Investigation on the Selective Separation of Chiral Carbon Nanotubes by Photoselective Laser Excitation at the Wave length of the Resonance Absorption Bands

这份报告由两部分组成。A部分是在选择性激光照射下碳纳米管在增溶溶液中的光选择性分离的研究。B部分是使用洗涤剂和生物聚合物对swcnts溶液进行溶解的物理化学。利用高功率光参量振荡器（OPO）脉冲激光在手性结构的共振吸收波段对分散在洗涤剂或溶液中的碳纳米管进行光选择性激发，研究了金属单壁碳纳米管与半导体单壁碳纳米管（m-SWNT&s-SWNT）的手性选择性分离。用NaDDBS（十二烷基苯磺酸钠盐）增溶的swcnts水溶液进行激光激发，激发波长分别为M_<11> (507nm)、S_<22> (732nm)和S_<11> (977nm)。随着脉冲数的增加，M_<11>的能带能量最高，对碳水化合物的结构降解更彻底。然而，S_<22>和S_<11>波段的激发只对s- swcnts造成损伤，而对m-碳纳米管没有造成结构损伤。这表明，在s-SWCNTs波长下对固化的swcnts溶液进行激发可以在牺牲s-SWCNTs的情况下得到浓缩的m-SWNT。拉曼光谱和原子力显微镜测量结果表明，在半导体波长激发处发生了热化现象。为了获得更多的光选择性手性激光分离的增溶剂，采用多种洗涤剂或生物聚合物（如十二烷基硫酸钠（SDS）或羧甲基纤维素（CMC））研究了增溶后的swcnts在溶液中的物理化学性质。研究发现，溶解后的swcnts在CMC溶液中的稳定性对溶液中的温度变化非常敏感。单壁碳纳米管在CMC中的溶解溶液对升温和降温变化都是不可逆的。结果表明，CMC溶液中溶解的swcnts可以作为一种很好的增强溶液中swcnts光选择性手性分离的剂，因为温度升高会使swcnts在激光激发波长下与溶液分离

This report is consisted of two parts. Part A is the inevestigation of the photoselective separation of carbon nanotube in the solubilized solution at the selective laser irradiatio. . The part B is the physical chemistry of the solubilized SWCNT solution by using detergents and bioploymer. . The investigation of the chiral selective separations of carbon nanotubes of the metallic and the semiconducting single-walled carbon nanotubes (m-SWNT&s-SWNT) has been pursued by the photoselective excitaion of the dispersed SWNT in the detergent or the biopolymer in solution at the high power OPO (optical parametric oscillator) pulsed laser excitation at the resonance absorption band of chiral structures.When the laser excitation was made for the aqueous SWCNT solution solubilized with NaDDBS (Dodecylbenzenesulfonic acid sodium salt) at the excitation wave length of M_<11> (507nm), S_<22> (732nm), and S_<11> (977nm), respectively. The highest bnand energy of M_<11> degraded the structure of carb … More onnanotube completely as the pulse number increased. However, the excitations at the wave length of S_<22> and S_<11> bands damaged only s-SWCNT, but did not give the structural damage of m-carbonanotubes. It indicates that the ecitations for the soliubilized SWCNT solution at the wave lengths of s-SWCNTs could give the concentrated m-SWNT at the sacrifice of s-SWCNT. Raman spectroscopic and AFM measurements revealed that there is ocurred the thermalization at the excitation of the semiconducting wave length. In order to have more idial solubilizing agents for the photo-selective chiral laser separation, the physical chemistry of the solubilized SWCNT in solution was invetstigated by using many kinds of detergents or biopolymer such as sodiumdodecylsulphate (SDS) or carboxymethylcellulose (CMC). It is found that the stability of the solubilized SWCNT in CMC solution is very sensitive for the temperature changes in the solution. The solubilized solution of SWCNT in CMC is irreversible for the rising temperature or the falling temperature changes. It indicates that the solubilized SWCNT in CMC solution is expected as a good agent for the enhancement of the photoselective chiral separation of SWCNT in solution, because the temperture rise will give the separation of SDWCNT from the solution at the laser excitaion wave length Less