Dilute solution behaviour of progressively hydrolyzed polyacrylamide in water–N,N dimethylformamide mixtures

The properties of native silk fibroin (SF) solution/gel from bombyx mori silkworms during the full fifth instar larval stage

“…Macromolecular conformational change is the chemical and/or physical interactions among macromolecules in a polymer solution and it can cause the change of specific viscosity of the solution. For example, the specific viscosity of a solution containing polymer macromolecules with fixed primary structure becomes greater when the polymer macromolecule chains are more extended (e g, solutions with solute interacting with solvent [32] ), or the interaction among the polymer macromolecule chains becomes intensified (e g, some polyelectrolyte solution system [31] ).…”

Solution Properties of a Polymer-Nonionic Surfactant Mixed System

“…In this context, it should be noted that the shape of the above polymers molecules are found to be spherical in aqueous and aqueous-organic (N,N dimethyl formamide) mixtures. [5] The change in the shape of the polymer molecules in presence of nonionic surfactant is, however, not surprising. It has already been suggested that the bound ions or molecules may significantly modify the local stiffness of the polymer chain resulting in the restructuring of the overall shape.…”

“…Recently, we reported dilute solution properties of unhydrolyzed and hydrolyzed polyacrylamides in water N,N dimethylformamide mixtures at various temperatures. [5] In this article, we report the results of our investigation on the interaction between polyacrylamide (PAM) and nonionic surfactant (Tx-100).…”

Structure and Water Relations of Melanoidins Investigated by Thermal, Rheological, and Microscopic Analysis

“…[39] K¢ has been reported both as a measure of the hydrodynamic interactions between the macromolecules, [23] and as a predictor of the degree of interaction between polymer and the solvent. [40,41,42] According to Bit et al, [40] the sign of K¢ is often taken as a measure of the type of interactions in the polymer chain and, in general, positive K¢ values indicate enhanced interunit attractive interactions. From the dependence of intrinsic viscosity on weight average molar mass (M w ) the molecular shape of polymers can be inferred, as reported for inulin Wolff et al [43] The critical concentration C* (g·100 mL −1 ) represents the amount of polymer contained in a given volume in conditions of total occupancy, i.e., without interpenetration of the macromolecules and can be derived from intrinsic viscosity with C*≈ 1/[h].…”