Study Of Synthesis, Properties And Structure Of CMC/EU Nanoparticles

CMC/metal nanoparticles material not only has the cellulosic macromolecular speciality,with metallic performance, and environmental friendliness、nontoxicity、cost effectiveness、green chemistry and sustainability. With test parameters of the complex system werecontrolled well, CMC/Eu nanoparticles were successfully synthesized using biodegradablematerials, CMC, and Eu3+under microwave or in water bath. The molecular structure wasanalyzed by FT-IR and XPS. SEM was used to observe the morphology. WAXD and TEMwere applied to characterize the crystalline structure. The fluorescence property wasinvestigated by UV-vis and PL. TG and DSC were utilized to record the thermal performance.In addition, more active DACMC was prepared by oxdiating the ligand CMC with periodicacid, and some characterization methods include13C NMR had been applied to confirm itsstructure and performance. Main conclusions of this paper were summarized as follow:1)Eu3+not only replacement reacted with CMC-Na, coordination bonds were also formedbetween it and the oxygen atom of ether or unsubstituted hydroxyl in the CMC molecularchains.2)Weak crystallinity, polycrystalline structure and homogeneous particle dispersion wereshown in the CMC/Eu nanoparticles.3)The ultroviolet absorption of CMC/Eu nanoparticles came from macromolecule ligand,i.e. CMC, which was the energy giver of Eu3+and made its fluorescence senstized. Allproduct particles exhibited typical fluorescence emission spectra of Eu3+, which consist of thecharacteristic transitions from5D0�'7F1(594nm) and5D0�'7F2(618nm).4)In the experimental range, with the microwave irradiation heating method was applied,The optimal conditions were70℃, pH value of7.0, CMC/Eu mass ratio of19/1and reactiontime of60s. The products of the supernatant and precipitation system had similar chemicalbond, but both the morphology and crystalline structure were different. In addition, thefluorescence performance of the resultant precipitation was higher than the supernatantsample.5)In the experimental range, with the water bath heating method was applied, the optimalconditions were70℃, pH value of7.0, CMC/Eu mass ratio of19/1and reaction time of35min. At the same experimental conditions such as temperature, pH value, and reactionsubstrate ratio, the fluorescence intensity obtained form microwave-assisted under shortedreaction time(30~120s) was significantly stronger than water bath under longer reactiontime(15~45min), reflecting the microwave-assisted heating with time-saving and efficient advantages.6)The crystallinity DACMC was larger than that of CMC, but along with poorer thermalstability was achieved. Additionally, as DACMC solution was involved in pseudoplastic fluid,there would greater viscosity noticed than in CMC solution because of the enhancedcross-link effect among molecular chains.