PH-responsive type magnetic composite microsphere with Janus structure, and preparation method thereof

A magnetic composite microsphere and responsive technology, which is applied in the field of composite materials and nanometers, can solve problems such as lack of environmental response performance, and achieve the effect of simple method and high feasibility

Inactive Publication Date: 2015-03-11
XIAMEN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This Janus particle is highly controllable in microsphere size and shape, but does not have environmental response performance

Method used

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  • PH-responsive type magnetic composite microsphere with Janus structure, and preparation method thereof
  • PH-responsive type magnetic composite microsphere with Janus structure, and preparation method thereof
  • PH-responsive type magnetic composite microsphere with Janus structure, and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0029] (1) Oleic acid modified Fe 3 o 4 Preparation of nanoparticles

[0030] 8.19g FeCl 3 ·6H 2 O and 4.35 g FeSO 4 ·7H 2 O was dissolved in 50mL of deionized water, and added to a three-necked flask equipped with a reflux condenser to deoxygenate with nitrogen for 30 minutes; 5.31g of NaOH was dissolved in 10mL of deionized water, and then slowly added to the three-necked flask, reacted at 70°C for 1 hour, and then added to prepare 10mL mixed solution of oleic acid and ethanol (oleic acid:ethanol = 1:1), heated to 80°C and matured for 1h, to obtain magnetic Fe with a size of 2-10nm and superparamagnetism 3 o 4 nanoparticles. Modification of oleic acid to Fe 3 o 4 The nanoparticles were washed three times with 10 mL of ethanol and deionized water to neutrality, and dried for later use.

[0031] (2) Preparation of magnetic fluid

[0032] Take 0.5g oleic acid modified Fe 3 o 4 Nanoparticles were dissolved in 0.5 mL of n-octane, ultrasonicated for 10 min, then 2 mL ...

Embodiment 2~4

[0038] With embodiment 1 technique, change Fe in (2) 3 o 4 The feeding materials are 0.1g, 0.3g, 0.7g respectively.

Embodiment 5~8

[0040] With the process of Example 1, change the content of trifluoroacetic acid in (4) to 0.2mL, 0.3mL, 0.4mL, 0.6mL respectively.

[0041] The obtained oleic acid modified Fe 3 o 4 The nanoparticles were characterized by XRD ( figure 1 shown), the structure of the obtained pH-responsive magnetic composite microspheres with Janus structure was characterized by transmission electron microscopy ( figure 2 As shown), it can be observed that the prepared microspheres have obvious Janus structure and core-shell structure, and the particle size is about 300-500nm. Among them, the core layer is polystyrene, the shell layer is polymethacrylic acid, Fe 3 o 4 The nanoparticles segregate inside the microspheres. From image 3 It can be observed that when the pH value is changed, the particle size of the microspheres changes, showing pH responsiveness.

[0042] The present invention utilizes emulsion polymerization to prepare a kind of magnetic composite microsphere (Fe 3 o 4 —...

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Abstract

The invention relates to a pH-responsive type magnetic composite microsphere with a Janus structure, and a preparation method thereof, and belongs to the fields of composite materials and nanotechnologies. The pH-responsive type magnetic composite microsphere is of a core-shell structure, an inner core is made of polystyrene wrapped with Fe3O4, and a shell layer is made of poly(tert-butylmethacrylate). The preparation method comprises the following steps: preparing magnetic Fe3O4 nano-particles, then adding oleic acid, washing to neutral to obtain oleic modified Fe3O4 nano-particles, then dissolving in normal octane, adding a styrene monomer and a tert-butyl methacrylate monomer after ultrasound to obtain a magnetofluid, and adding in a bottle equipped with a reflux condensing tube and a thermometer, adding deionized water, lauryl sodium sulfate and NaHCO3 in sequence, heating in a water bath, then introducing N2, adding ammonium persulfate, preparing a magnetic composite microsphere solution with the Janus structure after emulsion polymerization, then centrifuging, separating a lower sediment, washing to neutral, putting in the container after drying, and adding deionized water and trifluoroacetic acid with different pH values to obtain a product.

Description

technical field [0001] The invention belongs to the field of composite materials and nanotechnology, and relates to a pH-responsive magnetic composite microsphere with a Janus structure and a preparation method thereof, specifically a magnetic nanocomposite material with an asymmetric structure and controllability and its preparation method. Background technique [0002] Janus nanoparticles are used to describe a class of anisotropic asymmetric microspheres with central asymmetry and different chemical compositions on the surfaces of the two hemispheres. Because of their special morphology or chemical composition, such microspheres have unique physical properties. Chemical properties, and thus have great potential in new emulsifiers, molecular recognition and bio-intelligent materials. It can be seen that the preparation and morphology control mechanism of Janus microspheres and their self-assembly research are important in both basic research and practical application. abo...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08F212/08C08F220/18C08F2/26C08F2/44C08K9/04C08K3/22B01J13/02H01F1/42
Inventor 曾碧榕吴悦广戴李宗刘永洲袁丛辉许一婷刘新瑜何凯斌
Owner XIAMEN UNIV
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