3results about How to "Control dispersion" patented technology

The application discloses a kind of synergistic toughening and improving glass transition temperature core-shell nanoparticles / dynamic polyimide composite, the formula of the composite includes matrix phase polyimide resin and reinforcing phase polymer core-shell nanoparticles.Preferred raw materials include p-xylylene, triamine crosslinking agent, diamine, polymer core-shell nanoparticles and the like.The preparation route includes: first, polymer core-shell nanoemulsion is phase transferred or directly core-shell nanoparticles are compounded with dynamic polyimide polymer material to modify, the toughness, glass transition temperature and contact angle size of modified dynamic polymer material are significantly improved.The application provides a new means for the composite modification of dynamic polyimide material, and is expected to further broaden and deepen its application in resin matrix, composite and other fields.

The invention provides a metal cluster containing bound positive and negative ion pairs, a preparation method of the metal cluster, a high-dispersion metal catalyst and a preparation method and application of the high-dispersion metal catalyst. The preparation method of the metal cluster containing bound positive and negative ion pairs comprises the following steps: dissolving a metal compound in a mixed solution containing water, alcohols and a ligand, and mixing to obtain a metal precursor solution; and sequentially adding a protective agent and a reducing agent into the metal precursor solution, and mixing to obtain a solution of metal clusters containing bound positive and negative ion pairs. The high-dispersion metal catalyst provided by the invention can be directly prepared by dipping carrier particles into a metal cluster solution protected by bound positive and negative ion pairs; by dynamically loading bound positive and negative ion pairs on the metal surface, excessive metal aggregation in the catalyst preparation process can be prevented, so that the effect of controlling the metal dispersity is achieved, and the technical route of implementing bound positive and negative ion pair protection and cluster soft landing on metal clusters is realized.

This invention provides a method for preparing high-sphericity gold powder, relating to the field of nanomaterial preparation technology. The method involves sequentially adding a multi-ligand stabilizer solution and an acidic solution to a chloroauric acid solution, adjusting the pH of the reaction system to 4.0-5.0 to obtain solution A. Then, a dispersant solution is rapidly added to solution A for a first-stage mixing, followed by the rapid addition of a reducing agent solution for a second-stage mixing. Subsequently, a morphology-optimizing agent solution is added dropwise to the reaction system, and after sufficient reaction, the precipitate is collected to obtain high-sphericity gold powder. This invention achieves precise control of gold powder morphology through the competitive adsorption between ligands by adding a multi-ligand stabilizer to the chloroauric acid solution. Furthermore, the addition of an acidic solution to the chloroauric acid solution further consolidates the morphology control of the gold powder. The acidic pH of the solution after adjustment further slows down the reduction rate, resulting in better dispersibility and more uniform size of the gold powder.