Rheological Characterization of Carbopol® Dispersions in Water and in Water/Glycerol Solutions

• DOI: 10.3390/fluids4010003
• Publication Date: 2019-01-04T16:34:26Z
• Authors: Priscilla R. Varges; Camila M. Costa; Bruno S. Fonseca; Mônica F. Naccache; Paulo De Souza Me...
• Keywords: yield stress; QC120-168.85; Descriptive and experimental mechanics; 0103 physical sciences; Carbopol; Thermodynamics; QC310.15-319; 01 natural sciences; thixotropy

The influence of the solvent type on the rheological properties of Carbopol ® NF 980 dispersions in water and in water/glycerol solutions is investigated. The material formulation, preparation procedure, common experimental challenges and artifact sources are all addressed. Transient and steady-state experiments were performed. For both solvent types, a clearly thixotropic behavior occurs slightly above the yield stress, where the avalanche effect is observed. For larger stresses, thixotropy is always negligible. Among other findings, it is observed that, for a given Carbopol concentration, the dispersion in the more viscous solvent possesses a lower yield stress and moduli, a larger power-law index, and a longer time to reach steady state.