Study On Preparation Of Special Morphology Inorganic Film Of Aluminum Compounds And Its Wetting Performance

In recent years,superhydrophobic materials can be widely used in various fields such as self-cleaning,anti-corrosion,drag reduction,and oil-water separation due to their unique properties.The combination of special inorganic morphology and modification of organic low surface energy substances has broad prospects in the field of preparation of superhydrophobic materials.At present,the formation mechanism and preparation conditions of inorganic special morphology and the influence of surface structure formation are lack of systematic research.Boehmite is advantageous for the preparation of superhydrophobic materials because of its easy structure and rich morphology,but there are few reports about its research on amphiphobic materials.In addition,the inorganic system shows its outstanding advantages in amphiphobic materials because of the cheap and easily available raw materials and rich morphology.The development of new systems is also a hotspot in the research of such materials.In this paper,Al（NO₃）₃·9H₂O,Al₂（SO₄）₃·18H₂O were mainly used as aluminum sources,and Na HCO₃,Na₂SO₄and Na₃PO₄ were used as precipitants.Through a one-step hydrothermal method,a film with special morphology and high specific surface structure was successfully prepared on the substrate.After a simple modification by the low surface energy substances,a film with both superhydrophobic and oleophobic properties can be obtained.The preparation method has simple process,easy operation and low cost.Using XRD,SEM,FTIR,contact angle testing and other characterization methods to study the formation mechanism of morphology and the effects of preparation conditions on the morphology and properties of materials.The results show that when Al（NO₃）₃·9H₂O was used as the aluminum source and Na HCO₃was used as the precipitant to prepare the boehmite films.The hydrothermal reaction time,the concentration of the precipitant and the p H value of the mixed solution before the hydrothermal reaction play an important role in regulating the growth of boehmite nanocrystals and the formation of morphology.The surfactants within a certain concentration range and the presence of hydroxyl groups on the substrate also play a guiding role in the growth of boehmite.Under these conditions,most of the samples modified with low surface energy showed good superhydrophobic and oleophobic properties.When Al₂（SO₄）₃·18H₂O was used as the aluminum source and Na HCO₃,Na₂SO₄,Na₃PO₄ were used as precipitants,a new type of Na Al₃（SO₄）₂（OH）₆ film was prepared.The morphology of the film was significantly affected by the p H of the mixed solution before the hydrothermal reaction.After modification with low surface energy,most of the samples obtained have good superhydrophobic and oleophobic properties,but under the control of p H,the oleophobic properties of the samples obtained are poor.In addition,by exploring the anions in the reactants,it can be seen that the higher anion valence of the precipitant is more conducive to the formation of high specific surface morphology,and the presence of SO₄^2-not only has a regulating effect on the sample morphology,but also has an important effect on the chemical composition of the product.