Design,Preparation And Characterization Of High Refractive Index Polymeric Materials

Functional optical polymeric materials possessing a high refractive index have received much attention because of their wide variety of applications in ophthalmic lenses,optical adhesive,prisms and optical waveguides.The thickness and curvature of the optical device can be reduced effectively with a higher refractive index of the polymer and are better suited for use in modern photonic devices owing to reducing the weight and miniaturization of the optical element.In this dissertation,polymer materials with high refractive index are designed and successful prepared from the following three aspects,and performs performance testing and characterization of high refractive polymer materials according to the different application.1.Zn O-PAAcomposite hydrogels with high transparency,high refractive index,and excellent water absorption are fabricated by one-step polymerization of acrylic acid(AA)in presence of a cross-linker N,N'-methylene-bis-acrylamide(MBA)anda initiatorammonium persulfate(APS).The resultant Zn O-PAAnanocomposite hydrogelsreached 99% transmittancein the visible regionand their refractive index measured to be as high as 1.3783.The mechanical behavior and thermal stabilityincreased depending ratio of Zn O.In addition,Zn O-PAA composite hydrogels exhibited excellent antibacterial activity against Gram-negative(Escherichia coli)and Gram-positive(Staphylococcus aureus)bacteria.Overall,the results demonstrated that the obtained Zn O-PAA composite hydrogels could be considered as an excellent candidate for artificial cornea implants and a potential composite biomaterial for other applications.2.A series of Yx/PAA(Y is the solvent,and x is the volume ratio of different solvents)hydrogels with refractive index of1.3415-1.4479,which are composed of water-soluble solventand poly(acrylic acid)(PAA)were successfully prepared by simple free radical polymerization.The transmittanceof Yx/PAAhydrogelsare above 93%in the visible region,and they exhibit good mechanical propertieswith a maximum lap shear strength of 22.67 ± 3.45 KPa.Further,Yx/Zx/PAA(Y and Z represent different solvents in the same gradient refractive indexdistribution hydrogel,and x represents the volume ratio of solvent to water)hydrogelswith highly transparent and gradient refractive index distribution can be successfully prepared by cross-combination of the Yx/PAA hydrogel,The Yx/Zx/PAAhydrogel has potential application in biomedical fields such as minimally invasive surgical intraocular lens implants.3.The present work proposes a facile but effective method for the design and synthesis of a series of optical polymers withboth high refractive index and Abbe number(Vd)by the direct introduction and dispersal of elementalsulfur in polystyrene(PS).The excellent dispersal of the reaction products of elemental sulfur with styrene(St-S)in the PS result in the highest RI of 1.6220 and Vd of 27.3.The acceptable uniform dispersal of elemental sulfurin the PS is verified by photographic analysis,optical transmission spectra,scanning electron microscopy,andenergy dispersive spectroscopy analyses.The thermal properties of polymeric materials were investigated usingthermogravimetric analysis and differential scanning calorimeter.