胶原纤维固化黑荆树单宁对硼同位素的分离

Separation of boron isotopes by collagen fibers-immobilized black wattle tannin

使用戊二醛为交联剂,将黑荆树单宁(BWT)固化在胶原纤维(CF)表面,得到新型硼同位素分离树脂CF-BWT。通过FTIR、XPS、SEM、^(11)B MAS NMR分析,探究了CF-BWT吸附硼前后表面元素组成、形貌结构以及吸附机理等。研究结果表明,当pH为8.0,硼初始浓度为110mg/L时,CF-BWT的平衡吸附量可达1.9mg/g。吸附平衡符合Langmuir模型,平衡吸附量随温度升高而增加。吸附动力学可用准二级动力学模型描述,由模型计算得到的平衡吸附量与实验值接近。进一步研究发现,CF-BWT表面固化的黑荆树单宁与硼形成硼-单宁活性交换界面,促使^(10)B和^(11)B发生同位素交换反应,从而将^(10)B富集于CF-BWT表面,实现^(10)B和^(11)B的分离。当pH为7.0时,CF-BWT对^(10)B和^(11)B的单级分离因子可达1.17。当初始硼同位素丰度比(^(10)B/^(11)B)为0.2180时,以CF-BWT为填料的固定床对^(10)B和^(11)B进行分离,发现穿透段硼同位素丰度比(^(10)B/^(11)B)为0.2149,而在洗脱段则达到0.2234。

Glutaraldehyde was used as a cross-linking agent to immobilize black wattle tannin(BWT)on the surface of collagen fibers(CF)to obtain a new type of boron isotope separation resin(CF-BWT).Using FTIR,XPS,SEM and^(11)B MAS NMR,the elemental composition,morphology,structure and adsorption mechanism of CF-BWT to boron were explored.The results showed that the equilibrium adsorption capacity of CF-BWT could reach 1.9mg/g when the pH was 8.0 and the initial concentration of boron was 110mg/L.The adsorption isotherms of CF-BWT to boron could be described by the Langmuir equation and the adsorption capacity increased with the increase of temperature.The adsorption kinetics could also be described by the pseudo second-order kinetic model,and the equilibrium adsorption capacities calculated by the model were close to the experimental value.Furthermore,the boron-tannin active exchange interface formed by the tannin immobilized on the surface of CF-BWT promoted the isotope exchange reaction of^(10)B and^(11)B,thereby enriching^(10)B on the surface of CF-BWT and realizing the separation of^(10)B and^(11)B.The corresponding single stage separation factor could reach 1.17 at pH=7.0.When the initial boron isotope ratio(^(10)B/^(11)B)was 0.2180,the column of CF-BWT was used for the separation of^(10)B and^(11)B.The results showed that the boron isotope ratio(^(10)B/^(11)B)was 0.2149 at the penetration section and high up to 0.2234 at the elution section,suggesting effective separation of^(10)B and^(11)B.