{
    "content": "The text discusses the presence of amine groups (-NH2) and catechol functional groups in polydopamine and their significant role in enhancing hydrophilicity through strong molecular bonding and interactions with water, emphasizing that amine groups displace hydrated salts and facilitate the formation of robust non-covalent interactions such as hydrogen bonding, coordination bonding, and cation-π interactions, which ultimately contribute to the material independence and versatile surface modifications of polydopamine coatings.Tannic acid contains abundant hydroxyl groups that enhance its hydrophilicity by allowing for hydrogen bonding with water, while catechin derivatives, although poorly water-soluble, can form complexes with hydrophilic polymers like poly(ethylene glycol), increasing their effective interaction with water."
}