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1.
主要从3个方面介绍了二组分平衡体系的T-x相图。一是简单相图的介绍;二是简单相图的组合;三是实际体系复杂相图的认识。从而可以让学生理解和掌握相平衡中的二组分体系的气-液、液-液和液-固平衡的T-x相图,并为实际应用打下良好的基础。 相似文献
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在298.15 K下使用目测法和浊度法绘制了1-丁基-3-甲基咪唑四氟硼酸盐([Bmim]BF4)+十二烷基苯磺酸钠(SDBS)+水体系的三元相图,得到了狭窄的靠近离子液体和水一侧的双水相(ATPS)区域。从三元相图的双水相区域周围选择不同组成的样品,用等温滴定微量热(ITC)测定了样品中逐滴加入三次水后体系热量的变化,发现随样品中水含量的增加,量热曲线会出现一个不太明显的吸热和放热过程,且与三元相图中双水相的形成和消失的位置完全吻合,这说明ITC对于双水相体系的热力学研究是一种可行且有效的方法。对本文体系双水相的研究结果表明,双水相的形成是吸热过程(ΔH > 0),而消失是放热过程(ΔH < 0),由于双水相的形成是等温等压下的热力学自发过程(ΔG < 0),因此可以判断该体系双水相的形成是一个熵驱动过程,而消失是一个熵焓共驱过程。 相似文献
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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。 相似文献
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基于小分子醇双水相体系和离子液体双水相体系,建立了正丙醇与亲水性离子液体1-丁基-3-甲基咪唑四氟硼酸[Bmim]BF4和(NH4)2SO4形成的二元双水相体系萃取盐酸多西环素的新方法。考察了(NH4)2SO4含量、正丙醇用量、pH值、离子液体含量以及盐酸多西环素含量对盐酸多西环素分配行为的影响。结果表明:当醇和离子液体二元双水相体系的pH值在4.0~5.0范围内,(NH4)2SO4含量为34%,且盐酸多西环素的质量浓度在25~95 mg/L之间时,该体系对盐酸多西环素的萃取率可达90.26%~95.71%,分配系数可达62.452~149.401。 相似文献
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正负离子表面活性剂与高聚物混合双水相体系的相行为及蛋白质的分配 总被引:10,自引:0,他引:10
报道了由正负离子表面活性剂与高聚物混合溶液形成的一种可用于蛋白质的分离及分析的新型双水相萃取体系.研究了正负离子表面活性剂(溴化十二烷基三乙铵/十二烷基硫酸钠)分别与葡聚糖和聚乙二醇混合双水相体系的形成规律、相行为及牛血清蛋白和溶菌酶在双水相体系中的分配.通过在高聚物分子中接上亲和配基,研究蛋白质在双水相体系中的亲和分配.结果表明,在该体系中,表面活性剂与高聚物分别富集于不同相中.升高温度及加入无机盐均可促进双水相体系的形成,不同蛋白质可分配于不同的相中.亲和配基的引入极大地增强了蛋白质分配的选择性. 相似文献
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外加盐作用形成的正负离子表面活性剂双水相 总被引:1,自引:0,他引:1
癸基三乙基溴化铵-癸基磺酸钠(C10NE-C10SO3)等摩尔混合均相体系(即使在表面活性剂总浓度高达0.2 mol•L-1时仍然可形成稳定的均相溶液)在外加盐NaF、Na2SO4和Na3PO4的作用下可自发分离成两个水相(双水相).研究了该类双水相体系的形成、相行为及其对牛血清蛋白(BSA)的分配,并与普通的正负离子表面活性剂混合双水相体系进行了比较.结果表明,该类双水相体系克服了普通的正负离子表面活性剂混合双水相体系的一些不足,具有一些独特的优点.该类双水相体系的相行为可以通过外加盐进行调控,通过外加盐的种类来调控和优化BSA的分配行为.图1表2参8 相似文献
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建立了反相高效液相色谱(RP-HPLC)定量检测离子液体溴化1-乙基-3-甲基咪唑-水体系中青蒿素含量的方法.检测条件为:室温(25±1)℃,C18反向柱(250 mm×4.6 mm, 5 μm),以V(甲醇): V(0.01 mol/L HAc-NaAc溶液,pH=5.9)=60: 40混合溶液为流动相,流速0.5 mL/min,检测波长为260 nm.青蒿素浓度在5~30 mg/L之间线性回归方程为y=2.20326×107x-30928.7,相关系数r=0.9990.本方法回收率为100 2%;相对标准偏差(RSD)为0.42%. 相似文献
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G. R. Pazuki R. Azimaie V. Taghikhani 《Journal of Dispersion Science and Technology》2013,34(4):534-539
In this work, the proposed model by Pazuki et al. based on the Local Composition Concept (LCC), has been used in correlating the vapor-liquid phase behavior of polymer solutions and the liquid-liquid phase behavior of aqueous two-phase systems. The Flory-Huggins model has been used as the combinatorial part of the proposed model, as well as the model proposed by Pazuki et al. was considered as the residual term. The proposed model has been used in correlating the vapor-liquid phase behavior for a number of PEG-Water systems at constant temperature. The results obtained from the proposed model have been compared with those obtained from the Poly-NRTL and the Poly-Wilson models. The results showed that the proposed model can accurately correlate the VLE data for PEG-Water systems. Also, the proposed model has been used to obtain phase behavior of aqueous two-phase systems for PEG-DEX-Water systems. The results obtained from the proposed model have been compared with those obtained from the UNIQUAC and the UNIQUAC-NRF models. The results showed that the proposed model can accurately correlate liquid-liquid phase behavior of aqueous two-phase systems than the UNIQUAC and the UNIQUAC-NRF models. 相似文献
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脂肪酸盐-烷基吡啶盐混合体系的双水相 总被引:4,自引:0,他引:4
研究了脂肪酸盐和烷基吡啶盐混合水溶液中双水相的形成规律和性质.考察了形成双水相的组成范围和烷基碳链长的影响。测定了两相的密度及化学组成.应用电子显微镜观察了两相的微观结构.结果表明,两相均存在囊泡结构.两相含水均在95%以上.上相为表面活性剂富集的囊泡絮凝相,浓度远远大干下相,相差均在二十倍以上.下相为含有分散的囊泡的表面活性剂稀溶液. 相似文献
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对辛基三甲基溴化铵(OTAB)与辛基硫酸钠(SOS)正、负离子混合表面活性剂水溶液的相行为进行了研究.在高浓度的溶液中,混合表面活性剂形成液晶相,随着混合摩尔比OTAB/SOS接近于1,液晶结构由六角相转层状相,同时夹杂少量沉淀物;在中等浓度时,任意混合摩尔比例下皆为均相透明溶液;在低浓度下,在很宽的OTAB/SOS混合摩尔比的范围,出现双水相,其中的表面活性剂稀薄相,为不同大小的胶团与囊泡组成的稀溶液,另一表面活性剂富集相中则为数密度很大的囊泡聚集体,富集相对油溶性染料的增溶作用比非富集相高得多. 相似文献
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利用双水相体系的温度诱导效应萃取甘草酸 总被引:11,自引:0,他引:11
利用双水相分配技术结合温度诱导效应提取甘草酸,研究甘草酸单铵盐在环氧乙烷-环氧丙烷共聚物(EOPO)/混合磷酸钾(KHP)体系中的分配行为,通过实验确定了最佳体系:EOPO L64浓度为28(wt)%,K2HPO4浓度为32(wt)%。甘草酸单铵盐最大总收率达68.4%,为工业上采用双水相技术提取干草酸提供了一种新途径。 相似文献
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Xueyan Zhao 《Journal of Dispersion Science and Technology》2013,34(8):1080-1085
The triblock copolymer poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (L64, PEO13PPO30PEO13) in 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF4]) can form lamellar liquid crystalline (Lα). The effect of apolar cyclohexane molecules on the Lα phase was investigated by using polarized optical microscopy (POM) and small-angle x-ray scattering (SAXS). The results of POM and SAXS show that a suitable amount of cyclohexane can contribute to the formation of lamellar liquid crystals, and the ordering of Lα phase is increased. For comparison, the effect of polar water on Lα phase was explored. After adding water, both EO groups and [BF4]– anion can form hydrogen bonds with water molecules, which weakens the electrostatic interactions between L64 and [Bmim][BF4] and therefore the ordering of lamellar structures is destroyed. 相似文献
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一种用于鸡蛋中氯霉素残留测定的吡啶类离子液体双水相体系 总被引:5,自引:0,他引:5
建立了由亲水性离子液体N-乙基吡啶溴化盐([Epy]Br)和K2HPO4形成的双水相体系对鸡蛋中痕量氯霉素(CAP)检测的高效液相色谱方法.优化了离子液体[Epy]Br和K2HPO4成相的条件,研究了萃取CAP的最佳体系.采用混合溶液(pH=7磷酸盐溶液,NaCl溶液,甲醇)提取样品,离子液体双水相体系富集,V(甲醇):V(水)=30:70为流动相,流速1.0 mL/min,UV检测器,检测波长278 nm,柱温25 ℃,进样量20 μL.对鸡蛋中氯霉素残留进行了测定,在0.05~15 mg/L范围内,CAP的响应峰面积与其相应浓度呈良好相关性(r=0.9994).不同浓度的回收率为90.3%~101.7%,相对标准偏差为1.7%~2.6%.本该法检测鸡蛋中氯霉素残留具有干扰小、速度快、灵敏度高等优点.最低检出限为1 μg/kg. 相似文献
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采用等温溶解法研究了三元体系H3BO3 - MgCl2 - H2O在308.15 K和323.15 K的稳定相平衡;测定了上述体系液相中各组分的平衡溶解度及液相密度,并绘制了相应相图和平衡溶液密度组成图.结果表明,该体系在308.15 K和323.15 K时有一个共饱点、两条饱和溶解度曲线和两个结晶相区,无复盐及固溶体... 相似文献
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V. de Zea Bermudez S.M. Gomes Correia M.M. Silva S. Barros M.J. Smith R.A. Sá Ferreira L.D. Carlos C. Molina S.J.L. Ribeiro 《Journal of Sol-Gel Science and Technology》2003,26(1-3):375-381
Di-urea cross-linked poly(oxyethylene)/siloxane hybrids, synthesized by the sol-gel process and containing a wide concentration range of potassium triflate, KCF3SO3, have been analyzed by x-ray diffraction and differential scanning calorimetry. The pseudo-phase diagram proposed has been taken into account in the interpretation of the complex impedance measurements. The xerogels prepared are obtained as transparent, thin monoliths. At room temperature the highest conductivity found was 2 × 10–6 –1 cm–1. 相似文献
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Phase behavior and extraction ability of aqueous two-phase systems(ATPs) consisting of ionic liquids(ILs), Cs2CO3 and water were investigated in this paper. Four kinds of ionic liquids, namely, 1-amyl-3-methylimidazolium bromide([C5mim]Br), 1-hexyl-3-methylimidazolium bromide([C6mim]Br), 1-heptyl-3-methylimidazolium bromide ([C7mim]Br) and 1-octyl-3-methylimidazolium bromide([C8mim]Br), were examined to discuss the influence of alkyl groups. Binodal curves and tie-lines at 288.15, 298.15 and 308.15 K were obtained. The partitioning behavior for L-tryptophan in such ATPs was further investigated. The effect of temperature, pH, Cs2CO3 concentration and the structure of ionic liquids on the partitioning were discussed in detail. 相似文献
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