Effect of the alkyl chain and composition on the thermodynamics of mixing of small alcohols and water

2021 ◽  
pp. 116777
Author(s):  
Abdenacer Idrissi ◽  
Pál Jedlovszky
Author(s):  
Brigid R. Heywood ◽  
S. Champ

Recent work on the crystallisation of inorganic crystals under compressed monomolecular surfactant films has shown that two dimensional templates can be used to promote the oriented nucleation of solids. When a suitable long alkyl chain surfactant is cast on the crystallisation media a monodispersied population of crystals forms exclusively at the monolayer/solution interface. Each crystal is aligned with a specific crystallographic axis perpendicular to the plane of the monolayer suggesting that nucleation is facilitated by recognition events between the nascent inorganic solid and the organic template.For example, monolayers of the long alkyl chain surfactant, stearic acid will promote the oriented nucleation of the calcium carbonate polymorph, calcite, on the (100) face, whereas compressed monolayers of n-eicosyl sulphate will induce calcite nucleation on the (001) face, (Figure 1 & 2). An extensive program of research has confirmed the general principle that molecular recognition events at the interface (including electrostatic interactions, geometric homology, stereochemical complementarity) can be used to promote the crystal engineering process.


2015 ◽  
Vol E98.C (2) ◽  
pp. 127-128 ◽  
Author(s):  
Asami OHTAKE ◽  
Seiko UCHINO ◽  
Kunio AKEDO ◽  
Masanao ERA ◽  
Koichi SAKAGUCHI

1991 ◽  
Vol 56 (4) ◽  
pp. 736-744 ◽  
Author(s):  
Ondřej Drábek ◽  
Ivan Cibulka

Excess molar volumes of binary liquid mixtures of (acetic or propionic acid = hexane) at 25 and 35°C, and (acetic or propionic acid + heptane or octane) and (acetic acid + dodecane) at 25°C, measured with a tilting dilution dilatometer, are reported. The excess volumes are positive over the entire concentration range for all mixtures and increase with increasing length of an alkane molecule, decrease with increasing of the alkyl chain in a molecule of carboxylic acid, and increase with increasing temperature.


2004 ◽  
Vol 69 (6) ◽  
pp. 1292-1300 ◽  
Author(s):  
Tahahiro Tani ◽  
Kazuki Sada ◽  
Masatsugu Ayabe ◽  
Yuya Iwashita ◽  
Takanori Kishida ◽  
...  

Crystal structure of hexylammonium anthracene-9-carboxylate was investigated. The salt was arranged by a one-dimensional hydrogen bond network to form a columnar structure in the crystalline state. This columnar structure should be the model of fibrous assemblies in the organogels of anthracene-9-carboxylate alkylammonium salts having a long alkyl chain.


2012 ◽  
Vol 68 (4) ◽  
pp. o152-o155 ◽  
Author(s):  
Malcolm A. Kelland ◽  
Amber L. Thompson

Tetraisohexylammonium bromide [systematic name: tetrakis(4-methylpentyl)azanium bromide], C24H52N+·Br−, is a powerful structure II clathrate hydrate crystal-growth inhibitor. The crystal structure, in the space groupP3221, contains one ammonium cation and one bromide anion in the asymmetric unit, both on general positions. At 100 K, the ammonium cation exhibits one ordered isohexyl chain and three disordered isohexyl chains. At 250 K, all four isohexyl chains are disordered. In an effort to reduce the disorder in the alkyl chains, the crystal was thermally cycled, but the disorder remained, indicating that it is dynamic in nature.


2021 ◽  
pp. 129768
Author(s):  
Dou Luo ◽  
Xue Lai ◽  
Nan Zheng ◽  
Chenghao Duan ◽  
Zhaojin Wang ◽  
...  

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1883
Author(s):  
Martin Pisárčik ◽  
Miloš Lukáč ◽  
Josef Jampílek ◽  
František Bilka ◽  
Andrea Bilková ◽  
...  

Phosphorus-containing heterocyclic cationic surfactants alkyldimethylphenylphospholium bromides with the alkyl chain length 14 to 18 carbon atoms were used for the stabilization of silver nanodispersions. Zeta potential of silver nanodispersions ranges from +35 to +70 mV, which indicates the formation of stable silver nanoparticles (AgNPs). Long-chain heptadecyl and octadecyl homologs of the surfactants series provided the most intensive stabilizing effect to AgNPs, resulting in high positive zeta potential values and smaller diameter of AgNPs in the range 50–60 nm. A comparison with non-heterocyclic alkyltrimethylphosphonium surfactants of the same alkyl chain length showed better stability and more positive zeta potential values for silver nanodispersions stabilized with heterocyclic phospholium surfactants. Investigations of biological activity of phospholium-capped AgNPs are represented by the studies of antimicrobial activity and cytotoxicity. While cytotoxicity results revealed an increased level of HepG2 cell growth inhibition as compared with the cytotoxicity level of silver-free surfactant solutions, no enhanced antimicrobial action of phospholium-capped AgNPs against microbial pathogens was observed. The comparison of cytotoxicity of AgNPs stabilized with various non-heterocyclic ammonium and phosphonium surfactants shows that AgNPs capped with heterocyclic alkyldimethylphenylphospholium and non-heterocyclic triphenyl-substituted phosphonium surfactants have the highest cytotoxicity among silver nanodispersions stabilized by the series of ammonium and phosphonium surfactants.


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