CTAB改性累托石对DNA的吸附性能研究

Adsorption properties of salmon sperm DNA on CTAB modified rectories

以十六烷基三甲基溴化铵(CTAB)对累托石进行改性.采用XRD、FTIR、Zeta电位仪等表征手段对改性前后的材料进行表征,结果显示CTAB成功通过离子交换作用插层进入累托石层间,并改变了累托石的表面电荷.通过DNA浓度、溶液pH、解吸率等变量对比研究改性前后累托石对DNA的吸附性能.结果显示,改性后累托石对DNA的吸附量大大增加,能适应不同pH条件,吸附稳定性也显著增强.

Rectorite（REC） is a kind of clay minerals that consist of hydrated aluminum with Si–O tetrahedrons on the bottom of the layer and Al–O（OH）2 octahedrons on the top. In the study, to make the clay more compatible with organic materials, the cationic hexadecyltrimethyl ammonium bromide （CTAB） is chosen to modify rectorite. X-ray diffraction （XRD）, Fourier transform infrared （FTIR） and Zeta potential analysis are used to characterize the surface properties of CTAB–modified rectories（CTAB-REC） and REC. Experimental results demonstrate that CTAB successfully intercalate into the interlayer of clay and expand the layer space for DNA accommodation. The adsorption performances of CTAB-REC and REC are evaluated by DNA adsorption experiments with the concentration of DNA and pH in solution considered. CTAB significantly promoted DNA adsorption. The less desorption of DNA from modified clay suggests that the CTAB intercalated into rectorite increased the binding affinity of DNA. The information obtained in this study is of fundamental significance for understanding the behavior of extracellular DNA in clay minerals.