## 5 Properties of an Ideal AEM  
An ideal AEM has the following properties:  
* The membrane should have high ionic conductivity to facilitate the efficient transport of hydroxide ions (OH\({}^{-}\)) from the cathode to the anode.
* The membrane should be an electronic insulator to prevent short-circuiting within the fuel cell.
* The membrane must be chemically stable in high pH environments (typically pH > 13) to withstand the alkaline conditions in AEMFC.
* The membrane should resist degradation from oxidative and reductive environments, especially at the electrodes.
* The membrane should have sufficient mechanical strength to withstand the mechanical stresses during cell assembly and operation.
* The membrane should maintain its shape and size under varying conditions of humidity and temperature to prevent delamination or cracking.
* The membrane should be stable at elevated temperatures (typically up to 80-100 \({}^{\circ}\)C) to ensure efficient operation and to accommodate the heat generated during fuel cell operation.
* The membrane should have low permeability to gases (H\({}_{2}\) and O\({}_{2}\)) to prevent crossover, which can lead to mixed potentials and reduced fuel cell efficiency.
* The membrane should maintain adequate hydration to ensure high ionic conductivity without becoming overly swollen, which can compromise mechanical integrity.
* The membrane should facilitate the transport of water produced at the cathode to the anode to maintain proper hydration levels.
* The membrane should be cost effective to produce, as high costs can be a barrier to commercialization.  
* The membrane should have a long operational life to reduce the need for frequent replacements, contributing to overall cost effectiveness.
* The membrane should have good interfacial compatibility with the electrodes to ensure low contact resistance and efficient ion transfer.
* The membrane should adhere well to the electrodes to prevent delamination and ensure long-term stability.
* The membrane should be made from non-toxic materials to ensure safety during handling and disposal.
* The membrane should be made from sustainable or recyclable materials to minimize environmental impact.
* The membrane should be easy to fabricate into thin, uniform layers to ensure consistent performance across the fuel cell.
* The membrane should be scalable to large-area production to meet the demands of commercial applications.  
In recent years, there has been a growing trend toward eliminating fluorine-containing compounds, such as perfluorosulfonic acid (PFSA) membranes, in electrochemical applications due to environmental and health concerns associated with per- and polyfluoroalkyl substances (PFAS). These \"forever chemicals\" are persistent, bioaccumulative, and potentially toxic, prompting stricter regulations and a push for more sustainable alternatives. Styrene derivatives have emerged as promising candidates for anion exchange membranes (AEMs) in anion exchange membrane fuel cells (AEMFCs), offering advantages such as lower environmental impact, cost effectiveness, and tunable chemical properties. Unlike PFSA, styrene-based polymers can be synthesized from more benign and abundant materials, aligning with the broader goal of developing greener energy technologies. This shift not only addresses regulatory and ecological challenges but also opens new avenues for improving the performance and sustainability of AEMFCs.