| Chemistry, an ancient discipline, is vibrant with rapid development. It permeates every corner of our lives and promotes the development and progress of human society. Despite the rapid development of chemistry, most explores of chemical experiment still rely on manual mode. For example, for the synthesis of some nanomaterials, even sometimes it is very difficult to do and is toxic to human body, science researchers have to finish it by themselves. However, for such experiment, manual operation may not only cause low repeatability of the experiment but also bring personal injury. The development of modern information and automatic control technology has deeply changed the way of human’s life, which provides great convenience for us. We believe that these techniques may bring a qualitative leap to scientific research if they are applied to experimental research.Based on the potential application of automatic control technology in the scientific studies, after several years of efforts, we developed an automatic synthesis instrument of nanomaterials that can automatically control the experimental parameters, such as temperature, stirring speed, airflow velocity, rate of feeding and so on. By this way, we can synthesize nanomaterials automatically. Using this instrument to synthesize nanomaterials can significantly reduce the experiment errors, improve the repeatability and control precision of experiments, also it can provide more abundant experimental information for researchers to analyze the results.Due to the promising applications of the rare earth doped upconversion nanomaterials in biomedical and other fields in recent years, we chose it as an important synthesis of example of the automatic synthesis instrument. By successfully synthesizing the sub-10 nm Na YF4 nanoparticles repeatedly, this instrument shows us its striking capabilities in materials synthesis and exploration. It’s worth noting that, nanoparticles can be cleared by kidneys when their sizes are less than 10 nm, it proves that upconversion nanomaterials with small size have special advantages in the field of biomedicine. However, it is difficult to synthesize upconversion nanomaterials with small size in manual way, and the repeatability of experiments is low. In recent years, researchers synthesized sub-10 nm Na YF4 nanoparticles by doping Gd3+ or introducing oleylamine, they all used manual method that needs high learning costs, and it also can not solve the problem of experimental repeatability. While, one can synthesize upconversion nanomaterials by automatic synthesis instrument of nanomaterials after a simple training, it makes great contributions in learning cost, time, physical investment, material quality and experimental repeatability.Automatic synthesis instrument of nanomaterials is the first instrument at the international level which can reproducibly synthesize sub-10 nm Na YF4 nanomaterials. This instrument is to be advanced in the related fields in the domestic.We finished the following works based on this instrument:1. Developed several intelligent systems including temperature control system, stir system, feeding system and air system. In order to satisfy the synthesis requirements of nanomaterials with rare-earth doped, we optimized each system in many aspects including the choice of device types, hardware design and software design to insure that the instrument can repeatedly synthesize the nanomaterials via a thermal decomposition method. All systems not only can work alone but also can be coordinated to work together via a bus date.2. Written a master control program for the automatic synthesis instrument of nanomaterials and designed a friendly human-computer interface. Under the coordination of the master control program, automatic synthesis instrument can coordinate experiment temperature, airflow velocity, feeding rate and stirring speed. What particularly critical is that we make the instrument have a built-in template program, which can control the instrument to synthesize rare-earth doped upconversion nanomaterials automatically by clicking on the screen three times manually.3. Designed and produced a durable mechanical structure of the automatic synthesis instrument. We tried our best to make the mechanical structure easy to production, installation and maintenance. All control systems needed for thermal decomposition experiment were integrated reasonably in the instrument. We also solved the problem of mutual interference between multiple systems.4. Used a variety of security measures to ensure the safety of the Instrument. It can detect unexpected failures of temperature controlling, pneumatic controlling, stirring controlling and other control systems in the process of experiment and at the same time it will take appropriate measures to ensure safety. It provides this instrument the ability of working automatically without human attending.We successfully developed an automatic synthesis instrument of nanomaterials and used it for scientific research. The results of this study are as follows:1. Successfully synthesized sub-10 nm Na YF4 nanoparticles by using the automatic synthesis instrument of nanomaterials. We also successfully synthesized β-Na YF4 with the size of 8.5 nm. We repeatedly synthesized the β-Na YF4 for 20 times and from the statistical analysis we found that the relative standard deviation of these samples size is 2.013%. We have achieved a high repeatable synthesis of nanomaterials.2. Observed the phase transformation of nanomaterials from α phase to β phase through regulating the high temperature reaction time. We also realized the precise sizes controlling of the sub-10 nm nanomaterials and obtained nanomaterials of different sizes, including 3.1 nm, 3.8 nm, 4.9 nm, 7.0 nm, 8.5 nm and so on. At the same time, we studied the relationship between luminous efficiency and the size of those small nanomaterials.3. Found that the optimum doping ratio of Yb and Er for 8.5 nm β-NaYF4 is 13%Yb3+ and 4% Er3+ by taking advantage of the high repeatability of the automatic synthesis instrument.
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