Hygroscopic properties of potassium-halide nanoparticles

Figures & data

Table 1. Density of the dry particles , as well as density of droplet , water activity a_w and surface tension of the solution droplets.

Salt	Density of the dry particles	Density of droplet [Forsythe 2003]	Water activity aw [Robison and Stokes 2002]	Surface Tension
KBr	2750
	[Perry and Green 1997]
				[Shah et al. 2013]
KCl	1987
	[Hutchison 1944]
				[Shah et al. 2013]
KI	3130
	[Perry and Green 1997]
				[Ali et al. 2009]

Figure 1. Mobility-diameter growth factors of KBr nanoparticles. Experimental growth factors are shown by the data points: circles correspond to measurements recorded during deliquescence-mode experiments, and squares during efflorescence-mode experiments. In both cases the particles were generated by the vaporization-condensation technique. Lines show the growth factors of the theoretical model, including the Kelvin effect and a shape correction factor. Models are evaluated for 10 < w_t < 80%.

Table 2. Deliquescence and efflorescence RH values and growth factors at 75% RH of KBr, KCl, and KI nanoparticles.

	KBr					KCl					KI
	DRH range	DRH mean	ERH range	ERH mean	g (75%)	DRH range	DRH mean	ERH range	ERH mean	g (75%)	DRH range	DRH mean	ERH range	ERH mean	g (75%)
60 nm	72.4-78.1	75.3	55.3	55.8	1.57	—	—	—	—	—	53.6-64.3	59.0	40.6-49.9	45.3	1.53
			—
			56.2
40 nm	77.5-81.1	79.3	57.9	59.0	1.56	80.8-82.9	81.9	51.4-60.7	56.1	1.44	—		—		—
			60.0
30 nm	79.7-80.9	80.3	57.8–59.7	58.8	1.52	—	—	—	—	—	54.6-64.4	59.5	41.9-55.6	48.7	1.46
20 nm	80.7-81.7	81.2	58.0-62.1	60.1	1.54	79.6-85.5	82.6	52.6 – 61.8	57.2	1.33	57.1-63.9	60.5	43.1-57.1	50.1	1.45
15 nm	—		62.6-65.0	63.8	1.36	90.5-91.2	90.8	n.t.o.	n.t.o.	1.25	58.4-64.9	61.7	48.6-63.7	56.1	1.4
10 nm	86.9-89.6	88.3	61.0 –	64.3	1.43	—	—	—	—	—	—	—	—	—	—
			67.6
8 nm	89.7-91.1	90.4	—		—	n.t.o.	n.t.o.	—	—	—	n.t.o.	n.t.o.	—	—	—
Bulk	79.9-82.0^a	81.0	52.0^b			85 ± 1^c		56 ± 1^c
						84.3^d		53.0^d

^a Martin (2000); Cohen et al. (1987).

^b Martin (2000); Zhang and Chan (2002).

^c Cohen et al. (1987); Freney et al. (2009).

^d Tang et al. (1986). n.t.o.: no transition observed.

Figure 2. As in Figure 1, but for KCl nanoparticles. Models are evaluated for 10 < w_t < 75%.

Figure 3. As in Figure 1, but for KI nanoparticles. Models are evaluated for 10 < w_t < 75%.

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