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B Payandeh

Publications and source records attributed to B Payandeh.

5 recordsLinked to original sources
PubMed2006

Colloid interaction and pair correlation function of one-dimensional colloid-polymer systems.

The interaction and pair correlation function of weakly charged colloidal particles in quasi-one-dimensional colloid-polymer systems are determined by enhanced video microscopy and digital image analysis. The pair correlation function is found to depend not only on the polymer concentration, but also on the degree of confinement; in particular, it depends on whether the channel width is such that mutual passage of the colloid particles is possible or not. These findings are compared with exact results on short-range order in linear continuous systems.

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PubMed2001

Turbidity and critical behavior of a colloid-polymer system.

The osmotic compressibility and correlation length of a colloid-polymer system, consisting of grafted silica particles in cyclohexane in the presence of the soluble polymer polydimethylsiloxane, are determined by turbidity measurements in the entire one-phase liquid region, with emphasis on the critical region. The renormalized critical exponents of the osmotic compressibility and the correlation length are found to be respectively gamma(*)=1.39+/-0.01 and nu(*)=0.71+/-0.01, while the amplitude of the correlation length is 16.0+/-0.3 nm. Comparison is made with theoretical predictions.

Journal Article↗
PubMed2000

Order parameter and interfacial tension of a colloid-polymer system

The order parameter and interfacial tension of a colloid-polymer system consisting of grafted silica particles in cyclohexane in the presence of the soluble polymer polydimethylsiloxane are determined experimentally in the entire liquid-liquid coexistence region, from the liquid-solid boundary to the critical point. The renormalized critical exponents of the order parameter and interfacial tension are found to be, respectively, beta(*)=0.371+/-0.026 and &mgr;(*)=1. 30+/-0.08, and are discussed in the light of theoretical predictions.

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