Concentration, temperature, and salt-induced micellization of a triblock copolymer Pluronic L64 in aqueous media
Concentration, temperature, and salt-induced micellization of a triblock copolymer Pluronic L64 in aqueous media
复制标题
DOI：
10.1016/j.jcis.2005.06.013
复制
发表时间：
2005-12-15
影响因子：
9.9
通讯作者：
Bahadur, P
中科院分区：
文献类型：
--
作者：
Mata, JP;Majhi, PR;Bahadur, P
通过染料光谱变化、傅里叶变换红外光谱(FTIR)、差示扫描量热(DSC)、小角中子散射(SANS)、动态光散射(DLS)、粘度和浊点(CP)等方法，研究了共聚物浓度、温度和卤化钠(NaI、NaBr、NaC、NaF)对聚氧乙烷-聚氧丙烷-聚氧乙烷嵌段共聚(PEO-PPO-PEO)两亲共聚物(Pluronic L64：EO13PO30EO13)胶束化和胶束性能的影响。观察了L64的温度/聚合物浓度/盐依赖的聚集行为。报道了临界胶束浓度(CMC)、临界胶束温度(CMT)、临界胶束温度(Cp)、胶束大小和形状等数据。傅立叶变换红外光谱(FTIR)显示，在胶束化过程中，C-O-C伸缩变化带随温度变化，向更高的波数方向移动，带宽变宽，这归因于无水甲基的比例增加，而水合甲基的比例减少。差示扫描量热仪(DSC)提供了同一实验中的CMTS和CPS。由染料光谱变化得出的CMC值，随着盐的加入而显著降低。盐/共聚物浓度的增加降低了胶束化起始温度(CMT)。在总盐和共聚物浓度不变的情况下，卤素阴离子对CMT和CP的影响顺序为F->；Cl->；Br->；I-。SANS结果表明，由于温度/盐浓度的增加，胶束间的相互作用增加；这得到了粘度数据的支持。(C)2005 Elsevier Inc.保留所有权利。
The effect of copolymer concentration, temperature, and sodium halides (NaI, NaBr, NaCl, and NaF) on micellization and micellar properties of a poly(ethylene oxide)-block-polypropylene oxide)-block-poly (ethylene oxide) (PEO-PPO-PEO) amphiphilic copolymer (Pluronic L64: EO13PO30EO13), was examined by different methods such as dye spectral change, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), small angle neutron scattering (SANS), dynamic light scattering (DLS), viscosity, and cloud point (CP). Temperature/polymer concentration/salt dependent aggregation behavior of L64 was observed. The data on critical micelle concentration (CMC), critical micelle temperature (CMT), (CP), micelle size, and shape are reported. The Fourier transform infrared (FTIR) showed temperature dependent changes in C-O-C stretching variation band towards higher wave numbers and broadening of band width during the micellization process; this was attributed to increase in proportion of the anhydrous methyl groups, while the proportion of the hydrated methyl groups was decreased. Differential scanning calorimetry (DSC) provides CMTs and CPs from the same experiment. CMC values derived from dye spectral change, decrease significantly with the addition of salt. The increases in salt/copolymer concentration lower the onset temperature of micellization (CMT). Halide anions influence both CMT and CP in the order of F- > Cl- > Br- > I- when total salt and copolymer concentration kept constant. SANS results show the increase of inter-micellar interaction due to the increase in temperature/salt concentration; this is supported by viscosity data. (c) 2005 Elsevier Inc. All rights reserved.