Nayab Sana, Farrukh Aleeza, Oluz Zehra, Tuncel Eylül, Tariq Saadia Rashid, ur Rahman Habib, Kirchhoff Katrin, Duran Hatice, Yameen Basit
Department of Chemistry, Lahore College for Women University , Jail Road, Lahore, Punjab 54000, Pakistan.
ACS Appl Mater Interfaces. 2014 Mar 26;6(6):4408-17. doi: 10.1021/am500123k. Epub 2014 Mar 10.
A novel branched polyamine (polyethyleneimine, PEI) functionalized mesoporous silica (MS) adsorbent is developed via a facile "grafting-to" approach. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FT-IR) spectroscopy verified the effective surface functionalization of MS with monolayer and polymer. The transmission electron microscopy (TEM) was employed to reveal the morphology of the fabricated materials. The adsorption behavior of the polyamine functionalized mesoporous silica (MS-PEI) is assessed against anionic dyes. The adsorbent characteristics of MS-PEI are compared with a monolayer platform comprising of 3-aminopropyltriethoxy silane (APTES) functionalized mesoporous silica (MS-APTES). The adsorption behavior of the MS-PEI and MS-APTES toward anionic dyes is further evaluated by studying the effect of adsorbent dosage, pH, contact time, and temperature. Langmuir and Freundlich isotherm models are employed to understand the adsorption mechanism. The obtained kinetic data support a pseudo-second-order adsorption behavior for both monolayer and polymer functionalized MS. The associated thermodynamic parameters (ΔG°, ΔH°, and ΔS°) reveal that the process of adsorption with MS-PEI is more spontaneous and energetically favored as compared to the adsorption with MS-APTES. Taken together, the novel adsorbent system derived from a combination of MS and branched polymer (MS-PEI) shows the higher absorption efficiency and capacity toward the anionic dyes than the monolayer based adsorbent (MS-APTES).
通过一种简便的“接枝到”方法，开发了一种新型的支化多胺（聚乙烯亚胺，PEI）功能化介孔二氧化硅（MS）吸附剂。X射线光电子能谱（XPS）和傅里叶变换红外（FT-IR）光谱证实了MS与单层和聚合物的有效表面功能化。采用透射电子显微镜（TEM）来揭示所制备材料的形态。评估了多胺功能化介孔二氧化硅（MS-PEI）对阴离子染料的吸附行为。将MS-PEI的吸附剂特性与由3-氨丙基三乙氧基硅烷（APTES）功能化介孔二氧化硅（MS-APTES）组成的单层平台进行了比较。通过研究吸附剂用量、pH值、接触时间和温度的影响，进一步评估了MS-PEI和MS-APTES对阴离子染料的吸附行为。采用Langmuir和Freundlich等温线模型来理解吸附机理。所获得的动力学数据支持单层和聚合物功能化MS的拟二级吸附行为。相关的热力学参数（ΔG°、ΔH°和ΔS°）表明，与MS-APTES吸附相比，MS-PEI的吸附过程更自发且在能量上更有利。综上所述，由MS和支化聚合物（MS-PEI）组合而成的新型吸附剂体系对阴离子染料的吸附效率和容量高于基于单层的吸附剂（MS-APTES）。
