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1.
理想完全互溶双液系是两个组分都严格遵守Raoult定律的体系,从数学角度看,其平面相图有着确定的函数关系。本文以Clausius-Clapeyron方程为基础,推导了该类理想体系的p-x、T-x及p-T相图的函数解析式。  相似文献   

2.
用热分析法仔细地测定了邻、对位氯甲苯和邻、对位硝基氯苯两个系统在不同组成时的步冷曲线,并进行了结晶试验,从而确认它们都属于简单的低共熔型相图,而不是一个有最低凝固点的完全互溶固溶体相图。文中还根据这类异构物的物理和热力学特性,解释了实验观察到的相图特征。  相似文献   

3.
周志强  郭丽  荣春光 《化学教育》2018,39(24):67-70
就我国物理化学教材在介绍二组分固态不互溶系统液-固平衡相图和生成不稳定化合物的二组分凝聚系统相图中存在的若干问题进行了探讨与甄辨。探讨了在二组分固态不互溶系统液-固平衡相图的介绍中分平衡区来应用相律,以使相律的应用更有意义,使读者对相律的理解更加透彻;甄辨了在生成不稳定化合物的二组分凝聚系统相图的介绍中考虑“包晶”等动力学因素或称工程实际因素的重要性。以此为例,分析了教材与教师在教学中的关系。  相似文献   

4.
非理想溶液是实际工作中经常遇到的一类多组分体系,其中完全互溶双液系是基本的类型之一。研究气-液平衡中的气、液相组成,以及各组分的蒸气压对Raoult定律的偏差,有着重要的现实意义,其实际应用的一个很好的例子,是用于蒸馏过程的研究。在一些物理化学教材中,有这样的叙述:“二组分非理想完全互溶双液系,若组分A发生正偏差,则组分  相似文献   

5.
李俊新  崔敏  姚艳君 《化学教育》2020,41(4):103-106
对完全不互溶双液系的饱和蒸气压进行了实验研究与理论讨论,认为完全不互溶双液系的平衡蒸气压随两组分相互溶解度减小而趋于但总是小于两纯组分的饱和蒸气压之和;当完全不互溶两液相一起静置时,上层液体能有效但不能完全阻止下层液体的挥发,这种阻止作用源于缓慢溶解、扩散和挥发这些动力学过程;提出了阻止下层液体挥发的方法,即用与之完全不互溶且密度小的液体来覆盖,并且2种液体充满容器,阴凉处密闭静置保存。  相似文献   

6.
张启源 《大学化学》1987,2(4):40-42
二组分完全互溶的双液系的气液平衡相图实验是物理化学实验的基本内容之一,通常是用沸点仪在常压条件下测定双液系在不同组成时的沸点和气、液两相呈平衡时的组成,从而作出沸点-组成相图。外界压力不同时,同一双液系的相图也不尽相同,所以恒沸点和恒沸混合物组成与外压有关。因此,通常情况下,用标准数据去衡量学生实验所得的恒沸点和恒沸混合物的数据就不够精确。本文是用自制的简易恒压沸点仪,在不同的压力下,对丙酮-氯仿和异丙醇-环己烷体系的恒沸点,恒沸混合物组成进行了研  相似文献   

7.
部分互溶三元体系相图及逆流萃取过程理论塔板数图解的计算机绘图杨继红旋南华盖起贤杨宏志(云南大学,昆明650091关键词计算机图形学相图理论塔板数AcadAutolisp相图及相平衡过程的图解研究是物理化学中的一个重要部分,如萃取相图及萃取过程中的理论...  相似文献   

8.
本文通过热分析测定,X射线物相分析、分级结晶分离、固化分离及固化分离理论收率公式与经验收率公式的一致性等多角度验证,证明邻、对位氯甲苯固液平衡体系是一个具有最低凝固点(-50.75℃;26.88%对位)的完全互溶型固溶体。结果表明,目前国际公认的简单低共熔型相图的结论与实验事实不符。并且还给出了邻氯甲苯和对氯甲苯的粉末衍射卡。  相似文献   

9.
本文报导了醋酸-水、醋酸-醋酸乙烯酯、水-醋酸乙烯酯等三对二元系以及醋酸-水-醋酸乙烯酯三元系在液相完全互溶区的气液平衡实验数据。文中还计算了经校正了醋酸气相缔合后的活度系数,作了热力学一致性校验,并尝试用NRTL式进行关联。当使用三对二元系的NRTL特征参数,对三元系液相完全互溶区的气液平衡进行了预测,与实验结果基本相符。三元系液相部分互溶区的实验数据与热力学关联的结果,将于第Ⅱ报中报导。  相似文献   

10.
一、研究紧邻相区及其边界的关系的重要性相图是由若干个相区组成的。以图1的一个二元部分互溶的低共晶相图为例,这个相图由六个相区组成。研究相区组成相图的规律,主要就是要研究:(1)对于给定相区来说,符合什么条件的相区才能与其毗邻?(2) 这些紧邻相区之间的边界的性质如何?这就是说,要研究紧邻相区及其边界的关系。  相似文献   

11.
Depolarized light scattering measurements on single-phase mixtures of dissimilar polymers, poly(methyl methacrylate) (PMMA)/poly (acrylonitrile-co-styrene) (SAN, AN content = 15 wt %) and PMMA/poly (vinylidene fluoride) (PVDF) were carried out. The effective mean-square optical anisotropy γ2 of the mixtures was found to be much higher than that estimated by the simple additivity of γ2 of component polymers. From the deviation, the order parameter (1 + J12) was estimated to be in a range of 2–13, depending on the blend composition. This suggests local ordering in the single-phase mixtures, i.e., nematic alignment of the locally stretched dissimilar chains. In contrast, the deviation was slight in the polymer/solvent systems, SAN/MMA (monomer) and PVDF/butanone. The degree of ordering decreased with increasing temperature. T. The Specific interaction evidenced by FTIR spectroscopy exhibited a similar temperature dependence. Thus, local ordering seems to be induced by specific interactions and chain connectivity. The temperature dependence of J12 was successfully described by the Landau-de Gennes theory; J ∞ (T + T0)/ T, T0 being the isotropic-nematic transition temperature, as in the case of liquid crystals.  相似文献   

12.
通过对聚己内酯/硝基纤维素共混体系的热分析、傅立叶变换红外光谱的研究,证实了该共混体系在聚己内酯含量较高时,是一个热力学相容的体系,同时两组分之间存在强的氢键相互作用。在此体系中聚己内酯长成了清晰规整的环带球晶。聚己内酯结晶形态随结晶温度和共混物组成的变化表明,在共混体系中聚己内酯结晶速率与非晶第二组分的扩散速率存在一定的匹配关系,是影响环带球晶形成的重要因素。  相似文献   

13.
Oil-CO2 minimum miscible pressure (MMP) has significance in selecting appropriate reservoir for miscible gas injection and greatly governs performance of local displacement. Accurate determination of MMP is very expensive, time-consuming, and labor intensive. Therefore, the quest for a method to determine MMP accurately and save time and money is necessary. This study held a competition between neural network and support vector regression models and assessed their performance in prediction of MMP for both pure and impure miscible CO2 injection. Subsequently, a committee machine was constructed based on divide and conquer principle to reap benefits of both model and increases the precision of final prediction. Results indicated committee machine performed more satisfyingly compared with individual intelligent models performing alone.   相似文献   

14.
An ideal Fermi gas of identical particles confined inside a rectangular box is considered. Using the grand‐canonical formalism and performing the summations over the one‐particle states numerically, the temperature dependence of the chemical potential, of the average energy and of the heat capacity are derived before the thermodynamic limit is taken. These mesoscopic quantities differ from the corresponding thermodynamic quantities only quantitatively but are qualitatively similar. © 2013 Wiley Periodicals, Inc.  相似文献   

15.
The influence of miscibility on the transport properties of polymer electrolyte blends composed of a proton conductor and an insulator was investigated. The proton‐conductive component in the blends was sulfonated poly(ether ketone ketone) (SPEKK), while the nonconductive component was either poly(ether imide) (PEI) or poly(ether sulfone) (PES). The phase behavior of PEI‐SPEKK blends was strongly influenced by the sulfonation level of the SPEKK. At low sulfonation levels (ion‐exchange capacity (IEC) = 0.8 meq/g), the blends were miscible, while at a slightly higher level (IEC = 1.1 meq/g), they were only partially miscible and for IEC ≥ 1.4 meq/g they were effectively immiscible over the entire composition range. The PES‐SPEKK blends were miscible over the entire range of SPEKK IEC considered in this study (0.8–2.2 meq/g). At high IEC (2.2 meq/g) and at low mass fractions of SPEKK (<0.5), the miscible blends (PES‐SPEKK) had higher proton conductivities and methanol permeabilities than the immiscible ones (PEI‐SPEKK). The opposite relationship was observed for high mass fractions of SPEKK (>0.5). This behavior was explained by the differences in morphology between these two blend systems. At low IEC of SPEKK (0.8 meq/g), where both PEI‐SPEKK and PES‐SPEKK blend systems exhibited miscibility, the transport properties were not significantly different. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2253–2266, 2006  相似文献   

16.
The miscibility of poly (styrene-co-4-vinylphenyldimethylsilanol) (ST-VPDMS) and poly (n-butyl methacrylate) (PBMA) blends has been investigated by means of DSC and FT-IR spectroscopy. It was found that miscible blends were formed only for the copolymers containing 9–34 mol % 4-vinylphenyldimethylsilanol (VPDMS). The glass transition behavior of the miscible blends was analyzed by recently proposed equations in terms of the physical meaning of the fitting parameters. The results of FT-IR study were found to be fully consistent with the observation of the miscibility window obtained from glass transition temperature measurements. Quantitative information concerning intermolecular hydrogen bond interaction in the carbonyl stretching vibration region of the miscible blends was obtained by curve-fitting method. © 1994 John Wiley & Sons, Inc.  相似文献   

17.
18.
The dynamic mechanical properties of blends of diglycidyl ether of bisphenol-A-based epoxy resin and internally epoxidized polybutadiene rubber have been studied. It is shown that the influence of the composition of the continuous phase and of the dispersed phase can be studied not only from the variations of the glass transition temperature but also from the changes in the apparent enthalpy of activation associated with this transition. As the initial rubber content increases, the composition of the dispersed phase remains practically constant while more rubber is able to dissolve in the continuous phase. Analysis of the rubbery plateau region reveals that the shear modulus of the blends is not much affected by the presence of dissolved rubber in the continuous phase but strongly depends on the volume fraction of dispersed phase. This volume fraction can be obtained from the relative drop in shear modulus after modeling the results with the Kerner equation. The results compares well with independent measurements by scanning electron microscopy. © 1994 John Wiley & Sons, Inc.  相似文献   

19.
杨喜平 《化学教育》2016,37(12):14-17
在二组分理想溶液系统的气、液平衡的教学中运用了互动-探究的教学法,具体教学过程为:制定互动-探究的教学目标;通过设置互动环节,启迪学生深层次学习;通过对比分析,探讨结论,采用互动-探究式教学,能深刻挖掘所学内容在基本概念、基本理论方面的生长点等,取得了非常好的教学效果。  相似文献   

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