Slight asymmetry induces significant distortion of soot volume fraction measurements in counterflow diffusion flames with diffuse back-illumination imaging.

Counterflow diffusion flame is a favorable platform for fundamental investigation of soot kinetics. A diffuse back-illumination imaging technique for measuring soot volume fractions in these flames was rigorously demonstrated here. It was noticed that the technique is extremely sensitive to slight asymmetry of the flame. Misleading conclusions could be drawn due to the surprisingly large distortion of the measured SVF profile caused by flame tilting, even when the tilting is so slight as to be undetectable through the flame images. To address this issue, the effect of the flame tilting on soot measurements were quantitatively analyzed and a novel procedure was proposed to identify and correct the measurement distortions.

Hairy silica nanosphere supported metal nanoparticles for reductive degradation of dye pollutants.

Hairy materials can act as a sort of scaffold for the fabrication of functional hybrid composites. In this work, silica nanospheres modified with covalently grafted poly(4-vinylpyridine) (P4VP) brushes, namely, "hairy" silica spheres, were utilized as a support for the anchorage of metal nanoparticles (MNPs), thus resulting in the hierarchical SiO2@P4VP/MNP structure. In this triple-phase boundary heteronanostructure, the SiO2-supported MNPs are well stabilized by the P4VP matrix to avoid aggregation and leaching. These SiO2@P4VP/MNP nanocomposites exhibit good catalytic activity in the reductive degradation of organic dyes, i.e., 4-nitrophenol and rhodamine B and possess excellent stability and recyclability for five successive cycles.