Gold Nanoparticles - Properties - Centrifuge Speeds

When working with monodisperse nanoparticles, including spheres, rods, micron sized gold and gold nanowires, the centrifuge can be used for not only quick purification, but also size selection.

Table 1 shows the recommended centrifuge speeds as a function of spherical nanoparticle size. Please note that these are recommended speeds and that these speeds can change for a variety of reasons. We are also assuming that rpm=rcf, which is not true for many centrifuges. Finally, we recommend times on the order of 2 minutes per mL of gold nanoparticle solution.

Tables 2 through 7 shows the equivalent sphere size for the different sizes of nanorods, microgold, and nanowires. Using these Tables and then referring to Table 1 will give you the approximate speeds necessary for centrifugation of these shaped particles.

 

SGNP Size (nm) Speed (rpm) Notes
1.8-5 150000 Ultracentrifuge
7 20000  
10 15000  
15 12000  
20 10000  
30 6000  
40 5000  
50 4000  
60 3500  
70 3000  
80 2500  
90 2000  
100 1500  

Table 1 Recommended centrifuge speeds vs. spherical gold nanoparticle size

 

Nanorod Diameter (nm) Nanorod Length (nm) Nanorod Volume (nm3) Diameter of Equiv Sphere (nm)
       
10 19 1230 13
10 24 1622 15
10 29 2015 16
10 35 2486 17
10 38 2721 17
10 41 2957 18
10 45 3271 18
10 50 3663 19
10 55 4056 20
10 59 4370 20
10 67 4998 21
10 81 6097 23
10 102 7745 25
10 175 13476 30

Table 2. 10nm Nanorod diameter/length and calculated volume with equivalent sphere diameter

 

Nanorod Diameter (nm) Nanorod Length (nm) Nanorod Volume (nm3) Diameter of Equiv Sphere (nm)
       
25 34 12593 29
25 57 23877 36
25 71 30746 39
25 75 32708 40
25 85 37615 42
25 87 38596 42
25 90 40068 42
25 93 41540 43
25 96 43011 43
25 102 45955 44
25 119 54296 47
25 137 63127 49
25 245 116115 61

Table 3. 25nm Nanorod diameter/length and calculated volume with equivalent sphere diameter

 

Nanorod Diameter (nm) Nanorod Length (nm) Nanorod Volume (nm3) Diameter of Equiv Sphere (nm)
       
40 60 58613 48
40 68 68661 51
40 80 83733 54
40 92 98805 57
40 112 123925 62
40 124 138997 64
40 134 151557 66
40 148 169141 69

Table 4. 40nm Nanorod diameter/length and calculated volume with equivalent sphere diameter

 

Nanorod Diameter (nm) Nanorod Length (nm) Nanorod Volume (nm3) Diameter of Equiv Sphere (nm)
       
50 100 163542 68
50 110 183167 70
50 145 251854 78

Table 5. 50nm Nanorod diameter/length and calculated volume with equivalent sphere diameter

 

Microgold Diameter (nm) Microgold Length (nm) Microgold Volume (nm3) Diameter of Equiv Sphere (nm)
       
75 500 2097422 159
100 1000 7588333 244

Table 6. Microgold diameter/length and calculated volume with equivalent sphere diameter

 

Nanowire Diameter (nm) Nanowire Length (nm) Nanowire Volume (nm3) Diameter of Equiv Sphere (nm)
       
75 1000 4305234 202
75 2000 8720859 255
75 3000 13136484 293
75 4000 17552109 322
75 5000 21967734 348
75 6000 26383359 369
75 7500 33006797 398
75 10000 44045859 438

Table 7. Nanowire diameter/length and calculated volume with equivalent sphere diameter