Effective Antifogging Coating from Hydrophilic/Hydrophobic Polymer Heteronetwork

Fogging on optical devices may severely impair vision, resulting in unacceptable adverse consequences. Hydrophilic coatings can prevent surface fogging by instantly facilitating pseudo‐film water condensation but suffer from short antifogging duration due to water film thickening with further condensation. Here, an innovative strategy is reported to achieve longer antifogging duration via thickening the robust bonded hydrophilic/hydrophobic polymer heteronetwork coating to enhance its water absorption capacity. The combination of strong interfacial adhesion and hydrophilic/hydrophobic heteronetwork structure is key to this approach, which avoids interfacial failure and swelling‐induced wrinkles under typical fogging conditions. The developed antifogging coating exhibits prolonged antifogging durations over a wide temperature range for repetitious usages. Eyeglasses coated with this coating successfully maintained fog‐free vision in two typical scenarios. Besides, the coating recipes developed in this study also have potential as underwater glues as they demonstrate strong adhesions to both glass and polymer substrates in wet conditions.