• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Anion Exchange on Cross-linked Cationic Surfactant Micelles across Ultrafiltration Membranes.
【24h】

Anion Exchange on Cross-linked Cationic Surfactant Micelles across Ultrafiltration Membranes.

机译：跨超滤膜的交联阳离子表面活性剂胶束上的阴离子交换。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Surfactant micelles combined with ultrafiltration can partially, or sometimes nearly completely, separate various ionic and nonionic pollutants from water. To this end, the selectivity of aqueous micelles composed of either cetyltrimethylammonium (CTA+) bromide or cetylpyridinium (CP+) chloride towards many environmentally relevant anions (IO3-, F-, Cl-, HCO3-, NO 2-, Br-, NO3-, H2PO4-, HPO42-, SO42-, and CrO42-) was investigated. Selectivity coefficients of CTA+ micelles (with respect to Br-) and CP+ micelle (with respect to Cl-) for these anions were evaluated using a simple thermodynamic ion exchange model. The sequence of anion affinity for the CTA+ micelles and for the CP+ micelles were the same, with decreasing affinity occurring in the order: CrO42- > SO 42- > HPO42- > NO3 - > Br- > NO2- > Cl - > HCO3- > F- ≈ H 2PO4-. From the associated component mass balance and ion exchange (i.e., mass action) equations, an overall speciation model was developed to predict the distribution of all anions between the aqueous phase and micellar pseudo-phase for complex ionic mixtures. Experimental results of both artificial and typical surface waters were in good agreement to model predictions.;A significant issue with surfactant micellar enhanced ultrafiltration is the significant and constant loss of surfactant monomers across the membranes due to the fact that surfactant monomers within the micelles are in rapid equilibrium with the aqueous phase surfactant monomers. To overcome this issue, a new quaternary ammonium hydroxypropyl conjugated linoleic acid ester (QACLE) cationic surfactant was synthesized through the reaction of conjugated linoleic acid (CLA) and (2,3-epoxypropyl) trimethylammonium chloride (ETAC). When QACLE was present in aqueous micellar form, it was easily cross-linked, forming stable cross-linked quaternary ammonium stearic acid ester (QASE) nanoparticles with high anion exchange capacity.;The selectivity coefficients of the QACLE micelles towards the common anions in natural water were evaluated using the ion exchange thermodynamic model, and was compared to those measured for micelles composed of two commercially available cationic surfactants, cetyltrimethylammonium bromide (CTAB) and cetylpyridinium chloride (CPC). The sequence in anion affinity for all the three micellar phases was the same. Using the necessary mass balance and ion exchange reactions, a model was developed to predict the distribution of all anions between the aqueous and nanoparticle phases. The model was applied to predict anion association to QASE nanoparticles, contained in dialysis and ultrafiltration membranes, and the results indicate that the cross-linking of QACLE monomers did not alter the values of the selectivity coefficients for any of the anions. The relatively large affinities of the divalent anions and NO3-, and the experiment results (using artificial and real surface waters), indicate that the new QASE nanoparticles have the potential to recover anionic nutrients from natural and polluted waters.
机译：与超滤结合的表面活性剂胶束可以部分或有时几乎完全将各种离子和非离子污染物从水中分离出来。为此，由十六烷基三甲基溴化铵（CTA +）或十六烷基氯化吡啶鎓（CP +）组成的水性胶束对许多与环境相关的阴离子（IO3-，F-，Cl-，HCO3-，NO 2-，Br-，NO3- ，H2PO4-，HPO42-，SO42-和CrO42-）进行了研究。使用简单的热力学离子交换模型评估了CTA +胶束（相对于Br-）和CP +胶束（相对于Cl-）的选择性系数。对CTA +胶束和CP +胶束的阴离子亲和力序列相同，亲和力递减的顺序依次为：CrO42-> SO 42-> HPO42-> NO3-> Br-> NO2-> Cl-> HCO3- > F-＆ap; H 2PO4-。根据相关的组分质量平衡和离子交换（即质量作用）方程式，开发了一个总体形态模型来预测复杂离子混合物在水相和胶束伪相之间所有阴离子的分布。人工和典型地表水的实验结果与模型预测吻合良好。表面活性剂胶束增强超滤的一个重要问题是由于胶束中表面活性剂单体处于与水相表面活性剂单体快速平衡。为了克服这个问题，通过共轭亚油酸（CLA）和（2,3-环氧丙基）三甲基氯化铵（ETAC）的反应，合成了一种新型的季铵羟丙基共轭亚油酸酯（QACLE）阳离子表面活性剂。当QACLE以胶束形式存在时，容易交联，形成稳定的交联季铵硬脂酸季铵盐（QASE）纳米颗粒，具有高的阴离子交换能力。; QACLE胶束对天然阴离子的选择性系数。使用离子交换热力学模型评估水，并将其与由两种市售阳离子表面活性剂十六烷基三甲基溴化铵（CTAB）和十六烷基氯化吡啶鎓（CPC）组成的胶束的测量值进行比较。所有三个胶束相的阴离子亲和力序列相同。使用必要的质量平衡和离子交换反应，开发了一个模型来预测所有阴离子在水相和纳米颗粒相之间的分布。该模型用于预测与透析和超滤膜中包含的QASE纳米粒子的阴离子缔合，结果表明QACLE单体的交联不会改变任何阴离子的选择性系数值。二价阴离子和NO3-的亲和力相对较大，以及实验结果（使用人工和真实地表水）表明，新的QASE纳米粒子具有从天然水和污染水中回收阴离子养分的潜力。

著录项

  • 作者

    Chen, Ming.;

  • 作者单位

    Purdue University.;

  • 授予单位 Purdue University.;
  • 学科 Environmental engineering.;Civil engineering.;Environmental science.
  • 学位 Ph.D.
  • 年度 2017
  • 页码 166 p.
  • 总页数 166
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号