Almutairi, Fahad M.Adams, Gary G.Kök, Mehmet ŞamilLawson, Christopher J.Gahler, Roland2021-06-232021-06-2320130144-8617https://doi.org/10.1016/j.carbpol.2013.04.027https://hdl.handle.net/20.500.12491/7477The conformation and heterogeneity of lambda-carrageenan, a sulphonated galactan from red seaweed, solubilised in aqueous solvent with the assistance of microwave irradiation, has been assessed by a combination of analytical ultracentrifugation, size-exclusion chromatography, light scattering and capillary viscometry. Preparations appeared generally unimodal on the basis of sedimentation coefficient distributions from sedimentation velocity although at the highest concentrations a shoulder appears with a sedimentation coefficient approximately 1.1 times greater than that of the main component. Even under conditions commensurate with charge suppression simple linear regression was insufficient to represent non-ideal concentration dependence and the extraction of the Gralen concentration dependence parameter k(s). A more general fitting algorithm was therefore employed. Mark-Houwink-Kuhn-Sakurada analysis of the change in intrinsic viscosity [eta] with molecular weight, together with the Wales-van Holde ratio (combination of k(s), with [eta]) point to an extended flexible conformation for lambda-carrageenan in the (weight average) molecular weight range M-w = 340,000-870,000 g/mol. The origin of the larger sedimentation coefficient component appearing at the higher concentrations is considered. (C) 2013 Elsevier Ltd. All rights reserved.eninfo:eu-repo/semantics/closedAccessLambda-carrageenanIntrinsic ViscositySedimentation CoefficientConcentration DependenceMolar MassExtended Flexible CoilArticle10.1016/j.carbpol.2013.04.027971203209237695382-s2.0-84878418551Q1WOS:000321167300030Q1