研究证明,聚集高度功能化ODS@SiO2在基材上形成稳定的低能表面和多级分层结构,显著提高了超疏水涂层的耐久性和抗性。
低表面能和粗糙结构是实现超疏水性的两个关键因素。目前,获得低表面能的常见途径之一是通过有机硅烷的水解改性。然而,由于空间位阻,水解硅烷的以自缩合为主,由此产生的产物主要通过少量键物理吸附或附着在基材上,导致形成的超疏水表面容易受到外力的损伤,这大大抑制了它们的实际应用和长期使用。在此,研究人员在非水介质中制备了一种新型的功能化纳米二氧化硅,其具有高度化学接枝的十八烷基配体。对产物的共价键结构(ODS@SiO2)进行了验证,并计算了10链nm-2的平均接枝密度。
来源:欧洲涂料网
原文如下:
Fluorine-free, cost-effective and robust superhydrophobic coatings using nanosilica with highly covalently bonded octadecyl ligands
The research proves that aggregating highly functionalized ODS@SiO2 on a substrate creates a stable, low-energy surface and a multi-level hierarchical structure, which significantly improves the durability and resistance of the superhydrophobic coatings.
Low surface energy and rough structure are two key factors in achieving superhydrophobicity. Currently, one of the common routes to acquire low surface energy is via the hydrolytic modification of organosilanes. However, due to steric hindrance, self-condensation of hydrolyzed silanes predominates, whereby the resulting products are mainly physically adsorbed or attached to the substrate by few bonds, resulting in the formed superhydrophobic surfaces susceptible to damage by external forces, which significantly inhibits their practical application and long-term service. Herein, the reasearchers prepared a novel functionalized nanosilica with highly chemically grafted octadecyl ligands in a non-aqueous medium. The covalent bond structure of the product (ODS@SiO2) is approved, and an average grafting density of 10 chains nm-2 was calculated.