Method for preparing Nano silver grain, and prepared Nano silver grain

[0036] Example 1

[0037] The above-mentioned chitosan with a degree of deacetylation ≥70% and an average molecular weight of about 20,000 was dissolved in 0.02% acetic acid, and then the solution was mixed with a silver nitrate solution to obtain a mixed solution, which contained 0.005wt% chitosan Sugar and 2.0×10 -3 mol.L -1 Of silver nitrate. The pH of the mixed solution is adjusted to 3.0 with acetic acid; pure nitrogen is introduced for deoxygenation, and 60 Co source was irradiated with an irradiation dose of 10kGy to obtain a brownish-yellow solution; this solution was dropped on a copper net for drying, and then scanned with a transmission electron microscope. The result is shown in Figure 1A (TEM magnification of 40 thousand times, the scale of the figure is 50nm) As shown, the particle size distribution is shown in Figure 1B.

[0038] The results show that: it can be seen from Fig. 1A that the particle size of the silver nanoparticles prepared by the preparation method of the present invention is relatively uniform, and Fig. 1B can also prove that the particle size is uniformly distributed, and the average particle size is 16 nm.

[0039] Example 2

[0040] The above-mentioned chitosan with a degree of deacetylation ≥70% and an average molecular weight of about 20,000 is dissolved in 0.01% acetic acid, and then the solution is mixed with a silver nitrate solution to obtain a mixed solution, which contains 0.005wt% chitosan Sugar and 1.0×10 -3 mol.L -1 Of silver nitrate, the mixed solution is adjusted to pH 3.0 with acetic acid; pure nitrogen is passed in 60The Co source was irradiated with an irradiation dose of 10kGy to obtain a yellow solution; this solution was dropped on a copper net for drying, and then scanned with a transmission electron microscope. The result is shown in Figure 2A (forty thousand times magnification, the scale of the figure is 50nm). , The particle size distribution is shown in Figure 2B.

[0041] The results show that: it can be seen from FIG. 2A that the particle size of the silver nanoparticles prepared by the preparation method of the present invention is relatively uniform, and FIG. 2B can also prove that the particle size is uniformly distributed, and the average particle size of the silver nanoparticles is 10 nm.

[0042] Example 3

[0043] The above-mentioned chitosan with a degree of deacetylation ≥70% and an average molecular weight of 15,000 is dissolved in 0.03% acetic acid, and then the solution is mixed with a silver nitrate solution to obtain a mixed solution, which contains 0.005wt% chitosan Sugar and 5.0×10 -4 mol.L -1 Of silver nitrate, the mixed solution is adjusted to pH 3.0 with acetic acid; pure nitrogen is introduced for deoxygenation, with 60 The Co source was irradiated with an irradiation dose of 10kGy to obtain a bright yellow solution; this solution was dropped on a copper net for drying, and then scanned with a transmission electron microscope. The result is shown in Figure 3A (TEM magnification of 40 thousand times, the scale of the figure is 50nm) As shown, the particle size distribution is shown in Figure 3B.

[0044] The results show that: it can be seen from FIG. 3A that the particle size of the silver nanoparticles prepared by the preparation method of the present invention is relatively uniform, and FIG. 3B can also prove that the particle size is uniformly distributed, and the average particle size of the silver nanoparticles is 8 nm.