Micro-reaction device and method for synthesizing cadmium selenide nano-crystal by using temperature gradient

Abstract

The invention relates to a method and a device for micro-synthesizing cadmium selenide nanocrystals through temperature gradients. The temperature gradient of the reaction system can be adjusted by changing the relative distance between the high temperature section and the low temperature section or by selecting different thermal barrier materials. The temperature difference between the high-temperature section and the low-temperature section and the residence time in the two sections are changed to optimize the nucleation and growth process, and realize the continuous preparation of high-quality cadmium selenide nanocrystals. The invention shows the following advantages: (1) The temperature gradient method makes the particle nucleation and growth process in the microchannel flexible and reliable, and is widely applicable to chip microreaction systems and capillary microreaction systems; (2) the obtained nanocrystals The size distribution is narrow and has good performance; (3) high-quality continuous synthesis of various nanocrystals can be realized. Only need to change the precursor type and process parameters, the present invention can be widely applied to the solvothermal preparation of various nanocrystals.

Description

technical field [0001] The invention relates to a micro-synthesis device and method for controlling the nucleation and growth of cadmium selenide nanocrystals, the purpose of which is to realize the continuous preparation of high-performance cadmium selenide nanocrystals; the preparation of cadmium selenide nanocrystals by using the device has good stability, It has the characteristics of high product quality and flexible operation process; it belongs to the field of microchemical machinery and nanomaterials. Background technique [0002] The energy crisis and the deteriorating environmental problems have made miniaturization an important trend in the development of natural science and engineering technology. In particular, the development of nanomaterials and microelectromechanical systems has aroused great interest in small-scale and fast processes. The miniaturization of chemical / chemical machinery has significantly enhanced the heat transfer coefficient and mass transfer...

AI Technical Summary

Problems solved by technology

Among them, the organic solvothermal method in the flask synthesis device is a good example for the preparation of high-quality CdSe nanocrystals, but the whole reaction process has almost strict requirements on the reaction temperature, reaction time and the uniformity of the reaction materials, and the geometric amplification of the flask reaction device It will bring problems such as long control response time and poor precision, and it is difficult to ensure high consistency of reaction conditions

The effectiveness of high-temperature nucleation and low-temperature growth in controlling the reaction kinetics of nanocrystals has been widely verified. However, the lack of control accuracy and control response time of the flask device makes the determination of nucleation and growth temperatures difficult for different materials. large randomness

The application of micro-synthesis devices in the preparation of nanocrystals has effectively solved the control problem, but the existing micro-synthesis devices all use the same temperature for the nucleation and growth of nanocrystals, and the high temperature required for instantaneous nucleation makes the follow-up process of nanocrystals difficult. The growth process is out of control, which directly leads to the broadening of the size distribution of nanocrystals and the reduction of crystallization properties

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