The Fabrication And Its Crystal Orientation Of PEO Polymer Film Under Confinement Conditions

With the wide application of polymers with special microstructures in the fields of microelectronics,biomedicine,data storage and functional devices,the crystallization behavior of polymers in confined spaces has attracted wide attention from researchers.Based on the influence of the interface and the size of the space,the polymer exhibits different crystallization behavior in the body.The crystal arrangement of the polymer has a great influence on its properties,so the research on the crystal arrangement of the polymer not only helps us to understand the existing crystallization theory,but also helps us to better develop and use polymer materials.Therefore,the research on polymer restricted crystallization has become a hot topic in the field of polymers.This paper takes the typical crystalline polymer polyethylene oxide(PEO)as the research object,obtains a one-dimensional limited PEO film based on the solution spin coating method,uses thermal nanoimprinting technology to construct the microstructure of the film surface and is based on anodic aluminum oxide(AAO)nanotube channels are filled to obtain a two-dimensional restricted environment of PEO.In this paper,the surface morphology of the sample is studied by means of atomic force microscopy(AFM),polarized optical microscopy(POM)and scanning electron microscopy(SEM),using grazing incidence wide angle X-ray diffraction(GIWAXD)explores the crystal orientation of the sample,the results are as follows:The spin-coating method is adopted to obtain a film with a thickness of 30 ~1,000 nm by controlling the concentration of the solution and the spin speed of the spin coating,and the thermal history of the PEO film is eliminated by traditional heat treatment.It was found that the thickness of the PEO film and the solvent had significant effects on the surface roughness of the film,the looseness of crystallite accumulation,and the crystal anisotropy,but the effect of the crystallization temperature on the surface morphology of the PEO film was not obvious.The thinnerthe film thickness,the higher the degree of single orientation of the crystals.The crystal orientation in the original PEO film under chloroform solvent is 45 ° tilted orientation.After traditional heat treatment,the crystal orientation of some of the lamellar crystals in the film changes to parallel orientation of flat-on When the thickness of the film is 600 nm,the phenomenon that two orientations coexist is apparent.The crystals in the original film of PEO in DMF solvent exist in flat-on orientation.After heat treatment,the flat-on orientation of some of the platelets in the film is significantly weakened,and a small number of flat-on parallel-oriented platelets transform into The platelets are oriented at 45 °,and when the thickness of the film is 1,000 nm,the phenomenon of coexistence of the two orientations is obvious.The effect of crystallization temperature on the crystal orientation of PEO film under two solvents is not obvious.PEO line structure film was successfully obtained by thermal imprinting PEO film with grating structure polydimethylsiloxane(PDMS)elastomer as template,with period from 850 nm to 5 um and height from 110 nm to 3 um.During the preparation of the PEO line structure film,it was found that the thickness of the PDMS template has a significant influence on the choice of imprinting pressure.The crystal orientation of the PEO line structure film with a line width of about 0.9 um,a period of about 2.0 um,and a height of about 240 nm found that PEO exists in the line structure film in a highly flat-on crystal orientation to construct the crystal of the grating film The temperature,the solvent of the original film and the residual layer of appropriate thickness will not affect this crystal orientation in the PEO line structure film.Using the nanopore structure of the AAO template,a restricted system of PEO nanopillars and nanotubes was constructed.Using uncured PDMS to partially fill AAO nanochannels,a reusable PDMS / AAO hybrid template was successfully prepared.Using the prepared hybrid template based on thermal nanoimprinting technology,the PEO nanopillar array film was successfully constructed,and it was found that the imprinting system must be applied with greater pressure to successfully construct the PEO nanopillar array film.The PEO membrane was used to meltinfiltrate the double-pass AAO template,and PEO nanotubes with different diameters were obtained by controlling the number of melt infiltrations.The study found that it is difficult for the AAO nanotubes to be completely filled with polymer.For a long time,it may be unable to crystallize due to degradation.X-ray diffraction testing of PEO nanopillars and nanotubes revealed the existence of characteristic diffraction peaks of PEO.Therefore,PEO appears crystalline under the restricted environment of nanopillars and nanotubes.For reasons of time,the crystal orientation of PEO restricted nanopillars and nanotubes was not investigated.Through the exploration of the restricted environmental conditions of the polymer and the research on the crystal orientation of the polymer in the restricted environment,it can help people better study the crystallization of the polymer in different restricted environments,enrich and understand the existing crystal crystallization rules,Can enrich our methods of polymer crystal orientation control,help us to better develop polymer applications in many ways.