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Wang R.-H.,CAS Nanjing Institute of Soil Science | Wang R.-H.,Nanjing Forestry University | Zhu X.-F.,Nanjing Forestry University | Zhu X.-F.,Nanjing Institute of Supervision & Testing on Product Quality | And 4 more authors.
Environmental Science and Pollution Research | Year: 2015

The influence of pectin on Cu(II) adsorption by two variable-charge soils (an Oxisol and an Ultisol) was investigated. Pectin increased the adsorption, and the extent of adsorption increased linearly with the dose of pectin, being greater in the Oxisol than that in the Ultisol because the adsorption of pectin by the Oxisol was greater. Both Langmuir and Freundlich equations fitted the adsorption isotherms of Cu(II) for both soils well. The fitting parameters of both equations indicated that pectin increased not only the adsorption capacity of the soils for Cu(II) but also the adsorption strength of Cu(II). The effect of pectin decreased with rising pH in the pH range 3.5–6.0, although the extent of electrostatic adsorption of Cu(II) by both soils was markedly greater over the pH range. Fourier-transformed infrared spectroscopy analysis and zeta potential measurement of soil colloids indicated that adsorption of pectin by the soils made the negative charge on both soils more negative, which was responsible for the increase in the electrostatic adsorption of Cu(II) induced by the addition of pectin. In conclusion, pectin-enhanced adsorption of Cu(II) especially at low pH would be beneficial to the soils as it would decrease the activity and mobility of Cu(II) in acidic variable-charge soils. © 2015 Springer-Verlag Berlin Heidelberg


Wang J.-Z.,Nanjing Institute of Supervision & Testing on Product Quality | Zhang Y.-J.,Nanjing Institute of Supervision & Testing on Product Quality | Fu R.-J.,Nanjing Institute of Supervision & Testing on Product Quality | Liu B.,Nanjing Institute of Supervision & Testing on Product Quality | Liu K.,Nanjing Institute of Supervision & Testing on Product Quality
Yejin Fenxi/Metallurgical Analysis | Year: 2015

The stainless steel materials for ornament and decoration mainly include 200 and 300 series stainless steel. The properties of steel are greatly affected by the content of chemical elements. The element of nickel, chromium and manganese play an important role. Therefore, the accurate determination of these elements is significant. The determination of chemical elements in stainless steel materials is mainly based on the standards including SN/T 2718-2010, GB/T 18705-2002 and SN/T 3343-2012. In these methods, the calibration curves are plotted using the series mixed standard solution with matching of iron matrix. Then, the contents are determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). However, the procedures of previous preparation are complicated and time-consuming. Moreover, the compositions in solution for plotting calibration curve are not fully consistent with those in sample solution, resulting in large uncertainty of measurement. Therefore, the content of nickel, chromium and manganese in stainless steel was determined with the calibration curve prepared by series standard samples of stainless steel. These two methods for preparing calibration curve were compared. The effect of observation way on the determination results was investigated. The results showed that the accuracy of calibration curve prepared by series standard samples of stainless steel was much better than prepared by single standard solution (sample). In addition, the preparation method was simple, which could greatly shorten the detection time. The observation method of inductively coupled plasma atomic emission spectrometry had certain influence on the determination results of stainless steel composition. The radial observation was more suitable for the determination of nickel, chromium and manganese in stainless steel than axial observation. ©, 2015, Central Iron and Steel Research Institute. All right reserved.


PubMed | Nanjing Institute of Supervision & Testing on Product Quality, Nanjing University and Nanjing Forestry University
Type: | Journal: Journal of colloid and interface science | Year: 2016

Monodispersed hollow mesoporous silica nanoparticles (HMSNs) are successfully synthesized via a facile dual template method, in which poly(styrene-co-methyl methacrylate-co-methacrylic acid) (PS-PMMA-PMAA) particles are used as hard template for producing the hollow structure and cetyltrimethylammonium bromide (CTAB) used for introducing the mesopores in the silica shells. The obtained HMSNs possess uniform diameter and morphology, and the shell of which could be adjusted by changing the addition of silicon precursor. The synthesized HMSNs have been characterized by transmission electron microscopy (TEM) and nitrogen physisorption. Furthermore, the HMSNs are used as support for in-situ deposition of silver nanoparticles (Ag NPs) using n-butylamine as reducing agent for AgNO3 in ethanol. Significantly, Ag NPs were successfully supported in the HMSNs without any aggregation. The Ag-deposited HMSNs showed excellent dispersibility in ethanol and water, and their antibacterial activity against Escherichia coli (E. coli) ATCC 25922 and Staphylococcus aureus (S. aureus) ATCC 6538 have been demonstrated. Therefore, the unique nanostructure based on the HMSNs provided a useful platform for the fabrication of antibacterial agent with superior activity and accessibility. And also, it is expected to be a significant template for the synthesis of other novel nanostructures.

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