Study On Nano-patterning Technology And Application Based On Phase Separation Of Polymer Blends

Antireflective surfaces are of considerable utility because they can handle key technological problems in lots of emerging fields.For example,reducing the reflection of silicon substrates can greatly improve its photoelectric conversion efficiency.At present,multilayer antireflection coatings are mostly used in the industry,which are expensive and time-consuming to prepare.Moreover,this technology is difficult to reduce the thickness and has great disadvantages.Surface modification technology is mostly used in the laboratory,which often needs complex equipment and is difficult to put into production.As a result,the reported technology cannot meet the requirements of ultrathin thickness,insensitivity to incident angle(no rainbow color)and broadband.Anti-fingerprint is of great importance which challenges a great number of fields,such as optical lens,interactive system and so on,especially on the glass surface.At present,many studies have successfully prepared surfaces with anti-fingerprint or anti-stain properties,but most of them are toxic fluorinated coatings with poor mechanical durability.Although a few researches on introducing microstructures have been reported,few reports have directly got glass structures and often introduced a transparent coating such as PMMA coating on the substrate,which is difficult and often has poor mechanical durability.Unlike silicon-based materials,most kinds of glass have slow dry etching rate and complex process,which makes it difficult to produce in large areas and not suitable for low-cost applications such as small display device.In this paper,nanopillar and nanowire structures were fabricated based on phase separation technology of polyphenylsilsesquioxane/polystyrene(PPSQ/PS)polymer blend and etching process.The disordered structures fabricated by phase separation of blend polymer can effectively avoid the interference effect of periodic patterns.Therefore,it will not bring rainbow effect,and can obtain antireflection performance in broadband wavelength.PPSQ is a silicon-containing polymer,while PS is a silicon-free polymer,so this system has a relatively large etching rate selection to oxygen.After removing PS phase by plasma etching,nanopatterns with a large aspect ratio can be obtained.Phase separation system of PPSQ/PS is non-toxic,economic and easy to control parameters,components of which are suitable for phase separation.The morphology of nanopillar and nanowire structures can be controlled by adjusting etching time of dry etching and wet etching parameters such as concentration.We achieved a broadband antireflection performance with reflection of less than 0.2%in the visible region.We changed experimental conditions in order to get different nanostructures,so we can study the effects of height,space ratio and aggregation on the reflection performance.Due to its unique surface structure and chemical properties,high aspect ratio silicon nanowires have good amphiphobic properties,so as to clean itself in practical applications.The technique of polymer phase separation can also be applied to transparent flexible plastic.Through phase separation,etching,coating and lift off process,we first prepared the porous structure of the silicon template,and applied the method of thermal nanoimprint lithography with Si template to fabricate the nanopillar structures on the polycarbonate(PC)substrate.Due to high temperature and high pressure in the thermal nanoimprint lithography process,hard and brittle silicon template can be easily damaged and cannot meet the requirement of reusing,although it has the advantages of high resolution and high fidelity.Therefore,nickel template is often used to take place of silicon template and quartz template.Subsequently,silicon with nanopillar structures was prepared following the similar method,and with electroplating process,we fabricated the nickel template.The inverse structures of the template were also obtained on PC substrate.Reflectivity and transmission of PC samples were tested in the wavelength of 200-800nm.We fabricated the glass of gorilla(GG3)with structures of nanopillar and nanohole using phase separation and etching techniques.It is found that the structured glass samples have high transmission in the wavelength of 200-1 OOOnm.The contact angle test of water and n-hexadecane shows that the structured glass has amphiphobic surface.