Luminescence Performance Research Of Gel Materials Constructed In Ionic Liquid And Deep Eutectic Solvent

Generally,the ionic liquid(IL)refers to the ionic compound formed by cation and anion,characterized by a melting point lowered than 100 ℃.So far,the IL has been surveyed for nearly 110 years and constituted the complete ionic liquid system,together with functional IL and new ionic liquid--deep eutectic solvent(DES).These ILs possess the advantages of low saturated vapor pressure,stable chemical properties and high structural designability,which are beneficial to construct functional materials with long-term stability.As the common methods for creating new substances,discovering new structures and exploring new applications,self-assembly and organic synthesis take important place in preparing IL-or DES-based functional stuffs.In this thesis,we established the low-molecular-weight aggregates in IL and DES,and focused the effect of IL or DES composition on aggregate configuration and luminescence property.The fabricated aggregates could exhibit circularly polarized luminescence(CPL)or chemiluminescence.Additionally,we synthesized the DES with polymerization-induced fluorescence behavior in order to exploit the novel DES,and realized its anti-counterfeiting application,which provided an important reference for carrying the information encryption practice of DES.The details of this thesis are as follows:Chapter I,introduction.Firstly,we overviewed the basic contents of self-assembly,including the definition,classification,driving force,characteristics and so on.Next,we systematically summarized the structural features of guanine-like molecules(G),the construction principle,properties and applications of G-based assemblies,offering a theoretical foundation for Chapter Ⅱ and Ⅲ.Then,we concluded the definition,application and new types of IL and DES.At last,we reviewd the construction principle and species of IL-or DES-based assemblies,and focusd their luminescence function in order to highlight the research motivation,content and significance of this thesis.Chapter Ⅱ,G-quadruplex-based ionogels with controllable chirality for circularly polarized luminescence.In this section,the self-assembly behavior of guanosine with abundant interaction sites was investigated in room temperature IL ammonium nitrate(EAN).And the aggregates in EAN possessed characteristic chirality and fluorescence,generating the adjustable circular-polarized luminescence(CPL).It has been turned out that the guanosine could self-assemble into plane G-quartets through hydrogen bonds at first.then the ion-dipole interaction between the G-quartets and the head group of ethonium(EA+)pushed the G-quartets stacking into G-quadruplex,accompanied with the π-π interaction.Eventually,the non-covalent networks linked by G-quadruplex gelated the solvent.Here,the EAN not only provided the assembly medium as solvent,but also participated in the formation of aggregates as assembly elements.The generated ionogel emitted the intrinsic circular polarized luminescence with right-hand feature(R-CPL).However,the ion-dipole interaction of EA+could be replaced by K+ or Sr2+ after the metal ions were introduced,in which the EAN only served as the assembly solvent.And the Sr2+ changed the stacking polarity of G-quartets,inversing the chirality of the G-quadruplex,turning the R-CPL into left-hand circular polarized luminescence(L-CPL).This study provides a simple scheme for preparing gel materials with adjustable CPL characteristic.Chapter Ⅲ,chemiluminescent G-quadruplexes gels in deep eutectic solvents.In this section,the G-quadruplex gel was constructed by replacing IL with deep eutectic solvent(DES),and the effects of cationic chain length of DES hydrogen bond acceptor(HBA)and the type of DES hydrogen bond donor(HBD)on the configuration of G-quadruplex were investigated.When the chemiluminescence energy resonance transfer(CRET)donor and acceptor were non-covalently connected to the G-quadruplexes,the multi-color chemiluminescence of gel was established.The results showed that the diameter of the quadruplex was raised with the increase of the cationic chain length of HBA.And the interaction sites of HBD riched the hydrogen bond networks of the DES,decreasing the diameter of the G-quadruplex.After binding the hemin,the G-quadruplex was endowed with catalase property,which catalyzed the chemiluminescence reaction of luminol.The CRET platform consisted of catalytic G-quadruplex complexes,luminol(CRET donor)and fluorescent dye(CRET acceptor)could present blue,yellow-green,light pink or water red light,after the gel was emergd into H2O2 solution.This work provides an experimental basis for assigning eutectogel as pattern display material,and expands the application of DES in optical display field.Chapter IV,the DES-based polymer with unexpected polymerization-induced fluorescence for anti-counterfeiting.Limited by the strong fluidity of DES,the luminescent DES fluid cannot thoroughly demonstrate its potential.In order to enrich the type of DES and implement its practical application,we prepared the polymerizable DES with polymerization-induced luminescence behavior for the first time,and researched the formation mechanism,luminescence property and anti-counterfeiting application of DES.We found that the DESs promoted by acrylamide(AM)with SbCl3,ZnCl2 or InCl3 were polymerization-induced fluorescent.The coordination interaction among AM and SbCl3 lead to the prominent Sb-ligand charge transfer(SLCT)and ligand-ligand charge transfer(LLCT)in polymers,which respectively generated the chartreuse and blue fluorescence of poplymers.The results indicated that the quantum yield(QY)of SLCT emission was relative to the molecular weight of polyacrylamide and could be tuned by the reversible addition-fragmentation transfer(raft)polymerization for AM,reaching up to 15.32%.But owning to the absent coordination interaction among AM and ZnCl2 or InCl3,the fluorescence from corresponding polymers derived from the clustering-triggered emission(CTE)of polyacrylamide,characterized with low QY values.As a proof-of-concept application,we utilized the Sb-based DES as anti-counterfeit ink or electrostatic spinning precursor solution,successfully realizing the fluorescence encryption.This work highlights a feasible route to exploit novel DESs and provides a new practice for current DESs.