Novel CdTe/CdS/SiO2 core/multishell fluorescent composite nanoparticles were prepared by reverse microemulsion method in this paper. Water-soluble CdTe/CdS core/shell quantum dots (QDs) were synthesized with 3-mercaptopropionic acid as the stabilizers and thiourea as the sulphur source in aqueous solution. CdTe/CdS/SiO2 fluorescent nanoparticles were obtained by hydrolysis of tetraethyl orthosilicate (TEOS) at room temperature in cyclohexane solution when polyethylene glycol tert-octylphenyl ether (Triton X-100) as the surfactant and n-hexanol as the co-surfactant. The resultant core/multishell fluorescent composite nanoparticles were inert and chemically stable in harsh environments because of the silica layer. In this paper, the diameter of these particles was about 64 nm, and the maximum emission was about 678 nm. The coating of silica could provide a great convenience for the biological functionalization of the surface of luminescent QDs and be useful to label biological molecules in vitro and vivo in the biological analyses.
Bulk modification was applied to synthesize modified sugarcane bagasse cellulose (MSBC) cation exchange membrane using in electrodialysis device for the removal of ammonia nitrogen wastewater. The effect of MSBC mass fraction and pore forming agent in casting solution on membrane physico-chemical
properties was studied. XRD showed that the crystal lattice of cellulose in membrane transformed from cellulose I to cellulose II, and the FT-IR displayed that there were no new functional groups after the membrane formation. With the increase of MSBC, the moisture content and swelling degree
of the membrane decreased, but the mechanical strength increased and the IEC increased from 0.68 to 1.05 mmol/g. With the increase of pore-forming agent, the moisture content, swelling degree and increased in varying degrees, but the mechanical strength decreased, it is worth noting that ion
exchange capacity (IEC) has increased from 0.31 to 1.35 mmol/g as the amount of pore agent is four times that of MSBC. The influence of initial concentration of ammonia nitrogen wastewater, voltage and electrolysis time on the removal rate of ammonia nitrogen was investigated. The results
showed that the removal efficiency of ammonia nitrogen was higher when the initial concentration was 1500–2000 mg/L, and the removal rate of ammonia nitrogen can be up to 90.12% under the condition of the voltage is 10 V and the electrolysis time is 7 h. This implied that the cation
exchange membranes prepared from MSBC can be produced that can be appliedin wastewater treatment.
Hydrotalcites known as anionic clays are found in nature. Hydrotalcites, hydrotalcite-like compounds, and calcined hydrotalcites (as mixed or complex oxides) as highly active, selective catalysts play an important role in many base/catalyzed reactions. Mg/Al hydrotalcite (MAH) as precursor was used to prepare Mg/Al metal complex oxides (MAO), used as epoxidation catalysts in the current research. In this paper, some primary physical and catalytic properties of MAH and MAO were investigated. The results indicated that the qualified MAH (Mg/Al mol ratio of 3) can be achieved when the suspension was crystallized under 80°C for 16h, and after being filtered, dried at 100 °C for 5h in a oven. MAO was prepared by calcining MAH for 4h in a muffle furnace, and calcination temperature was determined to be 500 °C by a differential scanning calorimeter (DSC). Crystal structure and parameters of MAH and MAO were characterized by X/ray diffraction (XRD), good crystal structure was observed and typical peaks of MAH were detected when 2θ was at 11.5 (003), 23.0 (006), 35.0 (009), and 61.0 (110), respectively. The morphology of calcined precursor, i.e. MAO, was investigated with scanning electron microscopy (SEM); the finer lamellar structure and smaller average size of 3μm was observed. Molding research was performed and confirmed by SEM, the results indicated that the surface bulge and cavity with size of several micrometers were increased, which simultaneously suggested the increasing of specific surface area. The catalytic activity of molding MAO was finally examined by using octanol as starting reagent and ethylene oxide as reactant, and narrower molecular distribution was observed comparing with the traditional catalyst-KOH
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