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Wang Q.,East China University of Science and Technology | Wang Y.,East China University of Science and Technology | Meng Q.,Shanghai Pret Composites CO. | Wang T.,East China University of Science and Technology | And 4 more authors.
RSC Advances | Year: 2017

Graphene nanoplatelets with excellent electrical conductivity in polymer matrices are highly promising for the industrial application of electrical conductive materials, however, poor dispersion results in high contents of graphene nanoplatelets being required for electrical property enhancement. In this study, graphene nanoplatelets (GNP)@polyaniline (PANI) nanocomposites were synthesized by in situ polymerization whereas the compatibility between GNP@PANI nanocomposites and the polymer matrix improved significantly due to graphene nanoplatelet encapsulation with polyaniline. GNP@PANI nanocomposites were utilized to prepare a permanent antistatic high-density polyethylene (HDPE) composite through solution blending and press forming in order for GNP@PANI nanocomposites to be dispersed homogeneously in the HDPE. The dispersion and compatibility of GNP@PANI nanocomposites in the HDPE were verified by morphology characterization, resulting in significant improvement of the electrical properties of the GNP@PANI/HDPE composites. It was observed that surface resistivity (ρs) and volume resistivity (ρv) decreased sharply with a 10 wt% GNP@PANI addition of nanocomposites. The results displayed that in situ polymerization and solution blending were effective methods for a conductive network establishment by addition of only 2 wt% of GNP and 8 wt% of PANI. © The Royal Society of Chemistry.

Wei C.,East China University of Science and Technology | Zhang Y.,East China University of Science and Technology | Song Z.,Shanghai JiaoTong University | Xia Y.,Shanghai JiaoTong University | And 2 more authors.
Biomaterials Science | Year: 2017

Stimuli-responsive nanocarriers have been limited for bench-to-bedside translation mainly because the stimuli sensitivity and responsive rate are not high enough to ensure sufficient drug concentration at the target sites for superior therapeutic benefits. Herein, we reported an enhanced bioreduction-responsive and biodegradable nanocarrier based on the amphiphilic poly(ester urethane) copolymers (PAUR-SeSe) bearing multiple diselenide groups on the backbone. The copolymer could spontaneously self-assemble into stable micelles in aqueous medium with an average diameter of 68 nm, which could be rapidly disassembled in a reductive environment as a result of the reduction-triggered cleavage of diselenide groups. Furthermore, the PAUR-SeSe micelles showed an enhanced drug release profile and cellular uptake compared with the disulfide-containing analogue (PAUR-SS). CCK8 assays revealed that the antitumor activity of DOX-loaded PAUR-SeSe micelles was much higher than that of DOX-loaded PAUR-SS micelles. Besides, the blank micelles and degradation products were nontoxic up to a tested concentration of 50 μg mL-1. Therefore, the enhanced therapeutic efficacy and good biocompatibility demonstrated that this drug nanocarrier had great potential for smart antitumor drug delivery applications. © 2017 The Royal Society of Chemistry.

Geng T.-M.,Anhui Normal University | Geng T.-M.,Collaborative Innovation Center for Petrochemical New Materials | Wu D.-Y.,Anhui Normal University | Wu D.-Y.,Changzhou University
Luminescence | Year: 2015

We report the fabrication of a novel easily available turn-on fluorescent water-soluble polymeric chemosensor for Hg2+ ions that was simply prepared by micellar free radical polymerization of a water-insoluble organic rhodamine-based Hg2+-recognizing monomer (GR6GH), with hydrophilic monomers acrylamide (AM) and acrylic acid (AA). The chemical structure of the polymeric sensor was characterized by FT-IR and 1H NMR spectroscopy. The apparent viscosity average molecular weight Mη of poly(acrylamide-acrylic acid) [poly(AM-NaAA)] and the water-soluble polymeric chemosensor poly(AM-NaAA-GR6GH) were 1.76 × 106 and 6.84 × 104 g/mol, respectively. Because of its amphiphilic property, the water-soluble polymeric chemosensor can be used as a chemosensor in aqueous media. Upon addition of Hg2+ ions to an aqueous solution of poly(AM-NaAA-GR6GH), fluorescence enhancements were observed instantly. Moreover, other metal ions did not induce obvious changes to the fluorescence spectra. This approach may provide an easily measurable and inherently sensitive method for Hg2+ ion detection in environmental and biological applications. Copyright © 2015 John Wiley & Sons, Ltd.

Geng T.-M.,Anhui Normal University | Geng T.-M.,Collaborative Innovation Center for Petrochemical New Materials | Guo C.,Anhui Normal University | Guo C.,Collaborative Innovation Center for Petrochemical New Materials | And 5 more authors.
Polymers for Advanced Technologies | Year: 2016

A hydrophobic organic monomer GRBE with a polymerizable methacrylester moiety had been synthesized by reaction of rhodamine B-ethanediamine with glycidyl methacrylate. A water-soluble polymeric chemosensor poly(VP-GRBE) had been prepared via copolymerization with a hydrophilic comonomer (vinylpyrrolidone) and GRBE, which was able to sense environmentally poisonous cations in completely aqueous media. The chemosensor was a derivative of rhodamine B, which behaved as a fluorescent and chromogenic sensor toward various heavy cations, particularly Cr3+, Fe3+, and Hg2+. Titration curves of Cr3+, Fe3+, and Hg2+ were constructed using rapid, cheap, and widely available technique of fluorescence spectroscopies. The detection limits for Cr3+, Fe3+, or Hg2+ ions were found to be 2.20×10-12, 2.39×10-12, and 1.11×10-12mol/l in the same medium, respectively. Moreover, a colorimetric response from the polymeric chemosensor permitted the detection of Cr3+, Hg2+, or Fe3+ by "naked eye" because of the development of a pink or brown yellow color when Cr3+, Hg2+, or Fe3+ cations interacted with the copolymer in aqueous media. Copyright © 2016 John Wiley & Sons, Ltd.

Li Z.,East China University of Science and Technology | Wang Y.,East China University of Science and Technology | Cheng L.,East China University of Science and Technology | Guo W.,East China University of Science and Technology | Wu G.,Collaborative Innovation Center for Petrochemical New Materials
Journal of Wood Chemistry and Technology | Year: 2016

The impact of nano-CaCO3 on the structure and properties of holocellulose-fiber/polypropylene biomass composites was conducted. With different content of nano-CaCO3, the crystallization behavior and thermal properties of holocellulose-fiber/nano-CaCO3/polypropylene composites were investigated by X-ray diffraction, differential scanning calorimetry, polarizing microscope, and thermogravimetric analysis. The results illustrated that the structure and properties of the composites were affected greatly by the nano-CaCO3 and the optimal content of nano-CaCO3 was 5 wt.%. Water absorption of composites with 5 wt.% nano-CaCO3 decreased by 21.8% and the crystallinity increased by 14% compared with samples without nano-CaCO3. The mechanical properties of composites also kept high performance and the thermogravimetric analysis presented the enhancement of thermal stability. All results suggested that the synergistic effect of holocellulose-fiber and nano-CaCO3 developed a high mechanical property and low-water-absorption holocellulose-fiber/nano-CaCO3/polypropylene ternary composites. 2016 Copyright © Taylor & Francis Group, LLC

Liu H.,East China University of Science and Technology | Xiao Y.,East China University of Science and Technology | Xu H.,Collaborative Innovation Center for Petrochemical New Materials | Guan Y.,Collaborative Innovation Center for Petrochemical New Materials | And 2 more authors.
Chemical Communications | Year: 2015

Rationally designed polypeptides with similar molecular structures but varying patterns of hydrogen bonding between the side groups have been synthesized and demonstrated to possess distinct solubility and thermal behaviors. Further balancing the ratio of both isopropylamine and ethylenediamine side groups endows the random copolymer with reversible thermo-sensitivity. This journal is © The Royal Society of Chemistry.

Zhang J.,Shanghai Key Laboratory of Advanced Polymeric Materials | Xiao Y.,Shanghai Key Laboratory of Advanced Polymeric Materials | Xiao Y.,Shanghai Collaborative Innovation Center for Biomanufacturing | Xu H.,Collaborative Innovation Center for Petrochemical New Materials | And 3 more authors.
Polymer Chemistry | Year: 2016

The introduction of reactive groups such as -NH2, -COOH etc. onto a poly(ϵ-caprolactone) (PCL) backbone was necessary for further modification but a well-controlled approach remains a challenge for synthetic chemistry. Carboxyl functionalized PCL was typically prepared via three steps involving the synthesis of the corresponding monomer with a carboxyl-protecting group, polymerization and the removal of the protection. Except for obtaining purified monomers and a decent polymerization, the most critical step in carboxyl PCL synthesis was the deprotection from the degradable main chain. Therefore, electronic effects and steric hindrance of the protecting group were taken into account with the aim for controllable polymerization and feasible deprotection. Substituents including -CH3, H and NO2 with discriminative electronegativity on the para position of the benzyl protecting group have been selected to investigate their behavior in monomer preparation, polymerization and deprotection, respectively. It turned out that the electron donating group (-CH3) displayed the highest selectivity in the monomer preparation, excellent control over the polymerization degree and the most efficient removal of the protecting groups without degradation of the backbone. In addition, the reactivity of the pendant carboxyl groups on PCL was demonstrated by amidation with 4-amino-2,2,6,6-tetramethylpiperidinyloxy (4-amino-TEMPO). Our results also provide guidance information on preparing well-defined biodegradable polymers with pendant reactive groups such as polypeptides, expanding the library of novel biomaterials. © 2016 The Royal Society of Chemistry.

Wei C.,East China University of Science and Technology | Zhang Y.,East China University of Science and Technology | Xu H.,Collaborative Innovation Center for Petrochemical New Materials | Xu Y.,East China University of Science and Technology | And 2 more authors.
Journal of Materials Chemistry B | Year: 2016

Well-defined diselenide-centered biodegradable tri-block copolymers methoxyl poly(ethylene glycol)-b-poly(ϵ-caprolactone)-b-methoxyl poly(ethylene glycol) (mPEG-PCL-Se)2 were precisely synthesized by the combination of ring opening polymerization using di(1-hydroxyethylene) diselenide as a new initiator and a facile coupling reaction. The amphiphilic block copolymers enabled the formation of self-assembled micelles which revealed an excellent reductive response to glutathione (GSH) due to the unique reduction-responsive cleavage of the diselenide bond. Such GSH response ensured an enhanced release of anticancer drugs (DOX) from the micelles in simulative tumor microenvironments; moreover, the drug release could be changed to some extent through fine-tuning the chemical composition of the copolymers. Flow cytometry and confocal laser scanning microscopy (CLSM) measurements confirmed that the DOX-loaded micelles could be efficiently taken up by oral squamous carcinoma (HN30) cells and DOX was released into the nuclei of cancer cells following 4 h of incubation. The cell viability assays showed the diselenide-containing polymers were nontoxic up to a tested concentration (400 μg mL-1), while the DOX-loaded micelles exhibited an evident inhibition toward HN30 cells. Therefore, the reduction-labile biodegradable (mPEG-PCL-Se)2 may offer an alternative platform for tumor-targeting therapy. © The Royal Society of Chemistry 2016.

Lu L.,Anqing Teachers College | Lu L.,Collaborative Innovation Center for Petrochemical New Materials | Huang X.,Shandong University | Dong Y.,Anqing Teachers College | And 6 more authors.
Microchimica Acta | Year: 2015

A method is described for in-situ electrochemical preparation of nanoporous gold electrodes (np-GEs) via alloying and dealloying using ethylene glycol (EG) as a solvent. The np-GEs were prepared via cyclic voltammetry from a gold electrode in the presence of ZnCl2 in EG. Effects of temperature, number of scan cycles and scan rate were investigated. It is concluded that the process involves formation of interfacial elemental zinc and the formation of a gold-zinc alloy. At a temperature of 120 °C, the alloy is formed already after the first scan cycle, and ten further cycles do not cause substantial further changes in the morphology. Changes in the morphology were corroborated by data on the electroactivity of the np-GEs. The mechanism of the formation of np-GEs in EG obviously is different from that in other solvents due to the superior smoothing ability of EG for electroplating. This results in more uniform alloy layers and in a more evenly distributed porous structure. The self-supporting np-GE without any further modification displays an amperometric response to catechol (at a working voltage of 420 mV vs. SCE) in the 0.050 to 1.0 mM concentration range, with a detection limit of 1.78 μM (at an S/N of 3), indicating that the np-GE can be applied to convenient and effective determination of catechol. [Figure not available: see fulltext.] © 2015, Springer-Verlag Wien.

PubMed | East China University of Science and Technology and Collaborative Innovation Center for Petrochemical New Materials
Type: | Journal: Materials science & engineering. C, Materials for biological applications | Year: 2016

Drug-eluting stents with biodegradable polymers as reservoirs have shown great potential in the application of interventional therapy due to their capability of local drug delivery. Herein, poly(l-lactide-co--caprolactone) (PLCL) with three different compositions as carriers for ciprofloxacin lactate (CIP) was coated on ureteral stents by the dipping method. To simulate a body environment, degradation behavior of PLCL as both the bulk film and the stent coating was evaluated in artificial urine (AU, pH6.20) respectively at 37C for 120days by tracing their weight/Mn loss, water absorption and surface morphologies. Furthermore, the release profile of the eluting drug CIP on each stent exhibited a three-stage pattern, which was greatly affected by the degradation behavior of PLCL except for the burst stage. Interestingly, the degradation results on both macroscopic and molecular level indicated that the release mechanism at stage I was mainly controlled by chain scission instead of the weight loss or morphological changes of the coatings. While for stage II, the release profile was dominated by erosion resulting from the hydrolysis reaction autocatalyzed by acidic degradation residues. In addition, ciprofloxacin-loaded coatings displayed a significant bacterial resistance against E. coli and S. aureus without obvious cytotoxicity to Human foreskin fibroblasts (HFFs). Our results suggested that PLCL copolymers with tunable degradation rate as carriers for ciprofloxacin lactate could be used as a promising long-term antibacterial coating for ureteral stents.

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