Fabrication Of Polymer Brush Nanoscale Arrays And Their Biological Applications

Surface and interface science is one of the hot topics of current functional material fields,and is applied in many fields.Polymer brush materials are one of the surface and interface materials,which the polymer is grafted on the surface for corresponding function.Combining the fabrication techniques of micro-nano structure,such as lithography,colloid lithography,with the polymer brush lead to the patterned polymer brush materials.After several decades developing,the method of fabricating microscale patterned polymer brush are mature,but there are challenges on the fabrications of nanometric polymer brush are still refrained,such as the utilization of complex instruments or devices,the cost-deficient fabrication and the poor repeatability.Therefore,to efficiently study the relationship between the morphology and properties of nanometric polymer brush,it is very meaningful to develop a simple,cost-efficient technique for fabricating nanometric polymer brushes.The main work in this paper is to develop a new method to fabricate nanometric polymer brush arrays and to study their biological applications.In chapter two,we develop a new method to fabricate nanoscale polymer brush.Initially,we prepare the Au nanoparticles(AuNPs)masks on the silicon,through the interaction between the AuNPs and aminosilanized surface.Then,the substrate is set in the chamber of the plasma etching device and by using the oxygen etching and Au etchant the nanometric amino arrays are prepared.Finally,the atom transfer radical polymerization(ATRP)initiator arrays are grafted on the amino areas,and the nanometric polymer brush arrays are prepared by ATRP.Meantime,we adjust the parameters during the fabrication to get nanometric polymer brush arrays with different sizes and heights.The densities and sizes of the AuNPs masks highly effected the morphology of the polymer brush arrays.Utilizing the different sizes AuNPs and changing the adsorbing time of the AuNPs,we get the polymer brush arrays of variety of sizes and densities.In addition,we fabricate the micro-nano structure by using photo lithography technique.In chapter three,we successfully prepare a binary system by protein/polyethylene glycol(PEG)on quartz by bio-functionalizing the side group of poly(hydroxyethyl methacrylate)(PHEMA)brush.The densities and heights of the protein on the surface are changed to regulate the behaviors of MC3T3-E1 cells.We analyze the factors that produce the corresponding situation of the cells.Gradient polymer brush arrays are fabricated by dip coating.We observe the behavior of the cells by the different proportion of the protein areas on the surface of the gradient material.We prepare cell density gradient on the gradient protein materials.By using this method to fabricate nanoscale bio-functioned surface,the morphology and chemical composition on the surface can be easily regulated and samples can be made efficiently.Meantime,it is possible to study deeper cellular behavior,including differentiation of stem cells and proliferation or inhibition of cancer cells growth.