Green synthesis of cellulose graft copolymers for anion exchange water purification
Green synthesis of cellulose graft copolymers for anion exchange water purification
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DOI：
10.1007/s10570-023-05519-8
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发表时间：
2023-10
期刊：
影响因子：
5.7
通讯作者：
Stephen Schmal;Raghav Dosi;Adam Fessler;Carly Kwiatkowski;Abhispa Sahu;J. C. Poler
中科院分区：
文献类型：
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作者：
Stephen Schmal;Raghav Dosi;Adam Fessler;Carly Kwiatkowski;Abhispa Sahu;J. C. Poler
通过纤维糖醛酸与聚乙烯基苄基三甲基氯化铵（poly（vbTMAC））的全水官能化，合成了纤维素接枝共聚物（纤维素纳米树脂）。利用2，2，6，6-四甲基哌啶-1-氧自由基（克里思）介导的选择性C-6氧化反应氧化纤维素。纤维糖醛酸的Fischer-Speier酯化用于以简单的点击状机制将聚（vbTMAC）接枝到纤维素主链。利用动态光散射和zeta电位测量证实了纤维素纳米树脂的合成。采用电导滴定法测定纤维素醛酸的羧酸根含量和纤维素纳米树脂的官能化百分比，其分别为1.69 ± 0.03 mmol/g和61.2 ± 4%。使用荧光素二钠（NaFL）替代吸附物，测得CNR的最大吸附容量为26.8 ± 1.3 mg NaFL/g CNR，朗缪尔平衡结合常数Ks = 10.5 ± 2 ppm−1。当作为薄膜膜进行检查时，CNR的突破性研究表明，在不到30 s的时间内达到平衡负载，并且> 90%的负载发生在5 s内。这些数据表明，这些膜可以用作阴离子交换水净化的接触树脂。我们在这项工作中表明，这些膜在40次再生和再利用试验中保持> 99%的负载性能，这意味着这些膜是绿色和可再生的。初步测试显示，CNR可有效去除水中的全氟辛烷磺酸（PFOS），使其低于我们的检测限100 ppt。
A cellulose graft copolymer (cellulose nanoresin) was synthesized by the all-aqueous functionalization of cellouronic acid with poly (vinyl benzyl trimethyl ammonium chloride) (poly(vbTMAC)). Cellulose was oxidized using the highly reported 2,2,6,6-tetramethylpiperidine-1-oxy radical (TEMPO)-mediated selective C-6 oxidation reaction. Fischer–Speier esterification of cellouronic acid was used to graft poly(vbTMAC) to the cellulosic backbone in a facile click-like mechanism. Synthesis of cellulose nanoresin was confirmed using dynamic light scattering and zeta potential measurements. Conductometric titration was used to determine the carboxylate content of cellouronic acid and the percent functionalization of the cellulose nanoresin, which was 1.69 ± 0.03 mmol/g and 61.2 ± 4%, respectively. Using a disodium fluorescein (NaFL) surrogate adsorbate, the maximum adsorption capacity of CNR was measured to be 26.8 ± 1.3 mg NaFL per gram of CNR with a Langmuir equilibrium binding constant of Ks = 10.5 ± 2 ppm−1. When examined as a thin film membrane, a breakthrough study of CNR showed that equilibrium loading was achieved in less than 30 s, and that > 90% of loading occurred in under 5 s. This data suggests that these films can be used as contact resins for anion-exchange water purification. We show in this work that these films maintain > 99% of loading performance over 40 trials of regeneration and reuse, meaning that these films are green and regenerable. Initial testing shows that CNR is effective at the removal of perfluorooctane sulfonate (PFOS) from water to below our limit of detection of 100 ppt.