JOURNAL OF APPLIED POLYMER SCIENCE
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2019
·Vol. 137
·期 8
·48391
·
IF 2.188
Zhaofu Zhang,Shuo Wang,Geoffrey I. N. Waterhouse,Qihai Zhang,Lifang Li
Temperature-sensitive hydrogels are attracting increasing attention for controlled drug delivery. However, achieving high drug loadings and sustained drug release remains challenging. Herein, we describe the successful synthesis of a series of novel temperature-sensitive poly( N -isopropylacrylamide) (PNIPA)/mesoporous silica nanoparticles (MSN) hydrogels by physical crosslinking of NIPA with MSN. The external and internal structures, temperature sensitivity, drug-loading capacity, and blood compatibility of the PNIPA/MSN composite hydrogels are studied. Results show that MSN addition improved the network structure and adjusted the size of the hole, MSN could also act as drug carrier, thereby enhancing the drug loading capacity. The composite hydrogels underwent a phase transition at 33.7 °C (at the lower critical solution temperature). The hemolysis rate of the composite hydrogels was less than 1%, thus they can be classified as a nonhemolytic materials with good biocompatibility. The composite hydrogels reported here thus have great potential in drug transport and temperature-activated drug release. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48391.
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INORGANIC CHEMISTRY
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2018
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IF 4.7
Xiaofang Li,Chen Chen,Wenhua Xue,Shan Li,Feng Cao,Yuexing Chen,Jiaqing He,Jiehe Sui,Xingjun Liu,Yumei Wang,Qian Zhang
An n-type Bi-doped SnSe was synthesized by a facile solution method followed by spark plasma sintering. We used bismuth(III) 2-ethyhexanoate as a cationic dopant precursor, which can absorb on the powder surface and then diffuse into the lattice to realize the substitution of Sn by Bi. A strip structure with low-angle boundary was constructed for effective phonon scattering. With increasing content of Bi, the carrier concentration decreased from 1.35 × 1019 cm–3 (p-type) in undoped SnSe to 4.7 × 1014 cm–3 (n-type) in Sn0.99Bi0.01Se and then increased to 1.3 × 1015 cm–3 (n-type) in Sn0.97Bi0.03Se. The Seebeck coefficient changed from positive to negative and presented n-type conducting behavior in the whole measured temperature range from 300 to 773 K, reaching a maximum absolute value of ∼900 μV K–1 at room temperature and ∼300 μV K–1 at 773 K. Considering the rich variety of metal 2-ethylhexanoates, higher thermoelectric performance is expected by different cationic doping in solution-synthesized nanomaterials.
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CHEMICAL ENGINEERING & TECHNOLOGY
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2018
·Vol. 41
·期 6
·1180-1187
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IF 1.588
Haijiao Lu,Jingkang Wang,Beiqian Tian,Xin Huang,Jingtao Bi,Ting Wang,Hongxun Hao
As persistent and detrimental contaminants, azo dyes are difficult to be removed from wastewater. It is a worldwide challenge to develop efficient technologies for their removal. Adsorption is widely recognized to be a practical, efficient, and low-cost technology for removal of contaminants. Compared with various conventional adsorbents, MoS 2 nanocrystals possess larger specific surface area, higher surface energy, and better adsorptive properties. Since nitrogen-doping is a common approach for modification of materials, N-doped MoS 2 nanocrystals (NDMN) were first used as adsorbents for removal of the azo dye methyl orange. Compared with bulk MoS 2 and MoS 2 nanocrystals, NDMN showed much higher efficiency and reusability. This study provides inspiration for exploring and expanding the applications of NDMN.
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Nano Research
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2018
·Vol. 11
·期 4
·1905-1916
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IF 7.994
Jia Nan,Weng Qiang,Shi Yaru,Shi Xinyan,Chen Xinbing,Chen Pei,An Zhongwei,Chen Yu
Highly efficient metal-free, carbon-based, bi-functional electrocatalysts for the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) have attracted increased attention for use in electrochemical energy conversion systems, owing to their low cost and high activity. In this work, N-doped carbon nanocages (N-CCs) with a porous self-supported architecture and high specific surface area are synthesized by a facile interfacial assembly synthetic route. The materials are comprehensively characterized by scanning electron microscopy, transmission electron microscopy, nitrogen adsorption–desorption experiments, X-ray diffraction, and X-ray photoelectron spectroscopy. Cyclic voltammetry, chronoamperometry, and linear sweep voltammetry demonstrate that the as-prepared N-CC could serve as an effective metal-free electrocatalyst with excellent catalytic activity, long-term operation durability, and excellent methanol tolerance for the ORR in alkaline media. In the presence of 3 mM methanol, the half wave potential of the N-CCs for the ORR is 190 mV; this is more positive than that of the commercial Pt/C electrocatalyst. Meanwhile, the N-CCs also show an OER activity comparable to that of the commercial Ru/C electrocatalyst, revealing their bifunctional property.
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CARBOHYDRATE POLYMERS
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2013
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IF 3.479
Jing Wang,Xuesong Zhou,Huining Xiao
Semi-interpenetrating polymer network (SIPN) strategy was employed to fabricate a kind of novel hydrogels composed of cellulose and poly( N -isopropylacrylamide) (PNIPAAm) in the presence of N , N ′-methylenebisacrylamide (MBAAm) as the crosslinker and benzoyl peroxide (BPO) as the initiator. The results from FTIR and TGA indicated that the network indeed existed in the SIPN hydrogels. The data from experiments, those related to the swelling behavior of the hydrogels at different temperatures in particular, demonstrated the thermal sensitivity of these hydrogels. The impact of crosslinker content on the hydrogel properties was discussed as well. The swelling ratio of hydrogels decreased with increasing the content of MBAAm. Besides, the loading and releasing behavior of the hydrogels were examined using dimethyl methylene blue as a model drug. These novel hydrogels combining the advantages of natural polymer with thermal responsive behavior are of great potential to be applied to drug delivery and control release systems.
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Neural Regeneration Research
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2013
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IF 0.144
Yi Zhang,Shu Zhao,Weiren Dong,Suifen He,Haihong Wang,Lihua Zhang,Yinjuan Tang,Jiasong Guo,Suiqun Guo
The sonic hedgehog protein not only plays a key role in early embryonic development, but also has essential effects on the adult nervous system, including neural stem cell proliferation, differentiation, migration and neuronal axon guidance. The N-terminal fragment of sonic hedgehog is the key functional element in this process. Therefore, this study aimed to clone and analyze the N-terminal fragment of the sonic hedgehog gene. Total RNA was extracted from the notochord of a Sprague-Dawley rat at embryonic day 9 and the N-terminal fragment of sonic hedgehog was amplified by nested reverse transcription-PCR. The N-terminal fragment of the sonic hedgehog gene was successfully cloned. The secondary and tertiary structures of the N-terminal fragment of the sonic hedgehog protein were predicted using Jpred and Phyre online.
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FIRE SAFETY JOURNAL
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2014
·
IF 1.063
Yan Liu,Zhenhu Cao,Yan Zhang,Zhengping Fang
Zinc N -morpholinomethylphosphonic acid (MMPA-Zn) is synthesized by hydrothermal reactions used zinc acetate and N -morpholinomethylphosphonic acid as raw materials. TGA shows that the TG onset temperature of decomposition of MMPA-Zn is 391 °C and the final residue at 700 °C is 65.3 wt%, indicating its good thermal stability and char-forming ability. Then, MMPA-Zn is used as flame retardant in high density polyethylene (HDPE). The thermal property and flame retardancy of various HDPE compositions were investigated by TGA and cone calorimeter (Cone). TG data show that MMPA-Zn can improve the thermal stability and char residue yield, which is dependent on the loading amount of MMPA-Zn. The Cone data indicate that the PHRR and the emission of CO decreased obviously because of the joint effect of Zn and the MMPA in MMPA-Zn molecular, which can yield more char residue in the HDPE/MMPA-Zn system.
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Journal of Physical Chemistry C
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2013
·
IF 4.814
Zhiqiao He,Yuanqiao Shi,Chao Gao,Lina Wen,Jianmeng Chen,Shuang Song
A novel visible-light-active BiOCl/BiVO4 photocatalyst with a p–n heterojunction structure was prepared using a hydrothermal method. The photocatalytic activity of the heterojunction was investigated by monitoring the change in methyl orange (MO) concentration under visible-light irradiation. The results reveal that the composite exhibited markedly improved efficiency for MO photodegradation in comparison with pure BiVO4, BiOCl, and Degussa P25. This is ascribed to the B-type heterojunction structure with a strong oxidative ability and efficient charge separation and transfer across the BiOCl/BiVO4 p–n junction. The highest activity was obtained in the BiOCl/BiVO4 heterojunction using a composite of 13 mol % BiOCl and 87 mol % BiVO4. The removal of MO was mainly initiated by valence-band holes, but dissolved oxygen also played a crucial role in consuming the conduction-band electrons. This was verified by the effects of scavengers and N2 purging.
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COMBUSTION SCIENCE AND TECHNOLOGY
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2013
·
IF 1.011
Ming-Di Li,Zhong Wang,Yang Zhao,Rui-Na Li,Shuai Liu
An experimental study was reported on premixed ethanol/n-heptane/oxygen/argon flames at low pressure (4.655 kPa) with ethanol blending ratios of 0 (Flame 1), 15% (Flame 2), and 30% (Flame 3). The equivalence ratio was 1.0. Flame species were identified using molecular beam mass spectrometry with tunable synchrotron photoionization. The flame temperature profiles were measured with a Pt-6%Rh/Pt-30%Rh thermocouple. The mole fraction profiles of major and intermediate flame species under different ethanol ratios were analyzed in this article. Experimental results showed that the temperature profiles of measured flames fall almost on a single curve, which means that ethanol had little effect on flame temperature. The peak mole fraction of the main combustion products occurred 2–6 mm above the burner. With the increase of ethanol blending ratios, the mole fractions of H2, CO, and CO2 decreased, the mole fraction of H2O increased, and the mole fractions of intermediate combustion products (C2H2, C2H4, HCHO, C3H3) decreased. During the combustion process, the oxygen atom of ethanol partly replaces the O2, thus the final mole fraction of O2 increased with the increase of ethanol ratios.
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ACS Applied Materials & Interfaces
·
2015
·
IF 6.723
Kai Jiang,Shan Sun,Ling Zhang,Yuhui Wang,Congzhong Cai,Hengwei Lin
Fluorescent carbon dots (CDs) have attracted much attention in recent years because of their superior optical and chemical properties, thus demonstrating many potential applications. However, the previously reported CDs mostly show strong emission only in the blue-light region, and the long-wavelength (i.e., yellow- to red-light) emissions are usually very weak. Such a drawback restricts their further applications, particularly in the biology-relevant fields. Herein, a rare example of N-doped CDs that emit bright-yellow fluorescence (i.e., y-CDs) is reported using 1,2,4-triaminobenzene as carbon precursor. The as-prepared y-CDs exhibit not only respectable emission quantum yield and highly optical stabilities but superior biocompatibility and biolabeling potentials. In addition, the y-CDs are found to show an interesting “ON–OFF–ON” three-state emission with the stepwise addition of Ag+ and cysteine (Cys), indicating potential applications as a bifunctional sensing platform. Thanks to the highly intense emission of y-CDs, the gradual quenching and restoration of their fluorescence with the addition of Ag+ and further Cys could also be observed with the naked eye. More importantly, the ensemble of the y-CDs and Ag+ demonstrates practicability for the highly selective and sensitive detection of Cys in human plasma samples with satisfactory results.
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Journal of Materials Chemistry A
·
2014
·Vol. 2
·期 30
·11768-11775
·
IF 0
Yi Yao,Hui Xiao,Peng Wang,Panpan Su,Zhigang Shao,Qihua Yang
The development of non-precious metal catalysts for oxygen reduction reactions (ORRs) is of extreme importance for the construction of efficient H2/O2 polymer electrolyte membrane fuel cells (PEMFCs), one of the most promising clean energy technologies. Herein, we report the fabrication of core–shell structured CNTs@Fe–N–C composites with a Fe–N–C shell closely wrapped around a core of CNTs (carbon nanotubes) as efficient catalysts for ORR. CNTs@Fe–N–C composites afford comparable activity to commercial Pt/C catalysts with a loading of 20 μg Pt cm−2 towards ORR in alkaline media. The results of XRD, TEM, XPS and 57Fe Mössbauer characterizations suggest that the high ORR activity of CNTs@Fe–N–C composites are mainly attributed to the combined advantages of the unique core–shell nanostructure allowing close contact between Fe–N–C and CNTs, uniformly distributed FeN4/C species, and the presence of pyridine and graphitic nitrogen.
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JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2013
·Vol. 160
·期 8
·B102
·
IF 2.588
Qian Han,Yonghua Wang,Yihan Huang,Liju Guo,Yingzi Fu
In the present study, a novel approach was designed to construct a reagentless chiral biosensor for highly selective recognition of N-isobutyryl-cysteine enantiomers. The reduced-graphene oxide sheets (rGO) and thionine (TH) were firstly stepwisely synthesized onto modified glassy carbon electrode using glutaraldehyde as a bifunctional reagent, and γ-globulin was adsorbed on the electrode surface as a chiral selector. TH-rGO with excellent redox electrochemical activities brought in more redox probes for chiral recogniton, which could improve the sensitivity of the biosensor. Good reproducibility and sufficient stability were obtained with the advantages of TH-rGO and glutaraldehyde reagent. Moreover, the proposed biosensor showed an obviously decreased current peak after adsorption of N-isobutyryl-L-cysteine isomer. As compared with penicillamine or cysteine enantiomers, the current biosensor showed good enantioselectivity for sensing N-isobutyryl-cysteine enantiomers.
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