多组分体系相图中的杠杆原理形式

讨论了两相和三相多组分体系中杠杆原理的两种形式。对两组分体系,利用三相线上的杠杆原理关系式和凝固点降低公式,解释了熔化物体系冷却过程中的步冷曲线。另外,还讨论了三组分体系相图中,同一直线段上三个物系点之间的类杠杆原理关系式。该关系式可以用于不同浓度溶液的配制和三相体系相图的绘制。     

SDS/正戊醇-环己烷-水拟三元体系相图及温度对相图的影响

绘制了35, 45, 55, 65 ℃下, 十二烷基硫酸钠(SDS)/正戊醇-环己烷-水体系的拟三元相图. 分析了温度对相图和微乳液区域的影响. 结果表明, 温度对油包水(W/O)反相微乳液区域大小有影响, 但影响较小, 温度对水包油(O/W)微乳液区域的影响较大, 且随温度的增加, 区域增大. 电导率曲线与相图吻合很好, 并用电解质溶液理论进行了解释.     

应用相图边界理论勾画多元恒温截面相图

根据相图的边界理论,可以确定恒温截面图中紧邻相区及其边界关系,进而可以根据有限的实验数据,比较直接地勾画出整个恒温截面图。本文以5元相图和8元相图为例加以说明。     

硝酸盐型卤水体系的综合热力学模型与多温相图预测

硝酸盐型卤水是盐湖卤水、 硝酸盐工业、 废水处理中普遍遇到的电解质溶液体系. 硝酸盐具有极高的溶解度, 实现硝酸盐型复杂电解质体系物性和相平衡的精准热力学表达依然具有挑战性. 以煤化工废水的典型体系Na⁺//NO₃^- , Cl^-, SO₄^{2 -} -H₂O为对象, 以改进的eNRTL模型为基础, 由活度系数模型、 溶液物性模型、 物种热力学模型和固液相平衡模型构成了电解质体系的综合热力学模型. 利用二元体系的冰点、 饱和蒸汽压、 等压摩尔热容、 活度系数和渗透压系数等物性数据和三元体系等温相平衡数据, 采用多目标优化方法, 获得了表达研究体系的多温特性的12组液相特征参数和7个固相物种的热力学参数. 据此完成了3个二元体系、 3个三元体系等温相平衡的准确计算和三元、 四元完整相图的预测, 适用温度达到实验所及的全部温度范围(254.65~543.15 K); 适用浓度达到饱和程度, 其中NaNO₃的浓度高达226.88 mol/kg. 三元、 四元体系的多温相图预测结果与实验数据相吻合, 并给出了9个三元、 5个四元体系零变点的完整信息.     

Temperature-Concentration Phase Diagram of PEO-Urea

The present paper reports on the phase diagram of the system PEO/Urea as established by differential scanning calorimetry. From this phase diagram one PEO/Urea compound is indentified with a stoichiometry 1/2. This value is in agreement with results derived from X-ray diffraction.     

Phase Coexistence in a Dynamic Phase Diagram

Metastability and phase coexistence are important concepts in colloidal science. Typically, the phase diagram of colloidal systems is considered at the equilibrium without the presence of an external field. However, several studies have reported phase transition under mechanical deformation. The reason behind phase coexistence under shear flow is not fully understood. Here, multilamellar vesicle (MLV)‐to‐sponge (L₃) and MLV‐to‐L_α transitions upon increasing temperature are detected using flow small‐angle neutron scattering techniques. Coexistence of L_α and MLV phases at 40 °C under shear flow is detected by using flow NMR spectroscopy. The unusual rheological behavior observed by studying the lamellar phase of a non‐ionic surfactant is explained using ²H NMR and diffusion flow NMR spectroscopy with the coexistence of planar lamellar–multilamellar vesicles. Moreover, a dynamic phase diagram over a wide range of temperatures is proposed.     

CsF-RbF二元系相图

采用支持向量机(SVM)-原子参数模式识别法, 对75个一价金属同阴离子卤化物二元体系固溶体形成规律进行了研究, 根据研究结果, 预测CsF-RbF体系应形成固溶体. 用差热分析法重新测定了该体系的相图, 结果表明, 该体系为液固相连续互溶, 没有最低点和最高点的固溶体体系, 与文献中的热力学计算结果一致.     

Phase Diagram of the System NaF-KF-AlF3

The phase diagrams of the binary system KF-AlF₃ as well as the ternary system NaF-KF-AlF₃ in the range up to 50 mol% AlF₃, were measured using the thermal analysis method. In the system KF-AlF₃ the coordinates of the eutectic points are: E ₁: 8.0 mol% AlF₃, 821.2°C, and E ₂: 45.5 mol% AlF₃, 565.0°C. In the investigated concentration range of the ternary system 2 eutectic points have been found with the calculated coordinates: E ₁: 36.3 mol% NaF, 62.7 mol% KF, 1.0 mol% AlF₃; t=711.2°C; and E ₂: 51.9 mol% NaF, 27.4 mol% KF, 20.7 mol% AlF₃; t=734.5°C. Other eutectic points lie most probably beyond the investigated part of the system. This revised version was published online in July 2006 with corrections to the Cover Date.     

Physicochemical Characterization and Simulation of the Solid–Liquid Equilibrium Phase Diagram of Terpene-Based Eutectic Solvent Systems

The characterization of terpene-based eutectic solvent systems is performed to describe their solid–liquid phase transitions. Physical properties are measured experimentally and compared to computed correlations for deep eutectic solvents (DES) and the percentage relative error e_r for the density, surface tension, and refractive index is obtained. The thermodynamic parameters, including the degradation, glass transition and crystallization temperatures, are measured using DSC and TGA. Based on these data, the solid–liquid equilibrium phase diagrams are calculated for the ideal case and predictions are made using the semi-predictive UNIFAC and the predictive COSMO RS models, the latter with two different parametrization levels. For each system, the ideal, experimental, and predicted eutectic points are obtained. The deviation from ideality is observed experimentally and using the thermodynamic models for Thymol:Borneol and Thymol:Camphor. In contrast, a negative deviation is observed only experimentally for Menthol:Borneol and Menthol:Camphor. Moreover, the chemical interactions are analyzed using FTIR and ¹H-NMR to study the intermolecular hydrogen bonding in the systems.     

二组分体系的相图及其相图边界理论

主要探讨了二组分体系的相图,如气-液相图和液-固相图,总结了二组分相图的分类、绘制及相图分析,这有利于理解和掌握二组分相图的基本规律。并简单介绍了相图边界理论,扩展了相图的热力学研究。     

新戊二醇-三羟甲基甲胺二元体系相图

多元醇是一类具有技术和经济潜力的相变贮热材料［１ -３］．对多元醇及其二元体系贮热性能的研究已日趋完善,而对于其相图的研究则较少．本文采用以下三种实验技术测绘了ＮＰＧ ＴＡＭ二元体系相图：（１）热分析,以得到组成与相转变温度的关系;（２）变温红外光谱的研究,通过特征吸收峰随温度的变化,可以得到相转变温度区间,辅助相图的绘制;（３）Ｘ射线衍射,通过淬冷的方法来获得高温下的物相,测其Ｘ衍射图,进行相区分析．１实验１．１试剂ＮＰＧ：为超纯试剂,日本东京化成株式工业会社生产：ＴＡＭ：分析纯,北京化学试剂厂…     

Phase Diagram of the Neodymium Chloride-Sodium Chloride System

Differential thermal analysis was used to study the phase diagram of NdCl3-NaCl system. The peritectic reaction was found to occur at 540±7°C. The peritectic compound was confirmed to be Na3Nd5Cl18 by means of X-ray diffraction analysis. The homogeneity range Na3Nd5Cl18 could not be defined accurately, but appeared to be between 59 and 70 mol% of NdCl3 at temperatures between 300 and 540°C. This revised version was published online in July 2006 with corrections to the Cover Date.     

Cr-Ni二元相图

利用X射线衍射、电子探针微分析、扫描电子显微镜和差热分析测定了Cr-Ni合金样品和扩散偶Cr-Ni样品,构筑了Cr-Ni二元体系的相图.在此相图中存在、 γ和α相，这些相的结构分别属于A2, A1和型结构.它们的晶胞参数分别随着温度的增加和Cr含量的增加而增大.温度变化对晶胞参数的影响强于Cr含量变化对晶胞参数的影响.δ相仅存在于未退火的熔炼样品中和差热分析后的样品中.该相属于不稳定相.     

尼龙1010／尼龙6共聚物的表观相图研究

采用显微熔点法和ＤＳＣ测定了尼龙１０１０／尼龙６共聚物的表观相图；分析了投料比与链节结构单元含量的关系。最低熔点时尼龙１０１０／尼龙６的理论重量投料比为６０／４０，摩尔比为３３．３／６６．７，实验结果与此相近。     

The Al-Zn-Ga Phase Diagram Part II

The first part of this paper presented five experimental isopletic cuts in the Al-Zn-Ga ternary phase diagram. On these cuts, two isobaric ternary invariant reactions were determined and a significant retrograde miscibility of Ga in a α′_SS solid solution was observed. In the second part, the two isobaric invariant reactions are studied more precisely. In particular, the composition of the invariant phases are given and the Ga miscibility in the α_SS ternary solid solution is studied. Isothermal sections are established. The results confirm the existence of a vanishing point in the liquidus area, conjugated with a ternary critical point at about 290°C. A general perspective shape of the equilibria in the diagram is proposed. This revised version was published online in July 2006 with corrections to the Cover Date.     

The Al-Zn-Ga Phase Diagram Part I

The Al-Zn-Ga ternary phase diagram was earlier established by thermodynamic modellization [1], but no experimental study appears to have been carried out on this system, except for measurements of mixing enthalpies in the liquid [2]. The present experimental study was carried out by thermal analysis and X-ray diffraction at various temperatures, using the isopletic cuts method. Four isopletic cuts were established and two others were partly studied in the Al-rich corner of the diagram. On these cuts, two isobaric ternary invariant reactions were determined: a eutectic reaction at 23±1°C, and a metatectic reaction at 123±1°C. Evidence was found for the existence of a retrograde miscibility of Ga in a solid solution α′_SS which protrudes into the ternary system starting from the Al-Zn binary up to a Ga concentration of about 30%^*. This revised version was published online in July 2006 with corrections to the Cover Date.     

碱和盐对十二烷基硫酸钠/正戊醇-环己烷-水拟三元体系相图影响

拟三元相图的研究可为获得制备纳米材料的微乳液提供理论依据。本文首先通过实验绘制了45℃下十二烷基硫酸钠(SDS)/正戊醇-环己烷-水溶液体系的拟三元相图,并用电导法进行了验证,说明电导的测定结果与相图吻合的很好。其次,绘制了45℃及65℃下,SDS/正戊醇-环己烷-水、SDS/正戊醇-环己烷-硝酸锌水溶液和SDS/正戊醇-环己烷-氢氧化钠水溶液体系的拟三元相图并对6个相图进行了比较,研究了碱(NaOH)和盐(Zn(NO_3)_2)对SDS/正戊醇-环己烷-水拟三元体系相图影响。结果表明,硝酸锌及碱的加入使SDS/正戊醇-环己烷-水拟三元相图水包油(O/W)和油包水(W/O)区域明显的缩小。45℃时,SDS/正戊醇-环己烷-氢氧化钠水溶液体系的拟三元相图中的O/W区域甚至消失;65℃时,O/W和W/O区域均存在,且3个相图的W/O和O/W区域有重叠区。在此基础上,确定了制备纳米Zn O的微乳液的条件,即SDS/正戊醇-环己烷-硝酸锌水溶液和SDS/正戊醇-环己烷-氢氧化钠水溶液体系的拟三元相图中W/O区域的重叠区(各相图中的Ⅱ区)。制备的纳米氧化锌为多晶结构,平均粒径为80 nm。     

Al-Zn-Sn Phase Diagram Calorimetric Study of the Isobaric Invariants

A systematic study of Al-Zn-Sn ternary alloys by using a Tian-Calvet calorimeter with slow heating and cooling rate was carried out and supplemented by scanning electron microscopic observations. The results have shown that crystallization coupled with dissolution of tin into the α_ss′ ternary solid solution on heating is an endothermic process, while melting coupled with tin expulsion on cooling is an exothermic one. It seems that the thermal effects of phase transition are outweighed by much stronger ones due to a large composition change of the α_ss′ ternary phase. This revised version was published online in August 2006 with corrections to the Cover Date.     

聚胺与dna相互作用的相图

利用相图方法研究了聚胺(PA)与DNA的相互作用,初步考察了NaCl对精胺与DNA相互作用的影响。研究结果表明,聚胺与DNA之间不仅存在着强烈的静电作用,同时聚胺与DNA碱基对之间也存在着相互作用。在较低的精胺(SPM)浓度(0.025mmol/L)时就开始出现浊度,而在相同的条件下,亚精胺(SPD)-DNA体系和盐酸胍(GD)-DNA体系在聚胺浓度高达10mmol/L时浊度曲线仍无明显变化;SPD-DNA体系与GD-DNA体系的A260曲线相比,前者随着聚胺浓度的增加吸光度逐渐下降,说明SPD与DNA作用强于GD;由此可见聚胺所带正电荷越多,其与DNA的作用越强,水溶液条件下亚精胺(SPD)和GD与DNA间有较弱的相互作用,但不能使DNA产生相分离;加入NaCl后,由于外加电解质的静电屏蔽效应,SPM与DNA之间的相互作用减弱。NaCl浓度越大,二者之间相互作用越弱,SPM-DNA体系相图曲线的线性相关性越低。     

相变储热材料C10CoCl/C18CoCl二元体系相图

合成了具有层状钙钛矿结构的固-固相变材料四氯合钴酸癸铵(n-C10H21NH3)2CoCl4和四氯合钴酸十八铵(n-C188H37NH3)2CoCl4,并制得一系列C10CoCl/C18CoCl二元体系.利用差示扫描量热(DSC)技术测定其相变温度,并在此基础上绘制了C10CoCl/C18CoCl二元体系相图.在实验相图中确定了新的稳定化合物(n-C10H21NH3)(n-C18H37NH3)CoCl4的存在和2个不变的共晶点,共晶点温度分别为70和73℃.