| In recent years,tremendous researches have been focused on the microscopic materials.It is challenging and hot spot to explore suitable,controllable and simple methods for synthesizing nanomaterials with specifically designed morphologies.The particle size,morphology and position of metal NPs can be regulated by the nanoreactor,besides,the synthesis of the metal NPs has brought in a new stage of development.Therefore,it is important for the performance and application of Ag NPs with different morphologies to find a suitable material for the preparation of nanoreactors and the controlled synthesis of Ag NPs.Herein,developing new materials for fabricating nanoreactors is a necessary step to control the shapes of Ag nanoparticles that can be applied in practical applications.Polyarylene ether nitrile（PEN）is one type of high performance polyarylene ether polymers with a rigid benzene ring and a flexible arylene ether bond in the main chain and a polar nitrile group in the side chain.And the amphiphilic poly（arylene ether nitrile）block copolymer（amPEN）is one of polyarylene ether nitrile special polymers with strong intermolecular interaction and abundant self-assembled structures.The structure of the nanoreactor can be stably existed without cross-linking,which overcomes the shortcomings of the soft template and other methods.At the same time,the functional groups of the amphiphilic poly（arylene ether nitrile）block copolymer,such as cyano and sulfonic acid groups,can be used to coordinate with Ag ions to confine the morphology and control the position in the subsequent preparation of Ag NPS,which implies amPEN is an appropriate material for nanoreactor fabrication to realize the controlled synthesis of Ag NPs.In this work,systematic research has been conducted on the self-assembly of amphiphilic poly（arylene ether nitrile）block copolymers into PEN microspheres,the controllable synthesis of Ag NPs and its optical properties,and the preparation of SERS substrates by Ag NPs/PEN hybrid microspheres and application in dye molecules detection,the research content mainly includes the following parts:In the first section,the Ag NPs based on PEN microsphere nanoreactor are synthesized by the microemulsion method.Firstly,the amphiphilic poly（arylene ether nitrile）block copolymer self-assembles into PEN microspheres by microemulsion method.In this process,Ag ions complex to shell position of the oil-in-water PEN microspheres by coordinating with cyano and sulfonic acid groups.Afterwards,during the reduction of silver ions the shaped microsphere reactor acts as a template to tune the morphology of Ag NPs.By change the reaction conditions such as the ratio and concentration of the reactants,the type of surfactant,the stirring rate as well as the reaction time,the Ag NPs/PEN hybrid microspheres（Ag-PMS）with different sizes are obtained.We optimize the experimental parameters and obtain the designed Ag NPs with specific morphology and size distribution.Based on the optical spectroscopy tests,the Ag NPs are found to locate in the shell portion of PEN microspheres.However,the loading content and dispersion of Ag NPs in PEN microspheres is still quite limited.In order to increase the immobilization efficiency of Ag NP in PEN microsphere,the PEN microsphere nanoreactor has been prepared via reverse microemulsion in this part.During the self-assembly of amphiphilic poly（arylene ether nitrile）block copolymer into microspheres,the Ag ions in the aqueous solution of silver nitrate are highly concentrated at the core position of the microspheres through the interfacial interaction between the oil phase and aqueous phase.Water-in-oil Ag NPs/PEN hybrid microspheres with different morphologies are prepared by controlling the ratio of reactants and concentration,reductant solvent,reaction time and reaction temperature.The formation and development of Ag NPs are studied by UV-Vis absorption spectroscopy and fluorescence emission spectroscopy.It is clearly proved by spectra and SEM images that the reducing agent solvent is a key factor to influence the morphology of Ag-PMS.The prepared Ag NPs were densely encapsulated in the core of PEN microspheres.Moreover,the optical properties of Ag NPs are also prominent.The silver nanoparticles prepared by reverse microemulsion method have controllable morphology,high reproducibility,high Ag NP loading as well as high aggregation.After optimizing the morphology and size of Ag NPs/PEN hybrid microspheres,it`s necessary to apply this hybrid structure to SERS substrate and dye detection performance.In this part,the Ag NPs/PEN hybrid microspheres are used to prepare an active substrate for Surface Enhanced Raman Spectroscopy owing to the highly active properties of Ag NPs.The Ag NPs/PEN hybrid microspheres form a dense and uniform film after natural air drying,in which the Ag NPs/PEN hybrid microspheres are closely arranged.After testing the dye detection performance,the SERS substrate prepared by water-in-oil Ag NPs/PEN hybrid microspheres（5 mg amPEN,55.0μmol AgNO3,H2O as the reducing agent solvent）show the best performance and the single molecule detection for Rhodamine 6G can be realized.Overall,the amphiphilic poly（arylene ether nitrile）block copolymer can be self-assemble into polymeric microspheres by microemulsion method and reverse microemulsion.Besides,the PEN microspheres used as nanoreactor pave a new pathway for the synthesizing silver nanoparticles with the controllable morphology,size and position Ag NPs,which shows outstanding optical properties,overcomes the shortcomings of traditional soft template materials,and broadens the application range of poly（arylene ether nitriles）.Moreover,the prepared Ag NPs/PEN hybrid microspheres can be used to form highly sensitive SERS substrates and realize single molecule detection of Rhodamine 6G. |
