I need to prepare reverse micelles by CTAC as a surfactant. I have already prepared CTAC from CTAB by ion exchange resin. But I dont know why the mixture of CTAC+ Isooctane+n-pentanol+ water is not clear.
You need to check the cleanliness of STAS. Please note that the CMC STAS is about 5 times smaller than the STAB at 30 0C.
Thank you professor Mirgorod. But how the CMC of CTAC can affect the calculation of reverse micelle preparation by Isooctane /n-pentanol/water ?
To prepare a microemulsion, you must know the CMC STAС in isooctane or at least estimate this concentration. At STAС, it will be half as much as that of CTAB. When packing polar groups of surfactants in isooctane an empty volume appears. If it is not filled with water, the microemulsion is not formed. The radius of the empty volume in AOT micelles is 0.44 nm.
Dear Elnaz, if I well understood you, the mixture shows turbidity (not clear). This is a proof that you are so far from reverse micelles phase. Thus, as mentioned by Professor Yuri Mirgorod. to form reverse micelles, the surfactant concentration should be higher than its CMC. in other side, the amount of added water should be controlled carefully in relationship with the surfactant quantity....because for the high water amount the phase is no more reverse micelles....
Thank you Dr. Yuri Mirgorod, Dr. Ahmed El Alferni and Dr. Titus Sobisch.
As indicated by Yuri, you should start with characterization of purity of CTAC. It also seems possible that you introduced some contamination during ion exchange and CTAC concentration might be different you think is.
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