Synthesis And Application Of Multi-functional Magnetic Nanomaterials

Nanomaterial has shocked the world since its advent. Because of its tinystructure and unique properties, researchers concentrated on the nanomaterial in theseyears. With the increasing society requirements and researcher’s further exploration,magnetic nanomaterial was standing out from numerous nanomaterials due to its wellmagnetic capacity and broad application prospects, which also attracted researchers’concentrations. Millions of magnetic nanomaterials have been produced and wide lyused for magnetic separation and information storage.After years of exploration and challenge, researchers realized that it is essence toobtain stable nature, promising multifunctional nanomaterial through simple synthesisprocess, which claims more strict demands to present design strategy.Taking this requirement into account, we have synthesized variousmultifunctional magnetic nanomaterials through meticulous design and combinationof chemical vapor deposition method. Also, we investigated the nature andapplications of these nanomaterials and illustrated as follow:Magnetic graphene PCDA nanocomposite for optical imaging: Because of thewidely using of optical imaging, we choose optical imaging as the entrance toinvestigate the capacity and practical application value of multifunctionalnanomaterial. Based on TEM, UV-Vis, FL spectra and Raman spectra, we have fullymeasured the structure and property of as synthesized FeCo@C@PDAs nanoparticle.Furthermore, we utilized the intrinsic characteristic of material as ink which iscommon in present daily life. Through fluorescence and raman imaging methods, weobtained different patterns in different substrate such as glass, cloth and paper thatprinted by this ink which shows the potential of this na nomaterial for practicalapplication.Investigation of ultrasound and magnetic resonance imaging: ultrasound andmagnetic resonance imaging act critical roles in modern medical imaging. However,both of them need imaging agents which will lead to some adve rse effects more orless in human body. Thus, developing one kind of imaging agent that satisfieddifferent demands to decrease the uptake dose and adverse effects is promising andnecessary. Due to the superparamagnetism and magnetic gathering capacity ofFeCo@C@PDAs, we employ this nanomaterial for ultrasound and magneticresonance imaging application. Before the magnetic gathering, this nanoparticle cannot generate sufficient sound wave reflection and scattering because of its smallsize. After magnetic gathering, an obvious signal is detected from FeCo@C@PDAsand anticipated results were achieved through instrument’s signal processing.Moreover, we measured its MRI capacity based on its superparamagnetism nature.There is a significant weaken of T2signal intensity in the imaging process andenhanced the contrast of different sections in the image which exhibited superior MRIagents capacity.Nanomaterial combination property detection: the composite has everyindividual part’s properties and overcome each part’s drawbacks. Therefore, weevaluated the entire property of FeCo@C@PDAs and compared to the properties ofseparated components. Through pH experiment, we found that PDAs could respond tothe environment pH. Nevertheless, because of its response mec hanism, PDAs couldnot respond to the pH value precisely. Similar issue also occurred in the outer layer ofPDAs encapsulated FeCo@C nanoparticle. Fortunately, the combination propertyoffered us an alternative way. We utilized magnetic resonance method, based on theparticle’s tiny response to around hydrogen proton. Even a small change of hydrogenions concentration could be precise detected through magnetic resonance signal. Thus,we could have a correct judgment to the solution’s pH value. On the other hands, westudied the interesting color change of PDAs. The PDAs could change its colorirreversible from blue to red through heating. Interestingly, the introduction ofFeCo@C nanoparticle makes this change into reversible. We attribute thisphenomenon into the assistance of graphene. Graphene was treated as a well templatedue to its unique structure and superior physicochemical property which couldenhance the stability of PDAs whole structure.