Contents lists available at ScienceDirect Inorganic Chemistry Communications journal homepage: www.elsevier.com/locate/inoche Short communication Plasticizers free polyvinyl chloride membrane for metal ions sequestering Marco Consumi a,b, ⁎ , Gemma Leone a,b, ⁎ , Claudia Bonechi a,c , Gabriella Tamasi a,c , Stefania Lamponi a , Alessandro Donati a , Claudio Rossi a,c , Agnese Magnani a,b a Department of Biotechnology, Chemistry and Pharmacy, University of Siena, via A. Moro 2, Siena 53100, Italy b INSTM, via G. Giusti 9, 50121 Firenze, Italy c CSGI, via della Lastruccia 3, 50019 Sesto Fiorentino, Italy GRAPHICALABSTRACT ARTICLEINFO Keywords: PVC PVA Sensors Porosity Metal ions FTIR ABSTRACT The purpose of this work is to create a porous polyvinyl-chloride (PVC) membrane able of sequestering metal ions in solution avoiding the use of plasticizers that can affect ionophores distribution and performance. In the sensor here developed, the distribution of ionophore (i.e. protoporphyrin IX) is no longer due to plasticizers but to microcavities that allow it to easily penetrate inside the material. Microporosity was obtained adding water soluble components (Poly vinyl alcohol or NaHCO 3 ) as blends or crystals to PVC. Only blends show a uniformly distributed porosity (≈2 µm), that allows a rapid exchange thanks to the increased active surface. Membranes were characterized by Infrared Spectroscopy (IR), Differential Scanning Calorimetry (DSC) and Scanning Electron Microscopy (SEM). The effective complexion with metal ions was verified by IR and UV Spectroscopy. 1. Introduction Rapid and accurate detection of solute species, such as metal ions, is of major importance in several fields, from food analysis to pharma- ceutics production. The removal or detection of contaminating metals can be obtained using different tools [1–3]. Nevertheless, ion selective membranes (ISMs) still remain the most used tool to detect the presence of metal ions in liquid phases. The earliest ISMs were developed in 1960s and worked basing on the principle of ion exchange thanks to the presence of polymeric systems enriched with phosphate derivatives or rare-earth doped single crystals. Actually, ISMs can be distinguished in two sub-groups, membranes working on ion coordination through electrostatic interactions or on size exclusion effect [4–5]. Despite this difference, all ISMs are composed of a supporting material, commonly https://doi.org/10.1016/j.inoche.2020.108100 Received 12 February 2020; Received in revised form 17 June 2020; Accepted 6 July 2020 ⁎ Corresponding authors at: Department of Biotechnology, Chemistry and Pharmacy, University of Siena, via A. Moro 2, Siena 53100, Italy. E-mail addresses: marco.consumi@unisi.it (M. Consumi), gemma.leone@unisi.it (G. Leone). Inorganic Chemistry Communications 119 (2020) 108100 Available online 11 July 2020 1387-7003/ © 2020 Elsevier B.V. All rights reserved. T