合成規則性中孔洞有機矽薄膜並在有機矽孔壁存在分子尺寸規則排列

Periodic Mesoporous Organosilica Thin Films with Molecular Scale Order within the Organosilica Wall

吳昇穎(Sheng-Ying Wu)

指導教授 ： 黃暄益

國立清華大學/理學院/化學系/碩士(2007年)

摘要

我們成功的利用1,4-bis(triethoxysilyl)benzene (BTEB)作為前驅物 和旋轉塗佈的方式去合成出規則性中孔洞有機矽薄膜，並在薄膜裡面含有規則性的分子排列，我們從粉末式X-ray繞射圖形裡得知存在有六角堆積的中孔洞結構並在孔壁裡含有分子尺度的規則排列。並且在去除界面活性劑後仍可以保持中孔洞的性質還有分子尺度規則排列。我們在研究中也發現，我們的前驅物BTEB水解後縮合的程度很低，並且在每個分子中存在分子間氫鍵，這也是造成孔壁中含有規則性的分子排列的主要因素，而且跟之前的文獻比較起來，我們的分子間距離多了一個氫鍵的長度，在紅外線光譜儀裡也發現我們的薄膜裡含有大量的氫鍵，更進一步證明氫鍵是造成規則性分子排列的主因。在穿透式電子顯微鏡下，我們也清楚的看見在中孔洞的孔壁裡存在條紋狀的規則性排列。

關鍵字

中孔洞 ； 有機矽薄膜 ； 分子尺寸

並列摘要

Periodic mesoporous organosilica (PMO) thin films with long-range molecular order within the organosilica framework have been successfully prepared by spin-coating a solution of 1,4-bis(triethoxysilyl)benzene (BTEB), water, ethanol, HCl, and cetyltrimethylammonium bromide (CTAB) on 1 cm2 silicon substrates. Powder XRD patterns of these thin films reveal the presence of a hexagonal phase mesostructure as well as highly ordered molecular scale structure. The strong diffraction peaks at 8.8, 17.6, and 26.6° 2θ identify the long-range molecular order within the organosilica framework. The mesostructure and molecular scale order can be preserved upon solvent extraction to remove the CTAB surfactant template. The degree of silica condensation is relatively low, and hydroxyl groups formed in the hydrolysis reaction link the BTEB precursor molecules together in an end-to-end fashion via hydrogen bonding. This gives rise to the observed shift in the positions of the XRD peaks to slightly lower angles, as compared to the fully condensed state. FT-IR spectra of these thin films suggest that the PMO films contain a significant number of hydroxyl groups in a hydrogen bonding environment with a peak at 3200 cm–1. High-resolution TEM images reveal both the presence of mesopores and lattice fringes from the ordered packing of the hydrolyzed precursor molecules. Results from the 29Si-NMR will also be presented to provide additional evidence of the lower degree of organosilica condensation in these PMO thin films. This is the first time in which PMO thin films with both hexagonal mesostructure and high molecular scale order have been successfully prepared.

並列關鍵字

mesoporous ； organosilica thin films ； moleculae scale

參考文獻

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