Research On The Fluorescence Properties Of Hyperbranched Polyamide Amine And Its Influencing Factors

Fluorescent polymers are referred to as conjugated polymers, which areconstructed by π-aromatic building blocks functioning as emitting units. But in recentyears, the researchers found that a few kinds of polymers only containingauxochromes or unconventional chromophores, such as aliphatic tertiary amine,carbonyl, ester, and amide demonstrate strong luminescence under proper conditions.Poly(amido amine)(PAMAM) dendrimers and hyperbranched poly(amido amine)sbeing the outstanding representatives, which has been widely studied now. Comparedto organic materials bearing the traditional fluorescent chromophore, this kind oforganic fluorophores can find applications in many field, such as Green luminescentmaterial and biomedical fields, because it possesses excellent biocompatibility, highwater solubility and its molecular chain end contains a lot of activity groups. Thismakes it easy to functional modification. However, this kind of fluorescent materialresearch is still in preliminary stage, the luminescent mechanism and the influencingfactors has not been fully resolved. In this paper, using the characteristic ofHP-PAMAM preparation conditions loose, we prepared a series of nitrogencompounds from small molecules to oligomer to HP-PAMAM under the condition ofdifferent polymerization. Research founded that the distances between amine groupsplayed a crucial role in influencing the intrinsic fluorescence properties. This ishelpful to further illustrate the mechanism of fluorescence.In addition, by varying the experimental parameters and conditions, we observethat different factors, such as temperature, concentration, pH value, oxidation andsolvent might have significant effect on the fluorescent properties. And we also foundthe special photosensitive properties of HP-PAMAM by changing the lightwavelength, irradiation time and avoid light recovery conditions. The hope of thisdiscovery could expand its application in the field of fluorescent sensors. Furthermore,onion epidermal cells ingrained by HP-PAMAM could emit bright fluorescence underthe fluorescent microscope, this might provide basis for their application in fluorescent dye.