mercury porosimetry

**Mercury Porosimetry** is a **pore characterization technique that forces mercury (a non-wetting liquid) into pores under increasing pressure** — the pressure required to fill pores of a given size provides the pore size distribution, using the Washburn equation. **How Does Mercury Porosimetry Work?** - **Non-Wetting**: Mercury does not spontaneously enter pores (contact angle ~140°). - **Pressure**: Apply increasing external pressure to force mercury into progressively smaller pores. - **Washburn Equation**: $D = -4gammacos heta / P$ relates pressure $P$ to filled pore diameter $D$. - **Intrusion Curve**: Volume of mercury intruded vs. pressure gives cumulative pore volume distribution. **Why It Matters** - **Wide Range**: Measures pore diameters from ~3 nm to 400 μm. - **Total Porosity**: Measures total pore volume, bulk density, and skeletal density. - **Limitation**: Not used for thin films (requires bulk samples). Semiconductor use is limited to substrates and packaging materials. **Mercury Porosimetry** is **squeezing mercury into pores** — using pressure to probe the size distribution of voids in porous materials.