Colloidal Hydrothermal Synthesis Of Nano-tin Dioxide Powder

The nanometer tin dioxide powder aspects were prepared with the colloid-hydrothermal system which takes the merit of sol - gel law and hydrothermal method, and combine forming new preparing method -colloid-hydrothermal after the analysis of a large number of documents to the home and abroad and comparing to more than ten kinds of methods preparing the nanometer powder aspect, the nanometer stannic dioxide powder is prepared with the colloid hydrothermal system, and has avoided the pure sol - gel law to calcine with high temperature later period which causes the hard agglomeration.This law includes two steps: First step apply the sol - glue system to prepare pure concentrated stannic acid gel. Second step, the nanometer tin dioxide powder aspects are gone except the water of crystallization system by the way of hydrothermal. First step of the experiment, the research of terminal point PR's value, stannic salt solution consistency and reacts solvent that the influence factor of gel to prepare has been carried on. The optimum experiment condition has been reached: Solution initial consistency reaction on 30g/100ml,'s terminal point value reaction on 2.5,'s PH's solvent use purified water. The gel is more stable to less PH's value of hydrolysis terminal point Proceed with research to centrifugal washing mechanism at the same time, and the conclusion is that centrifugal wash possess the notable effect in eliminating Cl" ion. TG-DTA detection indicates the gel possesses the good superficiality ability. The research has been in progress to second step of characteristic and mechanism to hydrothermal preparing the powder aspect, and research has been in progress by pressure to in the experiment, time and the influence to the product capability of reaction medium. By way of a large number of experiment detection, the technology parameter for when pressure 4~6atm and time 4hour can be prepared out to form the soft agglomerative state product. By way of the experiment, think thatthe low surface tension property of inorganic material is not the major cause to eliminate the powder aspect to reunite . The new method is compared with the ordinary fire law, the characteristic of product such as to possess that the diametre is small and the size distributes narrow and the agglomeration level is light etc, and for further adopting the measure scatters providing the possibility.To improve the dispersivity of particles, research the agglomerative mechanism that the nanometer powder aspect universally exists to the liquid phase. Scattered effect having inspected the active agent of first cousin's face at hydrothermal course to the anything small and roundish has been defined that the active agent of optimum surface is : Dosage joined is the citric acid : 0.05-0.1g/50ml . And use that the vacuum is dry and the follow-up measure of sphere mill to the nanometer two tin oxide powder aspects to be in progress further to scatter. After the vacuum dry and the sphere mill, the level of agglomeration is low, the particle size is very small, spherical and the nanometer stannic dioxide powder with the aspects of good scattered nature is achieved. With the contrast of same product of abroad, it is very small to possess the particle diametre, the good characteristic of scattered nature.Having carried on level of kilogram experiment, has put forward the industrialize experiment what probably is faced with synthesis, wash, solid liquid separation, antisepsis, dry and dispersity etc, and the improvement measure of such problem.