In order to develop an environment-benignly chemical conversion process to substitute the toxic hexavalent chromium treatment on Al alloy surface, a new surface treatment technology based on rare-earth element, which is to form chemical conversion coating on 6063 Al alloy was presented. In this process, Ce(NO3)3 was adopted in the chrome-free preparing solution, and KMnO4 was used as oxidant to accelerate the coating formation on 6063 Al alloy. Furthermore, an L16(43) orthogonal experiment was carried out to examine the effect of Ce(NO3)3, KMnO4 and solution temperature on the coating growth on 6063 Al alloy. Accelerants of SrCl2 and NH4VO3 were added to the preparing solution to improve the coating performance. XRD, SEM and EDS were used to analyse the coating surface structure, morphology and composition. It was found that a good anti-corrosion coating which is mainly composed of the elements of Al, Ce, O, Mn, Mg could be formed in the optimal preparing solution of 5g/L Ce(NO3)3 , 4g/L KMnO4, 1.4g/L SrCl2 at the temperature of 20°C.
According to the mechanism of thermal insulation, closed pore perlite, hollow glass microsphere and nanoantimony tin oxide (ATO) powder three different kinds of functional fillers were adopted respectively to prepare obstructive, reflective and radiative thermal insulation coating base on polyvinylidene fluoride emulsion, and how the category and content of functional fillers effect the thermal insulation performance of the fluorocarbon thermal insulation coating (FTIC) was investigate. The test results showed that, all the three functional fillers has an significant effect on the thermal insulation performance of FTIC.
Methanol- and temperature-induced dissolution–recrystallization structural transformation (DRST) was observed among two novel CuII complexes. This is first time that the combination of X-ray crystallography, mass spectrometry and density functional theory (DFT) theoretical calculations has been used to describe the fragmentation and recombination of a mononuclear CuII complex at 60 °C in methanol to obtain a binuclear copper(II) complex. Combining time-dependent high-resolution electrospray mass spectrometry, we propose a possible mechanism for the conversion of bis(8-methoxyquinoline-κ2N,O)bis(thiocyanato-κN)copper(II), [Cu(NCS)2(C10H9NO)2], Cu1, to di-μ-methanolato-κ4O:O-bis[(8-methoxyquinoline-κ2N,O)(thiocyanato-κN)copper(II)], [Cu2(CH3O)2(NCS)2(C10H9NO)2], Cu2, viz. [Cu(SCN)2(L)2] (Cu1) → [Cu(L)2] → [Cu(L)]/L → [Cu2(CH3O)2(NCS)2(L)2] (Cu2). We screened the antitumour activities of L (8-methoxyquinoline), Cu1 and Cu2 and found that the antiproliferative effect of Cu2 on some tumour cells was much greater than that of L and Cu1.
In order to develop an environment-friendly method of forming a chemical conversion
coating on 2024 aluminium alloy surface without the toxic hexavalent chromium compounds, in
this paper a process with sodium molybdate and potassium permanganate as the main compositions
of the treating bath has been investigated. Solution composition and process parameters have been
optimized. The chemical conversion coating has good corrosion resistance, evaluated with dropping
test. Micro-structure and components of the conversion coating have been studied by various
micro-analysis methods, and the growth mechanism of the chemical conversion coating has also
been investigated.
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