共查询到20条相似文献,搜索用时 62 毫秒
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用新型泵式沸点仪测定了在100kPa下甲醇-乙酸、甲醇-丙酸、乙酸-丙酸3个二元体系以及甲醇-乙酸-丙酸三元系在不同液相组成时的沸点,并用间接法T-p-x(温度、压力和液相摩尔分数)推算了3个二元体系的汽相平衡组成。3个二元体系活度系数分别用Wilson模型、NRTL模型、Margules模型和van Laar模型进行关联,用最小二乘法求出了它们的液相活度系数模型参数,同时,用这些模型参数来计算它们的汽相摩尔分数。所得的液相活度系数来计算3个二元体系的过量吉布斯自由能函数,且所研究的所有体系中各组分之间不存在共沸点。用3个二元体系Wilson模型参数对所测的三元体系数据进行关联,建立该系统汽液平衡的热力学模型并计算平衡时的汽相摩尔分数和泡点温度。由面积积分法检验这些模型参数计算的3个二元体系相平衡数据,得到很好的热力学一致性。 相似文献
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草甘膦原药与50%KOH水溶液反应得到草甘膦钾盐水溶液,通过向其中加入适量甲醇使固体草甘膦钾盐从溶液中析出,从而实现其有效分离与提纯。选择甲醇、乙醇和乙二醇对醇析效果进行了比较,并研究了醇析温度和醇用量对固体草甘膦钾盐品质的影响。试验结果表明,甲醇为该工艺最适宜的醇析溶剂,醇析温度升高可提高产品纯度,而甲醇用量则是影响产品收率的主要因素。 相似文献
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二元表面活性剂混合水溶液的分子间相互作用——结构和温度对混合吸附的影响 总被引:1,自引:0,他引:1
通过表面张力的测定,用Gibbs吸附定理和Rosen以正规溶液理论为基础导出的吸附层组成公式,研究了十二烷基聚氧乙烯-3磺酸钠(C12E3)S与POE非离子表面活性剂(C10E5,C10E7)的二元体系在25℃和40℃下的纯水溶液中的表面吸附:并用分子间相互作用β参数和交换能ε讨论了吸附层中分子间的相互作用。结果表明:(1)非离子POE在混合吸附层中优先吸附,即使在溶液中的摩尔分数很低时(≈0.1),POE在表面层的摩尔分数也大于0.5。(2)两表面活性剂组分在吸附层中相互作用为吸引力。(3)POE的EO数增加,表面层中分子间作用力增强,POE的吸附趋势减弱,(4)温度升高,POE和C12E3S的吸附能力均降低,同时吸附层中分子间作用力减弱。 相似文献
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《化学工程》2016,(5):43-47
本实验采用平衡法测定了293.15—353.15 K下甘氨酸在水中的溶解度,及在不同比例甲醇水溶液中293.15 K至溶液沸点甘氨酸的溶解度。实验结果表明,甘氨酸的溶解度随甲醇摩尔分数的增加而下降,随温度的升高而逐渐增大。分别采用Apelblat方程,λh方程和(CNIBS)/Redlich-Kister方程对溶解度数据进行关联,结果表明:Apelblat方程和λh方程均能较好地表达甘氨酸在甲醇-水体系中的溶解度。(CNIBS)/Redlich-Kister方程能准确地关联溶剂中甲醇的摩尔分数x_2与甘氨酸溶解度x1的关系。利用van't Hoff方程估算得到甘氨酸在甲醇-水中的溶解熵和溶解焓,说明甘氨酸在甲醇-水体系中的溶解过程是吸热和熵驱动的。实验得到的溶解度数据和关联为其工业结晶过程设计和工艺优化提供了理论依据。 相似文献
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1 前言
在纳米炭黑、碳纳米管以及纳米SiO2、TiO2等无机纳米粒子表面上,当暴露出活性基团时,就可能与聚合物进行接枝反应。 相似文献
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方便并具有基本的清洁能力已经成为现代硬表面清洗剂一个重要的诉求点。此外,考虑到大量的家用产品是由各种塑料制成的,现代硬表面清洗剂也要求对表面安全并具有保护效果。研究了如何设计使用方便并对表面安全的硬表面清洗剂配方。 相似文献
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An experimental investigation of the effect of surface energetic heterogeneity on surface diffusion using Vycor and Graphon and as gases ethane, propylene, nitrogen, and helium confirms published reports that surface diffusion proceeds more rapidly on the energetically homogeneous Graphon surfaces. Activation energies for diffusion are found to be about the same for Vycor and Graphon; thus, it is postulated that a major factor in the difference is surface roughness. A comparison of surface diffusion models shows that Fick's Law correlated results about as well as a hydrodynamic model. Both models fail to allow adequately for surface coverage. A comprehensive form of Fick's Law for surface diffusion is proposed. 相似文献
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In this paper, an environmentally friendly etching system containing MnO2–H3PO4–H2SO4 colloid was used to investigate surface etching for ABS- polycarbonate (PC/ABS) as a replacement for conventional chromic acid etching solutions. In order to obtain a good etching performance, a swelling system, containing tetramethylammonium hydroxide (TMAH), and 1-Methyl-2-pyrrolidinone (NMP), was used to investigate the surface swelling for PC/ABS resin. Then the effects of H2SO4 concentration, and etching time on the surface topographies and surface contact angle were investigated. After the optimal swelling and etching treatment, the surface contact angle of PC/ABS resin decreased from 95.7° to 28.3°, and the adhesion strength between electroless copper film and PC/ABS resin reached to 1.04 KN m−1. The FT-IR spectra and XPS analyses indicated that hydroxyl and carboxyl groups formed on the PC/ABS surface as a result of the swelling and etching treatment, which improved the adhesion strength between PC/ABS substrate and elctroless copper film. 相似文献
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P. D. Sarkisov E. G. Vinokurov N. B. Gradova E. S. Babusenko V. V. Bondar’ 《Theoretical Foundations of Chemical Engineering》2013,47(1):14-18
The possibility of implementing a new scientific field—bioengineering of glass surface—was considered. The growth of different diatom algal cultures and the density of their immobilization on the surface of glass were studied. The experimental results that confirm the possibility of the bioengineering formation of glass surface micro- and nanostructures using diatom algae were represented. 相似文献
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Alien G. Sault 《Catalysis Letters》1994,29(1-2):145-158
Calculations of expected X-ray photoelectron spectroscopy intensity ratios for both homogeneous and segregated bimetallic particles demonstrate that a minimum particle size exists, below which reliable differentiation between homogeneous alloy particles and particles in which one component has segregated to the surface cannot be made. This minimum particle size varies between 3 and 8 nm depending on the specific metal combination in question. In cases of partial segregation of one component, the minimum particle size is even larger. The implications of these results for the study of surface segregation in supported bimetallic catalyst particles are discussed.This work was performed at Sandia National Laboratories for the US Department of Energy under contract DE-AC04-94AL85000. 相似文献
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《日用化学工业》2015,(8)
以自制硬脂酸甲基二乙醇胺双酯和γ-氯丙基甲基二甲氧基硅烷为原料,制备了酯基有机硅季铵盐(Si-QAS)。通过傅里叶红外光谱和核磁共振氢谱对产物的结构进行了表征。采用响应面分析法通过建立硬脂酸甲基二乙醇胺双酯的转化率与各因素之间的Central-Composite数学模型,对Si-QAS的合成工艺进行了优化。Si-QAS的最优制备工艺条件为:反应时间和微波功率分别为20.89 min和600 W,溶剂二甲基亚砜用量占体系总质量的33.1%。通过表面张力法测得25℃下产物水溶液的临界胶束浓度(cmc)为2.36×10-4mol/L,相应的表面张力(γcmc)为24.25 m N/m,胶束化标准自由能为-30.7 k J/mol,吸附化标准自由能为-56.0 k J/mol。 相似文献