Colloids and Surfaces A: Physicochem. Eng. Aspects 480 (2015) 343–350 Contents lists available at ScienceDirect Colloids and Surfaces A: Physicochemical and Engineering Aspects journa l h om epage: www.elsevier.com/locate/colsurfa Synthesis and aggregation properties of new biodegradable amphiphilic derivatives of p-tert-butylphenol for green separation of Gd(III) ions Alexey Stepanov a,∗ , Elmira Vasilieva a , Farida Valeeva a , Julia Elistratova a , Asiya Mustafina a , Lucia Zakharova a , Rustem Amirov b , Vladimir Morozov a , Sofia Kleshnina a , Svetlana Solovyeva a , Ildar Rizvanov a , Igor Antipin b , Alexander Konovalov a a A.E. Arbuzov Institute of Organic and Physical Chemistry, Arbuzov Street, 8, Kazan, Russia b Kazan Federal University, 420008 Kremlevskaya Str. 18, Kazan, Russia h i g h l i g h t s • Novel amphiphilic ethyleneoxide- ethylenecarbonate derivatives of p- tert-butylphenol. • Structure, pH and counterion affects on their aggregation in aqueous solu- tions. • Binding with Gd(III) ions as a trigger of a phase separation of the solutions. • Impact of supramolecular and stoi- chiometric binding modes in the phase separation. • Gd(III) induced phase separation in the solutions as extraction procedure. g r a p h i c a l a b s t r a c t a r t i c l e i n f o Article history: Received 1 July 2014 Received in revised form 18 August 2014 Accepted 21 August 2014 Available online 28 August 2014 Keywords: Amphiphiles Micelles Aggregation Lanthanide ions Solubilization power Phase separation a b s t r a c t The work introduces a synthesis of novel amphiphilic p-tert-butylphenol derivatives with the polyethyle- neoxide and biodegradable ionogenic polyethylenecarbonate moieties. The dependence of their aggregation behaviour on the lengths of polyethyleneoxide and polyethylenecarbonate chains indicates the impact of the hydrophilic moieties and ionogenic end-groups in the aggregation behaviour of the amphiphiles. The micelles of the amphiphiles are negatively charged, although neither pH nor counter ions (exemplified by Gd(III) ions) affects the values of their critical micelle concentrations. The presence of the ionogenic end-groups is the main reason of the pH and concentration dependent extraction of Gd(III) ions from the neutral (pH 6.2-7.2) aqueous solutions of the amphiphiles through their phase separation at room temperatures. The extraction regularities point on the stoichiometric binding of the amphiphilic molecules with Gd(III) ions as the main reason of the phase separation in their aqueous solutions. Nev- ertheless the micellization of the amphiphiles is responsible for the peculiar concentration effect on the extraction of Gd(III) ions from the aqueous solutions. © 2014 Elsevier B.V. All rights reserved. ∗ Corresponding author. Tel.: +7 843 2739365; fax: +7 843 2731872. E-mail address: aleksestepanov@yandex.ru (A. Stepanov). http://dx.doi.org/10.1016/j.colsurfa.2014.08.015 0927-7757/© 2014 Elsevier B.V. All rights reserved.