Rathnayake Suramya I, Xi Yunfei, Frost Ray L, Ayoko Godwin A
Discipline of Nanotechnology and Molecular Science, School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology (QUT), GPO Box 2434, Brisbane, Queensland 4001, Australia.
Discipline of Nanotechnology and Molecular Science, School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology (QUT), GPO Box 2434, Brisbane, Queensland 4001, Australia.
J Colloid Interface Sci. 2016 May 15;470:183-195. doi: 10.1016/j.jcis.2016.02.034. Epub 2016 Feb 13.
Bisphenol-A (BPA) adsorption onto inorganic-organic clays (IOCs) was investigated. For this purpose, IOCs synthesised using octadecyltrimethylammonium bromide (ODTMA, organic modifier) and hydroxy aluminium (Al13, inorganic modifier) were used. Three intercalation methods were employed with varying ODTMA concentration in the synthesis of IOCs. Molecular interactions of clay surfaces with ODTMA and Al13 and their arrangements within the interlayers were determined using Fourier transform infrared spectroscopy (FTIR). Surface area and porous structure of IOCs were determined by applying Brunauer, Emmett, and Teller (BET) method to N2 adsorption-desorption isotherms. Surface area decreased upon ODTMA intercalation while it increased with Al13 pillaring. As a result, BET specific surface area of IOCs was considerably higher than those of organoclays. Initial concentration of BPA, contact time and adsorbent dose significantly affected BPA adsorption into IOCs. Pseudo-second order kinetics model is the best fit for BPA adsorption into IOCs. Both Langmuir and Freundlich adsorption isotherms were applicable for BPA adsorption (R(2)>0.91) for IOCs. Langmuir maximum adsorption capacity for IOCs was as high as 109.89mgg(-1) and it was closely related to the loaded ODTMA amount into the clay. Hydrophobic interactions between long alkyl chains of ODTMA and BPA are responsible for BPA adsorption into IOCs.
研究了双酚A（BPA）在无机-有机粘土（IOCs）上的吸附情况。为此，使用了用十八烷基三甲基溴化铵（ODTMA，有机改性剂）和羟基铝（Al13，无机改性剂）合成的IOCs。在IOCs的合成中采用了三种插层方法，ODTMA浓度各不相同。利用傅里叶变换红外光谱（FTIR）确定了粘土表面与ODTMA和Al13的分子相互作用及其在层间的排列。通过对N2吸附-脱附等温线应用布鲁诺尔、埃米特和泰勒（BET）方法来确定IOCs的表面积和多孔结构。ODTMA插层后表面积减小，而Al13柱撑后表面积增大。结果，IOCs的BET比表面积明显高于有机粘土。BPA的初始浓度、接触时间和吸附剂剂量显著影响BPA在IOCs中的吸附。准二级动力学模型最适合BPA在IOCs中的吸附。朗缪尔和弗伦德利希吸附等温线均适用于IOCs对BPA的吸附（R(2)>0.91）。IOCs的朗缪尔最大吸附容量高达109.89mgg(-1)，且与粘土中负载的ODTMA量密切相关。ODTMA的长烷基链与BPA之间的疏水相互作用是BPA在IOCs中吸附的原因。
