route. First, poly(allyl methacrylate) (PAMA) brushes have been grown from the surface of silicon substrates using surface-initiated atom transfer radical polymerization. The obtained PAMA brushes with free pendant vinyl groups were further modified via radical thiol-ene addition reaction to attach l-cysteine moieties.

The chemical physics of sequential infiltration synthesis-A thermodynamic and kinetic perspective.

Sequential infiltration synthesis (SIS) is an emerging materials growth method by which inorganic metal oxides are nucleated and grown within the free volume of polymers in association with chemical functional groups in the polymer. SIS enables the growth of novel polymer-inorganic hybrid materials, porous inorganic materials, and spatially templated nanoscale devices of relevance to a host of technological applications. Although SIS borrows from the precursors and equipment of atomic layer deposition (ALD), the chemistry and physics of SIS differ in important ways.