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1603088 
Journal Article 
Impacts of internally and externally mixed anthropogenic sulfate and carbonaceous aerosols on East Asian climate 
Zhang Li; Liu Hongnian; Zhang Ning 
2011 
Yes 
Acta Meteorologica Sinica
ISSN: 0894-0525 
25 
5 
639-658 
WOS:000298293700008 
A crylamide (as monomer), N,N'-methylene-bis-acrylamide (as cross-linker), ammonium persulphate (as initiator), N,N,N',N'-tetramethylethyldiamine (as accelerator), and aluminium nitrate salt were used to produce a low temperature polymeric gel-net, in order to tailor the particle size of alumina powder. The monomers/salt ratio, metal ion/monomers interaction, furnace atmosphere, thermal stability and pore size of polymeric gel-net are the key factors to control the alumina particle size. Mercury porosimetry data and transmission electron microscopy (TEM) micrographs indicated that increasing the monomers/salt ratio from 1/1 to 3/1 resulted in polymeric gel-net with smaller pore size, and hence, nanopowders with narrower particle size distribution. The X-ray diffraction (XRD) patterns for nanopowders exhibited the amorphous phases below 1100 degrees C and a single phase alpha-Al2O3 above 1100 degrees C. Thermal analysis showed that for pre-oxidized samples below 200 degrees C polymeric gel-net possesses better thermal stability at higher temperature in the presence of inert gas. Trapping of metal ions, with specific coordination numbers, into polymeric gel-net pores prevents their migration and reduces the nanopowder particles agglomeration. These observations were also confirmed by Fourier transform infrared (FTIR) and UV-vis spectrometry measurments. Polymeric gel-net inhibits the aggregation of Al2O3 nanopowder, improves its homogeneity, and provides a powder with narrower particle size distribution. 
anthropogenic aerosols; externally mixed; internally mixed; climate effects