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1.
童爱军 《分析化学》1998,26(5):535-537
溴化十二烷基三乙胺(C12NE)和十二烷基硫酸钠(SDS)在一定条件下混合可以形成具有清晰界面的两个水相,称为阴阳离子型表面活性剂双水相。作者研究了利用该双水相萃取3种色氨酸衍生物和牛血清白蛋白的可能性.文中采用工作曲线校正扣除表面活性剂背景的影响,萃取结果准确可信。  相似文献   

2.
用Cadion-CPB光度法测定水中痕量阴离子表面活性剂   总被引:7,自引:0,他引:7  
研究了用于直接测定水相中痕量阴离子表面活性剂的新体系。在NaOH介质中,1-(4-硝基苯基)-3-[4-(苯基偶氮)苯基]-三氮烯(Cadion)与溴化十六烷基吡啶(CPB)形成离子缔合物(Cadion-CPB),当加入阴离子表面活性剂(AS)时,AS能定量置换出离子缔合物中的Cadion,而使吸光度下降。阴离子表面活性剂十二烷基苯磺酸钠(DBOSO3Na)、十二烷基磺酸钠(DOSO3Na)、十二烷基硫酸钠(DSO4Na)的表观摩尔吸光系数εmax分别为2.74×104、1.11×104、1.50×104L·mol-1·cm-1,服从比尔定律的范围分别为0~4.18、0~6.54、0~5.77mg·L-1。方法操作简便,用于测定合成水样及环境水样中痕量阴离子表面活性剂,结果满意。  相似文献   

3.
SYNTHESIS AND ̄(183)W NMR CHARACTERIZATI0N OF α-[P_2W_(15)O_(62)Ti_3] ̄(12-) HFTEROPOLYANIONSYNTHESISAND ̄(183)WNMRCHARACTERIZAT...  相似文献   

4.
RUTHENIUMCOORDINATIONCOMPOUNDSWITHPOLYPYRIDINESV.DNA-BINDINGSTUDIESOFRu(Ⅱ)COORDINATIONCOMPOUNDSWITH(2-PHENYL-)IMIDAZO[f]1,10-...  相似文献   

5.
UNUSUAL FORMATION OF ORGANO-NEODYMIUM AND -SAMARIUM CATIOHS AND X-RAY STRUCTURE OF[(MeOCH_2CH_2C_5H_4)_2Sm(thf)][Co(CO)_4]UNUSUA...  相似文献   

6.
ANEFFICIENTANDSTEREOSPECIFICSYNTHESISOF1-PALMITOYL-2-[(z,z,z)-9,12,15-LINOLENOYL]-SNGLYCEROPHOSPHOCHOLINE¥JieXIAandYongZhengH...  相似文献   

7.
STUDIESOFFAR-INFRAREDSPECTRAANDSOLID-SOLIDPHASETRANSITIONIN[n-C_nH_(2n+1)NH_3]_2CuX_4LAYERCOMPOUNDSWITHn=7-12,16¥NingGUO(Depart?..  相似文献   

8.
SYNTHESISANDCHARACTERIZATIONOFNOVELFUNCTIONALHOSTCOMPOUND2~[1]MONO-[6-O-(8-QUINOLYL)]-β-CYCLODEXTRINYuLIU;YiMinZHANG;YunTiCHE?..  相似文献   

9.
SOLID STATE SYNTHESIS AND CRYSTAL STRUCTURE OF THE CLUSTER COMPOUND[MwS_4Cu_3(PPh_3)_3Cl](Mw=0,56W+0.44M0)SOLIDSTATESYNTHESISAN...  相似文献   

10.
HYDROLYTICCLEAVAGEOFACMET-GLYPROMOTEDBYCIS-[Pd(MET)(D2O)2](NO3)2¥XiaoHuaCHEN;LongGenZHU;N.M.Kostic(CoordinationChemistryInsti...  相似文献   

11.
A new aqueous two-phase system is developed consisting of sodium perfluorooctanoate (SPFO) and dodecyltriethylammonium bromide (C12NE) cationic–anionic surfactant mixture. The two phases with a clear interfacial boundary formed when SPFO to C12NE molar ratio is 1.2:1 in the presence of 5% (v/v) nitric acid. The top phase is transparent and the bottom phase is opalescent. Extractions of dyes, porphyrin compounds with the two-phase system were performed. The results show that hydrophobic molecules were extracted into the surfactant-rich bottom phase with high extraction efficiencies. Positively charged porphyrins were extracted into the bottom phase with higher extraction efficiencies than negatively charged porphyrins. Such a new anionic surfactant two-phase system would be complementary to the C12NE–SDS (sodium dodecyl sulfate) cationic two-phase which has been proven to be effective for extractions of porphyrins with substituted groups like carboxyl or sulfonic acid groups.  相似文献   

12.
Akama Y  Tong A  Ito M  Tanaka S 《Talanta》1999,48(5):113-1137
An aqueous two-phase system of dodecyl triethylammonium bromide (C12NE, cationic surfactant) and sodium dodecyl sulfate (SDS, anionic surfactant) mixture is proposed for the extraction of some dyes and porphyrin compounds. Transparent two phase-systems are formed when the surfactant concentrations and C12NE/SDS ratios are in certain regions. In this study, the aqueous two phase-systems were prepared by mixing 0.1 mol l−1 C12NE and SDS with a molar ratio of 1.7:1.0. The results showed that negatively charged chlorophyll (sodium copper chlorophyllin) and positively charged dye (methyl violet) were efficiently extracted into the upper phase. The negatively charged methyl orange (pH>7) was moved into the upper phase mostly while amphoteric methyl orange (pH<3) was distributed in the two phases uniformly. Except for hydrophobic force, charge interaction between solute and surfactant also play an important role in the extraction process.  相似文献   

13.
正负离子表面活性剂复配系统   总被引:1,自引:0,他引:1  
南延青  郝力生 《化学进展》2007,19(9):1291-1300
正负离子表面活性剂复配系统,由于其带有相反电荷的离子头基间的强静电相互作用,具有强协同效应和高表面活性,在水溶液中可形成丰富的微观结构,表现出复杂的相行为。本文在相关研究的基础上,对于正负离子表面活性剂复配系统在表面(界面)性质,囊泡的制备及稳定性,虫状胶束的生成和性质,双水相系统的性质及其在萃取方面的应用,拟相分离模型、热力学胞腔模型、分子热力学模型及分子模拟等理论研究和作为模板合成纳米材料等方面的研究进展进行了综述。对于双水相系统的研究,指出了一些有待于进一步解决的问题。  相似文献   

14.
The effect of added salts (NaCl, KCl and NaBr) on the aqueous two-phase system (ATPS) formed in mixtures of Gemini(12-3-12, 2Br)/sodium dodecyl sulfate/polyethylene glycol has been investigated. Phase diagrams of the aqueous systems containing Gemini(12-3-12, 2Br), sodium dodecyl sulfate (SDS), polyethylene glycol(PEG) and a salt have been determined experimentally at 313.15 K. The results indicate that the addition of salts not only induces the appearance of ATPS-A (in which anionic surfactant is in excess), shortens the phase separation time, enlarges the regions of ATPS-C (in which cationic surfactant is in excess), and decreases the minimum concentration required for forming an ATPS, but also alters the matching between anionic and cationic surfactants. Extractive experiments also showed that these salts notably enhance the extraction ability of ATPS; the Gemini-rich phase exhibits prominent cohesive action with xylenol orange, regardless of whether or not it is the upper phase or the lower phase.  相似文献   

15.
表面活性剂的分子结构对蠕虫胶束的形成与性质有着重要影响。本文以十四酸和间苯三酚为起始原料,合成了一种三聚阴离子表面活性剂(2, 2', 2"-(苯基-1, 3, 5-三(氧))-三-十四酸钠,简写为Ph-TrisC14Na),并通过稳态和动态流变测试,研究了单组分的Ph-TrisC14Na和Ph-TrisC14Na/阳离子添加剂体系的粘弹性质。阳离子添加剂分别为正丁基三甲基溴化铵(C4TAB),正己基三甲基溴化铵(C6TAB)和正辛基三甲基溴化铵(C8TAB)。结果表明,依赖于独特的分子构型,Ph-TrisC14Na分子自身即可形成蠕虫胶束,使溶液表现出明显的粘弹性。阳离子添加剂的加入可进一步优化Ph-TrisC14Na的分子几何结构,促进蠕虫胶束更为快速地生长。随着阳离子添加剂疏水链长的增加,溶液的粘弹性显著增强,体系微结构对添加剂的敏感性也增加。对于50 mmol·L-1的Ph-TrisC14Na溶液来说,在C8TAB与Ph-TrisC14Na的摩尔比为0.5时,体系的零剪切粘度可达1535 Pa·s,蠕虫胶束的长度则达到4.0-7.5 μm。该体系体现出低聚表面活性剂在构筑表面活性剂粘弹溶液方面的优势,可拓展高粘弹性阴离子蠕虫胶束体系的研究范围。  相似文献   

16.
表面活性剂双水相界面性质的研究   总被引:2,自引:0,他引:2  
表面活性剂双水相是指正、负离子表面活性剂混合水溶液在一定浓度及混合比 范围内,自发分离形成的两个互不相溶的水相。前文报道了将其作为一种新型萃取 体系,用于生物活性物质的分离。目前有关其相行为、化学物质和生物大分子的分 配方面已有较多研究,但未见两相之间界面化学性质研究的报道。表面活性剂双水 相的形成是一种奇特的相分离现象,两个稀水溶液(含水量可高达99%以上)互不 相溶、平衡共存,其界面结构和界面张力必有其特殊性。  相似文献   

17.
通过引进新的溶液制备方法,以光散射、流变、电镜等方法研究了烷烃链长度不对称的阴/阳离子表面活性剂等摩尔混合体系,其中阳离子为二十二烷基三甲基溴化铵(C22TABr),阴离子是烷基羧酸钠(Cn-1COONa, n = 4, 6, 8, 10, 12, 14, 16).结果表明,烷烃链长度高度不对称时(C22/n4)生成了球状胶束,随着降低不对称度,聚集体向棒状、蠕虫状直至囊泡转变.在构成囊泡的体系中,随着降低链长不对称度,聚集体尺寸明显增大.机理分析表明,阴/阳离子对的几何形状决定了聚集体的形貌以及它们的转变.  相似文献   

18.
Zwitterionic mono- and bis-homoaromatics 2a–f and 5a comprised of positively charged NMe2, P(C6H5)2 or As(C6H5)2 bridges and anionic three-center two-electron (3c2e) delocalized boron heterocyclic units, were prepared and characterized by NMR as well as by X-ray structure analyses. The boron chemical shifts of the trishomoaromatic dianion 12a with an oxygen bridge compare well with those computed ab initio for model 12b. Analysis of the electronic structure of the bishomoaromatic 5u and its anionic analog 11u gives insight into the origin of the trend of increasing effectiveness of BC2, B2C and B3 3c2e bonds: higher electronegativity of carbon vs boron prevents symmetric delocalization in rings with B2C and especially BC2 centers.  相似文献   

19.
The gelation of mixed cationic/anionic surfactant vesicles of sodium dodecyl sulfate/didodecyldimethylammonium bromide and sodium dodecylbenzenesulfonate/cetyltrimethylammonium tosylate by hydrophobically modified sodium polyacrylate is studied rheologically. When the vesicles are cationically charged, mixtures with this anionic polyelectrolyte form precipitates. When the vesicles are anionically charged, however, these mixtures display a progression from a Maxwell fluid to a critical gel to a solidlike gel with increasing vesicle and/or polyelectrolyte concentration. Consideration of the viscous behavior with increasing vesicle and polymer volume fraction indicates that the gel network is formed by the bridging of the hydrophobically modified polymer between vesicles. The similarity between the gelation results for the two anionic systems suggests the results can be generalized to other similarly charged mixtures.  相似文献   

20.
合成了一系列直链烷基聚氧丙烯醚硫酸钠(CcPpS, c=8或16时, p=9;c=12时, p=3, 6或9)并鉴定了其结构. 与十二烷基硫酸钠(SDS)类似, C12P9S在氧化铝上的饱和吸附量以及对阳离子染料亚甲基蓝的吸附增溶行为共同证实该延展型表面活性剂在表面上形成了双层吸附胶束, 但由聚氧丙烯(PPO)连接基导致的橄榄球状分子及其导致的较大分子吸附面积, 使其吸附能力及其对亚甲基蓝的吸附增溶能力均稍弱于SDS. C12P9S@Al2O3对弱极性分子1-苯乙醇和难溶性分子苯乙烯的吸附增溶能力均明显强于SDS, 而且对1-苯乙醇的吸附增溶量达到SDS@Al2O3的8.5倍, 说明1-苯乙醇主要被增溶在C12P9S双层吸附胶束中PPO连接基所在的膨大部位, 这使延展型表面活性剂改性的氧化铝在废水处理和药物传递系统等领域具有潜在的应用前景.  相似文献   

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