Search results for "Self-Assembly"
showing 10 items of 438 documents
Fluorescent Nanowires Self-Assembled through Host-Guest Interactions in Modified Calcein
2011
Inside Cover: Fluorescent Nanowires Self-Assembled through Host-Guest Interactions in Modified Calcein (Angew. Chem. Int. Ed. 32/2011)
2011
Molecular Self-Assembly Versus Surface Restructuring During Calcite Dissolution.
2016
Organic additives are known to alter the mineral-water interface in various ways. On the one hand, organic molecules can self assemble into ordered structures wetting the surface. On the other hand, their presence can affect the interfacial morphology, referred to as surface restructuring. Here, we investigate the impact, of a class of calcium-complexing azo dyes on the dissolution of calcite (10.4) using high-resolution atomic force microscopy operated in aqueous solution, with a focus on the two constitutional isomers Eriochrome Black T and Eriochrome Black A. A very pronounced surface restructuring is observed in the presence of the dye solution, irrespective of the specific dye used and…
Where Is the Most Hydrophobic Region? Benzopurpurine Self-Assembly at the Calcite–Water Interface
2017
Control of molecular self-assembly at solid–liquid interfaces is challenging due to the complex interplay between molecule–molecule, molecule–surface, molecule–solvent, surface–solvent, and solvent–solvent interactions. Here, we use in-situ dynamic atomic force microscopy to study the self-assembly of Benzopurpurine 4B into oblong islands with a highly ordered inner structure yet incommensurate with the underlying calcite (10.4) surface. Molecular dynamics and free energy calculations provide insights by showing that Benzopurpurine 4B molecules do not anchor to the surface directly but instead assemble on top of the second hydration layer. This seemingly peculiar behavior was then rationali…
Mercaptophenol-Protected Gold Colloids as Nuclei for the Crystallization of Inorganic Minerals: Templated Crystallization on Curved Surfaces
1999
The self-assembly of monolayers of thiols on gold(111) surfaces yields substrates that are able to template in a controlled manner, the nucleation and growth of crystals of calcium carbonate from solution. In the absence of additives, various factors such as the nature of the thiol, the temperature, and the pH are now established as influencing the nature and relative amounts of the different CaCO3 phases (calcite, vaterite, and aragonite). Recently, we have been able to extend the use of thiol/gold self-assembled monolayers as templates for the growth of inorganic crystals by utilizing protected gold colloids instead of flat gold surfaces. The thiol monolayers that protect the colloids pro…
Cation binding resorcinarene bis-crowns: the effect of lower rim alkyl chain length on crystal packing and solid lipid nanoparticles
2012
A group of seven resorcinarene bis-crown ethers (CNBC5) with two polyether bridges at the upper rim and either propyl, butyl, pentyl, heptyl, nonyl, decyl or undecyl groups at the lower rim were synthesized and their binding properties with Cs+ were investigated by NMR titration. The bis-crowns form 1:2 complexes with Cs+ with binding constants of logK 4–5. Crystal structures of bis-crowns and their Cs+ and K+ complexes were studied and different packing motifs were found depending on the alkyl chain length. Short ethyl, propyl and butyl alkyl chains gave a layer or pillar packing where the polar and non-polar regions cannot be distinguished, whereas longer pentyl and decyl chains formed bi…
Switchable assembly of stable, ordered molecular layers
1999
Bisamidines can be assembled on self-assembled monolayers of mercaptoalkanoic acids on gold to form stable and ordered but pH-switchable layers (see diagram). At basic pH the layers are stable and charge selective towards charged surfactants and plasma proteins. The system can potentially be used to reversibly introduce new surface properties for given applications that use one single substrate.
Self-assembly in surfactant-based liquid mixtures: Bis(2-ethylhexyl)phosphoric acid/bis(2-ethylhexyl)amine systems
2010
Surfactant-based liquid mixtures constitute an interesting class of nanostructured materials with promising potential in specialized applications. Here, structural and conductometric properties of liquid mixtures composed of bis(2-ethylhexyl)amine (BEEA) and bis(2-ethylhexyl)phosphoric acid (HDEHP) have been thoroughly investigated with the aim to correlate structural features with system charge transport capability. The evolution of self-assembled local nanostructures with system composition has been investigated by FT-IR and XRD while the conductometric properties were probed by conventional AC complex impedance. Both pure components exhibit nano-segregation due to their amphiphilic natur…
ChemInform Abstract: Calixarenes in Self-Assembly Phenomena
2000
A Halogen-Bonded Dimeric Resorcinarene Capsule.
2015
Iodine (I2) acts as a bifunctional halogen-bond donor connecting two macrocyclic molecules of the bowl-shaped halogen-bond acceptor, N-cyclohexyl ammonium resorcinarene chloride 1, to form the dimeric capsule [(1,4-dioxane)3@1(2)(I2)2]. The dimeric capsule is constructed solely through halogen bonds and has a single cavity (V=511 Å(3)) large enough to encapsulate three 1,4-dioxane guest molecules.