Different-Crystallinity Pseudoboehmites for Enhancing  the Anti-fogging Performance of Polyethylene Film

As the most widely used greenhouse film material in the world, the fogging problem of polyethylene film seriously affects the light transmittance and the healthy growth of crops. In this work, the different-crystallinity pseudoboehmites were synthesized by hydrothermal method, and used to prepare anti-fogging coatings on polyethylene films by blending with surfactant (polyether). The crystallinity of pseudoboehmite raises with increasing of hydrothermal temperature (from 80°C to 180°C). As the crystallinity of pseudoboehmite increases, the number of hydroxyl groups in pseudoboehmite grows up. As the amount of hydroxyl groups increases, the pseudoboehmite crosslinks with polyether more tightly and firmly. All the pseudoboehmite/polyether coatings exhibit superhydrophilicity, excellent anti-fogging durability and wear resistance. The pseudoboehmite/polyether coating prepared form 180°C-hydrothermal pseudoboehmite shows the best anti-fogging performance. The thermal-fog persistence (60 °C) of this coating is more than 30 days . Meanwhile, the friction test shows that this coating is basically undamaged after 20 times friction tests.