Review Chitosan and alginate types of bio-membrane in fuel cell application: An overview N. Shaari a , S.K. Kamarudin a, b, * a Fuel Cell Institute, Universiti Kebangsaan Malaysia, 43600, UKM Bangi, Selangor, Malaysia b Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, UKM Bangi, Selangor, Malaysia highlights  Fuel crossover is the major problems in polymer electrolyte membrane fuel cell.  Chitosan and alginate-based biopolymer membranes are proposed to solve the problems.  This review performs the state-of-the-art chitosan and alginate-based membranes for fuel cell. article info Article history: Received 15 October 2014 Received in revised form 27 March 2015 Accepted 5 April 2015 Keywords: Fuel cell Bio-membrane Chitosan Alginate abstract The major problems of polymer electrolyte membrane fuel cell technology that need to be highlighted are fuel crossovers (e.g., methanol or hydrogen leaking across fuel cell membranes), CO poisoning, low durability, and high cost. Chitosan and alginate-based biopolymer membranes have recently been used to solve these problems with promising results. Current research in biopolymer membrane materials and systems has focused on the following: 1) the development of novel and efficient biopolymer materials; and 2) increasing the processing capacity of membrane operations. Consequently, chitosan and alginate- based biopolymers seek to enhance fuel cell performance by improving proton conductivity, membrane durability, and reducing fuel crossover and electro-osmotic drag. There are four groups of chitosan-based membranes (categorized according to their reaction and preparation): self-cross-linked and salt- complexed chitosans, chitosan-based polymer blends, chitosan/inorganic filler composites, and chito- san/polymer composites. There are only three alginate-based membranes that have been synthesized for fuel cell application. This work aims to review the state-of-the-art in the growth of chitosan and alginate- based biopolymer membranes for fuel cell applications. © 2015 Elsevier B.V. All rights reserved. 1. Introduction Membrane separation technology utilizes membranes to serve as barriers or filters for target species within liquid, gas or colloidal particle mixtures [1e4]. Non-conventional separation methods offer certain advantages, including higher separation efficiency, increased energy conversion and environmental protection, and increased versatility. Non-traditional membrane separation tech- nology utilizes enhanced selectivity and affinity membrane layers to increase separation efficiencies and reduce environmental problems due to a wider range of applications, which include water and contaminants treatment and processing and hazardous organic recovery. Membrane separation technology has played an impor- tant role in industry and daily lives because of its flexible and versatile features. Its use is more prominent when in the large-scale petroleum industry, but its effects can be seen even in small tech- nologies, such as drinking water filters, batteries, biomedical pu- rifications and controlled drug delivery. The composition and structure of the material in a membrane is the most important component in any membrane-based technol- ogy. Membrane performance can be optimized using multi- component or composite membrane materials, a practice which has been successfully implemented in the past decade [5e8]. This is important because basic materials, whether natural or synthesized, * Corresponding author. Department of Chemical and Process Engineering, Fac- ulty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, UKM Bangi, Selangor, Malaysia. E-mail address: ctie@eng.ukm.my (S.K. Kamarudin). Contents lists available at ScienceDirect Journal of Power Sources journal homepage: www.elsevier.com/locate/jpowsour http://dx.doi.org/10.1016/j.jpowsour.2015.04.027 0378-7753/© 2015 Elsevier B.V. All rights reserved. Journal of Power Sources 289 (2015) 71e80