Application of (polyaniline/zeolite X) composite as anticorrosion coating for energy recovery devices in RO desalination water plants

International Journal of Industrial Chemistry https://doi.org/10.1007/s40090-019-0182-7 RESEARCH Application of (polyaniline/zeolite X) composite as anticorrosion coating for energy recovery devices in RO desalination water plants Ahmed H. Abdel Aziz1 · Tarek S. Jamil2 · Marwa S. Shalaby3 · Ahmed M. Shaban2 · Eglal R. Souaya1 · Nabil A. Abdel Ghany4 Received: 5 April 2018 / Accepted: 14 March 2019 © The Author(s) 2019 Abstract Reverse osmosis desalination water plants have several operational issues such as corrosion in many areas like energy recovery devices that are accustomed to restore energy and scale back prices. Thus, there is a necessity to reduce the corrosion rate of the devices utilized in energy recovery. This study focuses on protection of some metals and alloys that are utilized in this industry by introducing a new anticorrosion coating. The new anticorrosion coating was formulated by the interaction of polyaniline and X-type zeolite that is employed as hosting material. Polyaniline was first formulated by conventional oxidation polymerization method of aniline in acidic medium at temperature below 5 °C by using ice bath. Then, ammonium persulphate was used as oxidizer. Numerous characterization techniques were used to demonstrate the encapsulation of polyaniline in X-type zeolite frames such as IR, UV–visible spectroscopy, scanning electron microscopy, transmission electron microscope, energy-dispersive X-ray and X-ray diffraction. The new anticorrosion coating was evaluated by using weight loss technique, Tafel polarization and electrochemical impedance spectroscopy; all of these techniques showed the effective anticorrosion properties of the prepared coating in which the corrosion rate from the polarization curves results, for all coated samples, was less than the bare ones as it recorded 2.403, 1.094, 23.48, 35.09 MPY for bare 304 and 316 stainless steel, Al and carbon steel, respectively, and 0.3132, 0.2733, 0.2506, 10.81 MPY for the coated samples. Corrosion results showed a noteworthy protection of the tested metals and alloys in saline water coated with the polyaniline/zeolite X. Keywords Polymer composites · Coatings · Corrosion · Energy recovery Abbreviations 2θ 2 theta CR Corrosion rate DTG Differential thermogravimetric analysis MPY Millie inch per year PANI Polyaniline * Ahmed H. Abdel Aziz 1 Chemistry Department, Faculty of Science, Ain Shams University, Khalifa El‑Maamon St., Abbasiya sq., Cairo 11566, Egypt 2 Water Pollution Control Department, National Research Center, 33 El Buhouth St., Dokki, Cairo 12311, Egypt 3 Chemical Engineering and Pilot Plant Department, National Research Centre, 33 El Buhouth St., Dokki, Cairo 12311, Egypt 4 Electrochemistry and Corrosion Lab., Physical Chemistry Department, National Research Centre, 33 El Buhouth St., Dokki, Cairo 12311, Egypt EIS Electrochemical impedance spectroscopy RO Reverse osmosis process SEM Scanning electron microscope TDS Total dissolved solids TEM Transmittance electron microscope TGA Thermogravimetric analysis XRD X-ray diffraction analysis Introduction Currently, one of the most important issues in several regions of the globe is water inadequacy. This inadequacy is caused by several factors, such as global warming, maximized urbanization, explosive population growth, excessive usage and altered water resource usage patterns. Water shortage is the issue limiting economic and social development in various cases. Water purification is required wherever water is saline; as much as 98% of the water in the world is saline (seawater, saline groundwater 13 Vol.:(0123456789) International Journal of Industrial Chemistry and saline seas) and therefore not appropriate for use as a beverage or in agriculture [1]. Desalination processes separate saline feed water, which may be brackish water or seawater, into product water with low salinity and concentrated brine. Such separation methods require energy input to manage many parameters, such as those of the separation method itself and the salinity and temperature of the incoming saline water [2]. The minimization of this needed energy is crucial because such minimization increases the value of the product water and reduces the generation of greenhouse gases and therefore reduces the disposal of various pollution products into the ocean or atmosphere. Therefore, a mechanism to decrease energy consumption is necessary; for this reason, energy recovery devices are used. The main function of an energy recovery device is to recover much of the energy held in the pressurized RO concentrate stream. Before continuing to disposal or treatment, the concentrate is sent through an energy recovery device, and the recovered energy is used to partially power the pumps [3]. In groundwater, the concentrations of many ions can vary within wide limits, and such variation can have a marked impact on the pitting and crevice corrosion of stainless steel (SS). Such materials tend to undergo pitting corrosion or other local corrosion in media containing aggressive ions, such as chloride [4]. Modern surface modification technology is becoming increasingly necessary in the enhancement of the corrosion resistance of many materials. If aluminiferous materials are not custom made, corrosion can propagate very rapidly [4]. Conducting polymers have become one of the most attractive subjects of investigation in recent decades. Their unique properties, such as electrical conductivity, reversible electrochemical behaviour and the possibility of both chemical and electrochemical synthesis, make them useful in a wide range of applications [4]. These materials are utilized in various technical applications, including chemical and electrochemical sensors [5], corrosion protection [6] and the removal of toxic materials [7]. The most popular conducting polymer is polyaniline (PANI) due to its acceptable chemical stability, comparatively high levels of electrical conductivity and monomer availability and ease of polymer synthesis. Several studies have targeted the corrosion protection performance of conducting polymers [8], particularly PANI [9]. PANI is often polymerized directly on a metal substrate acting as a protective primer film [10] or can alternatively be used as an additive in blends with insulating polymers [11]. Such blends are preferred (especially if a low concentration of PANI is adequate for active functionality) since the desired mechanical properties of coatings are often provided by the proper choice of the host polymer matrix. 13 Polymers can also be encapsulated for many reasons; however, the primary reasons are to shield materials from atmospheric and alternative types of chemical attack and for the separation of polymer chains to reduce inter-chain effects and improve the mechanical, thermal and chemical stability [12]. Zeolites are a category of micro-porous crystalline alumina silicates based on a 3D network of oxygen ions. Ze (...truncated)