Potencialo poveikio vandeninio tirpalo sluoksnio prie polimerinio paviršiaus savybėms tyrimas kvarco rezonatoriaus admitanso metodu /

Quartz Resonator Admittance Study of Potential Effect on the Properties of Aqueous Solution Layer at Polymeric Surface By utilizing the methods of electrochemical impedance spectroscopy and quartz crystal microbalance (QCM) it was determined that the minima of density viscosity products of interfacial solutions having different adsorptive capability anions coincide with the potentials of zero charge in the corresponding solutions at gold surface. The minima of anions with lesser adsorptive capabilities appear to be at more positive potentials. By analyzing the layers of interfacial solutions (Cl-, ClO4-, F-) at the surface of polyvinyl butyral (PVB) coated gold electrode showed similar tendency. The comparison of data obtained for quartz sensor covered with PVB and multi-crystalline wax Cosmoloid H80 shows that the nature of the coating does not considerably affect the dependence of ρη on the potential. Dependence of the product of density and viscosity on the potential in 0,1M NaF solution at PVB-coated Au surface determined by utilizing QCM was compared with the dependence of viscosity on the potential, calculated from the drag force on the gold-plated spherical body (coated with PVB) immersed in solution stream. The results obtained by using both methods correlate despite the substantial differences in flow regime. All the data presented in this research indicate that positive polarization of the polymer coated electrode surface decreases the viscosity. Apparently, the decrease of the interfacial solution viscosity results in fuller velocity profile in the boundary layer, what reduces the formation rate of vortices and increases the stability of the flow. This effect can be used for the control over the flow of wall-bounded fluid what allows to achieve the beneficial results. Hence, surface polarization could be utilized as the wall-bounded fluid flow stabilizer.

Grantor dc:publisher

Institutional Repository of Vilnius University

Year dc:date

2016

Author dc:creator

• Ambrulevičius, Filipas,

Contributors dc:contributor

• Daujotis, Vytautas

Statement dc:rights

• info:eu-repo/semantics/openAccess

Language dc:language

lit

Repository record dc:identifier

https://repository.vu.lt/VU:ELABAETD20217576&prefLang=en_US

OAI identifier oai:identifier

oai:vu.lt:elaba:20217576