Search results
Results from the WOW.Com Content Network
STM image of a quinacridone adsorbate.The self-assembled supramolecular chains of the organic semiconductor are adsorbed on a graphite surface.. Surface science is the study of physical and chemical phenomena that occur at the interface of two phases, including solid–liquid interfaces, solid–gas interfaces, solid–vacuum interfaces, and liquid–gas interfaces.
Reactions on surfaces are reactions in which at least one of the steps of the reaction mechanism is the adsorption of one or more reactants. The mechanisms for these reactions, and the rate equations are of extreme importance for heterogeneous catalysis.
Langmuir was awarded the Nobel Prize in 1932 for his work concerning surface chemistry. He hypothesized that a given surface has a certain number of equivalent sites to which a species can "stick", either by physisorption or chemisorption. His theory began when he postulated that gaseous molecules do not rebound elastically from a surface, but ...
Initially, at small molecular density on the surface, adsorbate molecules form either a disordered mass of molecules or form an ordered two-dimensional "lying down phase", [7] and at higher molecular coverage, over a period of minutes to hours, begin to form three-dimensional crystalline or semicrystalline structures on the substrate surface. [10]
The water surface is less salty than bulk, so whenever the water's surface area is increased, it is necessary to remove salt molecules from the new surface and push them into bulk. If the concentration of salt is increased a bit (raising the salt's chemical potential ), it becomes harder to push away the salt molecules.
Download QR code; Print/export Download as PDF; Printable version; In other projects Wikimedia Commons; ... Surface chemistry of neural implants; Surface conductivity;
The surface acidity and basicity of the oxide depends on the crystal structure and surface orientation. [20] The surfaces of zirconia have hydroxyl groups, which can act as Brønsted acids or bases, and coordination-unsaturated Zr 4+ O 2− acid base pairs which contribute to its overall acid–base properties. [ 20 ]
Schematic of the electrical double layer (EDL) in aqueous solution at the interface with a negatively-charged surface of a mineral solid. Blue + sphere: cations; red – spheres: anions. The number of cations is larger in the EDL close to the negatively-charged surface in order to neutralize these negative charges and to maintain electroneutrality.