Abstract
We present a modification of the conventional dynamic light scattering set-up which allows to monitor the intensity fluctuations of many independent spatial Fourier components of the density fluctuations, i.e. “speckles”, simultaneously by using a charge-coupled device (CCD) camera as area detector. By averaging over the intensity autocorrelation function the final 10–20% decay of the intermediate scattering function in very dense colloidal dispersions is obtained with much higher accuracy. At the same time this multi-speckle autocorrelation spectroscopy provides an alternative route for constructing ensemble-averaged intermediate scattering functions in nonergodic media by replacing the average over many independent sample volumes by an average over independent spatial Fourier components of the density fluctuations. We will survey the methods proposed so far to generate ensemble averages in nonergodic media and discuss their merits and limits. We then demonstrate the advantages of the new technique, taking as an example a colloidal dispersion where in the glassy state long-lived density fluctuations superimpose on the frozen ones. Finally, we make a direct comparison with another “speckle-averaging” technique, the “interleaved sampling” method, which has been proposed and applied to the same system recently [J. Müller, T. Palberg, Progr. Coll. Polym. Sci. (1996) 100:121–126].
Preview
Unable to display preview. Download preview PDF.
References
Berne BJ, Pecora R (1976) Dynamic Light Scattering. Wiley, New York
Chu B (1991) Laser Light Scattering. Basic Principles and Practice. Academic Press, New York
Schmitz KS (1990) An Introduction to Dynamic Light Scattering by Macromolecules. Academic Press, New York
Pusey PN (1991) In: Hansen JP, Levesque D, Zinn-Justin J (eds) Liquids, Freezing and the Glass Transition. North-Holland, Amsterdam, p 765
Segrè PN, Meeker SP, Pusey PN, Poon WCK (1995) Phys Rev Lett 75:958
van Megen W, Underwood SM (1993) Phys Rev E 47:248
van Megen W, Underwood SM (1994) Phys Rev E 49:4206
van Megen W (1995) In: Yip S (ed) Relaxation Kinetics in Supercooled Liquids — Mode Coupling Theory and its Experimental Tests, Transp Theory Stat Phys 24:1017
Bartsch E, Frenz V, Sillescu H (1994) J Non-Crystal Solids 172–174:88
Bartsch E, Frenz V, Baschnagel J, Schärtl W, Sillescu H (1997) J Chem Phys 106:3743
Bartsch E (1995) In: Yip S (ed) Relaxation Kinetics in Supercooled Liquids — Mode Coupling Theory and its Experimental Tests, Transp Theory Stat Phys 24:1125
Pusey PN, van Megen W (1989) Physica A 157:705
Pusey PN, van Megen W (1987) Phys Rev Lett 59:2083
Xue J-Z, Pine DJ, Milner ST, Wu X-L, Chaikin PM (1992) Phys Rev A 46:6550–6563
Müller J, Palberg T (1996) Progr Colloid Polym Sci 100:121–126
Kirsch S, Frenz V, Schärtl W, Bartsch E, Sillescu H (1996) J Chem Phys 104:1758
Renth F, Bartsch E, Kasper A, Kirsch S, Stölken S, Sillescu H, Köhler W, Schäfer R (1996) Prog Colloid Polym Sci 100:127–131
Ricka J (1993) Appl Opt 32:2860
Joosten JGH, Gelade ETF, Pusey PN (1990) Phys Rev A 42:2161
van Megen W, private communication
Joosten JGH, McCarthy JL, Pusey PN (1991) Macromol 24:6690
Schätzel K, Drewel M, Ahrens J (1990) J Phys: Condens Matter 2:SA393
Segrè PN, van Megen W, Pusey PN, Schätzel K, Peters W (1995) J Mod Opt 42:1929
Schätzel K (1987) Appl Phys B 32:193
Note that the weighing factor 〈I(Q)〉 T,j /〈I(Q)〉 E , even though applied, was erroneously omitted in Eq. (3b) of Ref. [16])
Author information
Authors and Affiliations
Editor information
Rights and permissions
Copyright information
© 1997 Steinkopff Verlag
About this paper
Cite this paper
Bartsch, E., Frenz, V., Kirsch, S., Schärtl, W., Sillescu, H. (1997). Multi-speckle autocorrelation spectroscopy — a new strategy to monitor ultraslow dynamics in dense and nonergodic media. In: Palberg, T., Ballauff, M. (eds) Optical Methods and Physics of Colloidal Dispersions. Progress in Colloid & Polymer Science, vol 104. Steinkopff. https://doi.org/10.1007/BFb0110743
Download citation
DOI: https://doi.org/10.1007/BFb0110743
Published:
Publisher Name: Steinkopff
Print ISBN: 978-3-7985-1085-2
Online ISBN: 978-3-7985-1661-8
eBook Packages: Springer Book Archive