Method for concentrating nano-silver particles in water

The invention discloses a method for concentrating nano-silver particles in water. The method includes the following steps that firstly, nano-silver dispersing liquid is prepared, a hydrazine hydrate solution is dripped into a water solution of silver nitrate and a polymeric protector for a reaction, and the nano-silver dispersing liquid is obtained; and secondly, concentration of nano-silver is conducted, the nano-silver dispersing liquid and an organic acid-alcohol solution are mixed according to a certain proportion to be sufficiently reacted, depositing, filtering, washing and drying are conducted after surface modification, and the nano-silver particles are obtained. The method has the beneficial effects that the simple method through which the nano-silver particles in water are concentrated is provided, the hydroxyl and organic acid on the surfaces of the particles are used for conducting a dehydration-condensation reaction, and the hydrophilic feature of the particles is changed into the oleophylic fea