Energy Storage And Optical Limiting Behaviors Of Low Aggregated Phthalocyanine-Based Materials Modified By Graphene Grafting,Binucleation And Covalent Framework Polymerization

The phthalocyanine compounds with large ring conjugate structure have the advantages of high structural stability,high capacity,good conductivity and strong design ability,and have great application potential in the field of energy storage and optical limiting.However,the phthalocyanine structural unit has problems such as dissolution in the electrolyte,easy agglomeration leading to low active point utilization,and poor lithium ion transmission channel,which greatly hinder the practical process of phthalocyanine electrode materials.In addition,the phthalocyanine macroring conjugate system based on the anti-saturation absorption principle has important laser protection value due to its advantages of fast light limit response speed,high linear transmittance,thermal stability and flexible structural design.However,the phthalocyanine macrocyclic conjugated molecules will inevitably produce the aggregation effect both in the solution state and in the solid matrix,which largely suppresses the optical limiting performance.To solve these problems,this thesis prepared phthalocyanine-graphene grafted polymer electrode materials with low aggregation effect by grafting phthalocyanine units to the GO matrix,which showed high specific capacity,long cycle stability and high rate cycling capacity.In addition,the low aggregation type of binuclear phthalocyanine compounds and phthalocyanine covalent organic frame polymer were constructed and dispersed in PMMA matrix to prepare them into solid devices,which showed improved optical limited performance.The low aggregated phthalocyanine materials constructed in this thesis would provide unique solutions to the problems faced by phthalocyanine compounds used as organic electrode materials and optical limiting materials.The main research contents are described as follows:（1）In order to solve the problems of dissolution in electrolyte,low active point utilization and poor lithium ion transmission channel,the phthalocyanine conjugate system is grafted onto graphene oxide through amide reaction,to obtain the phthalocyanine-GO polymer（GO-CONH-Ni Pc）with low aggregation effect.At a current density of 200 m A/g,the initial specific capacity of the GO-CONH-Ni Pc electrode was 934 m Ah/g,which is significantly higher than the initial specific capacity of 197 m Ah/g for the pristine CONH-Ni Pc electrode.After 450 cycles,the specific capacity of GO-CONH-Ni Pc electrode is maintained at 1021 m Ah/g,which is significantly higher than the pristine CONH-Ni Pc electrode（385 m Ah/g）,with a specific capacity increase of 2.6 times.The grafting of phthalocyanine to the GO base not only improves the solubility of the active substance in the electrolyte,but also effectively distributes the aggregation of phthalocyanine units to increase the specific surface area,thus revealing more lithium ion deinsertion sites（C=C/C=O）and accelerating the transmission rate of lithium ions.This strategy will open up new avenues for high-performance phthalocyanine-based organic electrode materials.（2）In order to solve the problem of the aggregation effect of the phthalocyanine conjugate units,to obtain the optical limiting materials with excellent photophysical,nonlinear absorption and anti-saturation properties.In this thesis,a new aggregation-free indium phthalocyanum（In-Pc-In）is prepared and doped into the poly-methyl methacrylate（PMMA）matrix to obtained the（In-Pc-In-PMMA）solid device.The aggregation of phthalocyanine molecules was effectively inhibited by the structural optimized spacing between In-Pc-In molecules（2.68 nm）and the angle between the large ring plane of phthalocyanine molecules（about 75^o）.The results show that the In-Pc-In-PMMA solid device exhibits a lower content fluorescence quenching process,which leads in long fluorescence lifetime and high quantum yield of T₁triplet state.At the same input energy,the In-Pc-In-PMMA device exhibits a better nonlinear absorption coefficient than the In-Pc-In-THF solution.The design strategies of binuclear phthalocyanine compounds and their solid-state devices provide useful ideas for the development of practical phthalocyanine-based optical limiters.（3）In order to eliminate the aggregation effect of phthalocyanine conjugate units and the inhibition of optical limiting performance by the uneven distribution of doped phthalocyanines in solid devices.The conjugated organic small molecule antiphenylenediamine（PDA）is grafted onto the phthalocyanine conjugate system through the azo condensation reaction,and the covalent organic framework polymer（PDA-In Pc）was obtained.Then it is doped into the polymethyl methylmethacrylate（PMMA）matrix to produce a phthalocyanine solid device with different thickness（PMMA-PDA-In Pc）.The results show that the fluorescence lifetime of PMMA-PDA-In Pc wasτ₁=0.52 ns（A₁=95.71%）andτ₂=11.5 ns（A₂=4.29%）,indicating that the phthalocyanine conjugate unit exists mainly as monomers.At the input laser energy of 9μJ,the nonlinear absorption coefficient of PMMA-PDA-In Pc device is(2.2×10^-9m/W),which is significantly better than PMMA-In Pc device(1.0×10^-9m/W),indicating that PMMA-PDA-In Pc has excellent nonlinear absorption and reverse saturation properties.The design idea of phthalocyanine covalent organic framework polymer device expands a new idea for the development of usable phthalocyanine optical limiters.