Abstract
Model calculations based on the multiple equilibrium approach indicate that the spontaneous formation of geometrically closed bilayer vesicles is geared primarily by the bilayer tension which in turn is largely determined by the work of bending the bilayer into a spherical vesicle, and a statistical-mechanical factor that accounts for the fluctuations in composition, chain packing density and shape. We demonstrate that the free energy required to form a spherical vesicle is made up of two main contributions: the (size-independent) work of bending the constituent monolayers and the work of stretching the bilayer that is determined by the planar bilayer tension. A previously undiscovered contribution to the work of bending a vesicle bilayer, originating from geometrical packing constraints, is presented. On this basis we obtain vesicle size distributions with maxima located at radii several orders of magnitude larger than where the local free energy minima of the equilibrium vesicle actually occur. Moreover, according to our analysis, the relative width of a vesicle size distribution, σ R/R max, is generally at full equilibrium equal to 0.283, independently of the energetic vesicle parameters. Our calculations of the bending work of mixed SDS/dodecanol bilayers predict vesicles with R max in the range of 0.1–10 μm and for mixed anionic/cationic bilayers we obtain small unilamellar vesicles with R max<1000 Å when one of the surfactants is in excess, in good qualitative agreement with recent experimental findings.
Preview
Unable to display preview. Download preview PDF.
References
Bergström M, Eriksson JC, Langmuir (in press)
Bergström M, Eriksson JC (1996) Langmuir 12:624
Bergström M (1996) Langmuir 12:2454
Tanford C (1980) The Hydrophobic Effect, Chapter 7. Wiley, New York
Mitchell DJ, Ninham BM (1989) Langmuir 5:1121
Gruen DWR, Lacey EHB (1984) In: Mittal K, Lindman B (eds) Surfactants in Solution, Vol. I, Plenum, New York, pp 279
Israelachvili JN, Mitchell DJ, Ninham BW (1976) J Chem Soc, Faraday Trans 2 72:1525
Hargreaves WR, Deamer DW (1978) Biochemistry 17:3759
Kaler EW, Herrington KL, Murthy AK, Zasadzinski JAN, (1992) J Phys Chem 96:6698
Marques E, Khan A, Miguel MG, Lindman B (1993) J Phys Chem 97: 4729
Zhao GX, Yu WL (1995) J Colloid Interface Sci 173:159
Kondo Y, Uchiyama H, Yoshino N, Nishiyama K, Abe M (1995) Langmuir 11:2380
Yaacob II, Bose A (1996) J Colloid Interface Sci 178:38
Author information
Authors and Affiliations
Editor information
Rights and permissions
Copyright information
© 1997 Steinkopff Verlag
About this paper
Cite this paper
Bergström, M. (1997). Reversibly formed bilayer vesicles: energetics and polydispersity. In: Rosenholm, J.B., Lindman, B., Stenius, P. (eds) Trends in Colloid and Interface Science XI. Progress in Colloid & Polymer Science, vol 105. Steinkopff. https://doi.org/10.1007/BFb0110990
Download citation
DOI: https://doi.org/10.1007/BFb0110990
Published:
Publisher Name: Steinkopff
Print ISBN: 978-3-7985-1086-9
Online ISBN: 978-3-7985-1660-1
eBook Packages: Springer Book Archive