|
Detail: |
Abstract:
A ultrafine aluminum hydroxide nanoparticle suspension was prepared via controlled titration of [Al(H2O)6]3+ with L-arginine to pH 4.6. The prepared material, predominantly 10-30 nm in diameter, was purified by GPC technique and subsequently identified as gibbsite (or hydrargillite) polymorph via FTIR, powder XRD, and elemental analysis. Chemical environment and morphology were probed using 27Al/1H NMR, FTIR, ICP-OES, TEM-EDS, XPS, XRD, and N2 adsorption experiments. Furthermore, by incorporating the newly developed synthetic route, Al(OH)3 was partially loaded inside the mesopores (2.7nm) of MCM-41. EDS and NMR analysis indicates both tetrahedral and octahedral Al (Oh/Td = 1.4) is incorporated at 11% w/w total Al and Si/Al of 2.9 indicating part of Al embedded into Si framework. In addition, differences in elemental composition between surface XPS and bulk EDS analysis provided insight into the distribution of Al within the material. Higher ratio of Si/Al was observed on the external surface (3.6) of MCM-41 compared to the internal (2.9) cavities. Estimated O/Al ratios suggest predominantly Al(O)3 and Al(O)4 motifs present near the core and external surface, respectively. This novel methodology produces Al-MCM-41 with relatively high Al content while preserving the ordered SiO2 framework and can be used in lateral applications where incorporating hydrated or anhydrous Al2O3 is desired.
Biosketch：
Dr. Long Pan received his Ph.D. in inorganic chemistry from the USTC. After securing a research Assistant Professor at Rutgers, he joined Colgate Palmolive Co. as a Sr. Research Scientist in 2006. He currently is a Manager of Technology leading a team in developing superior actives for oral care, personal care and home care to further strengthen Colgate Technology Innovation pipeline and provide Colgate a competitive advantage. He has been an inventor on more than 60 US/WO patents. In addition, he published over 74 peer-reviewed papers in Angew. Chem., JACS and other prestigious journals that revealed the chemistry behind product innovation. His research has been widely cited in the scientific community (total citation = 5800+, 6 papers > 400 citations). |
