Effects of metal ions on the self-assembly of chitosan molecules investigated with atomic force microscopy

Figures & data

Table 1. Height, roughness (Ra, Rq), and surface area difference of the chitosan molecular self-assembly in different chitosan concentrations and 0.05 mg/mL chitosan self-assembly in different KCl, NaCl, MgCl₂, and CaCl₂ concentrations.

Cations	Concentration (mg/mL)	Height (nm)	Ra (nm)	Rq (nm)	Surface area difference (%)
—	0.01	3.2 ± 0.3	0.466	0.692	0.105
	0.02	2.9 ± 0.2	0.323	0.544	0.063
	0.05	3.4 ± 0.1	0.896	1.270	0.387
	0.10	1.9 ± 0.1	0.526	0.642	0.209
K^+	0.20	3.8 ± 0.2	0.782	1.140	0.672
	0.50	3.5 ± 0.1	0.722	0.939	0.215
	1.00	3.01 ± 0.03	0.175	0.307	0.206
Na^+	0.20	1.57 ± 0.07	0.324	0.400	0.279
	0.50	1.4 ± 0.2	0.316	0.491	0.120
	1.00	1.2 ± 0.1	0.425	0.598	0.382
Mg^2+	0.20	9.9 ± 0.2	2.150	3.010	0.484
	0.50	1.9 ± 0.2	0.373	0.630	0.154
	1.00	1.5 ± 0.1	0.771	1.480	0.618
Ca^2+	0.20	5.4 ± 0.2	0.693	1.190	0.630
	0.50	4.4 ± 0.2	0.826	1.240	0.417
	1.00	1.6 ± 0.1	0.461	0.538	0.202

Figure 1. Typical AFM height images and section analysis profiles of chitosan self-assembly in different concentrations in 512 × 512 pixels. Scale bar = 1um.

(a) 0.01 mg/mL; (b) 0.02 mg/mL; (c) 0.05 mg/mL; (d) 0.1 mg/mL.

Figure 2. Typical AFM height images of chitosan self-assembly in KCl solution with different ions concentration in 512 × 512 pixels. Scale bar = 500nm. (a) 0.2 mg/mL; (b) 0.5 mg/mL; (c) 1.0 mg/mL.

Figure 3. Typical AFM height images of chitosan self-assembly in NaCl solution with different ions concentration in 512 × 512 pixels. Scale bar = 500nm. (a) 0.2 mg/mL; (b) 0.5 mg/mL; (c) 1.0 mg/mL.

Figure 4. Typical AFM height images of chitosan self-assembly in MgCl₂ solution with different ions concentration in 512 × 512 pixels. Scale bar = 500nm. (a) 0.2 mg/mL; (b) 0.5 mg/mL; (c) 2.0 mg/mL.

Figure 5. Typical AFM height images of chitosan self-assembly in CaCl₂ solution with different ions concentration in 512 × 512 pixels. Scale bar = 500 nm. (a) 0.2 mg/mL; (b) 0.5 mg/mL; (c) 1.0 mg/mL.