Surfactants vesicles

Baillie, A.J. et al.. The preparation and properties of niosomes-non-ionic surfactant vesicles, J. Pharm. Pharmacol., 37, 863, 1985. 

An extraordinary way of stabilizing RUO2-coated CdS colloids for H2 generation was chosen by Fendler and co-workers The colloidal particles were generated in situ in surfactant vesicles of dioctadecyldimethylammonium chloride and dihexa-decyl phosphate. Thiophenol as a membrane permeable electron donor acted as a sacrificial additive. Later, a surface active re-usable electron donor (n-C,gH3,)2N — (CHj)—CH2—CHj—SH, Br was incorporated into the vesicles. Its R—SS—R oxidation product could be chemically reduced by NaBH to regenerate the active electron donor. The H2 yields in these systems were only 0.5 %. However, yields up to 10% were later reported for a system in which CdS was incorporated into a polymerizable styrene moiety, (n-C,jH3jC02(CH2)2) N (CH3) (CH2CgH4CH=CH2>, CP, and benzyl alcohol was used as the electron donor. 

T. E Yen, J. K. Park, K. I. Lee, and Y. Li. Fate of surfactant vesicles surviving from thermophilic, halotolerant, spore forming, Clostridium thermohydrosulfuricum. In E. C. Donaldson, editor. Microbial enhancement of oil recovery recent advances Proceedings of the 1990 International Conference on Microbial Enhancement of Oil Recovery,... 

Mention should also be made in this section of niosomes, which are nonionic surfactant vesicles that have shown promise as inexpensive and chemically stable alternatives to liposomes [67]. 

Microscopic Studies of Surfactant Vesicles Formed During Tar Sand Recovery... 

With free radical initiator added (e.g., H202), the reaction takes minutes to complete. Based on the surfactant vesicles characterization derived from current investigations, it is suggested that these surfactants could retain their effectiveness necessary for bitumen recovery in the reservoir environment for a number of years. 

In order to determine whether these surfactant vesicles were of polymerized vesicle forms, a 25% V/V ethanol (standard grade) was added to the three year old sample solution. Alcohols are known (34) to destroy surfactant vesicles derived from natural phospholipids, however, synthetically prepared polymerized vesicles are stable in as much as 25% (V/V) alcohol addition. Photomicrographs shown in Figures 7c and 7d indicate that these vesicles partially retain their stability (being mesomorphic) and therefore are suspected to be polymerized surfactants. Whether surfactant molecules of these vesicles are single or multipla bonds in tail, or in head groups remains to be seen. 

Figure 5. Coalescence phenomena a few hours after completion of the processing [(a) transmittance and (b) reflectance]. Multilamellar surfactant vesicle development phenomena twelve hours after the completion of the processing [(c) transmittance and (d) reflectance].

Figure 6. MultilameUar surfactant vesicles four months following the processing [(a) transmittance and (b) reflectance].

Lukac S (1984) Thermally induced variations in polarity and microviscosity of phospholipid and surfactant vesicles monitored with a probe forming an intramolecular charge-transfer complex. J Am Chem Soc 106 4386 -392... 

Tricot, Y.-M. and Fendler, J.H., Colloidal catalyst-coated semiconductors in surfactant vesicles In situ generation of Rh-coated CdS particles in dihexadecylphosphate vesicles and their utilization for photosensitized charge separation and hydrogen generation, /. Am. Chem. Soc., 106, 7359,1984. 

Pt-catalysed reduction of methylene blue and 10-methyl-5-deazoisoalloxazine -3-propanesulfonic acid Polymerized surfactant vesicles. Catalytic efficiencies high in these systems Kurihara and Fendler, 1983... 

Regarding other pseudostationary phases for measurement of lipophilicity or lipophilicity-related properties (e.g., intestinal absorption, brain penetration), there are several reports on the use of vesicles such as phospholipid bilayer liposome (56-58), lysophospholipid micelle (59), DTAB/SDS vesicle (60), and double-chain synthetic surfactant vesicle (61), which are described in other chapters. 

Electrokinetic chromatography (EKC) using microemulsion is one of the most powerful tools for the rapid measurement of log P w with high reproducibility. Because it is relatively easy to manipulate the pseudostationary phases of EKC, a lot of phases have been reported for the measurement not only of physicochemical properties but also of the separation selectivity, such as polymer micelles (64) and double-chain surfactant vesicles (56-58,60,61). These phases are also interesting in terms of the correlation to bioactivity. 

Uncoated fused-silica capillaries have similarly been applied to elec-trokinetic chromatography (EKC) analysis of solute interactions with both liposomes (33,34) and surfactant vesicles (59,60). 

Chromatography of Drugs with Liposomes or Surfactant Vesicles as Interacting Phase... 

Tricot YM, Emeren A, Fendler JH (1985) In situ Generation of catalyst-coated CdS particles in polymerized and unpolymerized surfactant vesicles and their utilization for efficient visible-light-induced hydrogen-production. J Phys Chem 89 4721-4726... 

Yu WL, Pei J, Huang W, Zhao GX (1997) Formation of CdS nanoparticles in mixed cationic-anionic surfactant vesicle system. Mater Chem Phys 49 87-92... 

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