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1.
本工作研究了十二烷基三羟乙基氯化铵(C_(12)NE)和十二烷基硫酸钠(C_(12)SNa),十二烷基三羟乙基氯化铵(C_(12)NE)和八烷基硫酸钠(C_8SNa)两体系的正、负离子表面活性剂混合溶液的表面吸附和胶团形成。用液体积法测定了一系列不同比例C_(12)NE~C_(12)SNa、C_(12)NE~C_8SNa混合水溶液在25℃、总离子强度为0.1000m时的表面张力,用Gibbs公式计算了总吸附量和分吸附量。另外,初步探索了混合溶液的某些胶团性质。结果表明: 1.正、负离子表面活性剂混合物具有较高的表面活性。等摩尔C_(12)NE~C_(12)SNa混合溶液的cmc为4.0×10~(-5)m,分别为单个C_(12)SNa、C_(12)NEcmc的1/208和1/240。等摩尔C_(12)NE~C_8SNa混合溶液的cmc为7.4×10~(-4)m,分别为单个C_(12)NE、C_8SNa cmc的1/13和1/189。 2.对于碳原子数相同(如C_(12)NE~C_(12)SNa)的正、负离子表面活性剂的混合溶液,不论其混合比例如何,在饱和吸附时,总吸附量接近6.7×10~(-10)mol/cm~2,吸附层中也是近于等摩尔吸附,每个分子所占面积约为25A~2,这是由于正、负表面活性剂离子之间相互强烈作用导致表面层中成紧密排列结构。 碳原子数不同的正、负离子表面活性剂(如C_(12)NE~C_8SNa)的混合溶液,不论其比例如何,其饱和吸附时总吸附量接近5.4×10~(-10)mol/cm  相似文献   

2.
本文研究了七元瓜环Q[7]与双子型表面活性剂12-2-12在水溶液中发生的相互作用,探讨了瓜环对表面活性剂性能的影响。结果表明:Q[7]和12-2-12可以形成2∶1的配合物;当存在Q[7]时,表面活性剂的临界胶团浓度(cmc)和最低表面张力(γ_(cmc))增大,降低表面张力的效率(pC_(20))和表面压(Π_(cmc))下降,表面活性和发泡能力降低;同时,表面活性剂的饱和吸附量(Г_(max))降低,最小分子横截面积(A_(min))增大,表面活性剂在溶液表面排列更疏松。瓜环对表面活性剂的性能具有重要影响。  相似文献   

3.
以四氢呋喃为溶剂,在氧化镁存在下,用棕榈酰氯与二甘醇胺反应合成了棕榈酸二甘醇酰胺,产率可达95%。产品经红外光谱,质谱和核磁表征,证实为目标产物。棕榈酸二甘醇酰胺具有优良的表面活性和耐盐性,45℃下临界胶束浓度为1.48×10-5mol/L,γcmc为29.7 mN/m,在水/空气界面的饱和吸附量达到4.0×10-10mol/cm2,当浓度为0.5 mmol/L时在质量浓度高达1 800mg/L的Ca+2水溶液中不沉淀。将棕榈酸二甘醇酰胺作为主表面活性剂,通过与两性表面活性剂复配,45℃下能在总表面活性剂质量分数为0.05%~0.5%的范围内将大庆原油/地层水的平衡界面张力降到10-3mN/m数量级,无需添加任何碱、中性电解质或助表面活性剂。  相似文献   

4.
采用铂金板法测定羧酸盐型Gemini表面活性剂(CGS-12)的表面张力曲线,考察了溶液pH、无机盐以及醇的加入对CGS-12表面性能的影响规律,采用滴体积法测定CGS-12的动态表面张力曲线,并探讨其动态吸附机理。结果表明,CGS-12的临界胶束浓度(cmc)和临界表面张力(γcmc)分别为80μmol/L和26.37mN/m;当溶液pH值为6时,CGS-12的表面张力值最低,且其表面张力随溶液pH的变化具有可逆性;CGS-12的表面张力随NaCl浓度的增大先减小后增大,CGS-12的表面张力随着CaCl2浓度的增大先增大后基本不变;CGS-12的表面活性随着正丁醇浓度的增大而增加,随着醇碳链长度的增加,cmc的变化并不明显,但γcmc却明显降低;动态表面张力结果表明,CGS-12浓度较低时,吸附初期为扩散控制,吸附后期为混合动力学控制,浓度较高时,吸附初期曲线难以模拟,吸附后期为混合动力学控制。  相似文献   

5.
采用单油酸甘油酯和马来酸酐为原料,以丙酸钠为催化剂,经酯化、碳酸氢钠溶液中和,合成了单油酸甘油酯琥珀酸单酯羧酸钠盐阴离子表面活性剂。通过单因素实验确定了适宜的酯化反应工艺条件:马来酸酐与单油酸甘油酯摩尔比为2∶1;反应时间为1h;反应温度为90℃;催化剂用量10%(相对于单油酸甘油酯的摩尔分数)。单油酸甘油酯琥珀酸单酯羧酸钠盐的表面活性剂性能测试结果表明:该表面活性剂具有优良的性能,25℃时临界胶束浓度ccmc为1.37×10-4mol/L,对应的表面张力γcmc为33.9mN/m,饱和吸附量Γmax为2.52×10~(-10) mol/cm~2,分子最小吸附面积Amin为0.66nm~2,降低表面张力效率因子p(c20)为4.41,泡沫体积为300mL,泡沫稳定性为96.7%,乳化分水时间为144.5s.随着温度升高,ccmc,γcmc和Γmax均减小,Amin和pC20增大,发泡能力增强。  相似文献   

6.
可降解型阳离子表面活性剂的合成及结构表征   总被引:1,自引:0,他引:1  
文章以自制的缩水甘油硬脂酸酯(GS)和三甲基氯化铵为原料,经一步反应合成含酯基可降解型阳离子表面活性剂(CMESA)。通过元素分析和红外光谱等分析方法确定其化学结构。用乙醇为溶剂,pH为9-10,温度为45℃时反应1h后得到92%的产物.滴体积法测表面张力(γ)和临界胶团浓度(cmc),在25℃下其cmc为5.4×10~(-5)mol·L~(-1),在cmc时的γ_(cmc)= 40.20 mN·m~(-1).  相似文献   

7.
用脂肪酸制备了乙撑双(二甲基)季铵盐基双脂肪酸甲酯(B)及乙撑双(二甲基)季铵盐基双脂肪酸钠盐(C),用红外光谱对其结构进行了表征.经测定,分别用十二酸和十四酸制备的B1和B2其临界胶束浓度(cmc)分别为1.4×10-4和2.2×10-4 mol/L,其表面张力(γcmc)分别为30.5和37.8 mN/m;C1和C2的cmc分别为7.8×10-5和3.0×10-4 mol/L,γcmc分别为28.9和36.9 mN/m.结果表明,与普通表面活性剂相比,双子表面活性剂B1和B2的cmc要低1~2个数量级,γcmc也低了2~9个mN/m;C1、C2的cmc仅为普通表面活性剂的1/60~1/230,而γcmc相差不大.  相似文献   

8.
以芘(Py)为荧光探针,氯化十六烷基吡啶(CPC)为猝灭剂,芘的饱和水溶液为溶剂配制的新型二聚季铵盐表面活性剂溶液,根据芘的荧光强度比(I373/I383)随表面活性剂水溶液浓度的变化而变化,用稳态荧光探针法测定了该二聚季铵盐表面活性剂的临界胶束浓度(cmc)、胶束聚集数(N).结果表明,在25 ℃时该二聚季铵盐表面活性剂的cmc为0.711 mmol·L-1,与用表面张力法测定的结果基本一致.在猝灭剂氯化十六烷基吡啶浓度为0.16~0.24 mmol·L-1(25 ℃),表面活性剂溶液浓度是其临界胶束浓  相似文献   

9.
以葡萄糖和烷基胺(正辛胺、十二胺、十六胺)为原料制备了一系列不同链长的糖基双子表面活性剂,以傅里叶红外光谱和核磁共振氢谱表征了产物的结构.采用悬滴法和改进的Ross-Miles法对产物的表面张力、起泡性能进行了测试.结果表明,糖基双子表面活性剂可以将表面张力降低到33.038.6 mN/m,其临界胶束浓度在0.0738.6 mN/m,其临界胶束浓度在0.070.45 mmol/L范围内;同时,产物(A)和(B)具有良好的起泡性和稳泡性.这说明具有独特二聚结构的糖基双子表面活性剂有着更高的降低表面张力的能力和效率,表现出比传统线性表面活性剂优越的表面活性.  相似文献   

10.
混合表面活性剂在硝酸铵饱和溶液中的物化性质   总被引:2,自引:0,他引:2  
该文测定并比较了阴离子表面活性剂(C12H25SO4Na)与阳离子表面活性剂(C18H37NH+3CH3COO-)混合体系在硝酸铵饱和溶液中的一系列物理化学性质;计算了混合表面活性剂在硝酸铵饱和溶液中的饱和吸附量以及分子间作用参数。结果表明,混合表面活性剂在硝酸铵饱和溶液中的稳定性、表面活性、起泡性及饱和吸附量,均优于其组成的单一表面活性剂体系;理论计算表明,等摩尔混合表面活性剂分子间作用参数的绝对值大于非等摩尔体系;同时讨论了阴、阳离子表面活性剂之间的相互作用机理  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

18.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

19.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

20.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

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