Design And Preparation Of Phthalocyanine-based Nonlinear Optical Functional Materials

The design and synthesis of nonlinear optical (NLO) functional materials has been becoming the most challenged and highlight research topic in laser protection field. Phthaolcyanines(Pcs) and metal nanoparticles have been investigated as the promising NLO (including optical limiting) materials. On the basis of reviewing the NLO mechanisms and current developments of NLO functional materials, it is raised that simplifying the synthetic routes, hybridalizating the NLO materials with multi-mechanisms and facbrcating solid device to the benefit of preparation for the practical laser protection materials。An easy and versatile solution-based route for the synthesis of a new soluble Pc-based light-harvesting materials PCIGS is described in Chapter 2. The molecular structure of PCIGS is proposed in line with the EXAFS spectroscopy. The composite films are prepared in terms of spin-coating. It can be concluded that PCIGS displays a typical RSA feature, and the OL properties of Pc/PMMA solid films is beyond those of Pc solutions by studying the linear and NLO performance of solutions and solid films. In contrast to the dilute solution, the linear absorption coefficient of PCIGS complex in the solid state is about 150 times greater than the dilute solution.In Chapter 3, gallium phthalocyanine monomer and itsμ-oxo-briged dimmer are embedded into a available nonlinear active polymer poly(methylmethlacrylate) (PMMA) to produce composite films acting as passive solid-state optical limiters. The results show that Pc/PMMA composite display much larger nonlinear absorption coefficient and lower saturable fluence for optical limiting when compared to the same Pc molecules in solution. No evidence of film fatigue or degradation is observed in the Pc/PMMA film after numerous scans at varying laser intensity. The improved NLO properties of Pc/PMMA solid-state materials could be realized by altering the Pcs and the polymer matrix.Chapter 4 represents a new one-pot synthesis of an octasubstututed liquid crystalline copper Pc. In the solid state the compound shows signs of irreversible thermal damage when illuminated by laser at the lowest energy per pulse setting used. The ration of the excited and ground state absorption cross section and the linear optical absorption coefficient of this compound are measured in dry toluene solution, producing values of 2.4±0.5 and 1.4 cm-1, respectively. The NLO experimental results obtained at 532 nm show that both the nonlinear absorption coefficient (β1) and the third-order nonlinear susceptibility (Im{χ(3)}) drop with increasing incident intensity, being indicative of saturation effects arising from higher level triplet excitations.Composite materials combining Pcs and carbon for preparing broad band optical limiting are the development tendency of NLO materials. For this purpose, Chapter 5 accounts the design and preparation of Pcs axially and peripherally modified carbon materials. An unsymmetrically substituted metal-free aminophthalocyanine is directly reacted with multiwalled carbon nanotubes (MWNTs) with surface-bonded acryl chloride moieties to give PcH2-MWNTs; tetra(tert-butyl)-substituted titanium Pc adducts with the surface of singlewalled carbon nanotubes to get PcTi-SWNTs. The Pcs covalently linked on the surface of carbon nanotube proved by kinds of physics and spectroscopy technology. These materials exhibit strong nonlinear scattering at higher intensities, which evidently comes from carbon nanotubes counterpart.Final Chapter presents the functionalization for RGO. An axially substituted titanium Pc-RGO, with perfluorinated phthalocyanine side chain, was prepared using a modified synthetic route. On the other hand, an innovating technique that combining of multi-dimensional nanostructures. On the other hand, a two-component new metallic nanoparticles materials combined sliver nanoparticles prepared by chemical reduction method and CdS nanoparticles modified on the surface by colloidal chemistry method with the positive and negative effect is synthesized and adheres to on the surface of RGO by electrostatic interactions. Reaearches on the composite morphology, linear and NLO properties show that the indroduction of metal nanoparticles has no damage effect on the structure of RGO supporter. For nanoseconds laser pulses, the composite with excellent optical limiting properties, is available to the broad band laser protection.