Compatibilization is crucial for the blending of immiscible polymers to develop high-performance composites;however,traditional compatibilization by copolymers(pre-made or in-situ generation)suffers from weak interfac...Compatibilization is crucial for the blending of immiscible polymers to develop high-performance composites;however,traditional compatibilization by copolymers(pre-made or in-situ generation)suffers from weak interface anchoring,and inorganic particles have gained extensive attention recently owing to their large interfacial desorption energy,while their low affinity to bulk components is a drawback.In this study,an interfacial atom transfer radical polymerization(ATRP)technique was employed to grow polystyrene(PS)and poly(2-hydroxyethyl methacrylate)(PHEMA)simultaneously on different hemispheres of Br-functionalized SiO_(2) nanoparticles to stabilize a Pickering emulsion,whereby a brush-type Janus nanoparticle(SiO_(2)@JNP)was developed.The polymer brushes were well-characterized,and the Janus feature was validated by transmission electron microscope(TEM)observation of the sole hemisphere grafting of SiO_(2)-PS as a control sample.SiO_(2)@JNP was demonstrated to be an efficient compatibilizer for a PS/poly(methyl methacrylate)(PMMA)immiscible blend,and the droplet-matrix morphology was significantly refined.The mechanical strength and toughness of the blend were synchronously enhanced at a low content SiO_(2)@JNP optimized~0.9 wt%,with the tensile strength,elongation at break and impact strength increased by 17.7%,26.6%and 19.6%,respectively.This enhancement may be attributed to the entanglements between the grafted polymer brushes and individual components that improve the particle-bulk phase affinity and enforce interfacial adhesion.展开更多
A facile method for the synthesis of silver-silica （Ag-SiO2）Janus particles with functionalities suitable for textile applications is reported. Silica nanoparticles prepared by the StOber method were functionalized ...A facile method for the synthesis of silver-silica （Ag-SiO2）Janus particles with functionalities suitable for textile applications is reported. Silica nanoparticles prepared by the StOber method were functionalized with epoxy, amine, and thiol groups, which were confirmed by Fourier transform infrared analysis. The functionalized silica nanoparticles were used to produce Pickering emulsions, and the exposed surface was used for the attachment of silver nanoparticles （AgNPs） via the low-temperature chemical reduction method. The morphology and structure of the Ag-SiO2 Janus particles were characterized by scanning electron microscopy, scanning transmission electron microscopy, high-resolution transmission electron microscopy, energy-dispersive X-ray analysis, and UV-vis spectroscopy. Because of their specific functionalities, these Ag-SiO2 Janus particles are proposed for applications on textile substrates, as they can overcome several drawbacks of direct application of AgNPs on textiles, such as leaching, agglomeration, and instability during storage.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.22172028,21903015,and 22403017)Natural Science Foundation of Fujian Province of China(No.2022J05041)。
文摘Compatibilization is crucial for the blending of immiscible polymers to develop high-performance composites;however,traditional compatibilization by copolymers(pre-made or in-situ generation)suffers from weak interface anchoring,and inorganic particles have gained extensive attention recently owing to their large interfacial desorption energy,while their low affinity to bulk components is a drawback.In this study,an interfacial atom transfer radical polymerization(ATRP)technique was employed to grow polystyrene(PS)and poly(2-hydroxyethyl methacrylate)(PHEMA)simultaneously on different hemispheres of Br-functionalized SiO_(2) nanoparticles to stabilize a Pickering emulsion,whereby a brush-type Janus nanoparticle(SiO_(2)@JNP)was developed.The polymer brushes were well-characterized,and the Janus feature was validated by transmission electron microscope(TEM)observation of the sole hemisphere grafting of SiO_(2)-PS as a control sample.SiO_(2)@JNP was demonstrated to be an efficient compatibilizer for a PS/poly(methyl methacrylate)(PMMA)immiscible blend,and the droplet-matrix morphology was significantly refined.The mechanical strength and toughness of the blend were synchronously enhanced at a low content SiO_(2)@JNP optimized~0.9 wt%,with the tensile strength,elongation at break and impact strength increased by 17.7%,26.6%and 19.6%,respectively.This enhancement may be attributed to the entanglements between the grafted polymer brushes and individual components that improve the particle-bulk phase affinity and enforce interfacial adhesion.
基金partial financial support from the Department of Science and Technology,Government of India
文摘A facile method for the synthesis of silver-silica （Ag-SiO2）Janus particles with functionalities suitable for textile applications is reported. Silica nanoparticles prepared by the StOber method were functionalized with epoxy, amine, and thiol groups, which were confirmed by Fourier transform infrared analysis. The functionalized silica nanoparticles were used to produce Pickering emulsions, and the exposed surface was used for the attachment of silver nanoparticles （AgNPs） via the low-temperature chemical reduction method. The morphology and structure of the Ag-SiO2 Janus particles were characterized by scanning electron microscopy, scanning transmission electron microscopy, high-resolution transmission electron microscopy, energy-dispersive X-ray analysis, and UV-vis spectroscopy. Because of their specific functionalities, these Ag-SiO2 Janus particles are proposed for applications on textile substrates, as they can overcome several drawbacks of direct application of AgNPs on textiles, such as leaching, agglomeration, and instability during storage.
