<p>Yield stress is a key parameter in the study of soft materials, but its value depends on the experimental criterion used to define it. In this work, three representative systems are analyzed: a BBQ sauce as a low-strength colloidal dispersion, a hair gel as an intermediate polymer hydrogel, and a chitosan hydrogel as an example of a rigid polyelectrolyte network. The rheological results show that the obtained yield stress values vary depending on the method used. The comparison between systems shows that the concentration and type of polymer determine the magnitude of <InlineEquation ID="IEq1"> <EquationSource Format="TEX">\(\:{G}^{{\prime\:}}\)</EquationSource> </InlineEquation>, <InlineEquation ID="IEq2"> <EquationSource Format="TEX">\(\:{G}^{{\prime\:\prime\:}}\)</EquationSource> </InlineEquation> and <InlineEquation ID="IEq3"> <EquationSource Format="TEX">\(\:{\tau\:}_{0}\)</EquationSource> </InlineEquation> with chitosan being the strongest material due to its rigid structure and stronger interactions. The determination of the yield stress should not be interpreted as an absolute value but rather as an interval, considering the point at which the material begins to change its structure until it becomes completely liquid.</p> Graphical abstract <p></p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

The dependence of the yield stress on the rheological method and microstructure in soft materials

  • Erika L. García-Romero,
  • Lucy-Caterine Daza-Gómez,
  • Gabriel Ascanio,
  • Karen Y. Pérez-Salas,
  • Juan P. Aguayo

摘要

Yield stress is a key parameter in the study of soft materials, but its value depends on the experimental criterion used to define it. In this work, three representative systems are analyzed: a BBQ sauce as a low-strength colloidal dispersion, a hair gel as an intermediate polymer hydrogel, and a chitosan hydrogel as an example of a rigid polyelectrolyte network. The rheological results show that the obtained yield stress values vary depending on the method used. The comparison between systems shows that the concentration and type of polymer determine the magnitude of \(\:{G}^{{\prime\:}}\) , \(\:{G}^{{\prime\:\prime\:}}\) and \(\:{\tau\:}_{0}\) with chitosan being the strongest material due to its rigid structure and stronger interactions. The determination of the yield stress should not be interpreted as an absolute value but rather as an interval, considering the point at which the material begins to change its structure until it becomes completely liquid.

Graphical abstract