Polyethylene glycol trimethylnonyl ether is a nonionic surfactant widely utilized in various industrial and research applications. Part of the polyethylene glycol (PEG) ether family, it features a hydrophilic head and a lipophilic tail, making it suitable for emulsions, detergents, and solubilizers. In protein chemistry, it is particularly valuable for dissolving and stabilizing proteins such as membrane proteins for structural analysis techniques. Additionally, Polyethylene glycol trimethylnonyl ether has the capacity to interact with and penetrate cell membranes, offering potential applications in drug delivery and other medical fields.