Browsing by Author "Sun, Bin"

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Concentration-dependent self-assembly structures of an amphiphilic perylene diimide with tri(ethylene glycol) substituents at bay positions
(2017-01-01)
Wang, Xin
;
Zeng, Ting
;
Nourrein, Mohamed
;
Lai, Bo-Han
;
Shen, Kaiwen
In this work, an amphiphilic perylene diimide (1,7-TEG-PDI-C12) that bears two hydrophilic triethylene glycol (TEG) chains at its bay position, and two hydrophobic dodecyl chains at its imide position was synthesized to identify the roles of concentration and H-bonding on the self-assembly morphology of the amphiphilic PDI. Since 1,7-TEG-PDI-C12 was prepared from the reaction of two bifunctional reactants, TEG and N, N'-bis(n-dodecyl)- 1,7-dibromo-perylene-3,4: 9,10-tetracarboxylic diimide, careful choices of solvent, base, and the stoichiometry of crown ether and base were found to be critical in reaching high reaction yield under mild conditions. TEM and SEM results revealed the abundant concentration-dependent self-assembly morphologies of 1,7-TEG-PDI-C12. Characterization results including UV-vis, fluorescence, NMR, IR and XRD analysis show that the formation of the self-assembled structure is a synergetic result of the intermolecular pi-pi interaction and H-bonding of 1,7-TEG-PDI-C-12.
The morphologies and fluorescence quantum yields of perylene diimide dye-doped PS and PHVB microspheres
(2018-01-01)
Chen, Jia
;
Jia, Shuoxun
;
Ji, Xiaohuan
;
Nourrein, Mohamed
;
Xiang, Hengxue
Aggregation and continuous -stacking have been the major obstacles hindering the fluorescence (FL) quantum yield (phi(F)) of perylene diimide (PDI) derivatives in the condensed phase. To prepare polymer microspheres with nearly unity phi(F), in this work a POSS functionalized PDI derivative, POSS-PDI-POSS (PPP), was applied as the red fluorophore of poly(3-hydroxylbutyrate-co-3-hydroxyvalerate) (PHBV) and polystyrene (PS) microspheres. The electrosprayed PPP/PHBV and PPP/PS microspheres have unique hollow structures. Moreover, they show bright red FL under a fluorescence microscope. A photophysical study of the microspheres indicates a significant role of the polymer matrix in disrupting the aggregation state and the phi(F) of the embedded PPP fluorophore. Both the PPP/PHBV and the PPP/PS microspheres show higher phi(F) than most PDI materials in the condensed phase. The PPP/PHBV microspheres show phi(F) of 28%, whereas the PPP/PS microspheres give nearly unity phi(F).