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We have presented an enantiomer separation process based on the ultrafiltration of enantioselective micelles containing chiral selector molecules. The selector, an amino acid derivative-Cu(II) complex, is dissolved in nonionic micelles and applied to the separation of racemic amino acid mixtures. In the ultrafiltration experiments, we have shown that the operational enantioselectivity is influenced by the chain length of the nonionic surfactant and the pH of the medium. We developed a multistage separation process because the experimentally measured selectivity of 1.9 at pH 7 for a single-stage separation process is not sufficient to obtain both enantiomers at >99% purity. Experimental data and model calculations indicate that the productivity of the multistage process can be improved by reducing the affinity of the microheterogeneous media for the enantiomers. Ultrafiltration of microheterogeneous media in cascaded systems uses the benefits of chromatographic and distillation process: preferential binding under mild conditions and countercurrent flow of the micellar phase and the bulk phase through the apparatus. This concept provides a new basis for the development of large-scale separation techniques.
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTHighly Active Iron and Cobalt Catalysts for the Polymerization of EthyleneBrooke L. Small, Maurice Brookhart, and Alison M. A. BennettView Author Information Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290 DuPont Central Research and Development Experimental Station, Wilmington, Delaware 19880-0328 Cite this: J. Am. Chem. Soc. 1998, 120, 16, 4049–4050Publication Date (Web):April 14, 1998Publication History Received20 January 1998Published online14 April 1998Published inissue 1 April 1998https://pubs.acs.org/doi/10.1021/ja9802100https://doi.org/10.1021/ja9802100rapid-communicationACS PublicationsCopyright © 1998 American Chemical SocietyRequest reuse permissionsArticle Views14440Altmetric-Citations1303LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-AlertscloseSupporting Info (1)»Supporting Information Supporting Information SUBJECTS:Catalysts,Ethylene polymerization,Hydrocarbons,Ligands,Polymers Get e-Alerts
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Modern technologies and 70 years of experience have not shortened the time between discovery and market introduction for new polymeric materials. On the contrary, it seems to have increased.
