Five 1-O-methyl-4,6-O-ben- zylidene derivatives of the monosac- charides d-glucose, d-galactose, and d- mannose were synthesized. The b-iso- mer of the d-glucose derivative was sparingly soluble in most organic sol- vents, whereas the a-isomer of the d- mannose derivative was soluble in many organic solvents. The a-isomer of the d- glucose derivative and the a- and b- isomers of the d-galactose derivative acted as versatile gelators of various organic solvents ; this indicates that sac- charides are useful as potential tem- plates for the molecular design of chiral gelators.
Some methyl 4,6-O-benzylidene monosaccharides can act as strong low molecular weight gelators for various organic solvents. As they are accessible in a variety of homologues, each with a unique molecular architecture, they can be used for systematic studies of gelation phenomena. Structural details of their hydrogen-bond-based fiber network in the gel phase can be resolved by small angle X-ray scattering (SAXS).
Polymers are a widespread class of materials that provide an often advantageous combination of properties. Easy processability and high versatility combined with low costs make polymers the materials for an increasing number of high-tech and commodity applications. Semi-crystalline polyolefins are an important class of polymers, produced in more than 150 million metric tons per year. They are used to make a wide range of products ranging from fibers with superior mechanical properties to flexible packaging and molded parts.
Gelation tests of rod like liquid crystals (LCs), columnar LCs, and cholesteric LCs rod-like have been employed. 4-Cyanophenyl 4-n-alkoxybenzoates, 4-cyano-4’-alkoxybiphenyls, 4,4’-dialkanoyloxybiphenyls, azoxybenzene derivatives, 2,3,6,7,10,11-hexaalkoxytriphenylenes, and cholesteryl esters, except for cholesteryl alkyl carbonates and cholesteryl esters with alkenyl side chain, gelled organic liquids. By using these LCs as organogelator, terpene and perfume gels containing 95% or more of terpenes and essential oil could be prepared.
Graphene oxide (GO) has been recognized as a unique two-dimensional building block for various graphene-based supramolecular architectures. In this article, we systematically studied the three-dimensional self-assembly of GO sheets in aqueous media to form hydrogels. The gelation of GO can be promoted by different supramolecular interactions, including hydrogen bonding, π-stacking, electrostatic interaction, and coordination. Furthermore, the lateral dimensions of GO sheets also have strong influences on GO gelation.
Bei Verwerdung von Gel-bildnden Kondensationsprodukten von Aldehyden bzw. Ketonen mit Polyolen in Cyanacrylaten erhält man frombeständige Klibstoffe, Beschichtungs- und Dichtungsmassen. Sie sind lagerstabil und eignen sich vor allem zum Verkleben von porösen Substraten wie Papier oder Holz. Die Handhabung ist besonders einfach, wenn man abreibbare Klebestifte formt.
Rapid and isothermal (at room temperature) uptake of CO2 by solutions or, in some cases, organogels comprised of a primary or secondary aliphatic amine (1) and an organic liquid leads to in situ chemical transformation to the corresponding alkylammonium alkylcarbamate (2) based gels. Chemical reversibility is demonstrated by removal of CO2 from 2-based gels upon gentle heating in the presence of nitrogen. This is a general strategy for reversible self-assembly or disassembly of molecular aggregates relying on the initiation or termination of ionic interactions.
Fifteen different low molar mass compounds are assessed as CO2 solvents based on bubble-point loci on the solvent-rich end (0.6 to 1.0 solvent wt fraction) of the CO2-solvent pressure−composition diagram at 298.15 K. Four of the five best solvents (in descending order of solvent strength on a mass fraction CO2 dissolved basis), acetone, methyl acetate, 1,4-dioxane, and 2-methoxyethyl acetate, are oxygen-rich, low molar mass species possessing one or more oxygen atoms in carbonyl, ether, and/or acetate groups that can interact favorably with CO2 via Lewis acid/Lewis base interactions.
