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
6 NaCl + laminarin 1:3 0.82 ± 0.14 70.6 ± 3.0 0.23 0.99 ± 0.04 1.22 ± 0.02
7 NaCl + laminarin 1:4 None 69.0 ± 3.0 0.18 0.99 ± 0.02 1.18 ± 0.05
8 NaCl + laminarin 1:5 None Continuous 0.14 1.05 ± 0.02 1.14 ± 0.02
9 NaCl + glucose 2:1 None 69.2 ± 1.5 0.8 None 1.73 ± 0.03

NOMENCLATURE:

RH = Relative Humidity
g/g = grams of water per gram of dry solid

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