Rheology of silver nanocluster solutions under confinement

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Vol. 384; no. 1; pp. 570 - 573
• Main Authors: Karakashev, Stoyan I., Grozev, Nikolay, Díez, Isabel, Ras, Robin H.A., Tsekov, Roumen
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 05-07-2011
• Subjects: aqueous solutions; colloids; drainage; Fluorescent silver clusters; foams; interferometry; nanoparticles; polymers; Quantum dot nano-suspensions; rheology; silver; silver nitrate; Steric repulsion; Thin liquid film drainage; Thin liquid film drainage; Fluorescent silver clusters; Steric repulsion; Quantum dot nano-suspensions
• ISSN: 0927-7757; 1873-4359
• DOI: 10.1016/j.colsurfa.2011.05.015

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► Drainage of nano-cluster suspension stabilied by PMAA. ► Steric repulsion between film surfaces affected by Ag nano-clusters. ► Ag nano-clusters makes the structure of PMAA more expanded.
Drainage of solutions of silver (Ag) nano-clusters, pressed between the two apexes of a double-concaved drop situated in a capillary holder, was studied. The size of clusters was below 2
nm. The aqueous nano-suspension of Ag nano-clusters was stabilized by poly(methacrylic acid) (PMAA). The two tips of the double-concaved drop were pressed by a capillary pressure thus forming a foam nanofilm, the drainage kinetics of which was monitored by interferometry. For comparison, the drainage of foam films containing PMAA aqueous solutions with and without AgNO
3 was monitored as well. It was found that steric repulsion occurred between the two film surfaces due to the polymeric chains of PMAA. In addition, we observed also a significant change of this steric repulsion in nano-cluster suspensions, which is explained by changes of the polymer network in the film, affecting the entire drainage and stability of the suspension.