Ksv gives an idea about bimolecular quenching and unimolecular decay as it being the product of rate constant of the quenching process and lifetime of the probe in the absence of bimolecular quenching [33]. In general, a linear Stern–Volmer plot means that there is only a single population of fluorophores that is all equally accessible to the quencher [34] and [35]. High Ksv values suggest that an increase in quenching due to presence of both pyrene and quencher in strong hydrophobic environment.
The intensity ratio of the first and third vibronic peaks of pyrene, i.e., I1/I3 is considered to be an index of micropolarity of the system and so that these values were calculated from fluorescence measurements for studied systems. A value less than 1 generally indicated that pyrene is in nonpolar environment while values grater than 1 mean pyrene having a polar surrounding [33]. Also this I1/I3 values as a function of surfactant mixtures for all systems were listed in Table 2. As seen as Table 2, as the CTAB increasing, these ratios increased for all systems. The values are closest to that of methanol for mixtures except for pure CTAB.
The apparent dielectric constants of the medium (D) were calculated from the below relation [10].
equation(7)
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As seen from Table 2, these dielectric constants values show that there are no definite trend in D values but the values change in between 18 and 53 for higher mole fractions of conventional surfactant in binary mixtures. These values are close to the D values for methanol and ethanol [36], so that solubilized pyrene is in the short alcohol-like environment.
Ksv gives an idea about bimolecular quenching and unimolecular decay as it being the product of rate constant of the quenching process and lifetime of the probe in the absence of bimolecular quenching [33]. In general, a linear Stern–Volmer plot means that there is only a single population of fluorophores that is all equally accessible to the quencher [34] and [35]. High Ksv values suggest that an increase in quenching due to presence of both pyrene and quencher in strong hydrophobic environment.The intensity ratio of the first and third vibronic peaks of pyrene, i.e., I1/I3 is considered to be an index of micropolarity of the system and so that these values were calculated from fluorescence measurements for studied systems. A value less than 1 generally indicated that pyrene is in nonpolar environment while values grater than 1 mean pyrene having a polar surrounding [33]. Also this I1/I3 values as a function of surfactant mixtures for all systems were listed in Table 2. As seen as Table 2, as the CTAB increasing, these ratios increased for all systems. The values are closest to that of methanol for mixtures except for pure CTAB.The apparent dielectric constants of the medium (D) were calculated from the below relation [10].equation(7)View the MathML sourceTurn MathJax onเท่าที่เห็นจากตารางที่ 2 ค่าค่าคงที่เป็นฉนวนเหล่านี้แสดงว่า มีแนวโน้มไม่แน่นอนในค่า D แต่ค่าที่เปลี่ยนแปลงระหว่าง 18 และ 53 สำหรับสูงเศษส่วนโมลของสารทำความสะอาดทั่วไปในส่วนผสมไบนารี ค่าเหล่านี้อยู่ใกล้กับค่า D สำหรับเมทานอลและเอทานอล [36], เพื่อให้ solubilized ไพรีนอยู่ในสภาพแวดล้อมเหมือนแอลกอฮอล์สั้น
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