Si LI, Yu CHEN. Study on the Intrinsic Fluorescence of Hyperbranched Polyethylenimine-graft-poly(ethylene glycol) Copolymers[J]. Polymer Bulletin, 2018,31(7):69-73.
Si LI, Yu CHEN. Study on the Intrinsic Fluorescence of Hyperbranched Polyethylenimine-graft-poly(ethylene glycol) Copolymers[J]. Polymer Bulletin, 2018,31(7):69-73. DOI: 10.14028/j.cnki.1003-3726.2018.07.008.
Hyperbranched polyethylenimine-graft-poly (ethylene glycol) copolymers (HPEI-g-PEGs) were prepared through two steps. Fluorescence characterizations demonstrated that increasing the excitation wavelength (λ
ex
) led to the gradual red-shift of the maximum emission wavelength (λ
em
). Moreover
the emission intensity initially increased with the λ
ex
increase
and reached the maximum at 360 nm. Further increasing λ
ex
resulted in the gradual decrease of emission intensity. With λ
ex
= 360 and 470nm
HPEI-g-PEG could emit blue light with the maximum λ
em
= 455nm and green light with the maximum λ
em
= 535nm
respectively. The emission intensity of blue light was obviously stronger than that of green light. Raising the degree of substitution of PEG
increasing the polymer concentration and prolonging the oxidation time all favored to the elevation of the emission intensity ratio of green to blue light. Whereas altering the pH of solution had no marked influence on the emission intensity ratio of green to blue light. Compared with the blue emission
the green emission of HPEI-g-PEG was more selective toward metal ions.