21948-96-9Relevant academic research and scientific papers
Salt effects on the aqueous two-phase system of Gemini(12-3-12, 2Br -)/SDS/PEG
Al-Hakimi, Abdulaziz Mohammed,Shang, Yazhuo,Liu, Honglai,Hu, Ying
, p. 1307 - 1313 (2009)
The effect of added salts (NaCl, KCl and NaBr) on the aqueous two-phase system (ATPS) formed in mixtures of Gemini(12-3-12, 2Br-)/sodium dodecyl sulfate/polyethylene glycol has been investigated. Phase diagrams of the aqueous systems containing Gemini(12-3-12, 2Br-), sodium dodecyl sulfate (SDS), polyethylene glycol(PEG) and a salt have been determined experimentally at 313.15 K. The results indicate that the addition of salts not only induces the appearance of ATPS-A (in which anionic surfactant is in excess), shortens the phase separation time, enlarges the regions of ATPS-C (in which cationic surfactant is in excess), and decreases the minimum concentration required for forming an ATPS, but also alters the matching between anionic and cationic surfactants. Extractive experiments also showed that these salts notably enhance the extraction ability of ATPS; the Gemini-rich phase exhibits prominent cohesive action with xylenol orange, regardless of whether or not it is the upper phase or the lower phase.
Polycations. 19. The synthesis of symmetrical dicationic lipids with internal dimethylazonia functionalities separated by a spacer unit and pendant chains
Engel, Robert,Rizzo, JaimeLee Iolani,Montenegro, Diego,Leb, Jay,Coleman, Delroy,Hong, Carolyn,Jeanty, Herby,Thomas, Marie
, p. 105 - 108 (2009)
Herein is reported the preparation of several series of symmetrical polyammonium salts that serve as cationic lipids or precursors thereof, and are structurally based on several series of parent diamines where dimethylazonia functionalities are present, separated by a central structural unit, and pendant terminal chains. The resultant materials are of significant interest for a variety of purposes, such as serving as antihydrophobic species and as transfectins, the details of which are provided in separate reports. Attempts to effect selective alkylation to provide the corresponding unsymmetrical cationic lipids were without success, always leading to relatively useless mixtures of products.
First evaluation of the thermodynamic properties for spheres to elongated micelles transition of some propanediyl-α,ω-bis(dimethylalkylammonium bromide) surfactants in aqueous solution
Fisicaro, Emilia,Compari, Carlotta,Duce, Elenia,Contestabili, Cristina,Viscardi, Guido,Quagliotto, Pieriuigi
, p. 1744 - 1749 (2005)
The apparent and partial molar enthalpies, apparent molar volumes, and adiabatic compressibilities at 298 K of the aqueous solutions of the cationic gemini surfactants propanediyl-α,ω-bis(octyldimethylammonium bromide) (8-3-8) and propanediyl-α,ω-bis(dodecyldimethylammonium bromide) (12-3-12) have been measured as a function of concentration. The trends of the partial molar enthalpies versus concentration are the first well documented thermodynamic evidence of sphere to rod transition in the micellar phase, involving a detectable quantity of heat, and allow the determination of the change in enthalpy associated with this transition. The changes in enthalpies upon micellization and for the sphere to elongated micelles transition, ΔHs-r have been obtained from the experimental data by using a pseudo-phase transition approach: -1.5 kJ mol-1 for 8-3-8 and -3.9 kJ mol-1 for 12-3-12. No evidence of the above transition is found in the trends of volumetric properties versus m. The apparent adiabatic molar compressibilities for the compounds under investigation are also reported here for the first time: a negative group contribution for the methylene group is evaluated, when the surfactants are present in solution as a single molecule, reflecting its solvation structure. In the micellar phase, the -CH2- group contribution becomes positive. A value of 1.17 × 10-3 cm3 bar-1 mol-1 for the change in adiabatic molar compressibility upon micellization is obtained. The lower values of the methylene group contributions to the volumetric properties for the monomers support the hypothesis of partial association of the chains before the cmc.
Retarding action of poly(amidoamine) dendrimers and cationic gemini surfactants in acrylic dyeing
Sadeghi-Kiakhani, Mousa,Tehrani-Bagha, Ali Reza
, p. 323 - 330 (2015/11/24)
Two cationic gemini surfactants and two generations of poly(amidoamine) (PAMAM) dendrimers (G = -0.5 and G = 0.5) were studied as retarders in acrylic dyeing with a cationic dye. Effects of retarder concentrations, dyeing time, and temperature were investigated by means of UV-Vis spectrophotometry. The results indicated that the dye adsorption decreased in the presence of the species and more uniform dyeing was achieved. The PAMAM dendrimers had lower retarding action than the cationic gemini surfactants which was attributed to their non-permanent and lower cationic charge density. Kinetics of the dyeing systems were also evaluated by four different empirical models. The modified Cegarra-Puente model fitted the dyeing kinetic data somewhat better than the other empirical kinetic models. Moreover, the activation energy of the dyeing systems was calculated and reported.
Gemini surfactants foam formation ability and foam stability depends on spacer length
Kuliszewska, Edyta,Brecker, Lothar
, p. 951 - 957 (2014/11/08)
A series of cationic gemini surfactants containing different spacer length were synthesized and analyzed structurally. It was shown that the surface tension (σ) and critical micelle concentration (CMC), which had a maximum for the n-C4H8 spacer depended on the spacer length. The foaming ability and foam stability are high for the gemini surfactants with short spacers (C2H4 to n-C4H8), while longer spacers lead to a distinct decrease of these foam parameters. Foaming properties are discussed in terms of configuration and conformation of a surfactant molecule and in relation to micellization state kinetic.
Designing pH-sensitive gemini nanoparticles for non-viral gene delivery into keratinocytes
Donkuru, McDonald,Wettig, Shawn D.,Verrall, Ronald E.,Badea, Ildiko,Foldvari, Marianna
experimental part, p. 6232 - 6244 (2012/06/30)
This study aimed to develop a more effective non-viral gene delivery system for keratinocyte transfection. To this end, gemini nanoparticles were formulated from plasmid DNA, the lipid DOPE (dioleoylphosphatidylethanolamine) and surfactants, where the sur
Synthesis, molecular structure, spectral properties and antifungal activity of polymethylene-α,ω-bis(n,n-dimethyl-n-dodecyloammonium bromides)
Brycki, Bogumil,Kowalczyk, Iwona,Kozirog, Anna
experimental part, p. 319 - 335 (2011/04/18)
Hexamethylene-1,6-bis-(N,N-dimethyl-N-dodecylammonium bromide) (1), pentamethylene-1,5-bis(N,N-dimethyl-N-dodecylammonium bromide) (2), tetramethylene-1,4-bis(N,N-dimethyl-N-dodecylammonium bromide) (3), trimethylene-1,3-bis(N,N-dimethyl-N-dodecylammonium bromide) (4) and ethylene-1,2-bis(N,N-dimethyl-N-dodecylammonium bromide) (5) have been obtained and characterized by FTIR and NMR spectroscopy. DFT calculations have also been carried out. The optimized bond lengths, bond angles and torsion angles calculated by Hartree-Fock/3-21G(d,p) approach have been presented. MIC values for A. niger, P. chrysogenum, C. albicans have been determined and the relationship between MIC and spacer length has been discussed.
Long chain dicationic phase transfer catalysts in the condensation reactions of aromatic aldehydes in water under ultrasonic effect
Esen, Ilker,Yolacan, Cigdem,Aydogan, Feray
experimental part, p. 2289 - 2292 (2010/11/05)
Long chain dicationic ammonium salts were used successfully as phase transfer catalyst in the condensation reactions of aromatic aldehydes in water under ultrasonic irradiation for the first time. The quaternary salt having longer distance between the cation centers was more effective than the mono- and dicationic ones having short chain.
Specific ion pairing and interfacial hydration as controlling factors in gemini micelle morphology. Chemical trapping studies
Geng, Yan,Romsted, Laurence S.,Menger, Fred
, p. 492 - 501 (2007/10/03)
Results from chemical trapping experiments in micellar solutions containing 1.5-5 mM aqueous solutions of three didodecyl dicationic dibromide gemini surfactants with different methylene spacer lengths (12-n-12 2Br where n = 2-4 CH2 groups) gav
