Mahmoud Mamdoh R, Hassan Reham S, Rashad Ghada M
Nuclear Chemistry Department, Hot Laboratories Center, Atomic Energy Authority, P.O. Box 13759, Cairo, Egypt.
Analytical Chemistry and Control Department, Hot Laboratories Center, Atomic Energy Authority, P.O. Box 13759, Cairo, Egypt.
Appl Radiat Isot. 2020 Sep;163:109198. doi: 10.1016/j.apradiso.2020.109198. Epub 2020 Apr 30.
Sodium lauryl sulfate-loaded polyacrylonitrile (SLSLPAN) was synthesized in the present investigation using an in-situ one step process through gamma radiation-induced polymerization. The structure, composition, surface area and pore size and volume of the employed adsorbent were investigated by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) and nitrogen adsorption-desorption measurements. Adsorption of radioactive strontium(II) onto SLSLPAN was studied in the pH range 3-13. Batch kinetic data showed that the equilibrium was attained at 840 min and the pseudo-first-order was the best kinetic model for describing the kinetic data of the present adsorption process. The diffusion of strontium(II) into SLSLPAN was deeply studied using four diffusion models, namely, Bangham, Boyd, Weber-Morris and Mathewas-Weber models. Two-parameter (Freundlich, Langmuir and Temkin) and three-parameter (Redlich-Peterson, Toth and Generalized) isotherm models were used to analyze the adsorption equilibrium data of strontium(II) onto SLSLPAN. The maximum adsorption capacity calculated by the Generalized isotherm model is found to be 0.391 mmol strontium(II) per gram of SLSLPAN. The estimated mean free energy (E = 2.151 kJ/mol) indicated that strontium(II) radionuclides were physically adsorbed onto SLSLPAN. The value of enthalpy change (ΔH = 35.325 kJ/mol) and those of free energy change (ΔG = -15.278, -16.948, -18.619 and -20.288 at 303, 313, 323 and 333 K, respectively) confirmed that adsorption of strontium(II) radionuclides on SLSLPAN was endothermic and spontaneous process.
在本研究中，通过γ辐射诱导聚合的原位一步法合成了负载月桂基硫酸钠的聚丙烯腈（SLSLPAN）。采用傅里叶变换红外（FT-IR）光谱、X射线衍射（XRD）和氮吸附-脱附测量对所用吸附剂的结构、组成、表面积、孔径和孔体积进行了研究。研究了在pH值为3至13范围内放射性锶（II）在SLSLPAN上的吸附情况。间歇动力学数据表明，在840分钟时达到平衡，伪一级动力学模型是描述当前吸附过程动力学数据的最佳模型。使用四种扩散模型，即班汉姆、博伊德、韦伯-莫里斯和马瑟瓦斯-韦伯模型，深入研究了锶（II）向SLSLPAN中的扩散。采用双参数（弗伦德利希、朗缪尔和坦金）和三参数（雷德利希-彼得森、托特和广义）等温线模型分析了锶（II）在SLSLPAN上的吸附平衡数据。通过广义等温线模型计算得出的最大吸附容量为每克SLSLPAN 0.391 mmol锶（II）。估计的平均自由能（E = 2.151 kJ/mol）表明，锶（II）放射性核素被物理吸附在SLSLPAN上。焓变值（ΔH = 35.325 kJ/mol）和自由能变值（分别在303、313、323和333 K时为ΔG = -15.278、-16.948、-18.619和-20.288）证实，锶（II）放射性核素在SLSLPAN上的吸附是吸热且自发的过程。
