1,721,030 research outputs found
Water capacity and size data of reverse micelles formed by novel cationic surfactants
Full text linkThis paper contains data of water capacity (in terms of w 0 = molwater/molsurfactant) in reverse micelles formed by several commercial and non-commercial cationic surfactants in cyclopentane, petroleum ether, and iso-octane. Also reported are hydrodynamic diameters of the respective reverse micelles formed. Tested surfactants were (i) single-chained cationics: cetyl benzyl diethanolammonium bromide (CBDB), cetyl benzyl dimethylammonium bromide (CBMB), cetyl dibutyl ethanolammonium bromide (CDBEB), cetyl cyclohexyl dimethylammonium bromide (CCDB); and (ii) twin-chained cationics: didodecyl dimethylammonium chloride (DDMC), didodecyl diethylammonium bromide (DDEB), didodecyl dipropylammonium bromide (DDPB), didodecyl diethylammonium chloride (DDEC), dodecyl benzyl dimethylammonium bromide (DBDMB). Also reported are sizes of reverse micelles as determined by dynamic light scattering
Reazioni dello Ione Idrossido in Soluzioni Micellari Acquose: Ruolo della Struttura del Tensioattivo e del Meccanismo di Reazione
No full textAqueous Association Colloids as Reaction Media: Chemoselectivity and Synthetic Applications
No full textApparatus for preparing and studying clathrate hydrate
No full textA device for clathrate hydrates preparation by means of stirring of an aqueous solution in presence of gas, involve a motionless reactor (1), gas loading and pressure control media (2), temperature control and regulation media (3), liquid supply media (4) in constant pressure, solutes concentration detecting media (5), visual monitoring media (6), data acquisition and control media (7) and stirring media, preferentially magnetic, (10, 12) of the solution present in the reactor (1)
Effect of conditioners upon the thermodynamics and kinetics of methane hydrate formation. A preliminary structure-properties relationship study
No full textThe synthesis and stability of gas hydrates was found to be heavily affected by the presence of small quantities of additives, or conditioners, particularly surfactants. In a recent work, we showed that the enhancement of hydrate formation, both from previously described and newly synthesized surfactants, is probably due to surfactant monomers, rather than micelles, and that the features of hydrate induction time should not be used as a measure of critical micelle concentration. In the present paper, we discuss the results of a structure-properties relationship study in which a preliminary attempt to relate the structural features of several amphiphilic additives to some kinetic and thermodynamic parameters of methane hydrate formation - e.g., induction times, rate of formation, occupancy, etc. - is conducted. According to the present study, it is found that, for a particular conditioner, a reduction of induction time does not correlate to an increase of the formation rate and occupancy, and vice versa. This may be related to the nature of chemical moieties forming a particular amphiphile (e.g., the hydrophobic tail, head group, counterion, etc.). The understanding of the mechanisms by which those moieties play their differential role may be the key tool to the design and synthesis of tailored conditioners
Method for the production of binary clathrate hydrates of hydrogen
No full textA method for the effective production of binary clathrate hydrates of hydrogen and a co-former is provided, said method comprising the formation of water-in-oil nanoemulsions, such as, e.g., surfactant reverse micelles in an organic solvent, and the formation of clathrate hydrate nanocrystals from the water droplets thus obtained
Reazioni dello Ione Idrossido in Soluzioni Micellari Acquose: Effetto delle Dimensioni del Gruppo di Testa
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