本研究分別利用後合成法-直接後修飾法、交聯後修飾法及共縮合法,來合成含不同結構之胺基表面的奈米孔洞分子篩SBA-15,並藉由XRD、氮氣等溫吸/脫附儀、EA元素分析儀及NMR等儀器來鑑定其結構。 將不同胺基表面的SBA-15應用於對金屬吸附能力之探討,結果顯示含胺基表面的SBA-15對Hg2+有獨特的吸附能力且隨著溶液pH值的增加其吸附能力越強,且發現具有1級胺官能基的矽烷表面SBA-15在pH 1.5的溶液中對Hg2+金屬離子已有明顯的吸附能力;由實驗結果顯示含不同結構位置的胺基表面SBA-15對重金屬吸附能力為1級>2級>3級胺基表面,另顯示含胺基數目越多的胺基表面SBA-15,其對金屬離子的吸附能力越強。 本研究利用3-isocyanatopropyl-triethoxysilane 分別與DETA、TETA、TEPA、PEHA及PEI等胺基化合物和SBA-15,以交聯後修飾法,成功合成含多重胺基表面的SBA-15,其對Hg2+離子的吸附能力,顯示含胺基數目越多的多重胺基表面SBA-15,其吸附能力越強;如多重胺>七重胺>六重胺>五重胺>四重胺表面之SBA-15,其中含PEI之多重胺基表面SBA-15,在pH 2下對Hg2+的吸附能力達317 mg/g,將其運用於廢水中對Hg2+的移除,其移除能力達357 mg/g。
Different amine-grafted SBA-15 nanoporous silicas have been prepared by post-grafting and co-condensation of amine silanes such as primary (1°), secondary (2°), tertiary anins (3°), diamines, triamines, arylamine etc. These materials were characterized by elemental analysis, powder X-ray diffraction, nitrogen gas sorption and NMR analyses. These organo-silicas were used in the removal of heavy metal ions from aqueous solutions. These adsorbents have excellent Hg2+ adsorption capacity. Moreover, primary amine-grafted SBA-15 show better Hg2+ adsorption capacity than 2° and 3° ones and triamine-grafted SBA-15 has better adsorption capacity than diamine and uniamine ones. Tetra-amine, penta-amine, hexa-amine, hepta-amine and multi-amine were tethered on the outer and channel surface of SBA-15 via cross-linking reaction. Hg2+ adsorption capacity is multi-amine> hepta-amine> hexa-amine> penta-amine> tetra-amine >single amine grafted SBA-15. Hg2+ removal capacity of PEI- grafted nanoporous silica SBA-15 is 317 mg/g in aqueous solutions at pH 2 and 357 mg/g from wastewater.