We are currently exploring all-aromatic copoly(ester-imide)s based on N-(3'-hydroxyphenyl)trimellitimide(IM) and 4-hydroxybenzoic acid(HBA).Two different crystal phase polymers with molar ratio of IM/HBA a...
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We are currently exploring all-aromatic copoly(ester-imide)s based on N-(3'-hydroxyphenyl)trimellitimide(IM) and 4-hydroxybenzoic acid(HBA).Two different crystal phase polymers with molar ratio of IM/HBA as 0.3/0.7(semi-crystalline) and 0.7/0.3(amorphous) were obtained from a one-step melt polymerization method, namely 3-IM/7-HBA and 7-IM/3-HBA, *** both cases, thermoplastic polymers were obtained with a high volume fraction of infusible crystalline poly(HBA) or amorphous poly(IM).Composite films prepared by melt pressing are brittle but upon stretching(stretch ratios of 4 are possible) above their glass transition temperature(T) their ductility improves *** to different reinforcement mechanisms, the two molecular composites exhibit different thermo-mechanical properties.3-IM/7-HBA composite films show a strong dependence of the T on the stretch *** as prepared films exhibit a T of 205 ℃ and the T increased to 248 ℃ after stretching the films 3 times above *** tensile strength and elongation at break of the film increased by 0%(78 MPa) and 5%(3% elongation), respectively after one stretching *** the case of 7-IM/3-HBA, an increasing trend was observed in storage modulus(E').The room temperature storage modulus increased from 7 to 28 GPa after 3 stretching *** this case, however, there is no effect on *** as-prepared films could not be handled(too brittle) but after stretching the film once above T, a tensile strength of 161 MPa and elongation of 9% was *** the best of our knowledge, such improvements in thermo-mechanical properties in all-aromatic main-chain polymers have not been reported before.
Three novel rhodamine-based Hg^2+ fluorescent sensors were designed and synthesized. The sensors could work in semi-aqueous solutions with nearly neutral p H and showed high selectivity and sensitivity to Hg^2+ with...
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Three novel rhodamine-based Hg^2+ fluorescent sensors were designed and synthesized. The sensors could work in semi-aqueous solutions with nearly neutral p H and showed high selectivity and sensitivity to Hg^2+ with remarkable fluorescence enhancement. For these three sensors, the linear working range broadened(0–80, 0–100 and 0–140 μmol/L, respectively) and the sensitivity increased(7.7, 15.5 and 17.6 folds of the fluorescence enhancement and 512, 66.2 and 37.6 ppb of the detection limit) with the rising of the thiourea-unit numbers. Furthermore the sensors exhibited excellent interference immunity to multiple environmentally and biologically relevant metal ions. Pond and tap water assay showed good practicability of the sensors. The number of the bound Hg^(2+) equaling to that of the thiourea units and the irreversible recognition process implied a new interaction way between Hg^(2+) and the sensor.
Poly{bis[4-(4'-(S)-2-methylbutoxy)biphenyloxy]phosphazene}(PP-C) was designed and successfully synthesized, and then characterized by means of FT-IR spectroscopy, ~1H- and ^(31)P-NMR, GPC spectroscopy, wide a...
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Poly{bis[4-(4'-(S)-2-methylbutoxy)biphenyloxy]phosphazene}(PP-C) was designed and successfully synthesized, and then characterized by means of FT-IR spectroscopy, ~1H- and ^(31)P-NMR, GPC spectroscopy, wide angle X-ray diffraction and differential scanning calorimetry. The results indicated that for PP-C, the M_w is 2.18×10~5 and the PDI is 1.96. PP-C was a kind of crystallized polymer with a crystallizing point of -2.0 ℃ and a melting point of 28 ℃. The conformational chirality of the PP-C molecules was studied using circular dichroism spectrum. It was found that in dilute THF solution, the biphenyl groups in the PP-C molecules twisted randomly. However, when the PP-C formed aggregates, the biphenyl groups tended to twist single-handedly, which was controlled by the adjacent chiral alkoxy groups.
Photo-induced cancer therapy,such as photodynamic therapy(PDT) or photothermal therapy(PTT) treatment has shown great promise in precision nanomedicine owing to their selectivity,low systemic toxicity,negligible d...
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Photo-induced cancer therapy,such as photodynamic therapy(PDT) or photothermal therapy(PTT) treatment has shown great promise in precision nanomedicine owing to their selectivity,low systemic toxicity,negligible drug resistance,and non-invasive modality.1-3 In this presentation,we will demonstrate wavelength-dependent photoconversion regulation of Bodipy fluorophores through polymeric vesicles for either PDT or PTT treatment(Scheme 1).Bodipy is assembled with the terpolymer into polymeric vesicles in the conformation of both J-type and H-type aggregates,causing the red-shifted absorption into the near-infrared(NIR) region,low radiative transition,and ideal resistance to *** 660 nm irradiation,the vesicles mainly display remarkable singlet oxygen quantum yield through singlet-to-triplet transition,thereby leading to abundant intracellular singlet oxygen at the tumor for effective ***,under 785 nm irradiation,they primarily possess distinct photothermal conversion efficiency through non-radiative transition together with mild singlet oxygen generation,thus leading to potent hyperthermia at the tumor for robust PDT-synergized ***,the vesicles have preferable cellular uptake,effective cytoplasmic drug translocation through singlet oxygen-mediated lysosomal disruption,and enhanced tumor accumulation,which contribute to the total tumor ablation without any regrowth.4
We demonstrate here seven pure cyclic samples, which belongs to two series of oligoesters, cyclic oligo(trimethylene terephthalate)s (COTTs) and cyclic oligo(butylene terephthalate)s (COBTs), showing odd-even ...
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We demonstrate here seven pure cyclic samples, which belongs to two series of oligoesters, cyclic oligo(trimethylene terephthalate)s (COTTs) and cyclic oligo(butylene terephthalate)s (COBTs), showing odd-even effect of degree of oligomerization (repeating units number) on properties. The pentamer of COTT and trimer of COBT show much lower melting temperature, and the trimer of COTT and trimer of COBT show significant lower refractive index, which can be ascribed to the low packing density of cyclic oligoesters with odd number of degree of oligomerization. Our results reveal the discrete property change as a function of cyclic size of oligomers, which can be used to design materials with special properties.
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