Cationic bolaamphiphiles

Covesicles of the cationic nitrobenzoate 6 and DODAC, or corresponding DPP-analogues, e.g. 7, are hydrolysed at pH 8. Nitrophenolate absorption appears at 400 nm. The outer benzoate esters at the outer vesicle surface are hydrolysed within minutes and the same head groups on the inner surface survive for 1-15 hours (Figure 4.9). Detailed kinetics of flip-flop dynamics and OH permeation have been evaluated in these systems. Monolayer lipid membranes made of macrocyclic bolaamphiphiles showed enhanced dynamic stability. ... 

Figure 4.27 Long-chain bolaamphiphiles with an electroneutral and a cationic head group form membranes around anionic polymers (here DMA) and colloids. Synkinesis of organic-inorganic composite materials in bulk aqueous media can thus be achieved. ...

The anthraquinone-based bolaphile 7 or 8 could not form homogeneous membranes due to steric interactions (Scheme 3) however, they could be integrated into host membranes formed by dihexadecylphosphate and dime-thyldioctadecylammonium bromide. The bolaamphiphile fixed the quinone functionality in the center of the membrane and served as a model for pool quinones. [20] Electron transfer was further demonstrated by light-induced charge transfer between cationic porphyrins dissolved in water and membrane-bound anthraquinone bolaphiles. [27]... 

Figure 2.5.15 Organic polyelectrolytes (e.g., DNA) and inorganic colloids with negative surface charges are efficiently coated by cationic-neutral bolaamphiphiles. The neutralized colloid with the soft membrane surface does not precipitate and dissolves organic compounds on the surface.

Surfactants, Renewable resources. Carbohydrates, Polyols, Oils, Fats, Cationic emulsifiers, Gemini, Bolaamphiphiles synthesis. Surface propraties. Applications... 

Figure 15 Possible mechanism for adsorption (a) of bolaform cationic amphiphiles in mixed systems and (b) of single flexible bolaform cationic amphiphiles systems on glass. (Reprinted from J. Coll. Int. Sci. 337, Yun Yan, Ting Lu, Jianbin Huang Recent advances in the mixed systems of bolaamphiphiles and oppositely charged conventional snrfactants, 1, 2009 with permission from Elsevier.)...

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