The present work deals with fabrication and characterisations of nano-composite membranes composed of sulfonated poly (ether ether ketone) (SPEEK) cross-linked and reinforced with ethylene glycol (EG) and cellulose nanocrystals (CNCs) respectively. The thin films of cross-linked composite membranes were prepared by solvent casting method and further analysed for physicochemical and electrochemical properties to execute their applicability as promising proton exchange membrane (PEM) in fuel cells. The process of cross-linking helps to improve the strength and dimensional stability of bare SPEEK membranes without compromising with conductivity. However, presence of CNCs further improves the strength and provides an effective pathway for the conduction of protons in membranes by interacting through their surface hydroxyl and sulfonic acid groups with ionic moieties of polymer matrix. All prepared composite membranes showed good oxidative and thermal stability along with good proton conductivity. The cross-linked SPEEK membranes with 4 wt% loading of CNCs possess an appreciable proton conductivity of 0.186 S/cm at 95 °C and 95% RH which is comparable to Nafion 117. From the view point of above studies, the prepared nano-composite can be described as promising proton exchange membrane for fuel cells.

本工作涉及纳米复合膜的制备和表征，该复合膜由分别与乙二醇（EG）和纤维素纳米晶体（CNC）交联和增强的磺化聚醚醚酮（SPEEK）组成。通过溶剂流延法制备了交联复合膜的薄膜，并对其理化和电化学性质进行了进一步分析，以实现其在燃料电池中有望作为质子交换膜（PEM）的应用。交联过程有助于提高裸SPEEK膜的强度和尺寸稳定性，而不会影响导电性。然而，CNCs的存在进一步提高了强度，并通过质子在表面的羟基和磺酸基团与聚合物基质的离子部分相互作用，为质子在膜中的传导提供了有效的途径。所有制备的复合膜均显示出良好的氧化和热稳定性以及良好的质子传导性。具有4 wt％的CNC含量的交联SPEEK膜在95°C和95％RH下的质子电导率明显为0.186 S / cm，与Nafion 117相当。这种复合材料可以说是有前途的用于燃料电池的质子交换膜。