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Environments 2018, 5(9), 100;

Optimizing Spacer Length for Positioning Functional Groups in Bio-Waste

Science Department, Borough of Manhattan Community College, The City University of New York, New York, NY 10007, USA
Author to whom correspondence should be addressed.
Received: 8 August 2018 / Revised: 28 August 2018 / Accepted: 30 August 2018 / Published: 2 September 2018
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The goal of this study was to determine the optimal chain length needed for tethering functional groups on bio-wastes. The purpose of modifying the surface of bio-waste is to improve their affinity for phenols. To this end, four different aminated green tea leaves, with the amine group located at the end of 6, 8, 10, and 12 carbons were synthesized. Green approaches to functionalization lead to fewer reactive sites. Optimizing spacer length is one way to ameliorate this. The aminated tea leaves were prepared by a tosylation reaction followed by displacement with a diamine used in excess. The tea leaves with the amine at the end of six carbons proved to have the best ability to remove 2-chlorophenol (2-CP) from its aqueous solution. It was at least 3–4 times better than native spent tea leaves. The mechanism by which the phenol was removed proved to be primarily an acid–base reaction followed by H-bonding and dipole–dipole interactions. Because of the acid–base interactions, the relatively low-boiling 2-CP did not volatilize off the aminated tea leaves enabling recycling. On the other hand, with activated charcoal, the adsorbed 2-CP volatilized almost completely under ambient conditions. View Full-Text
Keywords: chain length; spacer; tethering; phenol; bio-waste; 4-aminoantipyrine; spent tea leaves; tosylation and amination chain length; spacer; tethering; phenol; bio-waste; 4-aminoantipyrine; spent tea leaves; tosylation and amination

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Iyengar, R.; Faure-Betancourt, M.; Talukdar, S.; Ye, J.; Navarro, A.E. Optimizing Spacer Length for Positioning Functional Groups in Bio-Waste. Environments 2018, 5, 100.

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