The column diameter is large enough to be packed by dry or slurry packing. However, I do recommend dry packing as the back pressure of the column would be too high for slurry packing.
Yet, it will be too difficult to run the column! One strategy can be immobilization of the nano-particles on the surface of larger particles.
Please see the following ref.:
Article Bimodal porous silica microspheres decorated with polydopami...