| Self-assembly is seen as a powerful tool for the creation of nature.Simple molecule or macromolecule units self-assemble by non-covalent interactions,constructing complicated functional structures,organs,systems,and materials,etc.Well-organized supramolecular self-asssembly structures allow those original systems to exhibit highly complex and advanced functions.Meanwhile,the concept of aggregation-induced emission(AIE)has been established firmly,and the research of AIE becomes one of the worldwide hottest topic in chemistry and materials science.Among all the AIE-related areas,the marriage of AIE and supramolecular self-assembly driven by non-covalent bonding have given birth to series of outstanding works.Great development is witnessed in AIE-active host-guest supramolecular systems,coordination-driven AIE-active metal-organic frameworks,as well as hydrophilic/hydrophobic interaction induced AIE-active self-assemblies.However,there are still fundamental problems that haven't been solved.This thesis aims at the combination of self-assembly techniques and AIE,in order to make a better understanding on related problems.The main contributions are listed below.Firstly,guided by the host-guest recognition of crown ethers and secondary ammonium salts,two tetraphenylethene(TPE)derivatives,TPE-DDBC and TPE-DBA,substituted with dibenzo[24]crown-8 and benzyl amino groups,respectively,were designed and synthesized,and a new AIE-active acid/base responsive host-guest supramolecular system was constructed.The self-assembly between two building blocks in acidic conditions triggered the restriction of intramolecular rotations(RIR),leading to the dramatic emission enhancement.Simultaneously some nanostructures were observed.In basic conditions,the disassembly sabotaged nano-assembly structure and turned off the emission.This research connects the fluorescence variation of the system with self-assembly and disassembly effectively.Secondly,inspired by the adsorption of hydrophobic dyes by hydrophilic agarose gels,we prepared fluoranthene-derived TPE derivatives TPE-DFA and TPE-FA,and loaded them into the frameworks of agarose gel matrix.According to the spectroscopic change after the docking between AIE probes with agarose hydrophobic region,the interaction of the AIE-active probe and polysaccharide structures were discussed.The large blue-shift in spectrum(30 nm)provided a clue to understand the way of existence and distribution of TPE-DFA probe in gel matrix.This provides unique evidence to decipher the condition and photophysical nature of the dye in interpenetrated networks.Finally,a facile and convenient AIE dot fabrication method was presented.The introduction of amphiphilic sodium citrate was important,and it could stabilize the nanoaggregates of TPE in the mixture of ethanol and water.The nanoparticle of TPE was collected with an intensity-average diameter of about 130 nm.In the meantime,the as-prepared TPE dot showed excellent electron diffraction pattern,indicating the nature of single-crystal of TPE by this method.Red emitting AIE dot,with 635-nm emission,can be prepared by TPE-TCF,and the TPE-TCF dot also possessed crystalline architectures.The sodium citrate assisted nanoparticle fabrication method we stated could be used to prepare organic nanoparticles with good organizations and low distribution,in an easy and fast way.This work provides us a new method as well as a new insight to fabricate AIE-active colloidal nanoparticles. |
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