Application Research Of Aminosilane Coupling Agents In Primer And Siliconbased Nano-fluorescent Materials

As one of the most commonly used silane coupling agents,the diversified amino functional groups of aminosilane coupling agents make them have unique physical and chemical properties.Therefore,they have been widely used in coatings,adhesives,new materials preparation and other fields.In this paper,aminosilane coupling agents have been used in the design and application of primer adhesion promoters and silicon-based nano fluorescent material.Besides,the application and mechanism of aminosilane coupling agent on improving the bonding performance of primers and preparing silicon-based nano-fluorescent materials by the sol-gel method have been systematically studied.The research contents two parts:(1)The optimal ratio of primer film-forming agent and tackifier was studied.The research focuses on the change of the adhesion performance of the primer and the mechanism of the curing process after aminosilane coupling agent was added as tackifier to the primer.In this way,it can bring guiding opinions for the use and development of such primers and provide theoretical and experimental basis for broadening the application fields of amino silane coupling agents.The main research contents are as follows:(1)The optimal ratio of the film-forming agent in the primer was studied by adjusting the mass ratio of ethyl orthosilicate: propyl orthosilicate: butyl orthosilicate in the primer,the best formulation of film-forming agent was confined as ethyl orthosilicate: propyl orthosilicate: butyl orthosilicate in a ratio of 1:3:1.The influence of different amino silane coupling agents on the adhesion performance of the primer was studied by adding five different amino silane couples agent(additional amount is fixed at 0.83 share)to the primer.N-aminoethyl-3-aminopropylmethyl two Methoxysilane(HD-103)can greatly improve the adhesion performance of the primer.The effect of HD-103 addition on the bonding performance of the primer was studied by adjusting the amount of N-aminoethyl-3-aminopropylmethyldimethoxysilane(HD-103),it is concluded that the addition of 0.83 share HD-103 can significantly improve the bonding performance of the primer.(2)In order to investigate the primer with the aminosilane coupling agent change on surface morphology and chemical bond with curing time,the physical and chemical changes on the curing process of were studied by scanning electron microscopy(SEM)and infrared spectroscopy(FT-IR).The research results show that the alkaline catalysis of amino groups can promote crosslinking reaction and bisalkoxy structure in HD-103 can promote the formation of a planar network structure of the primer on the surface of the substrate.In this way,adhesive performance of primer agent can be improved.(2)Two amino silane coupling agents:(3-(2-aminoethyl)-aminopropyltrimethoxysilane(DAMO),N-aminoethyl-3-aminopropylmethyldimethoxysilane(HD-103))and an amino compound(Nbutylethylenediamine)were combined with anhydrous formic acid to synthesize fluorescent materials under anhydrous conditions,and their fluorescence mechanisms were studied.This research not only expands the application fields of aminosilane coupling agents,but also promotes the development and use of aminosilane coupling agents in the synthesis of silicon-based nano fluorescent materials.The main work include the following three parts:(1)The optimal synthesis conditions of the hydrothermal method were studied by changing the reaction conditions of 3-(2-aminoethyl)-aminopropyltrimethoxysilane(DAMO)and anhydrous formic acid under hydrothermal conditions,the appropriate excitation wavelength and dilution factor of the product.The results of the study showed that the fluorescence intensity of the product was higher under the condition of3-(2-aminoethyl)-aminopropyltrimethoxysilane(DAMO)and anhydrous formic acid at a substance ratio of 1:3 at 190°C for 3 hours.With the red shift of the excitation wavelength,the maximum emission wavelength of the product would be red-shifted,and the maximum emission wavelength of the product is 455 nm when the excitation wavelength is 370 nm.In addition,with the increase of the dilution,the fluorescence intensity of the product of aqueous solution would first increase and then decrease,and the fluorescent product had fluorescence aggregation quenching effect.(2)Researching when the ratio of 3-(2-aminoethyl)-aminopropyltrimethoxysilane(DAMO),N-aminoethyl-3-aminopropylmethyldimethoxysilane(HD-103)and Nbutyl-ethylenediamine to anhydrous formic acid was 1:3,the fluorescence performance of the fluorescent product obtained under the condition of heating at 190°C for 3 hours.The research results showed that the fluorescence intensity(PL),quantum yield(QY)and fluorescence lifetime of silicon-based nano-fluorescent materials are better than those of silicon-free fluorescent materials,but the acid and alkali resistance,heavy metal ion responsiveness,and Cr(?)response of the three were relatively similar.It shows that the reaction products containing the amino moiety is the main source of the fluorescence performance and the silicon-oxygen defects in the siloxane reaction product can enhance the performance of the fluorescent material.Among of them,the product made by DAMO and anhydrous formic acid has the best fluorescence performance,probably because of it's the most silicon-oxygen defects..(3)Through the micro-characterization of the three products,the existence of conjugated system in the fluorescent product was explored: the infrared absorption spectroscopy(FT-IR)and ultraviolet absorption spectroscopy(UV-vis)tests of the three product was tested,the obtained product from the reaction of DAMO with anhydrous formic acid was tested by X-ray-photoelectron spectroscopy(XPS),and the product obtained by the reaction of N-butylethylenediamine and formic acid was subjected to gas chromatography-mass spectrometry(GC-MS)and high resolution(Q-TOF)test.The research results show that in the structure of aminosilane coupling agent,the amino compound obtained by the reaction of its amino functional group with carboxylic acid is mainly responsible for the fluorescence and the siloxane's link formed by the hydrolysis and condensation of the siloxane structure is conducive to the fluorescence performance improvement of the products.