Kevlar fibers airgel high temperature and the low temperature Preparation of Nano
Due to the cold Dress for warmth, light and functionality of the increasingly high, resulting in its basic materials – warm fiber requirements are also increasing. Aerogels fiber has a very high porosity, and other salient features of ultra-low density, thermal insulation effect is theoretically the best kind of fibers, the ultrafine fibers is expected to replace, or even subvert down, is the next-generation the most important development direction of warm fiber. However, the high porosity characteristics also contributed to the preparation of airgel facing great challenges. In view of this, and of Nano Nano Technology Research Institute, Chinese Academy of bionic Zhang aerogels team led by the same researchers nanofiber dispersion liquid obtained by dissolving a DuPont (TM) Kevlar fibers, and wet spinning, a special drying process of preparing a having a high porosity (98%) and high surface area (240 m2 / g) of the airgel Kevlar fibers, as shown in FIG. The airgel fibers having excellent mechanical properties, can be bent, knotting, weaving and the like. The airgel fiber also has excellent heat insulating properties, thermal conductivity rate was 0.027 W / m · K at room temperature, at low temperatures, the insulation is 2.8 times of cotton, in extreme environments may be -196 to 300 degrees Celsius under a long time to play a thermal insulation properties. In addition, the airgel fiber also has excellent chemical stability, can be a variety dye, hydrophobic, chemically-modified airgel plating does not damage the main backbone structure. Finally, the fibers may also airgel phase change material prepared by filling conditioned fiber, which can reach enthalpy 162 J / g, far more than the existing commercial air conditioning Outlast fibers enthalpy.