Co-reporter:Haoquan Zhong, Chunchen Liu, Wenjiao Ge, Runcang Sun, Fei Huang, and Xiaohui Wang
ACS Applied Materials & Interfaces July 12, 2017 Volume 9(Issue 27) pp:22875-22875
Publication Date(Web):June 19, 2017
DOI:10.1021/acsami.7b06168
A fluorescent “turn-on” sensor for fast measurement of aliphatic biogenic amines (BAs) was developed based on fluorescent carboxylated polyfluorene (PFTBTCOOH)/chitosan-graft-oleic acid (CS-graft-OA) micelles. In this system, biobased CS-graft-OA micelles, prepared by graft modification of CS with OA, serve as the vector of the hydrophobic fluorescent probe. Bright turn-on fluorescence was achieved by the intermolecular fluorescence resonance energy transfer of the encapsulated PFTBTCOOH, driven by the formation of an electrostatic complex with aliphatic BAs, which facilitate visual identification. The peak intensity ratio of the PFTBTCOOH/CS-graft-OA micelles toward an increasing amount of aliphatic BAs was calibrated, giving a linear relationship. The fluorescence response of PFTBTCOOH/CS-graft-OA micelles to aliphatic BAs in milk and yogurt matrixes reaches a detection concentration as low as 10 μM, showing that the PFTBTCOOH/CS-graft-OA micelle solution is a potential chemosensor for fast and selective detection of trace aliphatic BAs, which is of great significance to public health and food safety.Keywords: aliphatic biogenic amines; amphiphilic chitosan derivative; carboxylated functionalized polyfluorene; chemosensor; micelles;
Co-reporter:Yang Yang, Runcang Sun, Xiaohui Wang
Materials Letters 2017 Volume 189() pp:248-251
Publication Date(Web):15 February 2017
DOI:10.1016/j.matlet.2016.12.024
•A flexible, porous and conductive textile has been fabricated via simple “dipping and drying” method with Ag nanowires ink.•These conductive textiles have high conductivity and excellent chemical and mechanical stabilities.•These conductive textiles exhibit good electrochemical performance with capacitance of 159 F g−1 in energy storage device.•These conductive textiles possess excellent photothermal conversion properties.Smart textiles are attracting increasing attention due to their tremendous applications in wearable devices. Herein, we report a flexible and conductive textile prepared via simple “dipping and drying” method with Ag nanowires (Ag NWs) ink. The obtained Ag NWs/cellulose textiles have very high conductivity(sheet resistance 0.2 Ω/sq) and excellent chemical and mechanical stabilities, showing great potential in wearable energy storage and photothermal conversion. The supercapacitor made from the Ag NWs/cellulose textile showed a higher capacitance (159 F g−1) than the textiles functionalized with single-walled carbon nanotube (SCNT) and graphene. Besides, they presented excellent photothermal conversion property with about 50% improvement in temperature compared with pure textile. These multifunctional textiles would provide new opportunities for flexible and wearable electronics and sensors.
Co-reporter:Haoquan Zhong;Jinming Zhang;Yanzhu Guo;Lu Wang;Wenjiao Ge;Meiwan Chen
Cellulose 2017 Volume 24( Issue 2) pp:889-902
Publication Date(Web):22 November 2016
DOI:10.1007/s10570-016-1126-4
Novel cellulose nanomicelles self-assembled from amphiphilic cellulose-graft-poly(p-dioxanone) (MCC-graft-PPDO) copolymer were used to encapsulate and disperse hydrophobic fluorescent conjugated polymers (FCPs) in water for tumor cell imaging. Three different conjugated polymers were employed to demonstrate the versatility of the cellulose nanomicelles, resulting in highly fluorescent and stable polymeric nanoparticles with different emission wavelengths across the visible spectrum. Owing to the size effect of cellulose nanomicelles, the incorporated conjugated polymers present red-shifted emission to low-energy sites, and the fluorescence self-quenching of conjugated polymers at high concentration can be greatly inhibited. The in vitro studies using the liver cancer Hep3B cells and the breast cancer MAD-MB-231 cells indicate these amphiphilic cellulose/FCPs nanomicelles have negligible cytotoxicity even at high concentration of up to 100 μg/mL. Moreover, the light-emitting micelles are successfully uptaken by the cancer cells and located at the cytoplasm of the cells, suggesting their great potential for tumor cell imaging and early detection of tumor cells.
Co-reporter:Zicheng Liang, Mijeong Kang, Gregory F. Payne, Xiaohui Wang, and Runcang Sun
ACS Applied Materials & Interfaces 2016 Volume 8(Issue 27) pp:17478-17488
Publication Date(Web):June 17, 2016
DOI:10.1021/acsami.6b04826
The recent discovery of biomass-derived carbon quantum dots (CQDs) offers the potential to extend the sensing and imaging capabilities of quantum dots (QDs) to applications that require biocompatibility and environmental friendliness. Many studies have confirmed the exciting optical properties of CQDs and suggested a range of applications, but realizing the potential of CQDs will require a deeper fundamental understanding of their photophysical behavior. Here, biomass-derived CQDs were synthesized by hydrothermal processing methods from the aminopolysaccharide chitosan, and their fluorescence quenching behaviors were investigated. A family of nitroaromatics with different ring substituents was used to generate systematically varying CQD-quenching behaviors. Experimental evidence including a correlation between quenching constant and spectral overlap, fluorescence lifetime decay, and donor–acceptor distance all demonstrate that the primary mechanism for QCD-quenching is Förster resonance energy transfer (FRET) and not electron transfer. Spectroelectrochemical studies with redox-dependent quenching molecules and studies with complex dye molecules further support this conclusion. We envision this fundamental understanding of CQDs will facilitate the application of these emerging nanomaterials for sensing and imaging.
Co-reporter:Zicheng Liang, Hui Chen, Xiaohui Wang, Runcang Sun
Dyes and Pigments 2016 Volume 125() pp:367-374
Publication Date(Web):February 2016
DOI:10.1016/j.dyepig.2015.10.045
The cost-effective and rapid detection of nitroaromatic explosives is highly desired for growing con cern about the environmental pollution and terror threats. Herein, a facile sensing system for fast and trace detection of nitroaromatic explosives (e.g. picric acid (PA) and 2,4-dinitrotoluene (DNT)) in aqueous solution is developed. In this system, the self-assembled nanomicelles of commercial available Pluronic F127 are selected as vesicles and fluorescent conjugated polymers poly(9,9′-dioctylfluorene) (PFO) and poly(2,7-(9,9-hexylfluorene)-alt-4,4′-phenylether) (PFPE) are used as sensing materials. Through the microextraction effect of F127 nanomicelles, the hydrophobic conjugated polymers can be well dispersed in aqueous media and effectively quenched by trace amount of PA or DNT based on electron transfer mechanism. In compare with the conjugated polymers dissolved in organic solvents, the conjugated polymers encapsulated in F127 nanomicelles show dramatically enhanced sensing selectivity and sensitivity. The current nitroaromatic explosives sensing system is versatile. These results suggest that the F127/conjugated polymers system is a feasible method for detecting nitroaromatic explosives in water.A novel sensing system, fabricated of F127 nanomicelles as vesicles and conjugated polymers PFO or PFPE as sensing materials, was developed for nitro explosives detection of in aqueous media.
Co-reporter:Yang Yang, Yanzhu Guo, Runcang Sun, Xiaohui Wang
Carbohydrate Polymers 2016 Volume 145() pp:56-63
Publication Date(Web):10 July 2016
DOI:10.1016/j.carbpol.2016.03.012
•A new amphiphilic cellulose derivative (HEC-g-LA) was prepared.•HEC-g-LA can form stable nanomicelles in water.•HEC-g-LA micelles have good encapsulation efficiency and drug loading ability for β-carotene.•β-carotene loaded HEC-g-LA micelle showed a sustained release behavior in PBS medium.•Those nanomicelles are potential nanocarriers of hydrophobic active compounds for functional food applications.A series of linoleic acid conjugated hydroxyethyl cellulose polymers (HEC-g-LA) were synthesized and characterized. And their solubilities in a variety of solvents were compared. The prepared HEC-g-LA polymers showed typical properties of amphiphilic polymers and were able to self-assemble into spherical nanomicelles in aqueous solution. The micelle sizes and critical micelle concentrations (CMC) were found correlated with the molecular structure of polymers, and were varied in the range of 20–50 nm and 1.92–21.76 μg/ml, respectively. Furthermore, the hydrophobic active component β-carotene (β-C) was successfully encapsulated into the HEC-g-LA micelles by sonication-dialysis method. The β-C encapsulation efficiency and loading content were found to be as high as 84.67% (w/w) and 4.23%. The results of in vitro release showed that the encapsulated β-C was continuously released from the micelles in phosphate buffered saline (PBS) medium for about 7 days. The self-assembled HEC-g-LA nanomicelles are potential nanocarriers of hydrophobic active compounds for functional food applications.
Co-reporter:Yanzhu Guo;Li Zhang;Haiming Li;Ying Han;Jinghui Zhou
Colloid and Polymer Science 2016 Volume 294( Issue 1) pp:135-143
Publication Date(Web):2016 January
DOI:10.1007/s00396-015-3736-z
A series of α-tocopherol succinate-conjugated hydroxyethyl cellulose (HEC-TOS) polymers were synthesized in this study. The weight percentages of TOS in HEC-TOS were varied from 15 to 36 % by adjusting the weight ratios of TOS to HEC from 1:4 to 5:2. The HEC-TOS polymers exhibited typical properties of amphiphilic polymers and were able to self-assemble into spherical nanomicelle in aqueous solution as revealed by TEM. The micelle sizes and critical micelle concentrations (CMC) of HEC-TOS conjugates were correlated with their molecular structures and were in the range of 24.5–115.1 nm and 16–99 μg/ml, respectively. Paclitaxel (PTX) was encapsulated into the core of HEC-TOS micelle by sonication-dialysis method. The highest loading concentration of PTX in micelle was 315 mg/ml, which was about 50 times higher than that in water (6 mg/l). The in vitro study showed that PTX was continuously released from PTX-loaded micelle in phosphate buffered saline (PBS) medium for 108 h.
Co-reporter:Yang Yang;Chen Sun;Dr. Hin-Lap Yip;Dr. Runcang Sun;Dr. Xiaohui Wang
Chemistry – An Asian Journal 2016 Volume 11( Issue 6) pp:893-899
Publication Date(Web):
DOI:10.1002/asia.201501425
Abstract
Biomimetic mineralization is a powerful approach for the synthesis of advanced composite materials with hierarchical organization and controlled structure. Herein, chitosan was introduced into a perovskite precursor solution as a biopolymer additive to control the crystallization and to improve the morphology and film-forming properties of a perovskite film by way of biomineralization. The biopolymer additive was able to control the size and morphology of the perovskite crystals and helped to form smooth films. The mechanism of chitosan-mediated nucleation and growth of the perovskite crystals was explored. As a possible application, the chitosan–perovskite composite film was introduced into a planar heterojunction solar cell and increased power conversion efficiency relative to that observed for the pristine perovskite film was achieved. The biomimetic mineralization method proposed in this study provides an alternative way of preparing perovskite crystals with well-controlled morphology and properties and extends the applications of perovskite crystals in photoelectronic fields, including planar-heterojunction solar cells.
Co-reporter:Wenjiao Ge, Dong Li, Meiwan Chen, Xiaohui Wang, Shijie Liu, Runcang Sun
Carbohydrate Polymers 2015 Volume 117() pp:169-176
Publication Date(Web):6 March 2015
DOI:10.1016/j.carbpol.2014.09.056
•The self-assembled chitosan-based micelles were used for encapsulation of β-carotene.•The β-carotene loaded chitosan nanomicelles possessed good stability.•The β-carotene loaded micelles showed significantly improved antioxidant activities.β-Carotene (β-C) is a well-established natural antioxidant agent, but its poor water-solubility, low chemical stability and low bioavailability limit its application in food, pharmaceuticals and cosmetics industries. Thus it is critical to develop an efficient method to improve the water solubility and stability of β-C. In this research, amphiphilic chitosan-graft-poly (lactide) (CS-g-PLA) copolymer was synthesized via a homogeneous ring-opening polymerization (ROP) in ionic liquid. The obtained CS-g-PLA copolymer was able to self-assemble into about 14 nm micelles in water at low concentration, and β-C loaded micelles (β-C/M) had low β-C degradation after 15 days. The antioxidant properties of the β-C/M were investigated by the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) method and ferric reducing antioxidant power (FRAP) method, respectively. Significantly improved antioxidant activity was observed for β-C/M in compare with free β-C. The aqueous dispersion of β-C/M has potential to be applied in the field of functional food and cosmetics.
Co-reporter:Wenjiao Ge;Yanzhu Guo;Haoquan Zhong;Runcang Sun
Cellulose 2015 Volume 22( Issue 4) pp:2365-2374
Publication Date(Web):2015 August
DOI:10.1007/s10570-015-0663-6
In response to the shortage of petroleum resources and the growing need for sustainable development, cellulose-based amphiphilic copolymers have emerged as a new generation of value-added functional nanostructures from biomass resources. In this article, 17 amphiphilic hydroxyethyl cellulose-based graft copolymers with different side chains, including poly(lactide), poly(ε-caprolactone) and poly(p-dioxanone), were synthesized via homogeneous ring opening polymerization in ionic liquid 1-butyl-3-methylimidazolium chloride and characterized by FT-IR, 1H NMR, thermogravimetric analysis and gel permeation chromatography. The resultant copolymers can self-assemble into micelles with a low critical micelle concentration that varies in the range of 0.03–0.24 mg/ml. TEM observations revealed the obtained micelles had a spherical and well-distributed morphology, and DLS analysis showed the nanoscaled sizes were between 40 and 150 nm. These HEC-based micelles can be used as nano-sized vesicles and have great latent forces in drug delivery systems.
Co-reporter:Zicheng Liang, Lei Zeng, Xiaodong Cao, Qun Wang, Xiaohui Wang and Runcang Sun
Journal of Materials Chemistry A 2014 vol. 2(Issue 45) pp:9760-9766
Publication Date(Web):25 Sep 2014
DOI:10.1039/C4TC01714E
High quality blue fluorescent carbon quantum dots (CDs) were fabricated from a dilute NH4OH/water solution of waste biomass via one-step hydrothermal carbonization. Different from conventional synthesis methods, NH4OH was used as the solvent as well as passivation agent rather than organic amine compounds. The best quantum yield (QY) of the nitrogen-doped biomass CDs was up to 16%, which was higher than the non-doped CDs (only 2%) and those passivated by organic molecules (7%). Further investigations revealed the unique emission behaviours of the NH4OH-passivated CDs dependent on excitation, pH values and solvents and interesting up-conversion photoluminescence. In addition, an in vitro cytotoxicity test demonstrated the negligible toxicity of NH4OH-passivated CDs, and they were successfully applied in bio-imaging of murine embryonic stem cells. This low-cost and green chemistry method provides a feasible route for value-added and sustainable utilization of waste biomass.
Co-reporter:Xinliang Ye, Jie Zhang, Hui Chen, Xiaohui Wang, and Fei Huang
ACS Applied Materials & Interfaces 2014 Volume 6(Issue 7) pp:5113
Publication Date(Web):March 13, 2014
DOI:10.1021/am500270a
Novel self-assembled water-soluble nanomicelles that contain fluorescent conjugated polymers (poly(9,9-dioctylfluorene) (PFO) or poly[2,7-(9,9-dihexylfluorene)-alt-4,4′-phenylether] (PF-PE)) have been obtained and used as the highly sensitive/selective platform for Sudan dye detection. The Fluorescent nanomicelles exhibited a highly selective fluorescence quenching by the prohibited food additive Sudan I, while not for the natural pigments: Capsanthin and Beta-carotene, due to the more suitable matching of the LUMOs (lowest unoccupied molecular orbital) of the conjugated polymers with that of Sudan I molecules. The Stern–Volmer constants (KSV) of PF-PE/F127 and PFO/F127 for Sudan I were 1 040 480 and 665 000 M–1, respectively, which were more than 100 times higher than those of the same conjugated polymers in the orgainc solvents. The significantly enhanced sensitivity was due to the collective effect of the F127 micelles to both chromophore and analyte, through which the fluorophone–analyte binding interaction is significantly strengthened and efficient photoinduced charge transfer occurs. The as-proposed materials and approach may be potentially applied in the real-time food safety screening.Keywords: amphiphilic polymer carriers; biological sensing; conjugated polymers nanomicelles; hydrophobic synthetic dyes; self-assembly;
Co-reporter:Hui Chen, Meiwan Chen, Xiaohui Wang and Runcang Sun
Polymer Chemistry 2014 vol. 5(Issue 14) pp:4251-4258
Publication Date(Web):05 Mar 2014
DOI:10.1039/C4PY00120F
A novel sensing colloidal nanoprobe and indicator paper based on fluorescent carboxymethyl chitosan grafted poly(p-dioxanone) (CMCs-g-PPDO) copolymer nanomicelles which encapsulate hydrophobic conjugated polymer-poly(9,9-dioctylfluorene) (PFO) were developed for the fast and sensitive determination of banned food dye Sudan I. The PFO/CMCs-g-PPDO colloidal solution can selectively detect Sudan I in aqueous media among commonly appearing natural pigments: β-carotene, Monascorubrin and Lycopene. The sensing constant (Ksv) for the PFO/CMCs-g-PPDO aqueous solution toward Sudan I was 1.74 × 107 M−1, which was over 400 times larger than that of single PFO in toluene solution, due to the maximized interaction between the sensing material and the analyte within the chitosan-based nanomicelles. The fluorescent indicator paper functionalized with PFO/CMCs-g-PPDO also showed outstanding selectivity for Sudan I. By using this flexible and portable indicator paper, Sudan I dye could be immediately and visually distinguished from natural pigments. This material could be used for real-time and on-site food safety testing.
Co-reporter:Yanzhu Guo, Xiaohui Wang, Zuguang Shen, Xuancai Shu, Runcang Sun
Carbohydrate Polymers 2013 Volume 92(Issue 1) pp:77-83
Publication Date(Web):30 January 2013
DOI:10.1016/j.carbpol.2012.09.058
Self-associating cellulose-graft-poly(ɛ-caprolactone) (cellulose-g-PCL) copolymers were successfully synthesized via homogeneous ring-opening polymerization (ROP) of ɛ-CL onto softwood dissolved pulp substrate in ionic liquid 1-N-butyl-3-methylimidazolium chloride ([Bmim]Cl). An organic catalyst N,N-dimethylamino-4-pyridine (DMAP) was compared with the traditional metal-based catalyst (Sn(Oct)2) as the catalyst of the reaction, and exhibited higher catalytic activity. By controlling the cellulose:ɛ-CL feed ratio and reaction temperature, the molecular architecture of the copolymers can be altered, as evidenced by FT-IR, 1H NMR, 13C NMR, TGA and XRD. The self-assembly behavior of the copolymers in water was investigated and characterized using fluorescence probe, dynamic light scattering (DLS) and SEM. The results showed that the cellulose-g-PCL copolymers could form nanosized micelles (approximately 20–100 nm) in water, and the micelle size and critical micelle concentration (CMC) can be controlled by varying the grafting ratio of PCL. These cellulose-based nanomicelles are expected to be useful in broad application fields.Highlights► Novel biodegradable cellulose-g-PCL micelles were developed from dissolved pulp. ► Controlled molecular architecture was achieved by homogeneous ROP in ionic liquid. ► Cellulose-g-PCL copolymers can self-assemble into 20–100 nm nanomicelles in water. ► The self-assembly behaviors are correlated with the copolymer architecture.
Co-reporter:Xiaohui Wang, Yanzhu Guo, Dong Li, Hui Chen and Run-cang Sun
Chemical Communications 2012 vol. 48(Issue 45) pp:5569-5571
Publication Date(Web):07 Feb 2012
DOI:10.1039/C2CC30208J
A novel fluorescent amphiphilic cellulose nanoaggregates sensing system is designed and applied in detecting explosives in aqueous solution. Due to the maximized interaction between sensing material and analyte within the cellulose-based nanoaggregates, significantly enhanced sensitivity with 50-fold higher quenching efficiency is obtained.
Co-reporter:Yanzhu Guo, Xiaohui Wang, Xuancai Shu, Zuguang Shen, and Run-Cang Sun
Journal of Agricultural and Food Chemistry 2012 Volume 60(Issue 15) pp:3900-3908
Publication Date(Web):March 22, 2012
DOI:10.1021/jf3001873
A series of amiphiphilic cellulose-based graft copolymers (MCC-g-PLA) with various molecular factors were synthesized in ionic liquid BmimCl and characterized by FT-IR, 1H NMR, 13C NMR, XRD, and TGA. Their solubility in a variety of solvents was compared. The prepared MCC-g-PLA copolymers can self-assemble into spherical nanomicelles (10–50 nm) in aqueous solution. The self-assembly behaviors of the MCC-g-PLA copolymers were systematically investigated by fluorescence probe. Furthermore, the hydrophobic antitumor drug paclitaxel (PTX) was successfully encapsulated into the MCC-g-PLA micelles. The drug encapsulation efficiency and loading content were found to be as high as 89.30% (w/w) and 4.97%, respectively. Results in this study not only suggest a promising cellulose-based antitumor drug carrier but also provide information for property-directed synthesis of the cellulose graft PLA copolymers.
Co-reporter:Xiaohui Wang, Dong Li, Yanzhu Guo, Xiaoying Wang, Yumin Du, Runcang Sun
Optical Materials 2012 Volume 34(Issue 4) pp:646-651
Publication Date(Web):February 2012
DOI:10.1016/j.optmat.2011.09.013
Employing a biomimic method using polysaccharide as template, luminescent lanthanide ions doped CdS and ZnS quantum dots (QDs) were prepared. According to the results of TEM and absorbance, nanocrystals with an average size of 6 nm were formed under mild condition without any toxic and expensive agent applied. Differentiating from the un-doped CdS and ZnS QDs prepared in polysaccharide template, the lanthanide doped QDs exhibited obvious dopant emission in their photoluminescence spectrum. It was also found that the dopant PL became more prominent with increasing lanthanide doping concentration, while the highest PL intensity was obtained at a doping level of 1% for both of CdS and ZnS QDs. When different lanthanide ions were introduced into the CdS QDs in polysaccharide template, varied emission wavelength were able to be obtained. This study provides an easy, mild and environmental friendly alternative method to prepare doped quantum dots. In addition, the bioactivity and processabilities endowed by the polysaccharide template may expand the applications potential of this type of optical materials.Highlights► Luminescent lanthanide doped CdS and ZnS quantum dots are prepared in polysaccharide template. ► The doped quantum dots have controllable size. ► The nanocomposites have impurity doping concentration related photoluminescence. ► This nanocomposite is good candidate for extended applications.
Co-reporter:Yanzhu Guo;Dong Li;Hong Du;Xiaoying Wang;Runcang Sun
Polymer Bulletin 2012 Volume 69( Issue 4) pp:389-403
Publication Date(Web):2012 August
DOI:10.1007/s00289-012-0729-7
In this paper, a series of cellulose-based hydrophobic associating polymers were prepared by homogeneous acylation of microcrystalline cellulose with long-chain acyl chlorides including octanoyl, lauroyl, and palmitoly chlorides in the solvent of N,N-dimethylacetamide/lithium chloride (DMAc/LiCl) using pyridine as acid scavenger. Through controlling the chain length of fatty acyl chlorides and the molar ratio of acyl chlorides vs anhydroglucose unit, the hydrophobic cellulose derivatives with degrees of substitution in the range of 0.02–1.75 were successfully obtained. The chemical structures and properties of these hydrophobic derivatives were characterized by elemental analysis, FT-IR, CP/MAS 13C NMR, X-ray diffraction, and the thermogravimetry analysis. It was also found that, the cellulose-based polymers achieved an excellent solubility in organic solvents, such as benzene, methylbenzene, and pyridine, with the introduction of hydrophobic side chain into the cellulose backbone. Furthermore, it was found that these hydrophobic cellulose derivatives could self-assemble into spherical nanoparticles in aqueous solution, which indicates a tremendous potential of applications in pharmaceutical and medical fields.
Co-reporter:ShengJian Liu;ChengMei Zhong;Jie Zhang;ChunHui Duan
Science China Chemistry 2011 Volume 54( Issue 11) pp:1745-1749
Publication Date(Web):2011 November
DOI:10.1007/s11426-011-4386-8
A novel crosslinkable water/alcohol soluble conjugated polymer PFN-C containing oxetane groups and aminoalkyl groups in the side chains has been developed and used as highly efficient electron injection and transporting material for polymer light-emitting diodes (PLEDs). The unique solubility in polar solvents and crosslinkable ability of PFN-C render it a good candidate for solution processed multilayer PLEDs. It was found that PFN-C can greatly enhance the electron injection from high work-function metal cathode, due to its pendant amino groups. As a result, PLEDs with PFN-C/Al cathode exhibited comparable device performance to the devices with Ba/Al cathode. The resulting green light-emitting device showed promising performance with a maximum luminance efficiency of 13.53 cd A−1.
Co-reporter:Chunhui Duan;Wanzhu Cai;Chengmei Zhong;Yanhu Li;Fei Huang;Yong Cao
Journal of Polymer Science Part A: Polymer Chemistry 2011 Volume 49( Issue 20) pp:4406-4415
Publication Date(Web):
DOI:10.1002/pola.24881
Abstract
Three narrow-band-gap conjugated copolymers based on indenofluorene and triphenylamine with pendant donor-π-acceptor chromophores were successfully synthesized by post-functionalization approach. All the polymers have good solubility in common solvents and excellent thermal stability. The photophysical properties, energy levels and band gaps of the polymers were well manipulated by introducing different acceptor groups onto the end of their conjugated side chains. By using different acceptor groups, the band gaps of the polymers were narrowed from 1.86 to 1.53 eV by lowering their lowest unoccupied molecular orbital levels, whereas their relatively deep highest occupied molecular orbital levels of approximately −5.35 eV were maintained. Bulk-heterojunction solar cells with these polymers as electron donors and (6,6)-phenyl-C71-butyric acid methyl ester as acceptor showed power conversion efficiencies as high as 3.1% and high open circuit voltages more than 0.88 eV. The relationships between the performance and film morphology, energy levels, charge mobilities were discussed. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Co-reporter:Kai Zhang, Rongguo Xu, Wenjiao Ge, Meng Qi, Guangzhao Zhang, Qing-Hua Xu, Fei Huang, Yong Cao, Xiaohui Wang
Nano Energy (April 2017) Volume 34() pp:
Publication Date(Web):April 2017
DOI:10.1016/j.nanoen.2017.02.022
•Chitosan was used as cathode interlayer material in inverted organic solar cell by integrating self-assembly techniques.•The self-assembly process formed chitosan films were quite flat and uniform with controlled thickness on a nanometer scale.•Due to the highly ordered layer-by-layer chitosan films, both interfacial dipoles and molecular dipoles were formed.•With the modification of chitosan eLbL films, inverted OSCs exhibited power conversion efficiency (PCE) of 10.18%.In this work, we employed chitosan, which is the second most abundant biomass on earth after cellulose, and its derivatives as cathode interlayer (instead of substrate) materials in inverted organic solar cells (OSCs) by employing electrostatic Layer-by-Layer (eLbL) self-assembly technique. It was found that the eLbL self-assembly technique was a suitable strategy to obtain continuous films with full surface coverage, uniformity and controlled thickness under nanometer scale. What's more, due to the highly ordered layer-by-layer structure, both interfacial dipoles and molecular dipoles were formed and utilized to decrease the work function of the electrode and enhance device performance. With optimized chitosan eLbL films as cathode interlayer, inverted OSCs exhibited a power conversion efficiency (PCE) of 9.34%, which was approximately a 200% improvement over cells with no cathode interlayer. Moreover, the chitosan eLbL films can be utilized to improve the PCE of thick active layer (210 nm) OSCs to 10.18%.Chitosan and its derivatives were used as cathode interlayer materials in inverted organic solar cells (OSCs) by integrating electrostatic Layer-by-Layer (eLbL) self-assembly techniques. With the modification of chitosan eLbL films, inverted OSCs exhibited power conversion efficiency (PCE) of 9.34% with 100 nm active layer and 10.18% with 210 nm active layer.
Co-reporter:Yu Yang, Shengpeng Wang, Yitao Wang, Xiaohui Wang, Qun Wang, Meiwan Chen
Biotechnology Advances (15 November 2014) Volume 32(Issue 7) pp:
Publication Date(Web):15 November 2014
DOI:10.1016/j.biotechadv.2014.07.007
Nanomaterials based on chitosan have emerged as promising carriers of therapeutic agents for drug delivery due to good biocompatibility, biodegradability, and low toxicity. Chitosan originated nanocarriers have been prepared by mini-emulsion, chemical or ionic gelation, coacervation/precipitation, and spray-drying methods. As alternatives to these traditional fabrication methods, self-assembled chitosan nanomaterials show significant advantages and have received growing scientific attention in recent years. Self-assembly is a spontaneous process by which organized structures with particular functions and properties could be obtained without additional complicated processing or modification steps. In this review, we focus on recent progress in the design, fabrication and physicochemical aspects of chitosan-based self-assembled nanomaterials. Their applications in drug delivery of different therapeutic agents are also discussed in details.
Co-reporter:Xiaohui Wang, Yanzhu Guo, Dong Li, Hui Chen and Run-cang Sun
Chemical Communications 2012 - vol. 48(Issue 45) pp:NaN5571-5571
Publication Date(Web):2012/02/07
DOI:10.1039/C2CC30208J
A novel fluorescent amphiphilic cellulose nanoaggregates sensing system is designed and applied in detecting explosives in aqueous solution. Due to the maximized interaction between sensing material and analyte within the cellulose-based nanoaggregates, significantly enhanced sensitivity with 50-fold higher quenching efficiency is obtained.
Co-reporter:Yanpeng Li, Jinming Zhang, Yanzhu Guo, Meiwan Chen, Lu Wang, Runcang Sun and Xiaohui Wang
Journal of Materials Chemistry A 2016 - vol. 4(Issue 39) pp:NaN6461-6461
Publication Date(Web):2016/09/12
DOI:10.1039/C6TB01534D
Nanostructures encapsulating multiple quantum dots (QDs) are of special interests for live cell imaging and biomolecular recognition due to their inherent signal amplification. In this study, a novel type of biomass-based nanomicelles was prepared and characterized for facile loading and solubilization of fluorescent hydrophobic CdSe/ZnS QDs in water. The biobased nanomicelles were formed by the self-assembly of amphiphilic cellulose-graft-poly (p-dioxanone) (MCC-g-PPDO) synthesized via homogeneous ring-opening polymerization in an ionic liquid. Through a simple physical loading method, multiple lipophilic CdSe/ZnS QDs can be simultaneously encapsulated in one MCC-g-PPDO micelle showing an obviously enlarged micelle size, whereas the loaded QDs exhibited a negligible change in their size and size distribution. The QDs-loaded cellulosic micelles exhibited good optical stability, narrow emission bandwidth as well as an acceptable quantum yield of ∼27%. Successful tumor cell internalization and negligible cytotoxicity were observed with these light-emitting cellulosic micelles. It was found that over 90% of the cells were viable after 24 h of exposure and the fluorescent signal inside the cells reached a maximum after 2 h of exposure. These QDs-loaded cellulosic nanomicelles derived from biomass are a promising candidate for bioimaging or other functional applications.
Co-reporter:Zicheng Liang, Lei Zeng, Xiaodong Cao, Qun Wang, Xiaohui Wang and Runcang Sun
Journal of Materials Chemistry A 2014 - vol. 2(Issue 45) pp:NaN9766-9766
Publication Date(Web):2014/09/25
DOI:10.1039/C4TC01714E
High quality blue fluorescent carbon quantum dots (CDs) were fabricated from a dilute NH4OH/water solution of waste biomass via one-step hydrothermal carbonization. Different from conventional synthesis methods, NH4OH was used as the solvent as well as passivation agent rather than organic amine compounds. The best quantum yield (QY) of the nitrogen-doped biomass CDs was up to 16%, which was higher than the non-doped CDs (only 2%) and those passivated by organic molecules (7%). Further investigations revealed the unique emission behaviours of the NH4OH-passivated CDs dependent on excitation, pH values and solvents and interesting up-conversion photoluminescence. In addition, an in vitro cytotoxicity test demonstrated the negligible toxicity of NH4OH-passivated CDs, and they were successfully applied in bio-imaging of murine embryonic stem cells. This low-cost and green chemistry method provides a feasible route for value-added and sustainable utilization of waste biomass.
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