Preparation Of Ga-Pd/PMMA Nano-composite Materials By Ultrasonic

Nano Ga-Pd/poly(methyl methacrylate)(PMMA) composite materials were successfully prepared with the palladium chloride solution containing metal gallium,MMA as monomer and sodium dodecyl sulfate (SDS) as emulsifier without initiatoror reducer, in which Pd2+ ion was reduced to nano-palladium particles, meanwhile to produce Ga5Pd which was made from Pd atom and mimi-drop of liquid gallium, and the monomers were polymerizated simultaneously by ultrasonic. XRD indentified there are Pd, Ga, and Ga5Pd phase in PMMA matrix. The results of UV-Vis spectrum showed that there was a characteristic absorption peak at 200nm for nano-Ga/PMMA polymer solution, at 209nm for nano-Pd/PMMA polymer solution, nano Pd-Ga/PMMA of the absorption peak was shiftted to long wavelength at 218nm;X-ray photoelectron spectroseopy (XPS) proved that the O1s binding energy (531.82 eV) of C=O and the O1s binding energy (533.39eV) of C-O-C of nanocomposite polymer which reduced 0.68eV and 0.51eV respectively than the standards O1s binding energy (532.1eV) of C= O and (533.9eV) of C-O-C, the Ga2p3 binding energy (1118.81eV) raise 2.2eV than the standards Ga2p3 binding energy (1116.60eV),Ga2d3/2(18.02eV)and Ga2d5/2 (20.64eV) binding energy increased 0.5eV and 0.74eV respectively comparing with the standard binding energy Ga2d3/2 (18.7eV) and Ga2d5/2(18.9eV), however, d3d binding energy (335.43eV) reduced 2.17eV than the standards Pd3d binding energy (537.5eV), It is concluded that nano Ga5Pd was producted based on segment electronics shifting from Gallium to Palladium, and coordination was formed found on part electronics was diverted from Gallium to oxygen of PMMA ester group. Transmission electron microscopy (TEM) illuminated PMMA possessesd anisotropism ordered assembly around nano Ga-Pd particles, it further interpreted nano Ga-Pd particles had ordered-assembly inducetion effect and its long-range orientation selectivity.Poly(methyl methacrylate) (PMMA) was successfully synthesized by bi-in situ ultrasonic radiating the soap-free mulsion polymerization containing methyl methacrylate (MMA) monomer,SDS, and inorganic salt; no initiator in this method. The resultant polymer PMMA was charazcterized by infrared spectroscopy(FR-IR), high resolution transmission electron microscopy(TEM) and gel permeation chromatography(GPC). The experimental factors such as ultrasonic power, the concentration of SDS and contents of inorganic salt on the final conversion of monomer were also discussed. It is interesting that the polymerization was fairly rapidly in this system. The FR-IR spectrum of PMMA was collected after purification and pellet pressed together with potassium bromide.The characteristic peak of C=C (1637cm-1) nearly disappeared in PMMA spectrum, which indicated the polymerization of MMA.The molecular weight of PMMA was characterized by means of GPC.The result showed that the polydispersity of polymer was narrow.The size and morphology of PMMA latex particles were observed by TEM. Finally,the mechanism of ultrasonic irradiation soap-free emulsion polymerization was discussed.