## 1 Introduction  
Magnesium (Mg) and its alloys have been widely used in the automotive industry, optical equipment, electronics industry, aerospace, and other fields due to their low density, high specific strength and specific rigidity, excellent electromagnetic shielding performance, low processing cost, easy forming, etc. However, poor corrosion resistance of Mg alloys has limited their larger-scale applications, especially in special environments (such as seawater, organic/inorganic salt solutions, etc.) [1]. Thus, an anti-corrosion coating on Mg alloy is one of the most extensive and effective ways to improve corrosion resistance [2, 3]. Many techniques can be developed using to prepare anti-corrosion coatings, including chemical conversion, anodic oxidation, micro-arc oxidation, vapor deposition, electrodeposition, superhydrophobic coatings, etc. [4, 5, 6, 7, 8]. Among all the methods, building a superhydrophobic coating is considered an efficient and promising method, which can isolate the corrosive medium and the anti-corrosion coatings, and thereby significantly enhancing the corrosion resistance of Mg alloys and extending the service life of the coatings [9].  
Numerous techniques have been developed and applied to develop of superhydrophobic coatings on Mg alloys, including the hydrothermal process, chemical deposition,electrodeposition techniques, conversion coatings, polymer coatings, sol-gel coatings, laser processing, etc. [10; 11; 12; 13; 14; 15]. In general, two essential features are required to construct a superhydrophobic surface on Mg alloys, i.e., micro-nano hierarchical structure, and a low surface energy chemistry. However, many methods have many drawbacks, such as multi-step process, poor mechanical stability, low impact resistance, etc., which restrict their large-scale and practical application [16]. Both surface roughness and low surface energy should be obtained in one step to overcome these disadvantages and simplify the complexity of multi-step processing. Moreover, it is essential and inevitable to propose and construct a durable superhydrophobic coating with excellent wear resistance.  
Polyvinylidene fluoride (PVDF) has excellent thermal stability, excellent chemical stability and good processing properties, which is a semi-crystalline polymer, including amorphous and crystalline phases [17]. Due to its low surface energy and good physical and chemical properties, PVDF is widely used to prepare superhydrophobic coatings [18]. However, the softness of PVDF causes the superhydrophobic coating to be easily damaged by the friction surface, which reduces the adhesion to most substrates, resulting in a decrease or loss of superhydrophobicity [19].  
It is appropriate to use PVDF as the matrix of superhydrophobic coating, the finely dispersed SiO\({}_{2}\) particles is employed to improve the performances of superhydrophobic coating. In this work, a simple one-step spray technique is employed to manufacture PVDF/PROTES-SiO\({}_{2}\) superhydrophobic films on AZ31B Mg alloy. The wettability of the prepared coating can be adjusted by the mass ratio of PFOTES-SiO\({}_{2}\) to PVDF. The adhesion performance and wear resistance of the superhydrophobic nanocomposite coating are discussed. In addition, the corrosion behavior was evaluated by electrochemistry, long-time immersion, and salt spray corrosion. The as prepared superhydrophobic composite surface not only exhibited excellent wear resistance, but also showed good corrosion resistance. It is known that spraying coating is a straightforward method and can be applied to a large surface with low cost. Therefore, the goal of this investigation is to prepare corrosion-resistant PVDF/PROTES-SiO\({}_{2}\) coatings on a large scale.