Stabilization of bismuth ferrite suspensions in aqueous medium with sodium polyacrylate characterized by different molecular weights Chiara Ponzoni * , Maria Cannio, Roberto Rosa, Cristina Leonelli Department of Engineering “Enzo Ferrari”, University of Modena and Reggio Emilia, Via Vignolese 905, I-41125 Modena, Italy highlights graphical abstract  Electrostatic stabilization of bismuth ferrite BiFeO 3 suspensions in aqueous medium.  Use of polyacrylate as dispersant agent characterized by different M w .  Influence of BFO conc, dispersant agent conc and M w , and sonication time.  Dispersion efficiency in terms of sediment percentage and the zeta potential trend.  Spectrophotometric method to investigate the sediment percentage. article info Article history: Received 5 May 2014 Received in revised form 6 October 2014 Accepted 10 October 2014 Available online xxx Keywords: Electrostatic stabilization Bismuth ferrite suspension stabilization in aqueous medium Polyacrylate suspending agent abstract Electrostatic stabilization of bismuth ferrite BiFeO 3 (BFO) single phase micronized particles suspended for the first time in aqueous medium, using sodium polyacrylate (Na-PAA) as suspending agent, was investigated to form homogeneous films through electrophoretic deposition technique. The dispersion efficiency was evaluated in terms of the zeta potential trend as a function of pH and sediment per- centage, employing a fast and easy spectrophotometric method. All the tests were performed using three suspending agents characterized by the same polyacrylate functional group (-COONa) but with different molecular weights (Na-PAA M w ¼ 2100, 5100, and 20 000). The effect of BFO particles concentration (wt %), suspending agent concentration (wt%), suspending agent molecular weight and sonication time have been evaluated. The results showed that for all the experiments carried out the electrostatic stabilization of the BFO micronized particles in aqueous medium is accomplished in high basic pH range (8.5e9 or 9 e11) depending on the molecular weight of the polyacrylate additive. © 2014 Elsevier B.V. All rights reserved. 1. Introduction Bismuth ferrite, BiFeO 3 (BFO) has been studied for many years because of its exceptional simultaneous ferroelectric and weak ferromagnetic properties above room temperature [1e4]. The interactions between BFO magnetic and electric polariza- tions lead to additional functionalities, which make it a promising candidate in a wide range of different applications such as in spintronics magnetic recording media, sensors, photocatalysis and photovoltaic devices [5e9]. Besides the synthetic efforts aimed at the obtainment of bismuth ferrite single phase powder, many publications appeared about the production of electroceramic films and coatings. In fact the growth of a thin layer onto a wafer scale and conformal coverage are required to introduce a multiferroic material for a new generation of ferroelectric devices usable for the above mention applications. In the scientific literature several techniques, such as the pulsed laser deposition (PLD) [10e12], RF-magnetron sputtering (RF-sputtering) * Corresponding author. E-mail address: chiara.ponzoni@unimore.it (C. Ponzoni). Contents lists available at ScienceDirect Materials Chemistry and Physics journal homepage: www.elsevier.com/locate/matchemphys http://dx.doi.org/10.1016/j.matchemphys.2014.10.013 0254-0584/© 2014 Elsevier B.V. All rights reserved. Materials Chemistry and Physics xxx (2014) 1e8 Please cite this article in press as: C. Ponzoni, et al., Stabilization of bismuth ferrite suspensions in aqueous medium with sodium polyacrylate characterized by different molecular weights, Materials Chemistry and Physics (2014), http://dx.doi.org/10.1016/j.matchemphys.2014.10.013