Modulus and adhesion of Sylgard 184, Solaris, and Ecoflex 00-30 silicone elastomers with varied mixing ratios

Two-part, commercial silicone elastomers are used in a variety of fundamental soft materials research and industrial applications due to their wide availability, ease of use, low cost, and mechanical tunability. This work seeks to create a library of moduli for three common elastomer systems with varied mixing ratios: Sylgard 184, Solaris, and Ecoflex 00–30, as well as provide a comparison of their adhesive properties. Shear storage moduli are quantified using parallel plate oscillatory shear rheology. The work of debonding is measured with spherical probe adhesion testing, and the static, advancing, and receding contact angles are measured via goniometer. Sylgard 184 can have shear moduli ranging from ~0.5 kPa-620 kPa, Solaris from ~0.6 kPa-175 kPa, and EF from ~1.3 kPa-35 kPa measured at a frequency of 0.01 rad/s. In general, increasing mixing ratios creates softer samples. Additionally, softer samples are universally more adhesive, regardless of the material system. When comparing the different material systems, Sylgard 184 is generally the most adhesive, followed closely by Solaris, and then by Ecoflex 00–30. Our study offers a baseline dataset of modulus values and comparative adhesion to help researchers determine an appropriate commercial silicone for their application.