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1.
利用电导法研究了烷基三甲基溴化铵表面活性剂(CnTAB,n=12,14,16),即十二烷基三甲基溴化铵(DTAB),十四烷基三甲基溴化铵(TTAB)和十六烷基三甲基溴化铵(CTAB),在混合极性溶剂乙二醇/水(体积分数0~40%)中的胶团化行为。考察了温度对胶团形成的影响,应用相分离模型估算了三个表面活性剂的胶团热力学参数。结果表明临界胶团浓度(cmc)和反离子解离度(α)都随乙二醇组分的增加而增大。在乙二醇/水混合溶剂中胶团形成的标准吉布斯自由能相差很小,混合焓都是负值,而混合熵都为正值,说明焓-熵补偿效应在胶团形成中起主导作用。  相似文献   

2.
以光催化活性高的多酸阴离子CeW_(10)O_(36)~(9-)、不同结构阳离子表面活性剂为构筑基元,通过水/氯仿两相静电包埋技术制备了一系列表面活性剂@多酸复合物,并利用傅里叶红外光谱(FTIR)、热重分析(TGA)对复合物的组成及结构进行分析;以甲基橙为光催化降解底物分子、表面活性剂@多酸复合物为催化剂,考察不同表面活性剂、催化剂用量、甲基橙浓度、有机染料对光催化降解率的影响;不同表面活性剂@稀土多酸复合催化剂的光催化活性顺序为DTAB(十二烷基三甲基溴化铵)@CeW_(10)TTAB(十四烷基三甲基溴化铵)@CeW_(10)CTAB(十六烷基三甲基溴化铵)@CeW_(10)OTAB(十八烷基三甲基溴化铵)@CeW_(10)DODA(双十八烷基二甲基溴化铵)@CeW_(10)。  相似文献   

3.
应用表面张力法、NMR法和ESR法研究了全氟辛酸钠(SPFO)-十二烷基三甲基溴化铵(DTAB)混合体系水溶液胶束形成及混合胶束的微环境性质(微观粘度、微观极性等).结果表明,碳氟表面活性剂碳氟链和碳氢表面活性剂碳氢链之间具有强烈的相互作用,DTAB与SPFO在水溶液中形成混合胶束.DTAB与SPFO混合体系的表面活性高于单一的DTAB或SPFO,混合体系cmc较单一的DTAB和SPFO低.DTAB与SPFO混合胶束的微观粘度较DTAB胶束的大,而微观极性较DTAB的小.  相似文献   

4.
应用表面张力法、NMR法和ESR法研究了全氟辛酸钠(SPFO)-十二烷基三甲基溴化铵(DTAB)混合体系水溶液胶束形成及混合胶束的微环境性质(微观粘度、微观极性等)。结果表明, 碳氟表面活性剂碳氟链和碳氢表面活性剂碳氢链之间具有强烈的相互作用, DTAB与SPFO在水溶液中形成混合胶束。DTAB与SPFO混合体系的表面活性高于单一的DTAB或SPFO, 混合体系cmc较单一的DTAB和SPFO低。DTAB与SPFO混合胶束的微观粘度较DTAB胶束的大, 而微观极性较DTAB的小。  相似文献   

5.
通过小角X-射线散射技术,研究了十二烷基三甲基溴化铵(DTAB)、十四烷基三甲基溴化铵(TTAB)、十六烷基三甲基溴化铵(CTAB)三种阳离子季铵盐表面活性剂在Ch G和ChEG低共熔溶剂中的胶束行为并表征胶束的结构。研究结果表明,表面活性剂烷基链长及低共熔溶剂类型对胶束结构影响较大,而温度对其影响较小。所得结果为低共熔溶剂中有序分子聚集体的构建提供参考。  相似文献   

6.
本文通过荧光光谱法、紫外-可见吸收光谱法和透射电镜并结合电导率测定分别研究了水中卵清蛋白与阴离子表面活性剂十二烷基硫酸钠(SDS)和阳离子表面活性剂十二烷基三甲基溴化铵(DTAB)和十六烷基三甲基溴化铵(CTAB)之间的相互作用。研究结果表明卵清蛋白可以增加SDS和CTAB的临界胶束浓度,但对DTAB的临界胶束浓度没有影响。阴离子表面活性剂可以使卵清蛋白构象完全伸展,而阳离子表面活性剂却不具备此种作用。表面活性剂单体与卵清蛋白的相互作用强于表面活性剂胶束与卵清蛋白的相互作用。  相似文献   

7.
合成了N-十二烷基-N-(2-羟乙基)-N,N-二甲基溴化铵、N-十四烷基-N-(2-羟乙基)-N,N-二甲基溴化铵和N-十六烷基-N-(2-羟乙基)-N,N-二甲基溴化铵等3个季铵盐阳离子表面活性剂. 研究了它们以及N-十六烷基-N,N,N-三甲基溴化铵(CTAB)与阴离子表面活性剂十二烷基硫酸钠(SDS)复配系统在313.15 K时的双水相行为. 复配系统在两个非常狭窄的区域能形成双水相, 两相区近似以等摩尔线为中心对称分布, 随着阳离子表面活性剂碳链长度的增长, 富含阳离子表面活性剂的双水相区向阴阳离子表面活性剂摩尔比减小的方向稍有移动.  相似文献   

8.
双子表面活性剂溶液的表面活性的研究   总被引:8,自引:0,他引:8  
研究了阳离子型双子表面活性剂,二溴化-N,N'-二(二甲基烷基)乙(已)二铵,以及它们与阴离子表面活性剂十二烷基苯磺酸钠(SDBS)复配体系的表面活性,测定上述体系的平衡态表面张力。结果表明:双子表面活性剂的表面活性大大高于十二烷基三甲溴化铵(DTAB);对于两种双子表面活性剂,其表面活性和表面张力时间效应受其联接基团的影响远大于其烷基链的影响。双子表面活性剂与SDAB复配,其协同效应不如DTAB。动表面张力测定得到它们的各种参:t~i,t~m,γ~m,t*和n等值,结果表面双子表面活性剂的瞬时活性也高于DTAB。  相似文献   

9.
不同类型表面活性剂对纳米SiO2流体粘度的影响   总被引:1,自引:0,他引:1  
系统地研究了不同类型的表面活性剂对低浓度纳米SiO2流体粘度的影响规律,并在此基础上深入探讨了不同碳链长度的阳离子和非离子表面活性剂对纳米SiO2流体粘度的影响。结果表明,阴离子表面活性剂十二烷基苯磺酸钠(SDBS)对纳米流体粘度的影响较小,其相对粘度值维持在1.23左右;而阳离子表面活性剂十四烷基三甲基溴化铵(TTAB)、十六烷基三甲基溴化铵(CTAB)、十八烷基三甲基溴化铵(OTAB)、十六烷基氯化吡啶(CPC)、非离子表面活性剂OP-8、OP-10和两性离子表面活性剂DXS14、DXS18对纳米流体粘度的变化影响较大,其最大相对粘度值分别能达到3.42、1.82和8.87。同时也发现,阳离子表面活性剂碳链越长,纳米流体最高粘度值越大,且纳米流体最高粘度所对应的表面活性剂浓度均在其临界胶束浓度值附近。  相似文献   

10.
分别以2种阴离子表面活性剂(SDS、SDBS)、3种季铵盐阳离子表面活性剂(CTAB、TTAB、DTAB)和2种季铵盐型双子表面活性剂(12-3-12、12-4-12)修饰碳糊电极。通过原子力显微镜、接触角以及分析物在电极表面的电化学行为探讨了不同表面活性剂在电极表面的吸附情况,推测在浓度大于临界胶束浓度(CMC)时,季铵盐型阳离子表面活性剂CTAB、TTAB、12-3-12和12-4-12在碳糊电极表面形成了圆柱形的表面胶团,而DTAB和SDS可能是饱和单分子层吸附。以BPA为分析物,研究了表面活性剂修饰电极对BPA的电化学增敏机理,结果表明修饰电极对双酚A(BPA)的电化学增敏作用主要是因为表面胶团对BPA的增溶作用,表面活性剂和BPA间的阳离子-π作用是表面胶团增溶BPA的主要原因。  相似文献   

11.
The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.  相似文献   

12.
非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。  相似文献   

13.

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

  相似文献   

14.
Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.  相似文献   

15.
In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.  相似文献   

16.
Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, Mo, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

17.
翟宗玺  刘树深  夏树屏 《化学学报》1990,48(10):946-950
用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。  相似文献   

18.
19.
The enthalpies of solution of several oxosulfides of rare-earth elements and the high-temperature enthalpies of oxosulfides and oxosulfates of lanthanum and yttrium were measured using solution calorimetry and high-temperature microcalorimetry techniques. Standard enthalpies of formation and some thermodynamic properties of oxosulfides and oxosulfates were calculated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2 pp. 294–297, February, 1997.  相似文献   

20.
设计了铁的锈蚀实验,说明了铁钉的处理方法,增加了温度、酸、碱的影响条件,实现了铁跟蒸馏水及空气中氧气快速反应而生锈,使实验在5 min左右就能够得到准确的结果。  相似文献   

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