Solution dispersion method

In the solution dispersion method, first matrix resin is dissolved in solvent then treated inorganic whiskers are added and well stirred until evenly dispersed in solution. Next solvent is removed or polymerized, and a composite material is obtained. 

Considering epoxy resin filled with potassium titanate whisker as an example, the specific operation is as follows. Mix bisphe-nol A-glycidyl methacrylate (bis-GMA) and triethylene-glycol dimethacrylate at a mass ratio of 1 1 as a resin matrix add initiator benzoyl peroxide (BPO) and the polymerization inhibitor butylated hydroxytoluene (BHT, 264) and blend uniformly. Then mix surface-modified potassium titanate whisker into the resin, fill into the mold, and cure in an oven at 120°C for 30 minutes. 

The method for bismaleimide resin filled with whiskers is similar to the preceding. The mass ratio of BMI (bismaleimide) and BA (diallyl bisphenol A) is 1 0.8. First, heat BA to 130°C, then add BMI slowly, prepolymerize for 20 minutes, add the whisker, mix uniformly, pour into a glass mold coated with a release agent, vacuum and deaerate at 120-130°C for 15 minutes, and cure according to the following sequence l45°C/2 h + l60°C/2 h + 180°C/2 h + 200°C/2 h. Finally, posttreat at 220°C for 6 h. 

The characteristics of the solution dispersion method are low temperature, small viscosity of solution, and more uniform dispersion. However, this method is used mostly for the preparation of composite material of thermosetting resin filled with whiskers. 

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Nanolubricants of Indium, Tin and Bismuth via the Direct Solution-Dispersing Method... 

Figure 54 Schematic illustration of the formation process of metal nanoparticles by the direct solution-dispersing method...

Soft metals such as indium, tin and bismuth are good solid lubricants, but they cannot be used as a lubricating oil additive because of their poor dispersibility in oils. However, their nanoparticles prepared by the direct solution-dispersing method have been found to have better oil solubility and can be directly used as lubricating additives. Their tribological properties have been evaluated on a four-ball tester and the results are presented as follows. 

Figure 5.9 shows the TEM images and XRD patterns of Bi nanoparticles stabilized by SA (Bi-SA), Pb nanoparticles stabilized by SA (Pb-SA) and Pb nanoparticles stabilized by PEG (Pb-PEG) prepared by the surfactant-assisted solution-dispersing method [19, 20]. It can be... 

In conclusion, nanoparticles of low melting point metals, including indium, bismuth, tin and lead, can be easily prepared via the solution-dispersing method. The simultaneously formed oxide layer or the in situ generated surfactant layer is retained to prevent the reconjunction of little metal drops during the preparation process and improved the dispersibility of the... 

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