@misc{10481/67766,
year = {2020},
url = {http://hdl.handle.net/10481/67766},
abstract = {Even in absence of cross-linking, at large enough concentration, long polymer strands have a strong influence on the rheology of aqueous systems. In this work, we show that solutions of medium molecular weight (120,000 – 190,000 g/mol) alginate polymer retained a liquid-like behaviour even for concentrations as large as 20 % w/v. On the contrary, solutions of alginate polymer of larger (and also polydisperse) molecular weight (up to 600,000 g/mol) presented a gel-like behaviour already at concentrations of 7 % w/v. We dispersed micron-sized iron particles at a concentration of 5 % v/v in these solutions, which resulted either in stable magnetic fluids or gels, depending on the type of alginate polymer employed (medium or large molecular weight, respectively). These magneto-polymer composites presented a shear-thinning behaviour that allowed injection through a syringe and recovery of the original properties afterwards. More interestingly, application of a magnetic field resulted in the formation of particle clusters elongated along the field direction. The presence of these clusters intensely affected the rheology of the systems, allowing a reversible control of their stiffness. We finally developed theoretical modelling for the prediction of the magnetic-sensitive rheological properties of these magneto-polymer colloids.},
organization = {Ministerio de Economía, Industria y Competitividad, MINECO, and
Agencia Estatal de Investigación, AEI, Spain, cofounded by Fondo Europeo de Desarrollo Regional, FEDER,
European Union, project FIS2017-85954-R.
Ministry of Education and Science of the Russian Federation, projects 02.A03.21.0006; 3.1438.2017/4.6; 3.5214.2017/6.7 as well as to the Russian Fund of Basic Researches, project 19-52-12028},
title = {Role of particle clusters on the rheology of magneto-polymer fluids and gels},
doi = {http://dx.doi.org/10.1098/rsta.2019.0254},
author = {Suarez-Fernandez, William and Scionti, Giuseppe and García López-Durán, Juan De Dios and Zubarev, Andrey and López López, Modesto Torcuato},
}