Phase transition in colloidal suspensions

Among the colloidal crystal structures, the facc-ccnlcrcd cubic (fee) lattice was found to be the most stable structure both theoretically [50] and experimentally [47, 51, 52], compared with other crystal structures such as, body-centered tetragonal (bet) and hexagonal closed-packed (hep) structures. The Gibbs free-energy of fee structure is more stable by around 0.005RT(whcre R is the gas constant, and T is temperature) relative to that of hep structure, which has an identical close-packed volume [50]. 

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Fraden S 1995 Phase transitions in colloidal suspensions of virus particles Observation, Prediction and Simuiation of Phase Transitions in Complex Fluids ed M Baus, L F Rull and J P Hansen (Dordrecht Klu wer) pp 113-64... 

Fraden S (1995) Phase transitions in colloidal suspensions of virus particles. In Bans M, Rull LF, Ryckaert JP (eds) Observation, prediction and simulation of phase transitions of complex fluids. Kluwer Academic Publishers, Dordrecht Germany Oldenburg R, Wen X, Meyer RB, Caspar DLD (1988) Phys Rev Lett 61 1851 Maier EE, Krause R, Deggelmann M, Hagenbuchle M, Weber R, Fraden S (1992) Macromolecules 25 1125... 

The method of cumulants performs rather weakly for very broad distributions of the decay rate. In this case, the autocorrelation functions are better fitted by stretched exponentials (Williams and Watts 1970). The Williams-Watts analysis is mainly employed for phase transition in colloidal suspensions (Ruzicka et al. 2004 Katzel et al. 2007) and for polymer suspensions. 

The concept potential of mean force was used by Onsager [3] in his theory for the isotropic-nematic phase transition in suspensions of rod-like particles. Since the 1980s the field of phase transitions in colloidal suspensions has shown a tremendous development. The fact that the potential of mean force can be varied both in range and depth has given rise to new and fascinating phase behaviour in colloidal suspensions [4]. In particular, stcricaUy stabilized colloidal spheres with interactions close to those between hard spheres [5] have received ample attention. 

Rankin S.E., Macosko C.W., McCormick A.V. Sol-gel polycondensation kinetic modeling Methylethoxysilanes. AIChE J. 1998 44(5) 1141-1156 Ramakrishnan S., Zukoski C.F. Characterizing nanoparticle interactions Linking models to expai-ments. J. Chem. Phys. 2000 113(3) 1237-1248 Ramakrishnan S., Fuchs M., Schweizer K.S., Zukoski C.F. Entropy driven phase transitions in colloid-pol3mer suspensions Tests of depletion theories. J. Chem. Phys. 2002a 116(5) 2201-2212... 

We need to understand under which conditions a colloidal system will remain dispersed (and under which it will become unstable). Knowing how colloidal particles interact with one another makes possible an appreciation of the experimental results for phase transitions in such systems as found in various industrial processes. It is also necessary to know under which conditions a given dispersion will become unstable (coagulation). For example, one needs to apply coagulation in wastewater treatment so that most of the solid particles in suspension can be removed. Any two particles coming close to each other, will produce different forces. 

H.N.W. Lekkerkerker, G.J. Vroege, Liquid crystal phase transitions in suspensions of mineral colloids new life from old roots. Phil. Trans. R. Soc. A 371, 20120263 (2013)... 

Arora,AK. andTat,B.V.R. (1996). Dj namics of Charged Colloidal Suspensions Across the Freezing and Glass Transition. In Ordering and Phase Transitions in Charged Colloids. VCH Publishers, New York. 

Phase Transitions in Suspensions of Rod-Like Colloids Plus Polymers... 

The electric-tield-induced phase transition in an ER suspension was found to be different from that in general colloidal suspensions. Tao and Martin [55, 56] predicted theoretically tliat the bet structure has an energy lower than that of the fee (face-centered cubic) and other structures, based on dipolar interaction energy calculations. The dipolar interaction energy per particle for various crystal structures is shown in I able 3. The bet crystal structure is shown in Figure 6. 

For review articles, see Sood AK (1991) Solid State Phys 45 1-73 Dosho S et al. (1993) Langmuir 9 394-411 Schmitz KS (1993) Macroions in Solution and Colloidal Suspension. VCH Inc., New York Arora AK, Tata BVR (eds) (1996) Ordering and Phase Transition in Charged Colloids. VCH Inc., New York... 

There are other reports on the study of pretransitional dynamics in polymeric and lyotropic nematics. Quantitative measurements of ratios of Frank elastic constants and Leslie viscosities in the pretransitional range of poly-y-benzyl-glutamate polymeric nematic are reported by Taratuta et al. [85]. McClymer and Keyes [86-88] report light scattering studies of pretransitional dynamics of potassium laurate-decanol-D20 system. An interesting study of a magnetic-field induced I N phase transition in a colloidal suspension is reported by Tang and Fraden [89]. 

J. Tang, S. Fraden, Magnetic-field induced isotropic-nematic phase transition in a colloidal suspension, Phys. Rev. Lett. 1993,77,3509-3512. 

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