School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, Georgia 30332-0100, USA.
ACS Appl Mater Interfaces. 2013 Jun 26;5(12):5569-77. doi: 10.1021/am400810s. Epub 2013 Jun 7.
A series of aminopropyl-functionalized silicas containing of primary, secondary, or tertiary amines is fabricated via silane-grafting on mesoporous SBA-15 silica and the utility of each material in the adsorption of volatile aldehydes from air is systematically assessed. A particular emphasis is placed on low-molecular-weight aldehydes such as formaldehyde and acetaldehyde, which are highly problematic volatile organic compound (VOC) pollutants. The adsorption tests demonstrate that the aminosilica materials with primary amines most effectively adsorbed formaldehyde with an adsorption capacity of 1.4 mmolHCHO g(-1), whereas the aminosilica containing secondary amines showed lower adsorption capacity (0.80 mmolHCHO g(-1)) and the aminosilica containing tertiary amines adsorbed a negligible amount of formaldehyde. The primary amine containing silica also successfully abated higher aldehyde VOC pollutants, including acetaldehyde, hexanal, and benzaldehyde, by effectively adsorbing them. The adsorption mechanism is investigated by (13)C CP MAS solid-state NMR and FT-Raman spectroscopy, and it is demonstrated that the aldehydes are chemically attached to the surface of aminosilica in the form of imines and hemiaminals. The high aldehyde adsorption capacities of the primary aminosilicas in this study demonstrate the utility of amine-functionalized silica materials for reduction of gaseous aldehydes.
通过在介孔 SBA-15 硅上接枝硅烷，制备了一系列含有伯、仲或叔胺的氨丙基功能化硅胶，系统评估了每种材料在空气中吸附挥发性醛的用途。特别强调了甲醛和乙醛等低分子量醛，它们是高度问题性的挥发性有机化合物（VOC）污染物。吸附试验表明，具有伯胺的氨基硅材料对甲醛的吸附效果最佳，吸附容量为 1.4 mmolHCHO g(-1)，而含有仲胺的氨基硅材料的吸附容量较低（0.80 mmolHCHO g(-1)），含有叔胺的氨基硅几乎不吸附甲醛。含有伯胺的硅胶还通过有效吸附成功去除了其他较高的醛类 VOC 污染物，包括乙醛、己醛和苯甲醛。通过（13)C CP MAS 固态 NMR 和 FT-Raman 光谱研究了吸附机理，证明醛以亚胺和半亚胺的形式化学结合到氨基硅的表面。本研究中伯氨基硅的高醛吸附容量证明了胺功能化硅胶材料在减少气态醛方面的实用性。
