Preparation Of Bionic Microstructure And Wettability Research Of Hydrophobic Plant Leaves

With the development of society and the advancement of technology,the traditional material performance cannot adapt the times.Besides,there are various defects of the traditional material performance so it has been far from meeting the needs of people's production and life.Therefore,there are many scientists keeping on researching the new materials and paying all their attention to this area.In this field,learning from biology which has a special surface is one of the unchanging themes.By researching and imitating the creatures,human being can obtain materials with excellent properties.So it is more and more popular to research the surface of animals and plants with special infiltration in recent years.At present,great progress has been made in the study of invasive surface creatures and the methods of keeping their surfaces also have been developed.This new type of material has the ability of self-cleaning,anti-corrosion and anti-oil,which will bring great convenience and great economic development to the society.However,there are still many creatures with special invasive surfaces waiting for humans to discover and study.In this paper,the invasive plants in nature were used as research objects.Three kinds of plant surfaces with good hydrophobic properties were found,such as Typha angustifolia,Arudo donax and Carduus crispus.Besides,this paper prepared the PDMS bionic surface with three kinds of leaves as templates based on the template method.Moreover,in this paper,the surface of the leaves and the PDMS biomimetic were studied in detail by means of contact angle measuring instrument,scanning electron microscope and Fourier transform infrared spectrometer.The test results show that the static water contact angle of the Typha angustifolia leaves is 111.5°±2°and its surface microstructure is mainly composed of sub-millimeter periodic grooves,micron-order lattice mastoids and nano-scale scaly waxy layers.Then the results show that the static water contact angle of the PDMS biomimetic surface with Typha angustifolia leaves as a template was 148.8°±2°.When it comes to the Arudo donax leaves,the results show that the static water contact angle of Arudo donax leaves is 146.9°±2° and its surface is mainly composed by sub-millimeter periodic grating structure,micro-scale mastoids regularly distributed over the grating structure,long convex bulge and Nano-scale wax layer.Besides,the results show that the static water contact angle of the PDMS biomimetic surface with Arudo donax leaves is as high as 151.1°±2°.After these,this paper also researched the apparent morphology and the infiltration mechanism of the contact between the droplets and the surface of these two leaves.Then this research established a mathematical model to analyze the infiltration mechanism.It is found that the microstructure of the Typha angustifolia leave surface and Arudo donax leave surface in contact with the droplets is in accordance with the Cassie model.Besides,the surfaces of these two leaves are similar.Then using the Cassie model to analyze these two leaves,it is found that the surface of the rough solid Microstructure is a key factor in infiltration.Moreover,this paper also researched the Carduus crispus.The result shows that the static water contact angle of the Carduus crispus with fluffy is 153.6°±2°and the static water contact angle of the Carduus crispus without fluffy is 92.7°±2°.After researching Carduus crispus by scanning electron microscope and Fourier transform infrared spectrometer,it is found that that the fluff has a great influence on the wettability of Carduus crispus surface.This paper also finds that the static water contact angle of the PDMS bionic surface of the Carduus crispus with fluffy is 135.7°±2°and the static water contact angle of the PDMS bionic surface of the Carduus crispus without fluffy is 122.3°±2°.This means that PDMS is a low surface energy substance.And it can effectively enhance the hydrophobic properties of the surface.In conclusion,this paper shows that the the preparation method used in this research is easy to application,low in cost and there is no special processing equipment needed in this method.So it has good industrial application potential.Besides,this paper studied the mechanism of solid surface infiltration,which can help develop the theoretical basis of invasive research and establish the further classification system.