Background and overview[1]
Lithium benzoate appears as white crystals or powder and is hygroscopic. It turns into liquid crystal when heated. In aqueous solution, it does not decompose even when heated to high temperatures. The aqueous solution is slightly alkaline, with a pH of approximately 8. Its hemihydrate is colorless crystal. Monohydrate is a colorless crystal, which shows lavender fluorescence and slowly decomposes when illuminated by 3.65×10-7m wavelength. Its acid salt is colorless leaf-shaped crystals. It can be prepared by dissolving lithium carbonate in benzoic acid aqueous solution and used as a lubricant during tableting.
Structure
Apply[2-4]
Lithium benzoate is an excellent food preservative. It has the dual functions of benzoic acid and elemental lithium. It can be used for the preservative and sterilization of synthetic cream, juice, soda and beverages, etc., with good results. Benzoic acid is a pharmaceutical intermediate and fine chemical intermediate with significant physiological and chemical activities. It has significant antibacterial effects and can be used as a disinfectant and preservative to prevent and treat fungal infections of the skin, such as tinea corporis, tinea manuum and tinea pedis, etc. It can also be used as a preservative for food and medicine. In addition, it can be used to synthesize a series of high value-added products, which are cheap and easy to obtain. Lithium is an important biometallic element that has certain physiological activity in animals and humans. It can be used to treat manic depression, cyclic tension and other neuropathies, hyperthyroidism, thyrotoxicosis, thyroid cancer, paralysis shaking, Various diseases such as antidiuretic disorders, leukopenia, and aplastic anemic disorders.
Examples of applications of lithium benzoate are as follows:
1. Organic photovoltaic cells using lithium benzoate as the cathode modification layer belong to the field of organic photovoltaics. It includes a transparent conductive substrate 1, anode buffer layer PEDOT: PSS 2, active layer 3, cathode modification layer 4 and metal back electrode layer 5. The cathode modification layer 4 can be deposited on the active layer 3 by thermal evaporation or solution spin coating.
The preparation method includes:
(1) Clean the transparent conductive substrate and dry it;
(2) Spin-coat PEDOT:PSS anode buffer layer 2 and so on on the transparent conductive substrate 1 in the air or under the protection of inert gas.
In the present invention, lithium benzoate is used as the cathode modification layer of the organic photovoltaic device through thermal evaporation or solution spin coating. Compared with the traditional inorganic salt lithium fluoride (LiF) cathode modification layer, the lithium benzoate organic salt as the cathode modification layer can form a better interface contact with the active layer, thereby significantly improving the photovoltaic performance of organic photovoltaic cells. conversion efficiency and stability.
Manufacturing lithium niobate optical waveguide mainly includes cleaning the substrate sheet, preparing a mask on the substrate sheet, photolithography of the waveguide pattern, proton exchange, annealing, end-face polishing, waveguide adjustment and inspection steps. Since the proton source for proton exchange is a mixed solution of benzoic acid diluted with lithium benzoate, according to the chemical reaction principle of proton exchange, incorporating lithium benzoate into benzoic acid increases the lithium ion concentration in the solution and changes the H+ to The balance of Li+ reduces the H+ concentration, thereby reducing the reaction speed and lithium ion exchange volume, and reducing the refractive index difference between the waveguide and the substrate. Combined with annealing, a refractive index distribution more suitable for coupling with optical fibers is obtained, while the corrosion effect of benzoic acid is reduced, waveguide defects are reduced, and the loss of the waveguide itself is reduced.
2. Prepare an organic polymer solar cell. The main structure of the cell is composed of glass layer, indium tin oxide coating, ethylene dioxythiophene and polystyrene sulfonic acid mixed coating, polythiophene and fullerene mixed The coating is composed of a mixed coating of lithium benzoate and lithium fluoride and an aluminum layer; the spraying process is completed using a solution spin coating process at room temperature.
Advantages of this utility model: the photoelectric conversion efficiency and stability of the new organic polymer solar cell are greatly improved; the battery is light in weight, easy to carry, and suitable for field operations; the composition of the organic polymer material can be realized through chemical processes, and the material The cost is low; the processing technology is relatively simple and the production cost is low; the material itself has good flexibility and film-forming properties, and can achieve roll-to-roll mass production.
Preparation[2]
Lithium benzoate was synthesized using benzoic acid and lithium hydroxide as reactants: weigh benzoic acid and lithium hydroxide monohydrate at a molar ratio of 1:1. Place lithium hydroxide monohydrate into a large beaker, add an appropriate amount of deionized water,The hot solution is nearly boiling to completely dissolve the lithium hydroxide, and then slowly add benzoic acid to the solution, heat under reflux, keep the solution at 90 ℃, and stir for 4 hours to allow it to fully react. Concentrate the clarified solution in an electric furnace until a crystal film appears, and then cool it naturally to room temperature. After a large amount of solid has precipitated, filter it with suction, and wash it with absolute ethanol three times to obtain a white product, which is then mixed with an appropriate proportion of ethanol and water. The solution was recrystallized twice to obtain a white product. Place the sample in a vacuum drying oven, control the temperature to 50 ℃, and dry it. Finally, the samples were placed in a desiccator for later use.
Main reference materials
[1] Compound Dictionary
[2] Synthesis, structural characterization and thermochemical study of anhydrous lithium benzoate
[3] CN201010284047.7 An organic photovoltaic cell using lithium benzoate as the cathode modification layer and its preparation method
[4] CN01140590.2 Method for manufacturing lithium niobate optical waveguide by proton exchange
[5] CN201120477121.7 Organic polymer solar cell
