A Polyaniline Coating Material for Inhibiting Corrosion in Marine Environment

1999 ◽  
Vol 598 ◽  
Author(s):  
Yuan Lin ◽  
Sze C. Yang ◽  
Robert Clark ◽  
Richard Brown

ABSTRACTThe conventional molecular ion doped polyaniline undergoes dedoping in sea water because the sea water, with pH = 8, induces deprotontation of polyaniline. In this article we report polyaniline complexes that remain conductive in sea water. These complexes are useful for corrosion protection of metals in marine environment and for chromate replacement coatings. The reason for the pH stability of these polyaniline complexes was discussed. The polymeric complexes of polyaniline were used as an additive in an epoxy primer coating on AL7075-T6 without surface pre-treatment of the metal. Corrosion tests show that these polymeric complexes of polyaniline are effective for improving the corrosion inhibition in seawater for aluminum alloys.

2021 ◽  
Author(s):  
Juan Arévalo ◽  
Juan Manuel Ortiz ◽  
Eduard Borràs-Camps ◽  
Victor Monsalvo-Garcia ◽  
Maria D. Kennedy ◽  
...  

The world's largest demonstrator of a revolutionary energy system in desalination for drinking water production is in operation. MIDES uses Microbial Desalination Cells (MDC) in a pre-treatment step for reverse osmosis (RO), for simultaneous saline stream desalination and wastewater treatment. MDCs are based on bio-electro-chemical technology, in which biological wastewater treatment can be coupled to the desalination of a saline stream using ion exchange membranes without external energy input. MDCs simultaneously treat wastewater and perform desalination using the energy contained in the wastewater. In fact, an MDC can produce around 1.8 kWh of bioelectricity from the energy contained in 1 m3 of wastewater. Compared to traditional RO, more than 3 kWh/m3 of electrical energy is saved. With this novel technology, two low-quality water streams (saline stream, wastewater) are transformed into two high-quality streams (desalinated water, treated wastewater) suitable for further uses. An exhaustive scaling-up process was carried out in which all MIDES partners worked together on nanostructured electrodes, antifouling membranes, electrochemical reactor design and optimization, life cycle assessment, microbial electrochemistry and physiology expertise, and process engineering and control. The roadmap of the lab-MDC upscaling goes through the assembly of a pre-pilot MDC, towards the development of the demonstrator of the MDC technology (patented). Nominal desalination rate between 4-11 Lm-2h-1 is reached with a current efficiency of 40 %. After the scalability success, two MDC pilot plants were designed and constructed consisting of one stack of 15 MDC pilot units with a 0.4 m2 electrode area per unit. This book presents the information generated throughout the EU funded MIDES project and includes the latest developments related to desalination of sea water and brackish water by applying microbial desalination cells. ISBN: 9781789062113 (Paperback) ISBN: 9781789062120 (eBook)


2020 ◽  
Vol 1012 ◽  
pp. 412-417
Author(s):  
Misael Souto de Oliveira ◽  
Antonio Almeida Silva ◽  
Marco Antonio dos Santos ◽  
Jorge Antonio Palma Carrasco ◽  
João Vitor de Queiroz Marques

In this work the calibration of an Alternative Current Potential Drop (ACPD) system was performed to monitore laboratory mechanical tests on marine environment under cathodic protection. The calibration was done on CT type specimens of API 5L X65 steel dimensioned according to ASTM E1820 standard., The crack propagation during a tensile test with displacement control in an ACPD equipment was monitored through the performs points collection by two channels: one that monitors the crack growth and another that monitors a region free of crack. Using a profile projector and graphical data processing and analysis software, the area of ​​the fracture surface of the specimen was meansured, which allowed to correlate a crack size with a corresponding value of potential drop and the calibration curve. In order to verify verify the efficacy and precision of the technique, step loading tests were performed on API 5L X65 steel test specimens, submerged in synthetic sea water under the overprotection potential of-1300mVAg/AgCl. The results of the calibration showed few dispersed errors, and the main factors of this dispersion may be related to the geometry of the specimen and with variations in current flow density, which is influenced by corners and edges and by the presence of pick-up inductive. The calibration and its effectiveness can be verified through the results of the tests in marine environment, presenting crack lengths close to the actual values, confirming the effectiveness of the ACPD technique.


Author(s):  
M. L. Young

In marine organisms the fresh-weight concentrations of the trace metals zinc and iron are 102–105 times the concentrations in sea water. Study of the transfer of these metals along marine food chains is of interest because of the possibility of their being pollutants of the marine environment. Also65Zn and 65Fe are released to the marine environment and have been found, in many instances, to be the predominant radionuclides in food chains leading to man (Lowman, Palumbo & South, 1957; Lowman, 1960; Osterberg, Pearcy & Curl, 1964; Preston, 1967). The transfer of these metals along marine food chains is thus of interest also in the context of human radiation exposure.


Author(s):  
H. F. King ◽  
N. Glassman

The lubrication of machinery in a marine environment is not without challenges for researchers, designers and operators. These challenges stem in navy ships from the presence of salt water and salt-bearing air in contact with machinery already designed to the outside limits of high output and light weight. Thus, to users of machinery in a marine environment, the mastery over sea water is directly related to machinery reliability, maintainability and capability. For a machinery user such as a navy there are some additional lubrication problems caused by the need to conserve space in machinery design and the need to proceed quietly. This paper will be concerned with five machinery lubrication problems arising from the marine environment. They may be considered typical of and peculiar to that environment. They are timely because their solutions must be shared in by those in research and design as well as by the machinery operators. The cases are as follows: (a) The protection of vapour spaces in operating turbines by volatile rust-inhibiting chemicals in the lubricating oil. (b) The operation of petroleum oil hydraulic systems in the presence of sea-water intrusion. (c) The selection of lubricating greases for quiet ball bearings. (d) The development of a lubricant for a ‘marinized’ aviation gas turbine. (e) The lubrication of diesel engines of such weight-to-output ratio as to be competitive with steam and gas turbine propulsion. Each case will be presented by reviewing the background of the problems, the approaches considered in their solutions, the status of the solutions and expected future developments.


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