Study On Controllable Preparation Of Nano-copper Powder By Rotating Bed With Helical Channels High-gravity Reaction Technology

As a new generation of nanomaterials with the most development potential,nano-copper is used in sensor materials,optical materials,flexible electronic materials,electrode materials,solar cell materials,etc.due to its unique physical and chemical properties.more attention.In general,the application and performance of nano-copper mainly depend on its particle size and its stability.However,most of the existing synthesis processes cannot precisely control the particle size of nano-copper,and the prepared copper powder is difficult to meet the technical requirements of specific application scenarios.This makes the precise and controllable preparation of nano-copper one of the hotspots in nanomaterials research today.In this paper,a brief overview of the preparation and application of nano-copper is given,and the current difficulties in the synthesis of nano-copper are pointed out.Then,a new idea for the controllable preparation of nano-copper powder is proposed,that is,helical channel type rotating bed hypergravity reaction technology,through the reaction principle of this technology to prepare nano-precursors with controllable particle size,and obtain nano-copper powder with controllable particle size by reduction method.And the nano-copper was characterized by XRD,SEM,FESEM and so on.The main research conclusions are as follows:（1）Explore the optimal process conditions for the preparation of nano-copper precursors.It was found that when the concentration of Cu SO₄·5H₂O and Na₂CO₃was0.2 mol/L and the ratio was 1:1,10 g PVP dispersant was added to 2 L Cu SO₄·5H₂O solution,and the Na₂CO₃ mixture composed of 1.5 L water and 0.5 L ethylene glycol was added.When 10 g of PVP dispersant is added,the flow rate of the rotameter is1L/min,and the supergravity level is 1200 rmp,the copper precursor CuO with a particle size of 10-70 nm can be prepared,and the particle size distribution is uniform and the dispersion is good.（2）To explore the optimal process conditions for obtaining nano-copper by reducing precursor CuO with glycerol as reducing agent and medium at high temperature.It was found that when the reduction temperature was 200°C,PVP and ethylene glycol were added as dispersants during the preparation of the precursor,the rotational speed was 900 rpm,and the molar ratio of the precursor to PVP during the reduction process was 1.68,the prepared nano-copper had a uniform particle size distribution,The crystallinity is high,the crystal structure is complete,the average size is 600-700 nm,and it does not oxidize after being placed at room temperature for17 months,and the stability is good.（3）Further explore the optimal process conditions for obtaining nano-copper by using ethylene glycol as the medium and hydrazine hydrate as the reducing agent to reduce the precursor.It is found that when PVP is the dispersant,the reaction temperature is 60°C,and the volume ratio of ethylene glycol to reducing agent is 8:1,the particle size of the precursor CuO is controlled by the rotor speed,and then the precursor is reduced,and the particle size distribution can be obtained.It is 100-200nm,80-160 nm,70-150 nm,60-140 nm,50-120 nm,30-110 nm nano-copper,and the prepared nano-copper is placed at room temperature for 5 months without oxidation.（4）To explore the optimal process conditions for preparing nano-copper with glycerol as the medium and hydrazine hydrate as the reducing agent to reduce the precursor.It was found that when glycerol was used as the medium,PVP was used as the dispersant,the reduction temperature was 60°C,and the concentration of hydrazine hydrate was 1.65 mol/L,precursors with different particle sizes were controllably prepared by adjusting the hypergravity level,and then the precursors were reduced.Nano-copper with different particle sizes can be obtained in a controllable manner,and its particle size distribution is:100-200 nm,60-110 nm,60-100 nm,50-90 nm,35-70 nm,25-40 nm,and no oxidation occurs when placed at room temperature for 5 months.