Preparation And Analysis Of Non-metal Doped Phenol-formaldehyde Resin Nanomaterials

Non-metallic doping has a great influence on the optical,electrical and thermal properties of nanomaterials.Element doping of phenol-formaldehyde resin?PFR?is one of the principal means to effectively regulate the material properties.At present,research on element doping of PFR toughening and heat resistance has been widely concerned.However,there are limited reports on the improvement of fluoroscopy performance by non-metallic element doping,such as the quantum of PFR doped with nitrogen.The yield and photoelectric properties have been considerably improved.Based on this,PFR was doped with chlorine and sulfur to prepare PFR nanoparticles containing chlorine and sulfur,and its structural properties were characterized by scanning,transmission,infrared,Raman,ultraviolet and fluorescence and further load gold nanoparticles?Au NPs?and dioxide on the surface of PFR.Manganese?MnO₂?nanosheets were used to construct several detection probes with fluorescence resonance energy transfer?FRET?to achieve sensitive detection of Fe³⁺,melamine?MA?and glutathione?GSH?in the environment.As follows:?1?PFR,Br-PFR,NH₂-PFR,COOH-PFR,Cl-PFR were prepared by mixing phenol,p-bromophenol,p-aminophenol,p-hydroxybenzoic acid,p-chlorophenol and hexamethylenetetramine?HMT?under hydrothermal conditions.Five kinds of resins were investigated for the effects of doping of different elements or functional groups such as-Br,-NH₂,-COOH,-Cl on the fluorescence emission intensity of PFR.The experimental results show that the doping of chlorine can maximize the fluorescence emission intensity of PFR.Fe³⁺has a significant quenching effect on the fluorescence intensity of Cl-PFR nanoparticles in a certain concentration range.Under the optimal experimental conditions,Fe³⁺has a good linear relationship in the range of10-70?mol·L^-1,R²=0.987.The detection limit was 6×10^-77 mol·L^-1.?2?PFR,Br-PFR,NH₂-PFR,COOH-PFR,Cl-PFR were prepared by mixing phenol,p-bromophenol,p-aminophenol,p-hydroxybenzoic acid,p-chlorophenol and hexamethylenetetramine?HMT?under hydrothermal conditions.Five kinds of resins were investigated for the effects of doping of different elements or functional groups such as-Br,-NH₂,-COOH,-Cl on the fluorescence emission intensity of PFR.The experimental results demonstrate that the doping of chlorine can maximize the fluorescence emission intensity of PFR.Fe³⁺has a significant quenching effect on the fluorescence intensity of Cl-PFR nanoparticles in a certain concentration range.Under the optimal experimental conditions,Fe³⁺has a good linear relationship in the range of10-70?mol·L^-1,R²=0.987.The detection limit was 6×10^-77 mol·L^-1.?3?Using Fe₃O₄ as the core,phenol,HMT and thiourea as raw materials,the core-shell nanospheres?Fe₃O₄@S-PFR?with excellent fluorescence performance and good magnetic separation performance were prepared by a simple hydrothermal method.A ternary nanocomposite?Fe₃O₄@S-PFR@MnO₂?was obtained by loading a MnO₂ nanosheet on the surface of the S-PFR shell by a redox reaction.The MnO₂nanosheets have a quenching effect on the fluorescence emission of Fe₃O₄@S-PFR.When the reduced GSH is added,MnO₂ will be reduced to Mn²⁺and fall off,causing partial recovery of the fluorescence intensity of Fe₃O₄@S-PFR,thus realizing the sensitive detection of GSH.Under the optimal detection conditions,the fluorescence recovery degree of Fe₃O₄@S-PFR was linear with GSH concentration in the range of100-800?mol·L^-1,R²=0.9926,and the detection limit was 1?mol·L^-1.