# 🧪 Carbopol Ultrez 21 in propylene glycol, flow curve (community)

`dataset id: caggioni_pg_carbopol_2pct`

A single equilibrium flow sweep of 2% Carbopol Ultrez 21 dispersed in propylene glycol: 61 points from 10^-3 to 10^3 s^-1 at 20 C, measured with a concentric-cylinder geometry. Carbopol is a jammed microgel (a soft-particle glass) and propylene glycol is a viscous continuous phase; this combination is the textbook case where a three-component (TC) model separates the particle and viscous contributions better than Herschel-Bulkley. Originally measured for the rheofit fit-app walkthrough.

## 📈 Data

![Data for caggioni_pg_carbopol_2pct](_plots/caggioni_pg_carbopol_2pct.png)

## 🗂️ Metadata

| Field | Value |
| --- | --- |
| Material | 2% Carbopol Ultrez 21 in propylene glycol |
| Material kind | microgel |
| Source | Unpublished (community contribution) |
| DOI | — |
| Figure | — |
| Measurement type | flow_curve |
| Geometry | concentric-cylinder |
| Temperature | 20 °C |
| Protocol | Equilibrium flow sweep, shear rate 10^-3-10^3 s^-1, 61 points. |
| Provenance | community, digitized: no |

## 🧫 Samples

| Sample id | Label |
| --- | --- |
| carbopol_2pct | 2% Carbopol Ultrez 21 in propylene glycol |

## 📋 Data columns

| Role | Column | Units |
| --- | --- | --- |
| `x` | `shear_rate_1/s` | 1/s |
| `y` | `stress_Pa` | Pa |
| `sample` | `sample_id` | — |

## 🏷️ Tags

`yield-stress` `microgel` `carbopol` `flow-curve`