Controlled Synthesis And Applications Of Colloidal Spheres And Derived Porous Materials Through Polyphenol Chemistry

Porous carbon materials have attracted much attention in various fields,due to the unique characteristics of the material structure,such as low density,controllable pore structure,and thermal stability.Among them,mesoporous carbon spheres derived from polymer colloidal particles have shown promising prospects in limiting mass diffusion and tight packaging,because of their large pore size,good fluidity,and small face-volume ratio.It even underlies the dominance of the existing mesoporous carbon spheres,because the structure of polymer molecules can be clearly defined and reasonably controlled.Therefore,controllable synthesis of polymer and derived porous carbon materials containing definite pore structure and morphology,has been the long-term target.However,up to now,the types of existing polymer colloids are relatively simple,the co-assembly capacity of polymer and micelle is weak in the assembly process,and the structure cannot be regulated,thus all of those restrict the development of mesoporous carbon spheres.Therefore,how to prepare new polymer colloidal systems is still a challenge to achieve pore structures reasonably and orderly on colloidal particles.From the perspective of molecular synthesis,the novel and rational synthesis strategy for new polymer colloid systems not only promote the development of polymer colloid systems/porous carbon spheres but also expand the research about heteroatom-doped mesoporous materials.In this thesis,based on polyphenol chemistry,the widespread polyphenol compounds are used to explore a methodology to regulate the non-covalent bond forces.Consequently,we prepare polymer colloidal particles with both regular morphology and controllable size as well as derived mesoporous carbon spheres and even achieve the assembly mode based on the precisely regulation of elements.This thesis is expected to enrich the synthesis methods for polymer colloidal particles/mesoporous carbon spheres,and summarize the formation processes of various mesoporous structures.The possible pore-forming mechanisms are proposed,and the different application environments are explored.The research content of this thesis is as follows:（1）Based on amine-catalytic polymerization induced self-assembly controllable construction of polyphenol spheres.In this study,simple polyphenols are regarded as raw materials.Based on the characteristics of Michael addition and Schiff base reaction between polyphenol compounds and organic amines,the hydrogen bond interaction between oligomers and oligomers can be regulated by adjusting the ratio of the binary solvent system during the self-assembly process.Highly active polyphenol colloidal pellets p PG（x）with adjustable particle size and regular morphology are prepared.The regulating range of p PG（x）particle size is wide from 280 nm-1400 nm.The results show that p PG（x）has a high content of N about 19%,more active sites on the surface,and high adhesion,which can provide a powerful platform for fixing non-precious metal/metal nanoparticles such as Ag/Au/Fe₃O₄.Meanwhile,polyphenol-based colloidal spheres have the intrinsic characteristics of polyphenols and low cytotoxicity.Animal experiments have demonstrated that p PG（40）has the optimal activity,showing highly efficient consumption of reactive oxygen species,which is conducive to the regulation of reactive oxygen species in vivo,thus initiating high anti-inflammatory therapeutic effect,and has the optimal therapeutic effect on DSS-induced colitis.Therefore,the successful preparation of polyphenol-based colloidal particles expands the synthesis method of polymer/mesoporous carbon spheres,provides the experimental basis and theoretical basis for the reasonable regulation of pore structure,and has great potential in practical application.（2）Tunable hierarchically structured meso-macroporous carbon spheres from a solvent-mediated polymerization-induced self-assembly and their enzyme-like catalytic performance.In this study,we report a versatile solvent-mediated polymerization-induced self-assembly（PISA）strategy to directly synthesize highly N-doped hierarchically porous structured carbon spheres with a tunable meso-macroporous configuration,by using Pluronic F127 and P123 as a soft-template,1,3,5-trimethylbenzene（TMBZ）molecules as a mediator,and phlorogluol（PG）as the basic framework.The results show that the introduction of intermolecular hydrogen bonds is verified to enhance the interfacial interactions between block copolymers,oil droplets,and polyphenols.Moreover,the dominant hydrogen-bond-driven interactions can be systematically manipulated by selecting different cosolvent systems to generate diverse porous structures from the transformation of micellar and precursor co-assembly.The results show that hierarchically structured meso-macroporous N-doped carbon spheres present simultaneously tunable sphere sizes and mesopores and macropores,ranging from 1.2μm,9/50and 227 nm to 1.0μm,40,and 183 nm and 480,24,and 95 nm.Molecular dynamics simulation（MD）was used to calculate the number of hydrogen bonds between P123/F127 and PG-EDA in a binary solvent system.The results showed that the hydrogen bond force between P123/F127 and PG-EDA is promoted with the increase of ethanol concentration.It can be seen that by adjusting the binary solvent system and regulating the hydrogen bond force between the soft template and carbon precursor during the preparation process,the co-assembly mode of the soft template and carbon precursor can be regulated in coordination with the oil-water interfacial tension to realize the regulation of multilevel pore size.What is particularly attractive is that,it has a rich content of medium N about 11.8 wt%,providing abundant active sites for electron transfer and reaction,and its controllable size and multi-scale mesoporous and macroporous structure make it have excellent enzyme-like activities,including oxidase（OXD）-peroxidase（POD）-catalase（CAT）-and superoxide dismutase（SOD）-activities,NPCS-40 has the largest V_maxand the smallest K_m,in OXD enzyme-like catalyzed system V_max=0.33×10^-8M S^-1,K_m=0.22 m M.In the POD enzyme-like catalyzed system with H₂O₂as substrate V_max=5.03×10^-8M S^-1,K_m=3.64 m M.In the POD enzyme catalyzed system with TMB as substrate V_max=4.84×10^-8M S^-1,K_m=0.23 m M and CAT enzyme-like catalyzed system V_max=0.86 mg L^-1min^-1,K_m=0.14.In conclusion,this method provides a new method for preparing tunable hierarchically structured meso-macroporous carbon spheres.The resulting material also can be applied to catalytic drug loading and energy storage and conversion.（3）Formation of pores carbon spheres with tailored asymmetric morphologies and their catalytic properties study through interfacial tension mediated polymer-induced self-assembly.This study uses triblock copolymer（P123）as a pore-producing agent,TMBZ as pore expanding agent,and catechol（PGA）as the basic skeleton.By adjusting the binary solvent system,we could precisely regulate the self-assembly process of micelles and polyphenol oligomers,and achieve the regulation of pore structure.The test of contact angle and surface interface parameters shows that the dominant force of pore structure change is the oil-water interfacial tension combined with the research content of the previous chapter,which shows that the regulation of hydrogen bond force between the flexible template micelles and aggregates is a synergistic effect.The pore structure of polyphenol-based carbon spheres could be accurately regulated by this method,on the surface of carbon sphere,multi-chamber pore carbon spheres,bowl-like mesoporous spheres,bi-continuous structured carbon sphere and flower-like carbon nanosphere are synthesized respectively.NMCS-x are composed of C,N and O elements with the size of about 500 nm.The surface contains a large number of oxygen-containing functional groups C=O.Due to the bi-continuous structure mesoporous carbon sphere NMCS-40 has an interpenetrating 3D channel structure that can fully expose the abundant active sites for electron transfer and reaction,thus,it has the best performance in the catalytic oxidation of pollutants.The degradation rate of sulfamethazine（SMZ）in 12 min reaches 99%,and the reaction rate constant K is 0.050.NMCS-x can also be used for oxidative degradation of other pollutants.This study provides a new idea for the preparation of carbon spheres with abundant pore structure（4）Construction of multi-scale pours Zn-doped carbon spheres based on coordination-induced self-assembly,and their catalytic properties study.In this study,using ZIF-8 as template,F127 as surfactant and pore structure guide agent,TMBZ as pore expansion agent,tannic acid as carbon source.The multi-scale micro-mesoporous capsules with metal-polyphenol network structure is papered through a coordination-induced self-assembly strategy.The Zn-TA complex has a higher carbonization rate about25%,under nitrogen and high temperature conditions.It can be converted into the corresponding Zn-N co-doped hollow micro-mesoporous carbon capsules.The micropore diameter of micro-mesoporous Zn PN capsules is 0.38 nm,and the mesoporous pore diameter is mainly 3 nm and 10 nm.Due to multi-scale pores of the micro-mesoporous,Zn PN hollow carbon capsules can provide more active sites for SMZ,thus the ZIF-8-derived micro-mesoporous Zn PN carbon capsules have better catalytic performance.The catalytic rate constant is 0.035 min^-1and it is twice compared with the ZIF-8-derived carbon material.The both multi-scale pore structure and the hollow capsule structure have a constraint effect on SMZ.This study provides a theoretical basis for preparing metal-doped multi-scale pore structured hollow carbon spheres.With increasing efforts devoted,we expect that complex micro-mesoporous nanostructures might bring breakthroughs in the catalytic and energy-related fields.