排序方式: 共有29条查询结果,搜索用时 93 毫秒
21.
以三氯化钌为前驱体、聚乙烯吡咯烷酮(PVP)为稳定剂,三缩四乙二醇(TEG)为溶剂和还原剂,在适量十六烷基三甲基溴化铵(CTAB)存在下,制备得到了稳定的金属钌纳米棒.产物采用透射电子显微镜(TEM)、X-射线粉末衍射(XRD)、X-射线光电子能谱(XPS)、紫外-可见吸收光谱(UV-V is)等进行了表征. 相似文献
22.
利用等温滴定微量热法研究了β-环糊精(β-CD)与阳离子表面活性剂十六烷基三甲基溴化铵(CTAB)的包结作用,并在298.15、303.15、308.15 K温度下,计算了包结体系的包结常数和包结过程的热力学参数.研究发现,β-CD与CTAB可以形成物质的量的比为1∶1的包结物,整个包结过程是熵焓共同驱动的,温度越高,越有利于β-CD与CTAB自发地形成包结物,β-CD与CTAB的结合常数K越大,焓驱动逐渐增强,熵驱动逐渐减弱. 相似文献
23.
卤化盐对CRTAB-AS-H2O复配体系相行为的影响 总被引:1,自引:1,他引:0
研究了十六烷基三甲基溴化铵(CTAB)和十二烷基磺酸钠(AS)复配体系在稀溶液区的相行为.考察了氟化钠、氯化钠、溴化钠和氯化钾对其相行为的影响.研究表明,在318.15 K下,CTAB-AS复配体系在水溶液或0.10mol·kg-1盐水溶液中,均可形成两个双水相区.每个双水相区均位于一个各向同性溶液单相区和一个液晶单相区之间,在两个液晶单相区之间为非均相区.无机盐的加入使非均相区和双水相区面积增大,双水相区向邻近的各向同性溶液单相区的方向迁移. 相似文献
24.
Various morphologies of polythiophene have been designed and successfully prepared by chemical oxidative polymerization in the presence of phase transfer catalyst (PTC) cetyltrimethylammonium bromide (CTAB) in aqueous medium. The morphologies of polythiophene could be controlled in ribbons, fibers and spherical particles by changing the concentrations of reductant, oxidant and phase transfer catalyst. The structure, thermal stability and the conductivity have been characterized, and a mechanism for the transformation of the morphology of polythiophene has been proposed. 相似文献
25.
研究了三氮烯试剂4,4'-对偶氮苯重氮氨基偶氮苯(BBDAB)与阳离子表面活性剂溴化十六烷基三甲铵(CTMAB)的显色反应,并据此反应建立了分光光度测定CTMAB含量的新方法.在Tritonx-100的存在下,于pH=12.5的缓冲溶液中,BBDAB与阳离子表面活性剂形成1∶3蓝紫色稳定络合物,其最大吸收峰位于680nm处,线性范围是0-14.6mg/L,表观摩尔吸光系数达1.76×104L·mol-1·cm-1.该法用于合成水样中CTMAB的测定,结果令人满意. 相似文献
26.
研究发现,阳离子表面活性剂十六烷基三甲基溴化铵对阿莫西林的荧光有明显的增敏作用,据此建立了直接测定药片中阿莫西林含量的荧光光谱法.实验结果表明,阿莫西林的浓度在0.25~0.5和0.001~0.200mmol/L范围内与荧光度呈线性关系,检出限分别为34μmol/L和5.5μmol/L.该方法的回收率为99.6%~100.1%,相对标准偏差为0.16和0.18,用于阿莫西林样品的测定,结果令人满意. 相似文献
27.
The fluorescence of tetracycline was greatly enhanced by chelation with Eu3+ in Tris-HCl buffer (pH8.5). The addition of cetyltrimethylammonium bromide, a cationic surfactant, further enhanced the fluorescence
of tetracycline-Eu3+ chelates. This spectrofluorimetric method for the determination of tetracycline yielded a linear responses in the range of
10 nmol/L–10 μmol/L. The detection limit was 5 nmol/L (or 2.22 ng/mL). The recovery of tetracycline spiked in serum at levels
of 1 and 0.09 μg/mL was 97.9% and 97.8%, respectively. This method is fast, sensitive and suitable for the determination of
tetracycline in biological specimens.
Foundation item: Supported by the National Natural Science Foundation of China
Biography: Huang Zu-yun (1963-), male, Ph D. 相似文献
28.
粘度测定法研究了十六烷基三甲基溴化铵在0.2MNaBr溶液中在30-50℃温度范围内的球-棒转变。溶液粘度的增大是由于棒形胶束的生成。发现溶液粘度表面活性剂浓度呈指数函数关系变化而不出现转折点,说明胶束的球-棒转变是一个逐步进行的过程。 相似文献
29.
In this work, the effect of octane concentration on the phase behavior of CTAB/water/1-butanol system was studied by using pulsed field gradient spin-echo NMR measurements and freeze fracture electron microscopy (Cryo- TEM and FFEM). When the octane concentration increases, the liquid crystalline phase is destabilized and a continuous single-phase microemulsion region from the water apex to the oil apex is formed. The conductivity behavior has a distinct percolative phenomenon, which indicates that the single-phase microemulsion is changed continuously from oil- in-water (o/w) structure via a bicontinuous structure to water-in-oil (w/o) structure. This result is consistent with those of the PGSE-NMR, Cryo-TEM, and FFEM. In the w/o region, the self-diffusion coefficient of water is relatively high ((1—6)×10-10 m·s-1) due to the higher solubility of water in the continuous phase consisting of octane (10% by weight) and 1-butanol. The penetration of a large amount of octane molecules between surfactant chains results in the much lower self-diffusion coefficient of octane. 相似文献