| Colloidal superparticles (SPs) are size-and shape-controlled nanoparticle (NPs)assemblies in the form of colloidal particles, which can exhibit the intrinsic physicalcharacteristics of their nanometer-sized building blocks as well as the collectiveproperties of these building blocks due to coupling effects. This ability also allowsfor the creation of multifunctional materials by combining two or moreindependently tailored NP building blocks. Whereas, NPs are encapsulated in thesolid SPs with low efficient active area with surrounding, that limits the applicationin catalyze and sensor. Fe3O4is one of the nanomaterials that attract most academeresearchers, including biotechnology, biomedicine, magnetic resonance imaging(MRI), separation and catalyze. Various multifunctional nanostructures based onFe3O4are synthesized to develop the application of Fe3O4, such as core/shell,dumbbell, multicomponent hybrid structures and so forth, despite the complicatedprocess to construct such structures.NPs exhibit unique properties for their specific size. Whereas, NPs tend tointegrate in result forming clusters or integrations due to the high surface energy,which out of question limit the application of NPs. It is necessary to introducepolymer to NPs, not only improve the stability, but also congregate the function ofpolymer. In this paper, unitary and binary Fe3O4-containing SPs are fabricated via an oil-in-water microemulsion template. The stability and biocompatibility areimproved by modify Polypyrrole (PPy) shell on the surface of SPs.In chapter2, we demonstrate the self-assembly of Fe3O4NPs into3D SPsfollowing an oil-in-water microemulsion template method. By controlling theself-assembly of Fe3O4NPs, the diameters of the SPs are tunable from32to64nm.This significantly increases the molar extinction coefficient of Fe3O4NPs from3.65×106to1.31×108M-1cm-1. The envelopment of Fe3O4SPs with PPy shellfurther enhances the molar extinction coefficient to1.12×109M-1cm-1. As a result,the photothermal performance is greatly improved, which is represented by the rapidtemperature increment of aqueous Fe3O4suspension under an808nm laserirradiation. Primary cell experiments indicate that PPy-enveloped Fe3O4SPs are lowtoxic, and capable to kill Hela cells under near-infrared (NIR) laser irradiation.Owing to the low cost, good biocompatibility and biodegradability, thePPy-enveloped Fe3O4SPs are promising photothermal platform for establishingnovel diagnostic and therapeutic methods.In chapter3, binary SPs are fabricated from preformed NPs as building blocksbased on the method synthesis SPs as mentioned in chapter2. The integratedfunctions of binary SPs are due to their components, such as magnetic/catalyticFe3O4/Au binary SPs, magnetic/luminescent Fe3O4/CdTe binary SPs, and so forth.This protocol gave a facile and flexible approach to integrate differentlyfunctionalized NPs into nanometre-sized spheres. Besides, the structural stability ofSPs was improved through the decoration of the polymer shell.In chapter4, we further improve the method that synthesis of binary SPs.Control of the evaporation rate of organic solvents in oil droplets produces solid,hollow and bowl-like SPs. The component Fe3O4and in particular Pd NPs cancatalyze H2O2degradation to create hydroxyl radicals and therewith degrade variousdyes, while magnetic Fe3O4NPs also permit to recycle the SPs with the help of magnet. Since the hollow and bowl-like SPs increase the contact area of the NPswith surroundings in comparison to solid SPs, the catalytic activity is greatlyenhanced. To improve the structural stability, the SPs are further enveloped with athin PPy shell, which does not weaken the catalytic activity. Because the currentmethod is facile and feasible to create recyclable catalysts, it will promote thepracticability of NP catalysts in treating industrial polluted water. |
PDF Full Text Request