| 摘要: | 本篇論文主要合成兩種磷酸官能基化的中孔洞材料，並分別探討磷酸官能基化之中孔洞材料對於吸附鑭系金屬中的鉺金屬以及除草劑巴拉刈的吸附效果。
合成方面分為兩大部分，第一部分是以非離子型界面活性劑Brij-76當作模板，以1,4-bis(trithoxysilyl)benzene (BTEB) 和3-(Trihydroxysilyl)propyl methylphosphonate (SPMP) 當作共同矽源，在低酸量的條件下以直接共聚合成法合成出雙官能基的中孔洞材料BS-x，第二部分同樣是以Brij-76當作模板，利用SPMP和Tetraethyl orthosilicate (TEOS) 為共同矽源，合成出含有磷酸官能基的TS-x材料，兩者的磷酸官能基含量皆可高達到40 %。並利用X-ray 粉末繞射、固態核磁共振光譜、等溫氮氣吸脫附、熱重分析儀、穿透式電子顯微鏡及掃描式電子顯微鏡等儀器鑑定材料的結構，同時也鑑定官能基含量對孔洞性質的影響。
應用方面，首先探討鑭系金屬中鉺金屬的吸附，並比較兩種磷酸官能基材料的吸附能力，由結果可得知，若材料中磷酸官能基含量越多，越利於提升金屬的吸附效果，且吸附的最佳條件為pH = 3.5。比較於其他鑭系金屬，含有磷酸的材料對於鉺金屬有較佳的吸附能力，在經過四次重複利用後仍然保有99 %以上的重複使用能力。
在吸附除草劑巴拉刈的實驗部分，發現若修飾上的磷酸官能基越多可能會使孔洞阻塞而不利於巴拉刈的吸附，由於巴拉刈為具有芳香環的分子，利用含有苯環的BS系列材料，藉由 π-π 分子間的吸引力讓巴拉刈更容易進入到孔洞內部和官能基鍵結，進而提升吸附效果。
;Here we report synthesis of two kinds of materials functionalized with tunable content of phosphonic acid groups, to adsorb Erbium ions and Paraquat.
One is bifunctional materials, synthesized by co-condensation of two different organosilane precursors, that is, 1,4-bis(triethoxysilyl)benzene (BTEB) and sodium 3-(trihydroxysilyl)propyl methyl phosphate (SPMP), under acidic condition using nonionic surfactant Brij-76 as template. These materials were periodic mesoporous organosilicas (PMOs) with benzene bridging groups in the silica wall, and denoted as BS-x, where x is the mole ratio of phosphonic acid groups.
The other is synthesized by co-condensation of tetraethyl orthosilicate (TEOS) and SPMP under same condiction like BS-x, and is called TS-x.
Materials were characterized by powder X-ray diffraction (XRD), nitrogen sorption measurements, solid-state 13C and 29Si MAS NMR spectroscopy, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and transmission electron microscopy (TEM).
In adsorption experiment, first, we used BS-x and TS-x to adsorb erbium ions.
The adsorption process was carefully studied with differernt factors.The results reveal that the adsorption of erbium ion on mesoporous silica is strongly dependent on the content of phosphonic acid (PA) groups, and increases with the PA content increases.Theses materials retained more than 99 % metal removal efficiency after use for four consecutive cycles.
The second adsorption experiment suggested that there is a benefit for the use of aromatic groups as the enhanced π-π interaction between the aromatic groups of the BS-x materials and paraquat increase the adsorption in comparison to TS-x.The synthesized materials are promising for adsorption of herbicides. |
