Real-time analysis of MOF adsorption behavior

Researchers have developed a technology to analyze the adsorption behavior of molecules in each individual pore of a metal organic framework (MOF). This system has large specific surface areas, allowing for the real-time ...

Highly resorptive metal-organic frameworks

Gases and pollutants can be filtered from air and liquids by means of porous, crystalline materials, such as metal–organic frameworks (MOFs). To further partition these pores and enhance their sorption capacity, a team ...

The subtle role of surfaces in ion stickiness

How ions stick to surfaces greatly influences vital processes in everything from water purifiers to batteries. For decades, scientists have debated the mechanics of such binding, or adsorption. Certain ions in water didn't ...

Preventing concrete bridges from falling apart

Extremes of temperature, rain, exposure to corrosive substances—all of these environmental factors contribute to the degradation of concrete. Specifically, a gas present in our environment, called hydrogen sulphide, turns ...

Better chemo drug adsorption onto targeted delivery capsules

The efficacy of chemotherapy treatment depends on how effectively it reaches cancerous cells. Increasing targeted delivery could mean decreasing side effects. Scientists are enhancing methods of selectively transmitting active ...

Soaking up the water and the sweat—a new super desiccant

UNSW scientists have developed a new carbon-based material that could revolutionise moisture control in applications as diverse as electronics, packaging, air conditioning – and keeping footwear fresh.

Naked-eye detection of solvent vapor

Sensors are important for detecting contaminants and monitoring environmental conditions. Fluorescent sensors can reveal the presence of a contaminant according to the change of the intensity and/or wavelength of light that ...

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Adsorption

Adsorption is the adhesion of atoms, ions, biomolecules or molecules of gas, liquid, or dissolved solids to a surface. This process creates a film of the adsorbate (the molecules or atoms being accumulated) on the surface of the adsorbent. It differs from absorption, in which a fluid permeates or is dissolved by a liquid or solid. The term sorption encompasses both processes, while desorption is the reverse of adsorption. It is a surface phenomenon.

Similar to surface tension, adsorption is a consequence of surface energy. In a bulk material, all the bonding requirements (be they ionic, covalent, or metallic) of the constituent atoms of the material are filled by other atoms in the material. However, atoms on the surface of the adsorbent are not wholly surrounded by other adsorbent atoms and therefore can attract adsorbates. The exact nature of the bonding depends on the details of the species involved, but the adsorption process is generally classified as physisorption (characteristic of weak van der Waals forces) or chemisorption (characteristic of covalent bonding). It may also occur due to electrostatic attraction.

Adsorption is present in many natural physical, biological, and chemical systems, and is widely used in industrial applications such as activated charcoal, capturing and using waste heat to provide cold water for air conditioning and other process requirements (adsorption chillers), synthetic resins, increase storage capacity of carbide-derived carbons for tunable nanoporous carbon, and water purification. Adsorption, ion exchange, and chromatography are sorption processes in which certain adsorbates are selectively transferred from the fluid phase to the surface of insoluble, rigid particles suspended in a vessel or packed in a column. Lesser known, are the pharmaceutical industry applications as a means to prolong neurological exposure to specific drugs or parts thereof.

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