Título: Soft MatterImportada do Authenticus Pesquisar Publicações da Revista

Vol. 8 Nº 24

Páginas: 6445-6453

ISSN: 1744-683X

Editora: Royal Society of Chemistry

ISI Web of Knowledge - 14 Citações

ISI Web of Science

Scopus - 19 Citações

FOS: Ciências da engenharia e tecnologias > Engenharia dos materiais

ID Authenticus: P-002-GC4

DOI: 10.1039/c2sm25654a

Abstract (EN): 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.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 9