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A Langmuir monolayer or insoluble monolayer is a one-molecule thick layer of an insoluble organic material spread onto an aqueous subphase in a Langmuir-Blodgett trough. Traditional compounds used to prepare Langmuir monolayers are amphiphilic materials that possess a hydrophilic headgroup and a hydrophobic tail.
The idea of a Langmuir–Blodgett (LB) film was first proven feasible in 1917 when Irving Langmuir (Langmuir, 1917) showed that single water-surface monolayers could be transferred to solid substrates. 18 years later, Katharine Blodgett made an important scientific advance when she discovered that several of these single monolayer films could be stacked on top of one another to make multilayer ...
The following chart shows the solubility of various ionic compounds in water at 1 atm pressure and room temperature (approx. 25 °C, 298.15 K). "Soluble" means the ionic compound doesn't precipitate, while "slightly soluble" and "insoluble" mean that a solid will precipitate; "slightly soluble" compounds like calcium sulfate may require heat to precipitate.
[1] [2] In some cases, molecules that form the monolayer do not interact strongly with the substrate. This is the case for porphyrins on HOPG [3] and two-dimensional supramolecular networks [4] of PTCDA on gold [5]. In other cases, the head group has a strong affinity for the substrate and anchors the molecule. [6]
(a) Structure of a hexagonal TMD monolayer. M atoms are in black and X atoms are in yellow. (b) A hexagonal TMD monolayer seen from above. Transition-metal dichalcogenide (TMD or TMDC) monolayers are atomically thin semiconductors of the type MX 2, with M a transition-metal atom (Mo, W, etc.) and X a chalcogen atom (S, Se, or Te).
In polymer science, dispersion polymerization is a heterogeneous polymerization process carried out in the presence of a polymeric stabilizer in the reaction medium. . Dispersion polymerization is a type of precipitation polymerization, meaning the solvent selected as the reaction medium is a good solvent for the monomer and the initiator, but is a non-solvent for the po
Boiling tea leaves in water extracts the tannins, theobromine, and caffeine out of the leaves and into the water, as an example of a solid-liquid extraction. Decaffeination of tea and coffee is also an example of an extraction, where the caffeine molecules are removed from the tea leaves or coffee beans, often utilising supercritical fluid ...
By controlling the temperature and the pressure, the system can be brought to any point on the phase diagram. From a point in the solid stability region (left side of the diagram), increasing the temperature of the system would bring it into the region where a liquid or a gas is the equilibrium phase (depending on the pressure).