本研究為利用靜電紡絲技術製備銳鈦礦相二氧化鈦奈米纖維。靜電紡絲法是一種利用高分子溶液或融熔態在高電場作用下由噴嘴噴出進行紡絲的過程，我們使用溶膠?凝膠(Sol-gel)法製備前驅溶液，將聚乙烯?咯烷酮(PVP)與異丙醇鈦混合在酒精溶液之中，當液滴在高電場作用下由針頭注射出形成靜電射流後，會形成PVP及非晶二氧化鈦的複合奈米纖維。接著這些纖維再於空氣中利用450°C退火處理去除高分子及殘留溶劑，並使二氧化鈦結晶形成銳鈦礦相。此外，我們可藉由改變四種電紡的製程參數：PVP濃度、注射速率、電壓及收集距離，探討其對二氧化鈦奈米纖維形貌與直徑的影響；藉由加入硝酸銀至前驅溶液，可以合成出二氧化鈦/銀的複合奈米纖維；藉由加入礦物油至前驅溶液進行共紡，可製備出具有中空結構的二氧化鈦奈米管；藉由改變收集器的形式變成兩平行導電電極，可製備出具有序排列的奈米纖維。 接著我們將異丙醇鈦及醋酸鈷分別溶於乙二醇單甲醚中並混合均勻，再加入PVP高分子。以此前驅溶液進行電紡，經由不同的退火溫度而得到鈦酸鈷的奈米纖維，可應用於氣體感測器及光催化等方面。 In this study, we utilized electrospinning technique to fabricate anatase TiO2 nanofibers, by using a polymer solution or melt injecting from a small nozzle under the influence of high voltage electric field. We used the sol-gel method to synthesis the precursor which containing both poly(vinyl pyrrolidone) (PVP, Mw ? 1,300,000) and titanium isopropoxide in ethanol. When the liquid was injected through a needle under a strong electrical field, composite nanofibers made of PVP and amorphous TiO2 were formed as a result of electrostatic jetting. The polymer or residual solvent in these nanofibers could be subsequently removed and these nanofibers could convert into anatase phase via annealing in air at 450°C. In addition, we fabricated TiO2 nanofibers by using different parameters: PVP concentration, feeding rate, voltage, and collecting distance. We discussed how these parameters affected the morphology and the diameter of TiO2 nanofibers. By adding AgNO3 to our TiO2/PVP precursor, we could fabricate TiO2/Ag composite nanofibers. By using co-electrospinning method by adding mineral oil to TiO2/PVP precursor, we could fabricate hollow TiO2 nanotubes. By modifying the form of the collector to two parallel conducting electrodes, we could generate nanofibers as uniaxially aligned arrays. Then titanium isopropoxide and cobalt acetate were dissolved in 2-methoxyethanol followed by adding PVP. Using above solution as the precursor for electrospinning, via different annealing temperature, we could obtain CoTiO3 nanofibers. The CoTiO3 nanofibers could be used in gas sensors and photocatalysts.
