Abstract

Time-resolved fluorescence quenching (TRFQ) and electron paramagnetic resonance (EPR) were employed to characterize micelles of dodecyltrimethylammonium bromide and chloride (DTAB and DTAC) as reaction media. For DTAB, the aggregation numbers, N, and the quenching rate constant of pyrene by hexadecylpyridinium chloride, kq, were measured with TRFQ. Both these aggregation numbers for DTAB and those for DTAC taken from the literature depend only on the concentration of counterions in the aqueous phase, Caq, whether these counterions are supplied by the surfactant alone or by surfactant plus added salt. Both surfactants conform to the power law N = N0(Caq/cmc0)γ where N0 is the aggregation number at the critical micelle concentration in the absence of any additives (cmc0). N0 and γ differ for the two surfactants and vary with temperature in DTAB. EPR is employed to investigate the microviscosity and the hydration of the polar shell using a spin probe. The hydration is expressed by the nonempirical polarity p...

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.