International Center for Materials Nanoarchitechtonics (MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki, 305-0044, Japan.
International Center for Materials Nanoarchitechtonics (MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki, 305-0044, Japan.
Chemosphere. 2021 Aug;276:130181. doi: 10.1016/j.chemosphere.2021.130181. Epub 2021 Mar 3.
Microporous organosilicas assembled from polysilsesquioxane (POSS) building blocks are promising materials that are yet to be explored in-depth. Here, we investigate the processing and molecular structure of bispropylurea bridged POSS (POSS-urea), synthesised through the acidic condensation of 1,3-bis(3-(triethoxysilyl)propyl)urea (BTPU). Experimentally, we show that POSS-urea has excellent functionality for molecular recognition toward acetonitrile with an adsorption level of 74 mmol/g, which compares favourably to MOFs and zeolites, with applications in volatile organic compounds (VOC). The acetonitrile adsorption capacity was 132-fold higher relative to adsorption capacity for toluene, which shows the pores are highly selective towards acetonitrile adsorption due to their size and arrangement. Theoretically, our tight-binding density functional and molecular dynamics calculations demonstrated that this BTPU based POSS is microporous with an irregular placement of the pores. Structural studies confirm maximal pore sizes of ∼1 nm, with POSS cages possessing an approximate edge length of ∼3.16 Å.
由聚倍半硅氧烷（POSS）构筑块组装而成的微孔有机硅是一种很有前途的材料，但尚未得到深入研究。在这里，我们研究了通过 1,3-双（3-（三乙氧基硅基）丙基）脲（BTPU）的酸性缩合合成的双丙基脲桥联 POSS（POSS-urea）的加工和分子结构。实验表明，POSS-urea 对乙腈具有优异的分子识别功能，吸附量为 74mmol/g，与 MOFs 和沸石相比具有优势，可应用于挥发性有机化合物（VOC）。乙腈的吸附容量相对于甲苯的吸附容量高出 132 倍，这表明由于其尺寸和排列，孔对乙腈的吸附具有高度选择性。从理论上讲，我们的紧束缚密度泛函和分子动力学计算表明，这种基于 BTPU 的 POSS 是微孔的，其孔的位置不规则。结构研究证实最大孔径约为 1nm，POSS 笼的近似边长约为 3.16Å。
