TY - JOUR N2 - The article presents an experimental investigation of the rheological properties of carbomer microgels. All of the tested fluids were made up from commercial polyacrylic acid, Carbopol Ultrez 30. In total, eighteen microgels were prepared, differing in concentration; 0.2, 0.4 and 0.6 wt%, with six levels of neutralisation for pH from 4.0 to 9.0. Based on the experimental flow curves it was found that all tested microgels are yield stress shear-thinning fluids. Therefore, the Herschel–Bulkley model was used and its rheological parameters were determined. It was found that both the concentration and the pH value significantly affected the yield stress. As the Carbopol concentration increased, the yield point also increased. With the increasing value of pH, the yield stress first increased until a certain maximum level and then decreased. The maximum values of yield stress were obtained for pH = 6 to 7, depending on polymer concentration. It was also found that flow curves of the tested microgels could be described using one universal master curve, thus they have common rheological behaviour. L1 - http://journals.pan.pl/Content/115805/PDF/art01.pdf L2 - http://journals.pan.pl/Content/115805 PY - 2020 IS - No 3 EP - 182 DO - 10.24425/cpe.2020.132540 KW - microgel KW - Carbopol KW - Herschel–Bulkley model KW - yield stress fluid A1 - Story, Anna A1 - Story, Grzegorz A1 - Jaworski, Zdzisław PB - Polish Academy of Sciences Committee of Chemical and Process Engineering VL - vol. 41 DA - 2020.10.26 T1 - Effect of carbomer microgel pH and concentration on the Herschel–Bulkley parameters SP - 173 UR - http://journals.pan.pl/dlibra/publication/edition/115805 T2 - Chemical and Process Engineering ER -