Synthesis and study by FTIR, 31 P NMR and electrochemical impedance spectroscopy of vanadium zinc phosphate glasses prepared by sol–gel route Driss Rair a, ⁎, Abdelhadi Rochdi b , Abdelilah Majjane a , Touria Jermoumi a , Abdelkrim Chahine a , Mohamed Ebn Touhami b a Laboratoire de Physico-Chimie des Matériaux Vitreux et Cristallisés, Université Ibn Tofail, Faculté des Sciences, Kénitra 14090, Morocco b Laboratoire d'Electrochimie, Corrosion et Environnement, Université Ibn Tofail, Faculté des Sciences, Kénitra, Morocco abstract article info Article history: Received 18 July 2015 Received in revised form 24 October 2015 Accepted 1 November 2015 Keywords: Sol–gel synthesis; Energy efficient; Phosphate-based glass; IR-NMR; EIS-corrosion inhibitors Ternary phosphate glasses of the system (ZnO) (0.45 − x) –(P 2 O 5 ) (0.55 − y) –(V 2 O 5 ) z , (y = 0; x = z = 0.01, 0.1; 0.2) and (x = 0, y = z = 0.1; 0.2) are prepared via the sol–gel process using zinc acetate, ammonium metavanadate and phosphoric acid as precursors. Spectroscopic investigations reveal a phosphate glass system depolymeriza- tion by systematic conversion of PO 3 − metaphosphate chains into (P 2 O 7 ) 4− pyrophosphate, with the formation of P–O–V and V–O–V bonds, which replace P–O–P ones. Heat treatment of the dried xerogels containing 10% of V 2 O 5 at temperatures 400–600 °C shows a similar trend in their infrared spectrum then that of glass obtained by melt quenching at 1000 °C. Inhibitive effect of the glass composition (ZnO) 0.45 –(P 2 O 5 ) 0.45 –(V 2 O 5 ) 0.1 obtained at 600 °C and 1000 °C in simulated water was studied by electrochemical impedance spectroscopy (EIS). Inhibitory efficiency for both samples is the same ~95%. © 2015 Elsevier B.V. All rights reserved. 1. Introduction The production of glasses by the sol–gel method is an area that has important scientific and technological implications. This has pro- duced a wide range of compositions with better purity and homoge- neity [1], in several forms, such as powders, fibers, coatings and monoliths… [2,3,4]. For power saving reasons, this process is of great interest for the development of glasses at low temperatures of about 400–600 °C. These glasses are usually obtained by conventional methods at higher temperatures (above 1400 °C). The amorphous compounds based on vanadium oxides have been prepared in the form of evaporated thin films [5], xerogels [6] and glasses. It is possible to prepare pure V 2 O 5 glass [7], but its mechanical properties are improved on addition of other glass forming compounds such as P 2 O 5 . The similarity in the chemical formulae of V 2 O 5 and P 2 O 5 and in the structures of certain vanadates and phosphates might lead one to expect that V 2 O 5 like P 2 O 5 would be a glass forming oxide, and that vanadate glasses would have similar properties to the phosphate glasses. In fact the two oxides behave very differently. V 2 O 5 forms a very fluid melt having a much lower vapor pressure than fused P 2 O 5 and on cooling it crystallizes rapidly. Clearly the melt structures must be very different. For the treatment of water cooling circuits several formula- tions have been developed to protect the pipes from both scale formation and corrosion. The majority of inhibitors that can act in these mediums are inorganic ions [8,9,10], the important an- ions: chromate, phosphate, vanadate and molybdate. Cations of strontium, cerium and the lanthanides, and zinc are inorganic cationic inhibitors. The aim of this work is to study the influence of vanadium addi- tion on the structure of zinc metaphosphate glass. The comparison of structure and the inhibitive corrosion of glasses obtained by heat treatment at 600 °C and those obtained by quenching method are also discussed. 2. Experimental 2.1. Sol–gel synthesis The glass samples having the general composition (ZnO) (0.45 − x) –(P 2 O 5 ) (0.55 − y) –(V 2 O 5 ) z , (y = 0; x = z = 0.01; 0.1; 0.2) and (x = 0, y = z = 0.1; 0.2), have been prepared by the sol–gel route from stoichiometric mixtures of zinc acetate Journal of Non-Crystalline Solids 432 (2016) 459–465 ⁎ Corresponding author. E-mail address: rairdriss@gmail.com (D. Rair). http://dx.doi.org/10.1016/j.jnoncrysol.2015.11.001 0022-3093/© 2015 Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect Journal of Non-Crystalline Solids journal homepage: www.elsevier.com/ locate/ jnoncrysol