Organic-inorganic hybrid ion exchange membranes have been developing into a fascinating new field of research. The attractive characteristics of this kind of membranes are the improved chemical/mechanical/thermal stability, porosity, high adherence to different substrates, enhanced selectivity and/or permeability. In this article, we will focus on the recent patents concerning the preparations and applications of hybrid ion exchange membranes. Some related literature reports will also be introduced. The preparation methods mainly include sol-gel process, impregnation and mixing and surface grafting of inorganic substrates with silane. And the applications mainly comprise of diffusive dialysis (DD), fuel cells, microfiltration and ultrafiltration, and other separation processes. Through the patent and literature review, this article is intended to reveal the high level of diversity in the properties, the applications and the productions of the hybrid ion exchange membranes.
Recently, Alkaline Polymer Electrolyte Membrane Fuel Cells (APEMFCs) have been attracting worldwide attention mainly due to the prospect of using non – platinum – group metal catalysts. In addition, there is growing evidence that these fuel cells can operate with the presence of carbonate. This mini review will introduce the state – of – the – art in understanding of alkaline anion – exchange membranes (AAEMs) in solid alkaline fuel cells. Ionomers for membrane electrode assembly (MEA) fabrication and the chemistry of the carbonate and bicarbonate forms of the AAEMs are also discussed. Key references to the latest scientific literature and reviews are included, along with a brief overview of directly relevant patents.
Ion exchange membranes-based technology, as a non-hazardous technology in nature, is extending towards the newly emerging fuel cells beyond its successful application in various industrial processes, e.g. electrolysis, electrodialysis, diffusion dialysis, etc. Ever since the famous DuPont product Nafion®, a large number of cation exchange membranes for fuel cells application (known as proton exchange membranes) have been prepared to make fuel cells reliable, durable and feasible. Since most of commercial products originate directly from patents, it is of great importance, at the time when proton exchange membrane fuel cells are on the brink of commercialization, to make a special review focusing on proton exchange membranes reported in patents. To get a better understanding of the state of the art of proton exchange membranes from a viewpoint of patents, most relevant patents during the last decade are surveyed in this review and some critical comments on the tendency and prospect of proton exchange membranes are made.
Separation of ions with same charges but different valences using ion exchange membranes is not only desired for industrial requirements but also challenging for academic explorations. The aim of the present contribution was to review recent developments of cation exchange membranes with monovalent ion selectivity in several aspects, such as separation mechanisms, membrane-forming materials, manufacturing methods and its relevant applications reported in the open literatures, especially in the patents. And, the relevant advantages and disadvantages with respect to some cases were discussed and compared in detail. Furthermore, some future research directions in this field were also put forward tentatively.
A review of patents published between 2005 and beginning of 2011 on organic ion-exchange membranes and electro-membrane processes is given. The electro-membrane processes include classical electrodialysis (ED), ED with a bipolar membrane, metathesis ED, electro-electrodialysis, and electrolysis. The applications of ion-exchange membranes are diverse and can be divided into the following groups: desalination and purification, removal of harmful substances, recovery of valuable substances, regeneration of spent solutions, production of new compounds. The patents on reversed ED for electric energy production are also surveyed. A large number of patents published indicates that the efficiency and environmental friendliness of electro-membrane processes are widely recognized.
Pervaporation is a newly emerged separation process, known for its higher efficiency, lower energy consumption lower capital cost and so on. The main research field in pervaporation falls into three aspects: 1) the investigation of new membranes of good separation performance; 2) methods for manufacturing pervaporation membrane with high performance; 3) process modeling to find the bottleneck in the separation process. To date, lots of research papers are published and patents concerning the above mentioned research aspects have also been brought into the sight of those skilled in the art. As a branch membrane for pervaporation purpose, an ion exchange membrane, which is prepared from the charged polymers containing either anionic or cationic groups, has an important influence on the development of pervaporation. This paper thus discusses some valuable patents concerning the research of ion exchange membrane for pervaporation. Some basic processes using anionic membrane or cationic membrane, ways for the modification of charged polymers, manufacturing of pervaporation membrane and some insights of the mass transfer behavior are reviewed in this paper and finally a perspective conclusion is made.
Ion exchange membranes (IEMs) are the newly-developed technology for the separation of various species from mixed solutions. Among which, IEMs for the separation of substances by adsorption method have become attractive. This patents review is to summarize the recent and important patents on the preparations and potential applications of IEMs as adsorbents in various adsorptive separation fields. Two major parts are involved: (i) recent patents on the synthesis of organic IEMs and hybrid IEMs with different matrixes, (ii) recent patents on the potential applications of IEMs as adsorbents in industry via adsorptive separation, such as the adsorptive separation of heavy metal ions, biomedical species and natural organic matter (NOM). Especially, their applications for the adsorptive separation of heavy metal ions from contaminated water using hybrid ion exchange membranes (HIEMs) are highlighted. The present states and future perspective are also discussed.
The recent patents and progress of electrodeionization (EDI) in fields of water deionization and wastewater treatment are reviewed in the present paper. The discussion focuses on such major aspects: applied ion exchange media, inner configuration and operation manner of the EDI, integrated membrane processes based on EDI and new applications of the technology. As the newest outstanding technology for water deep desalting, EDI has been widely used for ultrapure water production in many industries and laboratories together with important improvements in recent years. Durative advancements have been achieved by inventors such as more even current distribution, higher contact efficiency between water and ion exchanger, more effective precipitation preventing and lower energy consumption. Besides, some improvements also have been achieved in other new fields in addition to pure water production. The application in water softening, seawater desalination and wastewater treatment were introduced for example. It is believed that the electromembrane process of EDI will play an important role in water desalting, wastewater reclamation and cleaner production of chemical engineering near future.
Electromembrane processes are considered to be one of the promising industrial applicable ones using an electrical potential as high energy-efficient processes. Their applications can be found in various fields such as water desalination, water and wastewater treatment, food industries, production of acids and bases, elimination of toxic components, regeneration of metal ions from industrial waste streams, ultra pure water production and etc. The electromembrane process integration with other processes has received more attention recently in the patents as well as published articles since it provides versatile tools for industrial separations, increasing process effectiveness by optimization of the utilization of electromembrane processes. A substantial number of industrial applications for the integration of electromembrane process can be found mainly in areas of chemical unit operations, pressure-driven membrane processes, and biochemical unit processes. This review presents the recent progress on electromembrane based integrations for industrial separations based on patents as well as some published articles. The patent search has been performed in different databases in which the patents can be searched and in most cases downloaded. The keywords such as “Electromembrane process, Integration, Separation, Purification, Electromembrane” were considered for the current patents on electromembrane based integrated/ hybrid processes.
Ion-exchange membranes (IEM) are used in the agri-food sector since the early 1950s. Their main applications are based on the demineralization of agri-food products or effluents. In these applications, anion- and cation-exchange membranes are stacked alternatively in an electrodialysis cell to produce two solutions, one concentrated and one impoverished in minerals. In this article we will focus on the recent patents published in the 5 last years and presenting the more recent uses and applications of ion-exchange membranes in this sector. These patents concerns mainly, the rectification of wine and grape juice, the production of salt and concentrated mineral solutions, the production of drinking water and functional drinking water, the demineralization of dairy and plants products, the production of sugar derivates, the bacterial decontamination of solution and the demineralization and purification of fermentation broth. These approaches will be discussed in terms of originality and novelty in comparison with current applications, as well as for their potential of application in the sector.