Please use this identifier to cite or link to this item: https://hdl.handle.net/10216/105553
Author(s): Laura Campo Deano
Francisco J. Galindo-Rosales
Fernando T. Pinho
Manuel A. Alves
Mónica S. N. Oliveira
Title: Nanogel formation of polymer solutions flowing through porous media
Issue Date: 2012
Abstract: A gelation process was seen to occur when Boger fluids made from aqueous solutions of polyacrylamide (PAA) and NaCl flowed through porous media with certain characteristics. As these viscoelastic fluids flow through a porous medium, the pressure drop across the bed varies linearly with the flow rate, as also happens with Newtonian fluids. Above a critical flow rate, elastic effects set in and the pressure drop grows above the low-flow-rate linear regime. Increasing further the flow rate, a more dramatic increase in the slope of the pressure drop curve can be observed as a consequence of nanogel formation. In this work, we discuss the reasons for this gelation process based on our measurements using porous media of different sizes, porosity and chemical composition. Additionally, the rheological properties of the fluids were investigated for shear and extensional flows. The fluids were also tested as they flowed through different microfluidic analogues of the porous media. The results indicate that the nanogel inception occurs with the adsorption of PAA molecules on the surface of the porous media particles that contain silica on their surfaces. Subsequently, if the interparticle space is small enough a jamming process occurs leading to flow-induced gel formation.
Subject: Engenharia dos materiais
Materials engineering
Scientific areas: Ciências da engenharia e tecnologias::Engenharia dos materiais
Engineering and technology::Materials engineering
URI: https://repositorio-aberto.up.pt/handle/10216/105553
Related Information: info:eu-repo/grantAgreement/FCT - Fundação para a Ciência e Tecnologia/Projectos de I&DT em Todos os Domínios Científicos/PTDC/EME-MFE/099109/2008/ANEURYSM - Estudo Hemodinâmico em Aneurismas Cerebrais/ANEURYSM
info:eu-repo/grantAgreement/FCT - Fundação para a Ciência e Tecnologia/Projectos de I&DT em Todos os Domínios Científicos/PTDC/EME-MFE/114322/2009/EXTENSION - Escoamento extensional de fluidos complexos em microcanais/EXTENSION
Document Type: Artigo em Revista Científica Internacional
Rights: restrictedAccess
Appears in Collections:FEUP - Artigo em Revista Científica Internacional

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