Electro-orientation of Ag nanowires in viscoelastic fluids Martín-Martín, Sergio Delgado Mora, Ángel Vicente Arenas-Guerrero, Paloma Jiménez Olivares, María Luisa Alginate Silver nanowires Gel Electro-orientation Particle-polymer interactions In this work we study the electro-orientation (through electric birefringence experiments) of silver nanowires in polymer solutions eventually capable of forming gel networks. Information on the structure of the polymer solution is obtained by evaluating the electro-orientation of the nanowires. It is found that in presence of poly(ethylene oxide), Kerr’s law (birefringence proportional to the square of the field) is fulfilled, and the randomization process after switching off the external field is purely diffusive, controlled by the viscosity of the Newtonian polymer solution. In the case of (gelating) sodium alginate solutions, measuring at larger distances from the bottom (where the source of cross-linking Ca2+ ions is deposited) means a smaller degree of cross-linking, and a less stiff gel. In fact, it is found that after a certain time the birefringence signal gets frozen at the bottom, indicating that a gel network is formed which hinders particle orientation. The viscosity deduced up to that point agrees well with rheological determinations, with increasing deviations found at longer times due to the inhomogeneous gel formation. This process has an interesting consequence on birefringence response: Kerr’s law fails to be fulfilled, appearing a ”yield” applied electric field, larger the longer the time after preparation. 2022-05-10T08:40:27Z 2022-05-10T08:40:27Z 2022-05-06 journal article Martín-Martín, Sergio et al. Electro-orientation of Ag nanowires in viscoelastic fluids. Journal of Colloid And Interface Science 622C (2022) pp. 700-707 http://hdl.handle.net/10481/74776 https://doi.org/10.1016/j.jcis.2022.04.164 eng http://creativecommons.org/licenses/by/3.0/es/ open access Atribución 3.0 España Elsevier