Carbohydrate Hygroscopicity
Table 1: Hygroscopicity refers to the absorption of water by sugar under the condition of high air humidity. The experimental method involved water uptake measurements of aerosol particles using a Hygroscopicity Tandem Differential Mobility Analyzer (HTDMA) under sub-saturated conditions (RH < 100%). Polydisperse particles were dried, charged, and size-selected before exposure to controlled RH in a hydration chamber. Humidified size distributions were measured using a scanning mobility particle sizer (SMPS) during hydration and dehydration processes. Atomic force microscopy (AFM) was used to image and analyze particles on silicon wafers under varying RH for hygroscopicity studies.
| ID | Type | Mass Ratio | Organic Volume fraction | Deliquescence RH | Hygroscopicity Parameter | RH 60% (g/g) | RH 80% (g/g) |
|---|---|---|---|---|---|---|---|
| 1 | NaCl + glucose | 1:1 | 0.71 ± 0.15 | 72.0 ± 2.0 | 0.68 | 1.14 ± 0.03 | 1.56 ± 0.02 |
| 2 | NaCl + glucose | 1:2 | 0.85 ± 0.14 | 67.3 ± 2.0 | 0.57 | 1.20 ± 0.02 | 1.48 ± 0.03 |
| 3 | NaCl + glucose | 1:3 | None | Continuous | 0.34 | 1.13 ± 0.02 | 1.24 ± 0.03 |
| 4 | NaCl + laminarin | 1:1 | 0.47 ± 0.21 | 73.8 ± 2.0 | 0.54 | 0.99 ± 0.04 | 1.51 ± 0.03 |
| 5 | NaCl + laminarin | 1:2 | 0.70 ± 0.15 | 73.0 ± 1.0 | 0.48 | 0.99 ± 0.03 | 1.44 ± 0.04 |
NOMENCLATURE:
Reference: Estillore, A. D., Morris, H. S., Or, V. W., Lee, H. D., Alves, M. R., Marciano, M. A., Laskina, O., Qin, Z., Tivanski, A. V., & Grassian, V. H. (2017). Linking hygroscopicity and the surface microstructure of model inorganic salts, simple and complex carbohydrates, and authentic sea spray aerosol particles. Physical Chemistry Chemical Physics, 19(31), 21101-21111. DOI: https://doi.org/10.1039/c7cp04051b
Table 2: Temperature-dependent hygroscopicity of selected carbohydrates.
| ID | Temperature (K) | Hygroscopic Correlation |
|---|---|---|
| 1 | 297.00 | Fructose > Sucrose/Glucose > Sucrose > Sucrose/Maltose > Glucose > Lactose |
| 2 | 303.15 | Fructose > Sucrose/Glucose > Sucrose > Sucrose/Maltose > Glucose > Lactose |
| 3 | 310.10 | Fructose > Glucose > Sucrose/Glucose > Sucrose > Sucrose/Maltose > Lactose |
NOTE: Calculated at 90% RH.
Reference: B. J. Donnelly, J. C. Fruin, and B. L. Scallet. Copyright 1973 by the American Association of Cereal Chemists, Inc. Weblink: https://www.cerealsgrains.org/publications/cc/backissues/1973/Documents/chem50_512.pdf