四級銨鹽對聚（N-乙烯吡咯烷酮）與十二烷基硫酸鈉交互作用影響之研究: 四級銨鹽碳鏈長度的影響

Abstract

The interaction between poly(N-vinylpyrrolidone) (PVP) and sodium dodecyl sulfate (SDS) and symmetrical tetramethyl-, tetraethyl-, tetrapropyl-, and tetrabutylammonium bromides (TMAB, TEAB, TPAB, and TBAB, respectively), has been investigated by tensiometric and fluorescent techniques to determine the critical aggregation concentration (cac) of the surfactants in the presence of polymer. The cac values were compared to the values of the critical micelle concentration (cmc) of the surfactants in the absence of polymer. The cmc was found to decrease in the sequence: NaCl ~ AB > TMAB > TEAB > TPAB > TBAB. The data indicate that the degree of the conuterion binding is found to increase with the increasing size of the alkyl chain length of the tetraalkylammonium bromides (TAAB). However, the cac showed the different outcome. There is not the maximum value of cac in the TBAB experimental system. It implies that the degree of the conuterion binding is too large to form the complex. In three components system of TAAB/SDS/PVP, the NMR results show that SDS interacts with PVP, forming micelle-like clusters bound onto the polymer, and furthermore suggest that the SDS/PVP complex formation implies the synergic effects of the electrostatic attractions and the hydrophobic interaction. Both of them are weak influences, so the clusters are looser than micelle structures. It also hints that only the superficial layer of SDS aggregates is affected by the presence of PVP.