去氧胆酸钠在水溶液中的簇集行为

用外源荧光探针法和旋光度、电导率及pH滴定法研究了去氧胆酸钠(SDOC)在水溶液中的簇集行为.SDOC浓度低于5×10~(-3)～6×10~(-3)mol/L时在水溶液中以二元缔合物形式存在,具有较高的对称性和较弱的碱性并能提供一定的疏水性微环境;浓度高于该值后簇集成胶束,但簇集数(8～10)较小,同时伴随着对称性略微降低和碱性有所提高.     

系列双亲卟啉在水溶液及盐溶液中的不同聚集行为

分析了中性条件下在水溶液及盐溶液中系列双亲卟啉随其浓度连续变化的紫外-可见吸收光谱。结果表明,在中性条件下不同侧链取代基对双亲卟啉的聚集行为有很大影响,盐的加入导致卟啉的聚集形态发生改变,初步解释了影响卟啉聚集的原因。     

壳聚糖在稀溶液中的聚集行为

壳聚糖在稀溶液中的聚集行为;荧光探针;荧光偏振;聚集行为     

Aggregation Behavior of Pyridinium-Based Ionic Liquids in Aqueous Solution

Aggregation of the ionic liquids 1-butylpyridinium tetrafluoroborate, 1-butylpyridinium triflate, 1-butyl-2-methylpyridinium tetrafluoroborate, 1-butyl-3-methylpyridinium tetrafluoroborate, 1-butyl-4-methylpyridinium tetrafluoroborate, 1-butyl-3-methylpyridinium dicyanamide, and 1-octyl-3-methylpyridinium tetrafluoroborate in aqueous solution has been characterized at 298.15 K through density, ρ, speed of sound, u, and conductivity, σ, measurements. In addition, apparent molar volumes, V _φ , and isentropic compressibilities, κ _s , have been calculated from the experimental data. To characterize the formation of aggregates, the critical aggregation concentration of the ionic liquids, cac, the degree of ionization of the aggregates, β, and the standard Gibbs energy of aggregation, DG_m^°\Delta G_{\mathrm{m}}^{\circ}, have been obtained, with good agreement between results derived from the different methods. The dependence on the structural variation of these ions has been analyzed by comparing the results obtained for this series of ionic liquids.     

Thermal Aggregation of Methyl Cellulose in Aqueous Solution: A Thermodynamic Study and Protein Partitioning Behaviour

The formation of a biphasic system from aqueous solutions of methyl cellulose induced by temperature was studied through heating curves of the polymer solution measured by absorbance spectroscopy, differential scanning calorimetry and solution viscosimetry. The treatment of the heating curve data according to a reversible two-state transition model allows us to calculate the middle point temperature (T_m) of the formation of the two phases and the thermodynamic functions associated to the polymer aggregation. The middle point temperature was found within the range 50–70 °C. It decreased significantly in a Na₂SO₄ 0.3 M medium when the polymer concentration increased. The heat associated to the two-phase formation was positive and it increased with increases in temperature. Cosolutes that affect the water structure induced changes in the T_m values, which suggests the presence of a hydrophobic effect in the two-phase formation from the polymer solution. Hydrophilic proteins were partitioned in favour of the methyl cellulose rich phase according to their surface hydrophobicity. The partition was also influenced by the presence of salts that modify the protein hydrophobicity such as sodium sulphate.     

血卟啉在胶束介质中的聚集状态研究

用光谱法研究了光敏剂血卟啉在水溶液中的聚集状态，并以胶束作为生物膜模型，探讨了血卟啉在胶束介质中的聚集状态状态变化，用原子力显微镜研究了血卟啉聚集状态的微观结构及其在胶束介质中的聚集状态。     

水溶液中亚甲蓝分子聚集状态的研究

用分光光度法研究了亚甲蓝(MB)染料在水溶液中的聚集状态及其与表面活性剂的相互作用,讨论了无机盐对亚甲蓝在阴离子表面活性剂溶液中聚集状态的影响。推导了水溶液中亚甲蓝单体和二聚体的动态平衡关系式。利用计算机程序不仅求出了与作图法结果非常接近的MB单体的摩尔吸光系数和聚合平衡常数,而且求出了MB二聚体的摩尔吸光系数及相应浓度下MB单体所占的比例系数。     

Gemini 阴离子表面活性剂水溶液的聚集性质

合成了一种Gemini阴离子表面活性剂,测定了其临界胶束浓度cmc和cmc时的表面张力γcmc,与传统的单基表面活性剂相比,其临界胶束浓度降低了一个数量级,具有突出的降低水的表面张力的效率;研究了该种Gemini表面活性剂的浓度对于胶束聚集数的影响,结果表明,随着浓度的增加,胶束聚集数出现了一个极大值,同时观察到液晶微相的生成.     

激光光散射研究天花粉蛋白的聚集过程

运用激光光散射技术研究天花粉蛋白在水溶液及不同浓度KSCN水溶液中的聚集过程．KSCN的加入能提高天花粉在水溶液中的稳定性. KSCN浓度大于0．5mol•L－1时，天花粉溶液透明、稳定，溶液中天花粉以单个分子与聚集体两种形式存在．聚集体主要是由约120个天花粉分子组成，平均流体力学半径Rh值约为49nm，在溶液中排列疏松，类似θ溶剂中的无规线团。     

Influence of Natural Polysaccharides on Aggregation of Aqueous Protein Dispersions

The kinetics of aggregation of aqueous protein dispersions under the action of flocculants, natural polysaccharides (cationic chitosan and anionic sodium alginate), were studied turbidimetrically in relation to the protein : polysaccharides ratio in the solution and the pH value. Sodium alginate and chitosan were tested in treatment of wastewater from the flotation processing of hydrobiontics.     

C60吡咯烷羧酸衍生物的合成及其在水溶液中的聚集行为

C60与亚氨基二乙酸甲酯[NH(CH₂COOMe)₂]的光化学反应制得2,5-双(甲氧羰基)富勒烯吡咯烷(1), 产率为52% (基于已反应的C60). C60吡咯烷衍生物1与氯乙酸甲酯(ClCH₂COOCH₃)的N-烃基化反应, 在微波辐射、无溶剂及相转移条件下, 得到2,5-双(甲氧羰基)-N-(甲氧羰基)甲基富勒烯吡咯烷(2), 产率47%(基于C60吡咯烷衍生物1). C60吡咯烷衍生物1和2用NaH, CH₃OH水解后, 经盐酸酸化得相应的二羧酸衍生物3和三羧酸衍生物4, 产率分别为65%和53% (基于C60吡咯烷衍生物1和2). C60吡咯烷衍生物1～4的结构由¹H NMR, ¹³C NMR, IR, FAB-MS和元素分析证实. 用电导法测定了C60吡咯烷二羧酸3和三羧酸4钠盐的临界聚集浓度(CAC), 分别为3.58×10^－4 mol/L (3)和3.33×10^－4 mol/L (4). 这一结果被C60吡咯烷衍生物3和4, 在临界聚集浓度(CAC)附近的UV-Vis光谱的特征变化所支持. 透射电子显微镜(TEM)和静态光散射(SLS)等方法也被用于检测C60吡咯烷衍生物3和4在临界聚集浓度(CAC)时的聚集行为, 结果显示, C60吡咯烷衍生物3在缓冲溶液中(0.001 mol/L NaCO₃-NaHCO₃), 其聚集体粒径的大小(R_g≈21 nm)不同于C60吡咯烷衍生物4 (R_g≈23 nm). C60吡咯烷二羧酸3钠盐的临界聚集浓度(CAC)比C60吡咯烷三羧酸4钠盐的临界聚集浓度(CAC)大, 聚集体粒径大小的不同, 表明C60单加成衍生物加成基团中羧基(COOH)数目的多少对其聚集行为的影响. 用化学发光法分别检测了C60吡咯烷二羧酸3和C60吡咯烷三羧酸4在缓冲溶液(0.05 mol/L NaCO₃-NaHCO₃)中对邻苯三酚自氧化产生的超氧阴离子(O₂^－·)的清除活性. C60衍生物3和4对 O₂^－· 的清除呈现有明显的剂量效应, 但当超过一定浓度时(3: ～3.50×10^－4 mol/L, 4: ～3.25×10^－4 mol/L), 清除效率出现转折, 并下降. 这一现象与电导率测定时出现的CAC现象相一致, 进一步证实了C60吡咯烷二羧酸3和C60吡咯烷三羧酸4在较高浓度的水溶液中有聚集的倾向, 也说明了C60吡咯烷二羧酸3和C60吡咯烷三羧酸4的聚集会影响其清除超氧阴离子(O₂^－·)的活性.     

H＋对水溶液中脱氧胆酸钠聚集体的影响

运用pH滴定、傅立叶变换红外光谱、紫外可见光谱、激光光散射谱、ICP和元素分析等方法研究了H＋的加入对水溶液中脱氧胆酸钠（NaDC）聚集体的影响.结果表明,浓度大于cmc的NaDC水溶液具有一定的缓冲能力,NaDC浓度越高,缓冲能力越大;随溶液中H＋浓度的增加,首先形成质子化胶团,质子化胶团通过酸盐结构的氢键作用使NaDC初级胶团长大,形成较大的高级胶团,甚至形成凝胶体,最终形成HnNam(DC)n＋m沉淀.     

Adsorption and Aggregation Behavior of n-Undecyl Ammonium Acetate Ionic Liquid in Aqueous Solution

A surface active ionic liquid (IL), [CH₃(CH₂)₁₀NH₃][OOCCH₃], was synthesized and characterized by FTIR, ¹H NMR, and ¹³C NMR. Its surface activity and aggregation behavior in aqueous solution were investigated using surface tension measurements, conductivity measurements, transmission electron microscopy (TEM), and dynamic light scattering (DLS). The results reveal that the CAC and γ_cac of this IL are 15.3 mM and 23.1 mN/m, respectively. We observed a strong interaction between the counter-ions, leading to ion pairs that self-assemble into spherical vesicles in aqueous solution, with an average diameter in the range of 120 to 130nm.     

双亲性C60衍生物水相聚集行为

富勒烯C₆₀几乎不溶于水中,从而阻碍了对富勒烯的进一步研究和潜在应用。双亲性C₆₀衍生物在水相中自组装形成聚集体,在水相具有一定的溶解度,其特殊的结构及性能引起了科学家的广泛关注。本文对双亲性C₆₀衍生物在水相中聚集行为的研究现状及研究进展进行了详细系统的介绍。本文第一部分主要阐述了双亲性C₆₀衍生物的结构,根据修饰到C₆₀表面的功能基类型对双亲性C₆₀衍生物进行了分类。第二部分主要阐述了双亲性C₆₀衍生物在水相的聚集行为以及pH值、溶剂极性、浓度、温度和抗衡离子等因素对聚集行为的影响。     

反相破乳剂SP169及DMEA169在溶液中的聚集行为

以芘(Py)为荧光探针,十六烷基氯化吡啶(CPC)为猝灭剂,采用稳态荧光探针法测定了反相破乳剂SP169和DMEA169的临界胶束浓度(cmc)及胶束聚集数(N_agg),并考察了两者在溶液中形成的胶束内部的微环境极性大小,采用动态光散射法测定了两者胶束的流体力学直径(D_h),并通过耗散粒子动力学(DPD)方法模拟了两者在溶液中聚集形态的动力学变化过程。结果表明,两者的临界胶束聚集数分别为N_m(SP169)=28,N_m(DMEA169)=18;SP169的流体力学直径小于DMEA169,但其增长速度前者大于后者;DPD模拟的结果显示,由于起始剂在胶束内部与其他粒子间相互作用的不同,SP169聚集成棒状胶束,而DMEA169聚集成舒展的球状胶束,这解释了实验结果：相同浓度下前者胶束的流体力学直径及胶束内部的微环境极性皆比后者小,同时由于SP169起始剂的疏水性,使得其具有较大的胶束聚集数。     

用吸收光谱法研究亚甲蓝在表面活性剂存在时的聚合状态

应用紫外－可见吸收光谱研究了光敏试剂亚甲蓝在溶液中的聚合状态及其与表面活性剂之间的关系。当添加阴离子表面活性剂的浓度于其临界胶束浓度时，亚甲蓝二聚体的比例将出现一极大值；用环己烷剂萃取后，测得亚甲蓝二聚体的吸收光谱，其最大吸收波长位于６０４ｎｍ。     

Quantitative Raman Analysis of Carotenoid Protein Complexes in Aqueous Solution

Carotenoids are naturally abundant, fat-soluble pigmented compounds with dietary, antioxidant and vision protection advantages. The dietary carotenoids, Beta Carotene, Lutein, and Zeaxanthin, complexed with in bovine serum albumin (BSA) in aqueous solution, were explored using Raman spectroscopy to differentiate and quantify their spectral signatures. UV visible absorption spectroscopy was employed to confirm the linearity of responses over the concentration range employed (0.05–1 mg/mL) and, of the 4 Raman source wavelengths (785 nm, 660 nm, 532 nm, 473 nm), 532 nm was chosen to provide the optimal response. After preprocessing to remove water and BSA contributions, and correct for self-absorption, a partial least squares model with R² of 0.9995, resulted in an accuracy of the Root Mean Squared Error of Prediction for Beta Carotene of 0.0032 mg/mL and Limit of Detection 0.0106 mg/mL. Principal Components Analysis clearly differentiated solutions of the three carotenoids, based primarily on small shifts of the main peak at ~1520 cm⁻¹. Least squares fitting analysis of the spectra of admixtures of the carotenoid:protein complexes showed reasonable correlation between norminal% and fitted%, yielding 100% contribution when fitted with individual carotenoid complexes and variable contributions with multiple ratios of admixtures. The results indicate the technique can potentially be used to quantify the carotenoid content of human serum and to identify their differential contributions for application in clinical analysis.     

二苯胺重氮盐与十二烷基硫酸钠在水溶液中的相互作用

报道了二苯胺-4-重氮盐(DDS)与十二烷基硫酸钠(SDS)在水溶液中的相互作用.实验结果表明,体系粘度随SDS/DDS物质的量比(ξ)的变化而急增急降.当ξ=0～0.9时,二者形成沉淀,体系的粘度基本不变;当ξ=1.9～2.3时,沉淀溶解并伴随着体系粘度急增,最高粘度达初始值的2520倍;之后,随ξ的增大,体系粘度迅速下降至初始值.对DDS-SDS聚集体的微观结构与体系粘度的关系进行了初步讨论.同时发现体系粘度是光敏性的,紫外光照可使其迅速下降.     

压力诱导溶液中蛋白质构象变化的谱学研究

高压诱导蛋白质发生构象变化,引起蛋白质去折叠,并在某种条件下发生聚集,其结果是蛋白质原有的构造被破坏、发生变性。这些过程与蛋白质本身的结构密切相关。同时,折叠中间体结构的揭示对于研究蛋白质去折叠过程也具有重要意义。本文综述了高压诱导下多种谱学方法用于蛋白质构象变化的研究进展,主要包括高压红外光谱、高压荧光光谱及高压小角X射线扫描等多种技术手段在研究中蛋白质构象变化方面所能提供的重要信息,并对相关领域存在的问题及今后的发展作出展望。