碘金酸-阳离子表面活性剂缔合微粒体系的吸收光谱研究及分析应用

在 0 0 1mol·L-1HCl介质中 ,[AuI4]-在 35 0nm处有一吸收峰 ;当十六烷基三甲基溴化铵(CTMAB)与 [AuI4]-共存时体系呈红紫色 ,在 5 2 0nm处产生一新的吸收峰。CTMAB浓度在 0～ 7 0× 10 -5mol·L-1范围内符合比耳定律 ,回归方程为A52 0nm =0 989× 10 4cCTMAB +0 0 138,相关系数R为 0 9997,摩尔吸光系数ε为 1 0 5 8× 10 4L·mol-1·cm-1,据此建立了一种测定阳离子表面活性剂含量的分光光度新方法 ,并用于合成样品和新洁尔净样品中阳离子表面活性剂测定 ,结果满意。共振散射光谱研究表明 ,[CTMAB]+ 与 [AuI4]-可通过静电引力作用形成疏水性的 (AuI4 CTMAB)缔合物分子 ,并进一步聚集形成稳定的 (AuI4 CTMAB) n 缔合纳米微粒。由于该缔合纳米微粒在 5 80和 4 70nm处产生共振散射效应 ,故体系呈红紫色。

Absorption Spectra Study of Cation Surfactant-[AuI4]- Association Particle System and Its Analytical Application

In 0.01 mol x L(-1) HCl medium, there is an absorption peak at 350 nm for [AuI4]-. The association particle system of CTMAB-[AuI4]- exhibits violet-red color. It has a new absorption peak at 520 nm. The CTMAB concentration cCTMAB in the range of 0-7.0 x 10(-5) mol x L(-1) is linear to the A(520 nm) value. Its regression equation is A(520 nm) = 0.989 x 10(4) cCTMAB + 0.0138, regression coefficient is 0.9995, and the mole absorption coefficient is 1.059 x 10(4) L x mol(-1) x cm(-1). A new spectrophotometry has been proposed for the determination of cation surfactant. The resonance scattering spectra show that the CTMAB+ and [AuI4]- combine to form (AuI4-CTMAB) association molecule with hydrophobicity by means of attraction forces. The association molecules automatically aggregate to form (AuI4-CTMAB)n association particles. So, the particles exhibit two resonance scattering peaks at 580 and 470 nm, and the system exhibits violet-red.