The Fabrication Of Micro-nanometer Pattern And Controllment Of Condensed Structure For P3HT And PHB Polymer Film

In recent years,with the development of nanoscience and technology and the in depth study of the structural properties of polymer materials the relationship between polymer material properties and patterned nanostructures has become more and more tight.Patterned polymer Micro-Nanostructures have a very important impact on the application and performance improvement of polymer materials.How to effectively and quickly pattern polymer film and explore its influence on material properties has become a hot issue in polymer science.Nanoimprint technology is actually a simple process of copying patterns using templates.Only one template with a micro-nano size pattern is needed,and then the patterned micro-nano structure can be constructed multiple times and in large quantities.This technology is very simple and convenient and efficient.The template can be reused many times,and it is a micro-nano structure construction technology with very high cost performance.In this thesis,the polymer micro-nano structure film constructed by the two imprinting methods is consistent with the pattern information on the template,which proves that the replication is successful.The orientation behavior and physical modification of molecules and crystals under successful conditions were investigated for the successful construction of polymer micro/nano structures.The molecular andcrystal orientation changes of polymers under restricted crystallization were investigated to explore molecules and crystals.The effect of orientation change on polymer properties.The main contents of the paper are as follows:First,poly(3-hexylthiophene,P3HT)was used as the research object.The P3 HT micro/nano structure film was constructed by micro-nano imprint technique.The AAO template was studied by atomic force microscopy(AFM)and scanning electron microscopy(SEM).Characterization was performed with a patterned film morphology.A film structure with uniform distribution,uniform size,regular pattern and matching with template information was obtained,which proved successful.To further understand the orientation of molecules and crystals in P3 HT nanofilms.The P3 HT film before and after imprinting were diffracted by grazing incidence X-ray diffraction(GIWAXD)to investigate its crystal structure and molecular orientation.The micro-nano imprint technique constructs a successful P3 HT nanofilm,and the molecular and crystal orientation changes from edge-on orientation to face-on orientation.Finally,the morphology and thermal stability of polymer nanostructures under thermal annealing conditions were studied by the morphology analysis of patterned polymer films under thermal annealing conditions.After the thermal annealing treatment of the patterned film,when the temperature rises to about 180?,the nanostructures collapse,and the molecular and crystal orientation alignment in the collapsed film only has a face-on orientation and no edge-on orientation.Secondly,Poly-3-hydroxybutyrate(PHB)was used as the research object.Different sizes of PHB patterned micro-nanostructured films were fabricated by hotstamping.The PDMS template and the patterned PHB film were characterized by atomic force microscopy(AFM).Observing the morphology change of the polymer PHB after hot stamping,the experiment obtained a uniform and regular line structure film and matched with the template information,which proved the imprinting success.The method of constructing the micro/nano structure is a hot stamping method.Next,we explored the effect of temperature on the crystallization of the polymer.We experimented with the crystallization of the polymer at the same film thickness and temperature.The results indicate that different temperatures will only change the crystallization rate of the polymer,affect the crystal size,and not change the morphology of the crystal without changing other conditions.During the imprinting experiment,we further found that when the concentration of the solution is too low and too high,it will affect the limited crystallization of PHB in the template.When the concentration is low,it is difficult to obtain a complete nano-patterned film.At a higher concentration,the remaining residual layer of the imprint will grow together with the crystals in the template,interfering with each other and affecting the restricted crystallization.Finally,we thermally annealed the PHB micro-nano film and characterized it with AFM.The results show that after the thermal annealing,the nano-line film,when the temperature reaches 160 o C,the PHB nano-column melts and widens with temperature,and collapses,although the period of the pattern contour remains unchanged.However,when the temperature was raised to 190 o C,a relatively uniform and regular nano-pillar profile could not be seen,and the film surface tilt became flat.In addition,when the polymer film was cooledto room temperature,the deformation or similar smooth surface morphology remained unchanged to the state before the thermal annealing.To a certain extent,this thesis provides a new idea for exploring the orientation of molecules and crystal orientation under nano-constrained conditions.