| 摘要: | 本研究的主要的目的在於製作奈米級MFI沸石粒子,再利用界面活性劑聚集這些沸石粒子。期望產物有微孔-中孔的層次結構,以增進產物的利用價值。 在實驗合成的步驟上,我們利用Kirschhock於1999年發表的文獻為基礎,從透明的MFI precursor製備至奈米沸石粒子。接下來直接在沸石懸浮溶液中加入界面活性劑,希望溶液中的沸石粒子間可以聚集出具有中孔結構之二次粒子。我們發現只有一次的水熱程序的溶液中,會生成奈米沸石粒子與subcolloid particle的共存情形。因此我們使用二次水熱程序的方式,使溶液中的subcolloid particle完全轉換成奈米沸石粒子,使溶液中幾乎只存在奈米沸石粒子。 我們發現使用二次水熱程序下所獲得之奈米沸石粒子團聚物,在XRD測量是非晶態,但是經過1300C 24 hr之蒸氣處理後,會得到MFI的吸收峰。由氮氣恆溫吸附的結果發現,吸附量會因蒸氣處理的溫度及時間的增加而有較高微孔的吸附量。用TEM 觀察發現溶液中幾乎全為10 nm左右的奈米沸石粒子。用SEM觀察產物之表面也只看到約20 nm的沸石粒子。 The objective of this study is to prepare nano zeolite particles, and then, use surfactant to aggregate these nano particles. We wish to produce the aggregation of nanoparticles, with intercrystalline mesoporousity. We follow approach of Kirshhock et al. to prepare precursor of MFI-nano zeolitic particles. We have used the method of addition of surfactant into the zeolitic solution to aggregate nano particles. Particles show meso -pores between them. We discover that, when we use only one heating step to make particles, we find nano zeolite particles and subcolloidal particles coexisting. So,we have changed our process to double heating process. If we use this process, we find subcolloidal particles almost become nano particles. When we use double heating process to prepare nano zeolitic particles, we need higher steaming temperature and longer steam time. We can see the XRD diffraction peaks and value of microporous adsorption also in-creases. We have used SEM and TEM to observe the nano zeolitic particles. We believe that, this process can be used to make the assembly of MFI nano zeolitic structure,with intercrystalline mesoporousity. |
