Absorption (physical)
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A physical or chemical phenomenon or a process in which atoms, molecules, or ions enter some bulk phase - gas, liquid or solid material. This is a different from Adsorption, since the molecules are taken up by the volume, not by surface.
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Bubble
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A globule of one substance in another, usually gas in a liquid. Due to the Marangoni effect, bubbles may remain intact when they reach the surface of the immersive substance.
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Capillary Action
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(capillarity, capillary motion, wicking) The movement of a liquid relative to a substance in contact. A result of the adhesive intermolecular forces between the liquid and the substance being stronger (or weaker) than the cohesive intermolecular forces inside the liquid. Causes a concave (or concave) meniscus to form where the liquid touches the surface. Can cause raising or lowering (e.g. mercury in glass) of the liquid.
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Chemisorption
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A type of adsorption whereby a molecule adheres to a surface through the formation of a chemical bond, as opposed to the Van der Waals forces which cause physisorption
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Conic Capillary Effect
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A conical capillary tube results in a meniusci having different curvature, This causes the liquid to flow in the direction of of the meniscus having the greater curvature.
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Entrainment
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The movement of one fluid due to the motion of another.
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Fermentation
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In an industrial context, fermentation refers to the breakdown of organic substances and re-assembly into other substances. Somewhat paradoxically, fermenter culture in industrial capacity often refers to highly oxygenated and aerobic growth conditions, whereas fermentation in the biochemical context is a strictly anaerobic process.
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Hydrogenation
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Hydrogenation is the chemical reaction that results from the addition of hydrogen. The process is usually employed to a reduce or saturate organic compounds. The process typically constitutes the addition of pairs of hydrogen atoms to a molecule.
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Osmosis
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A physical process in which a solvent moves, without input of energy, across a semipermeable membrane (permeable to the solvent, but not the solute) separating two solutions of different concentrations.Osmosis releases energy, and can be made to do work.
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Ostwald Ripening
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An observed phenomenon in solid solutions or liquid sols that describes the change of an inhomogeneous structure over time, i.e., small crystals or sol particles dissolve, and redeposit onto larger crystals or sol particles. Occurs because larger particles are more energetically favored than smaller particles. This stems from the fact that molecules on the surface of a particle are energetically less stable than the ones in the interior. Ostwald ripening is also observed in liquid-liquid systems, causing diffusion of monomers (i.e. individual molecules or atoms) from smaller droplets to larger droplets due to greater solubility of the single monomer molecules in the larger monomer droplets.
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Physisorption
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(or physical adsorption) A type of adsorption in which the adsorbate adheres to the surface only through Van der Waals (weak intermolecular) interactions, which are also responsible for the non-ideal behaviour of real gases.
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Porosity
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The quality of being porous - i.e. having voids or spaces within a solid substance within or through which fluids can be present.
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Redox Reactions
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Redox (shorthand for oxidation-reduction) reactions describe all chemical reactions in which atoms have their oxidation number (oxidation state) changed. This can be either a simple redox process, such as the oxidation of carbon to yield carbon dioxide (CO2) or the reduction of carbon by hydrogen to yield methane (CH4), or a complex process such as the oxidation of sugar(C6H12O6) in the human body through a series of complex electron transfer processes.
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Reduction
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A chemical reaction that involves the gain of electrons or a decrease in the oxidation state by a molecule, atom or ion.
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Solvation
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(commonly called dissolution) The process of attraction and association of molecules of a solvent with molecules or ions of a solute. As ions dissolve in a solvent they spread out and become surrounded by solvent molecules. The bigger the ion, the more solvent molecules are able to surround it and the more it becomes solvated.
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Sorption
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The action of both absorption and adsorption taking place simultaneously, i.e. the effect of gases or liquids being incorporated into a material of a different state and adhering to the surface of another molecule. Absorption is the incorporation of a substance in one state into another of a different state (e.g., liquids absorbed by solid or gas absorbed by liquid). Adsorption is the physical adherence or bonding of ions and molecules onto the surface of another molecule.
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Supercritical Fluid
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Any substance at a temperature and pressure above its critical point. It can diffuse through solids like a gas, and dissolve materials like a liquid. Additionally, close to the critical point, small changes in pressure or temperature result in large changes in density, allowing many properties to be 'tuned'.
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Vacuum
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A volume of space that is essentially empty of matter, such that its gaseous pressure is much less than atmospheric pressure. A perfect vacuum would be one with no particles in it at all, which is impossible to achieve in practice. Physicists often discuss ideal test results that would occur in a perfect vacuum, which they simply call 'vacuum' or 'free space', and use the term partial vacuum to refer to real vacuum.
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Wetting
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The ability of a liquid to maintain contact with a solid surface, resulting from intermolecular interactions when the two are brought together. The degree of wetting is determined by a force balance between adhesive and cohesive forces. Adhesive forces between a liquid and solid cause a liquid drop to spread across the surface. Cohesive forces within the liquid cause the drop to ball up and avoid contact with the surface.
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