01363nab a2200169 4500 20260520001935.0 260224s2011 xxu Dilute iota- and kappa-carrageenan solutions with high viscosities in high ene. 2011 26/05/2011 ; 26/05/2011 7 p. ; 304-311 Transcripción del resumen del autor: We evaluated the rheological characteristics of - and -Carrageenan in aqueous solutions. Viscosities strongly increased with increasing polymer concentration or salinity. Monovalent Na+ cations were more effective in increasing viscosity than divalent Ca2+ cations. A more complex brine containing Na+, Mg2+ and Ca2+ cations also showed high viscosities at a high salinity. We observed shear thinning behavior for these polysaccharide solutions. We explain these rheological phenomena with molecular processes, specifically the conformation change of the -Carrageenan from random coil to double helix. In the context of enhanced oil recovery, -Carrageenan solutions can reach much higher viscosities at high salinities than standard polyacrylamide solutions. Moreover, Carrageenans are renewable, nontoxic, green substances. 3-4 Journal of Petroleum Science & Engineering 75 ARTICULO 182001 182001 0 0 0 0 249820 BAAB BAAB 2026-03-05 200054041 0 200054041 2026-03-05 23:52:08 2026-03-05 ARTICULO