微电极技术在分子有序组合体中的应用

【作者】 徐建新；

【导师】 郭荣； 刘天晴；

【作者基本信息】 扬州大学 ， 物理化学， 2003， 硕士

【摘要】 以铂微电极伏安法测定三种典型的表面活性剂（SDS、CTAB、Triton X-100）微乳液体系中胶束的扩散系数和层状液晶中表面活性剂分子的扩散系数。结果表明，在恒定质量比表面活性剂／醇时，随着体系中水含量的增加，表面活性剂在微乳液、层状液晶中的扩散系数均增加；在恒定质量比表面活性剂／水时，随着醇含量的增加，表面活性剂在微乳液、层状液晶中的扩散系数均增加；在恒定质量比水／醇时，随着表面活性剂含量的增加，表面活性剂在微乳液、层状液晶中的扩散系数均减小。O／W微乳液液滴的扩散系数比W／O微乳液液滴的扩散系数大约两个数量级，比层状液晶中表面活性剂分子的扩散系数大约四个数量级。CTAB分子的扩散系数＞SDS分子的扩散系数＞Triton X-100分子的扩散系数。 以铂微电极伏安法测定了亚甲蓝（MB）、牛血清蛋白（BSA）在三种典型的表面活性剂体系(SDS／n-C₅H₁₁OH／H₂O、CTAB／n-C₅H₁₁OH／H₂O、Triton X-100／n-C₁₀H₂₁OH／H₂O)微乳液和层状液晶中的电化学扩散系数。结果表明，在恒定质量比表面活性剂／醇时，随着体系中水含量的增加，MB在微乳液、层状液晶中的扩散系数均增加；在恒定质量比表面活性剂／水时，随着醇含量的增加，MB在微乳液、层状液晶中的扩散系数均增加；在恒定质量比水／醇时，随着表面活性剂含量的增加，MB在微乳液、层状液晶中的扩散系数均减小。MB在CTAB层状液晶中的扩散系数＞MB在Triton X-100层状液晶中的扩散系数＞MB在SDS层状液晶中的扩散系数。 在恒定质量比表面活性剂／醇时，随着体系中水含量的增加，BSA在层状液晶中的扩散系数增加；在恒定质量比表面活性剂／水时，随着醇含量的增加，BSA在层状液晶中的扩散系数增加；在恒定质量比水／醇时，随着表面活性剂含量的增加，BSA在层状液晶中的扩散系数减小。BSA在SDS层状液晶中的扩散系数＞BSA在TritonX-100层状液晶中的扩散系数＞BSA在CTAB层状液晶中的扩散系数。扬州大学硕士论文 在SDs/n-CsHllOH八王20和SDS厄A刀HZO体系中，超声使胶束、微乳液液滴分散，超声停止后，立即测定胶束、微乳液液滴形成过程的电流和电导率，用伏安法测得的速率常数和用电导率测得的速率常数基本一致。随着水含量和正戊醉含量的增加，SDS的峰电流均增加，胶束、微乳液液滴恢复到平衡所需的时间均减小。随着SDS含量的增加，SDS的峰电流减小，胶束、微乳液液滴恢复到平衡所需的时间增加。更多还原

【Abstract】 The diffusion coefficients of three typical surfactants (SDS, CTAB, Triton X-100) in the microemulsion and lamellar liquid crystal systems have been determined.The results show that the diffusion coefficients in three typical microemulsions and the lamellar liquid crystals increase with the water content at constant weight ratios of surfactant/alcohol, and do with alcohol content at constant weight ratios of surfactant/water, but decrease with .surfactant content at constant weight ratios of water/alcohol. The diffusion coefficients of the O/W droplets are nearly two orders larger than that of W/O droplets, and nearly four orders larger than that of surfactant molecule in lamellar liquid crystal. The diffusion coefficients of the CTAB molecule in the CTAB lamellar liquid crystal > that of SDS molecule in the SDS lamellar liquid crystal > that of Triton X-100 molecule in the Triton X-100 lamellar liquid crystal.The diffusion coefficients of Methylene Blue (MB) in the three typical microemulsions and lamellar liquid crystals have been determined. The results show that the diffusion coefficients of MB increase with the water content at constant weight ratios of surfactant/alcohol, and do with alcohol content at constant weight ratios of surfactant/water, but decrease with surfactant content at constant weight ratios of water/alcohol in the three typical microemulsions and the lamellar liquid crystals. The diffusion coefficients of the MB molecule in CTAB lamellar liquid crystal > that in Triton X-100 lamellar liquid crystal> that in SDS lamellar liquid crystal.The diffusion coefficients of Bovine Serum Albumin (BSA) in three typicalsurfactant lamellar liquid crystals have been determined. The results show that the diffusion coefficients of BSA increase with the water content at constant weight ratios of surfactant/alcohol, and do with alcohol content at constant weight ratios of surfactant/water, but decrease with surfactant content at constant weight ratios of water/alcohol in the three typical lamellar liquid crystals. The diffusion coefficients of the BSA molecule in CTAB lamellar liquid crystal > that of the BSA molecule in TritonX-100 lamellar liquid crystal> that of the BSA molecule in SDS lamellar liquid crystal.The micelle and microemulsion could be broken by the ultrasonic waves in the SDS/BA/H2O and SDS/n-C5HnOH/H2O systems. The SDS peak current and the conductivity of the recovering and congregation process of micelle and microemulsion droplet were determined immediately after ultrasonic by the methods of voltammetry and conductivity. The rate constants obtained by the two methods were very consistent. With the increase content of water in the systems, the cathodic peak current of SDS rises, and the recovering time decreases. The more n-pentanol in the system, the more large the cathodic peak current of SDS and the less time taked for the micelle and microemulsion to recover. When the SDS content increase, the cathodic peak current of SDS reduces, and the recovering time increases.更多还原