Controlled refractive index polymer

A variety of PFCB aryl ether polymers with a combination of good chemical and thermal stability, controllable refractive index, low birefringence, and low... 

For several decades, carbon black and fumed silica have been used in tires, tubings, sealants and so on.[162,163] More recently, functionalized silica nanoparticles were reported to copolymerize with MMA to produce transparent films with good surface finish and controllable refractive index. [162] The sol-gel process is another research topic to prepare the polymer nanocomposites. The principal sol-gel process includes two steps the formation of a colloidal suspension, i.e. sol, and the gelation of the sol to formulate a network in a continuous liquid phase, i.e. gel. For example, the hydrolysis and poly condensation of silicon alkoxides in the presence of MMA will produce a polymer nanocomposite with superior optical and mechanical properties.[163]... 

From a materials point of view, synthesis of two-photon chromophores with even higher two-photon cross-sections is required, so that photopolymerization may be induced by less expensive picosecond, nanosecond and even CW lasers for commercial applications. Also the high 5 materials would enable polymerization simultaneously from multibeam split out of one output of a laser for batch production. Also desired is the use of copolymerization of functional molecules and resins, or doping of other functional components like nanocrystals into resins, so that particular functions could be imparted to polymerized devices. Uniform dispersion of the alien components into the matrix polymer is an important problem to solve. Finally, we need to synthesize functional polymers in other words, instead of doping, we directly induce functional chromophores as a bonded component of monomers or oligomers, so that functions such as light-emission, polarization control, refractive index tuning and so forth become more pronounced. 

The next step in this study is to test this control algorithm on the actual laboratory reactor. The major difficulty is the direct measurement of the state variables in the reactor (T, M, I, W). Proposed strategy is to measure total mols of polymer (T) with visible light absorption and monomer concentration (M) with IR absorption. Initiator concentration (I) can be monitored by titrating the n-butyl lithium with water and detecting the resultant butane gas in a thermal conductivity cell. Finally W can be obtained by refractive index measurements in conjuction with the other three measurements. Preliminary experiments indicate that this strategy will result in fast and accurate measurements of the state vector x. 

The refractive indices before and after photoirradiation were measured for a series of mesoionic compounds including 3-phenyl-l,2,3,4-thiatriazolium-5-thiolate. The knowledge of these data allows controlling the optical properties of polymers. The results obtained in <2002MI2290> suggest the applicability of photoelimination of 3-phenyl-l,2,3,4-thiatriazolium-5-thiolate to make various refractive index patterns for polymeric film. It has also been shown that the refractive index changes of mesoionic compounds are proportional to the number of sulfur atoms in the mesoionic skeletons. 

---