水中可分散单壁碳纳米管的制备及光谱分析

Preparation and Spectral Analysis of Dispersible Single-Walled Carbon Nanotubes inWater

水中可分散高纯度单壁碳纳米管(SWNTs)在纳米技术领域中应用广泛。利用水溶性羧甲基壳聚糖(WSCC)为分散剂,制备了水中可分散的高纯度SWNTs分散液。实验首先以脱乙酰化壳聚糖和氯乙酸为原料,合成分散剂WSCC。经红外光谱分析后,证明成功合成了水溶性WSCC。然后在超声波辅助下把SWNTs样品分散在WSCC水溶液中,经过离心分离,得到了在水中可分散的SWNTs分散液。采用扫描电镜、紫外-可见近红外光谱和共振拉曼光谱等表征手段进一步考察了SWNTs在WSCC水溶液中的分散行为。在相同的实验方法条件下,与SWNTs在去离子水和脱氧胆酸钠中的分散行为进行了比较分析。最后,经红外光谱分析,水溶性WSCC和SWNTs之间以非共价键作用力相结合,揭示了SWNTs在WSCC水溶液中可分散的实质。

The dispersible single-walled carbon nanotubes(SWNTs)in water have been widely used in the field of nanotechnology.A water soluble carboxymethyl chitosan(WSCC),as a dispersant,assisted individual dispersion of SWNTs was reported.Firstly,the dispersing agent WSCC was successfully syn‐thesized by deacetylated chitosan and chloroacetic acid,which was strongly confirmed by the Fourier transform infrared spectroscopy(FTIR).Secondly,the purified SWNTs were dispersed in an aqueous solution of WSCC under ultrasonic vibrations.Finally,the dispersion of SWNTs was subjected to cen‐trifugation to collect individually dispersed SWNTs,which were evidenced by by scanning electron mi‐croscopy(SEM),UV-vis-NIR spectroscopy and resonance Raman spectroscopy.In comparison with the sodium deoxycholate assistant dispersion of SWNTs,the WSCC dispersed ones demonstrated selec‐tive dispersion of SWNTs with smaller diameters.FTIR analysis identified a charge transfer between WSCC and SWNTs,revealing the dispersing ability of WSCC towards SWNTs in water media.