標題: Optically Evolved Assembly Formation in Laser Trapping of Polystyrene Nanoparticles at Solution Surface
作者: Wang, Shun-Fa
Kudo, Tetsuhiro
Yuyama, Ken-ichi
Sugiyama, Teruki
Masuhara, Hiroshi
應用化學系
應用化學系分子科學碩博班
Department of Applied Chemistry
Institute of Molecular science
公開日期: 29-Nov-2016
摘要: Assembling dynamics of polystyrene nanoparticles by optical trapping is studied with utilizing transmission/reflection microscopy and reflection microspectroscopy. A single nanoparticle assembly with periodic structure is formed upon the focused laser irradiation at solution surface layer and continuously grows up to a steady state within few minutes. By controlling nanoparticle and salt concentrations in the colloidal solution, the assembling behavior is obviously changed. In the high concentration of nanoparticles, the assembly formation exhibits fast growth, gives large saturation size, and leads to dense packing structure. In the presence of salt, one assembly with the elongated aggregates was generated from the focal spot and 1064 nm trapping light was scattered outwardly with directions, while a small circular assembly and symmetrical expansion of the 1064 nm light were found without salt. The present nanoparticle assembling in optical trapping is driven through multiple scattering in gathered nanoparticles and directional scattering along the elongated aggregates derived from optical association of nanoparticles, which dynamic phenomenon is called optically evolved assembling. Repetitive trapping and release processes of nanoparticles between the assembly and the surrounding solution always proceed, and the steady state at the circular assembly formed by laser trapping is determined under optical and chemical equilibrium.
URI: http://dx.doi.org/10.1021/acs.langmuir.6b02433
http://hdl.handle.net/11536/132801
ISSN: 0743-7463
DOI: 10.1021/acs.langmuir.6b02433
期刊: LANGMUIR
Volume: 32
Issue: 47
起始頁: 12488
結束頁: 12496
Appears in Collections:Articles