【摘要】 以溶胶凝胶法制备出了TiO₂纤维,对纤维的可拉丝条件和TiO₂纤维的结构转变进行了研究。结果表明:当R_w≤2时（R_w=H₂O/Ti（OC₄H₉）₄）,溶胶液的可拉丝性较好。当加水量R_w>2时,可拉丝性逐渐变差。X射线小角散射结果表明,低R_w下TiO₂凝胶结构为链状聚合体。在本系统中,随R_w值增大,溶液的胶凝时间有延长的趋势。随热处理温度升高,发生了非晶态转变成晶态的锐钛矿,然后再转变成金红石的相变过程。在热处理温度达315℃,TiO₂纤维中已基本脱去羟基、烷基和分子水基团。R_w=2样品的密度要大于R_w=1样品的密度,且化学稳定性较好。更多还原

【Abstract】 TiO₂ fibers have been developed via sol-gel approach. The drawing possibility and the structural transformation of TiO₂ fibers are studied. Results show that the good spinnability of sols is easy to obtain under the condition of R_w≤2 （R_w=H₂O/ Ti（OC₄H₉）₄）; and when R_w>2, the drawing of TiO₂ fibers from sols tends to difficulty. Results of small angle X-ray scattering （SAXS） demonstrate that the structure of TiO₂ gels with low R_w is made up of the chainlike polymers. With an increase of the R_w value, the gelation time of sols will be prolonged in this system. As the temperature of heat-treatment rises, occurs the transformation from amorphous state to anatase and then into rutile. When the heating temperature reaches 315℃, the structural groups of hydroxyl, alkyl and molecular water in the TiO₂ fibers are removed. The density of TiO₂ fibers with R_w =2 is larger than that of the samples with R_w =1. Moreover, TiO₂ fibers with R_w=2 have a better chemical durability.更多还原