利用膠體模板製備中空二氧化鈦微球之研究

Abstract

本研究利用均一粒徑尺寸的塑膠微球作為犧牲模板(Sacrificial Template)，結合層接層法與化學水熱合成法製作無機材質二氧化鈦/塑膠微球之核殼結構。吾人藉由添加不同的分散劑，調查添加分散劑與否以及添加不同性質的分散劑對合成的中空二氧化鈦微球的影響。研究發現吾人所使用之犧牲模板添加分散劑與否都能形成中空二氧化鈦微球，吾人計算破球數與總中空球數的比值發現非離子型分散劑TX-100出現破球的機率為2.19%、未添加任何分散劑為1.55%、添加陰離子型分散劑PSS為1.6%，而添加陽離子型分散劑PDADMAC為0.22%，其中以添加PDADMAC所合成出的中空二氧化鈦微球的良率最佳。以TEM觀察微球的顯微結構，在未添加任何分散劑時的殼層厚度估計約為47 nm，吾人利用電荷相反產生靜電吸引力的作用，配合層階層法反覆吸附PDADMAC再被覆TALH的步驟5次形成(PDADMAC/TALH)5的中空二氧化鈦微球(註：(PDADMAC/TALH)n，n代表重複的次數)，以SEM觀察，(PDADMAC/TALH)1殼層厚度約為57 nm，(PDADMAC/TALH)5殼層厚度約為165 nm；從TEM觀察，前述(PDADMAC/TALH)n分別估計殼層厚度為63 nm與189 nm，但是(PDADMAC/TALH)5之機械強度似乎不是很好，出現破球的機高達3.8%；從FTIR的觀察中發現在波數465-795cm-1的穿透峰值隨溫度上升而增加，可能為Ti-OI伸展與Ti-OII彎曲特性峰所造成；從TEM觀察與熱重分析中發現經過550oC熱處理後可形成中空二氧化鈦微球，且從顯微外觀圖中發現吾人所合成出的粒子尺寸均一性佳。由吾人研究中所使用的模板合成方法，應可藉由改變核心基材的形狀與尺寸大小，來達到控制所合成的中空結構之形狀與尺寸。

This research synthesized hollow TiO2 microspheres via hydrothermal method together with colloidal organic latex spheres as a sacrificial template. The organic latex particles of uniform shape and size were coated with layers of titanium precursors hydrothermally, and effects of dispersants of various natures on the synthesized TiO2 hollow micro-spheres were examined. Form our experimented results, TiO2 hollow microspheres can be synthesized with and without the dispersants. Nonetheless, the yield for “good” hollow microspheres is different. When dispersant was not uesd, probability of the broken hollow microspheres was 1.55%. When nonionic dispersant TX-100 was used, probability for the formation of broken hollow microspheres was 2.19%. When anionic dispersant PSS was added, probability for the broken hollow microspheres was 1.6%. Finally, when cationic dispersant PDADMAC was added the probability reduced to 0.22%. By use of the layer-by-layer method, (PDADMAC/TALH)5 with multiple PDADMAC/TALH coatings were synthesized, in which (PDADMAC/TALH)n, n stands for the number of repeated adsorption of PDADMAC/TALH. From SEM, the shell thickness of (PDADMAC/TALH)1 was 57 nm, (PDADMAC/TALH)5 was 165 nm. From TEM, the shell thickness of n=1 was 63 nm, and n=5 was 189 nm. The mechanical strength of (PDADMAC/TALH)5 seems to be low, so that the probability of the broken hollow microspheres was 3.8%. The transmittance peak value at 465-795 cm-1 was increased by increasing temperature from FTIR analysis, arising from the characteristic peaks of Ti-OI stretch and Ti-OII bend. Hollow TiO2 spheres can be synthesized after thermal treating in 550oC by TEM and TG/DTA analyses. The particles have uniform size. In this study, synthesis of hollow microspheres can been control in terms of their shape and size, by changing core.