Preparation And Properties Of Amphiphilic Polyarylene Ether Nitriles

Nowadays,the synthetic dyes that generally used in industry field usually contain a large quantity of toxic substance.When the untreated dyes contaminants were directly discharged into natural environment,it would certainly threaten the whole ecosystem.Owing to the coexisting hydrophilic and hydrophobic groups,the amphiphilic polymer exhibited various physicochemical properties like adsorption,flocculation,dispersion,thickening,especially it was potential in disposing dyes effluents.Polyarylene ether nitriles?PEN?is a kind of high performance engineering plastic with excellent comprehensive properties,such as high thermostability,corrosion resistance,flame retardancy,strong dimensional stability,processability and designability,and it is promising in the field of aerospace,petrochemical industry,automobile manufacturing and so on.On the basis of nucleophilic substitution polycondensation mechanism,the functional PEN with optical,electrical,magnetic properties and a lot of related productions have been developed.Thus,this work will focus on the amphiphilic PEN of varied structures,aiming to reveal the connection among the structure,amphiphilicity and assembly ability of PEN,and expand their functional applications in dyes adsorption and catalysis fields.1.By introducing hydrophilic groups on the side chains of PEN,five different amphiphilic polyarylene ether nitriles?AmPEN-H?were synthesized,and then they were transformed into ionic AmPEN-Na by the deprotonation using sodium hydroxide.It was found that all AmPEN were soluble in polar organic solvents.Compared with AmPEN-H,the AmPEN-Na exhibited higher thermal stability with the T_5%not less than430 ^oC.Moreover,the hydrophilicity of AmPEN-Na was also better than AmPEN-H,as the AmPEN-Na have lower contact angle and higher water adsorption.Among all AmPEN,the deprotonated PEN?S-P-7/3?possessed the best hydrophilicity and was even soluble in water,which also exhibited a maximum adsorption capacity to methylene blue?MB?as high as 1375.2 mg/g.Therefore,it was believed that the improved hydrophilicity of AmPEN-Na was beneficial to the adsorption of dyes.2.Based on the nucleophilic substitution polycondensation mechanism,two kinds of amphiphilic block polymers containing the same hydrophilic segment and different hydrophobic segments were synthesized,which were named as B-b-S and B-b-S-P.With an“oil in water”method adopted to explore the self-assembly behavior of B-b-S and B-b-S-P,the uniform PEN microspheres with average diameters around 0.6?m and0.7?m were obtained.It was found that both the B-b-S and B-b-S-P microspheres followed pseudo-second order kinetic equation model and Langmuir isotherm model in the adsorption of MB.Besides,the adsorption was endothermic and spontaneous,and the maximum adsorption capacity of B-b-S and B-b-S-P microspheres were 188.3 mg/g and 119.1 mg/g,respectively.Moreover,the alkaline environment would contribute to the ionization of active groups on microspheres,which then enhanced the electrostatic interaction between microspheres and MB,leading to the improved adsorption capacity of microspheres to MB.Furthermore,?-?interaction and Van der Waals Force also promoted the MB to gather on the microspheres.3.A series of PEN?S-P-7/3?-Al adsorbents were prepared by crosslinking PEN?S-P-7/3?using aluminum ion(Al³⁺).Compared with PEN?S-P-7/3?,the PEN?S-P-7/3?-Al presented much higher stability both at high temperature or in aqueous solution.Due to the repulsion of same charges,the PEN?S-P-7/3?-Al with anionic active groups could hardly adsorb dyes.As a contrast,the adsorption capacity of PEN?S-P-7/3?-Al to MB could reach up to 1721.3 mg/g.Moreover,PEN?S-P-7/3?-Al displayed high adsorption selectivity to MB from the binary mixed solution containing MB and golden orange G?OG?or MB and methyl orange?MO?.Data analysis and simulation suggested that the high adsorption capacity was mainly ascribed to the electrostatic interaction between PEN?S-P-7/3?-Al and MB,indicating amphiphilic PEN was very potential in selective adsorption to cationic dyes.4.For further decrease the hazard of dyes,the visible-light catalyst of zinc phthalocyanine?ZnPc?was prepared and then the related ZnPc/B-b-S hybrid microspheres were fabricated by“oil in water”method.The synthesized ZnPc possessed excellent light absorption and light emission properties,moreover,it was capable to release large quantity of singlet oxygen for the degradation of MB under visible light.After ZnPc was introduced into B-b-S microspheres,the obtained ZnPc/B-b-S hybrid microspheres also exhibited strong photo-electricity activity.Besides,the ZnPc/B-b-S hybrid microspheres maintained adsorption and photocatalysis properties,and the higher content of ZnPc in hybrid microspheres helped the catalytic degradation of MB,while the higher content of B-b-S in hybrid microspheres helped the adsorption of MB.By contrast,the hybrid microsphere containing 42.9wt%ZnPc displayed the highest removal efficiency to MB,in which system only 0.8%MB was left after adsorption for 60 min and light illumination for 240 min.Results suggested that the ZnPc/B-b-S hybrid microsphere was a kind of efficient dyes sewage treating agent.Moreover,it was demonstrated that the amphiphilic block PEN was advantageous in fabricating functional micro-nano material and it was worthy for in-depth study.5.With the B-b-S-P microsphere as carrier,four B-b-S-P/TiO₂ hybrid microspheres that used for disposing MB were fabricated by in-situ loading anatase titanium dioxide?TiO₂?on the surface of microsphere using the sol-gel method.Along with the increased content of TiO₂,both the thermal stability and glass-transition temperature of B-b-S-P/TiO₂ hybrid microspheres were subsequently improved,their diffraction peaks got more and more stronger and the absorption peaks presented successive red-shift from 300 nm to 400 nm.The most efficient hybrid microsphere of B-b-S-P/TiO₂-3containing 40.7wt%TiO₂ could reach an adsorption-desorption equilibrium to MB in 60min,and the remaining 42.0%MB was almost completely degraded in the following 60min under light illumination.Besides,the hybrid microsphere still maintained high treatment efficiency for MB after three cycles.In conclusion,the amphiphilic PEN hybrid microspheres hold flexible designability,good stability and outstanding functional synergy,and this work would be a guide for the further exploration about the PEN related functional micro-nano structures.