Polymer Chemistry
·
2019
·Vol. 10
·期 28
·3851-3858
·
IF 4.76
Jin'an Wu,Chunlai Ding,Dong Xing,Zhengbiao Zhang,Xiaofei Huang,Xiulin Zhu,Xiangqiang Pan,Jian Zhu
This paper describes a novel ε-caprolactone monomer modified by a phenylseleno group at the α-position of the carbonyl. Poly(α-phenylseleno caprolactone) (PCLSePh) with a well-controlled molecular weight and narrow molecular weight distribution (Đ < 1.20) was prepared through ring-opening polymerization. Hybrid polymers with properties superior to those of polyester materials were also prepared though selenide-mediated radical polymerizations under UV light irradiation. Subsequently, a carbon–carbon double bond was introduced into the main chain of the polymer by the oxidative elimination of the phenylseleno groups with high efficiency. Various side groups were further introduced into the polymer chain through a nucleophilic thiol–ene reaction. This strategy enables the synthesis of PCL with functional groups that allow the multifunctional integration of polyester materials. Furthermore, this monomer can be copolymerized with ε-caprolactone to form both random and block copolymers. The glass transition temperature, crystallinity and degradation rate of the copolymers can be adjusted both by oxidation and tuning the composition of the copolymer.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Huichang Li,Senlin Wang,Junhui Ye,Weijun Liang,Yanxiu Zhang,Jian Gu
A unique 3D hierarchical mesoporous Al-doped α-Ni(OH) 2 /reduced graphene oxide (NH/rGO) composite for supercapacitor has been successfully synthesized via homogeneous precipitation method. In this process, urea as the alkali source and mild reducing agent, to make graphene oxide (GO) convert into rGO. Thus, The NH uniformly grew on the rGO nanosheets . The as-prepared mesoporous NH/rGO composite exhibited high capacitance performance with a specific capacitance of 2558 F g −1 at the current density of 1 A g −1 , and presented good rate capability with still held 75.3% capacity at 30 A g −1 . Moreover, we used the NH/rGO as the positive electrode and the rGO aerogel as the negative electrode to assemble an asymmetric supercapacitor (ASC) device. This ACS device showed excellent specific energy of 166.97 Wh kg −1 at the power density of 0.38 kW kg −1 , and it still retains the specific energy of 100.91 Wh kg −1 under the higher specific power of 7.76 kW kg −1 . And it also displayed high rate performance and cycling durability with keeps 72% of the initial capacity after 3000 cycles (at 3 A g −1 ).
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES B-BIOINTERFACES
·
2019
·
IF 3.973
Lifen Wang,Pengpeng Xue,Mengqi Tong,Rui Chen,Waigeng Yang,Deli ZhuGe,Jiandong Yuan,Qing Yao,Yingzheng Zhao,Helin Xu
Inflammatory bowel diseases (IBDs) are chronic relapsing disorders of the gastrointestinal tract characterized pathologically by intestinal inflammation and epithelial injury. Laquinimod (LAQ), a poorly water-soluble compound, was proved to be effective for colitis remission at low dose of 0.5 mg/kg in patients with Crohn’s disease. Due to its extremely low solubility in water, it was difficult to develop an injectable liquid dosage form. Herein, D-α-Tocopheryl polyethylene glycol-1000 succinate (TPGS) polymeric micelles were developed as a delivery vehicle of LAQ for the management of inflammatory bowel disease. Using the LAQ/TPGS ratio of 1:100, LAQ-loaded micelles were successfully prepared by thin-film dispersion method. The solubility of LAQ in water was significantly increased from 10.5 μg/mL in pure water to 500 μg/mL in TPGS micelles. LAQ-loaded micelles of TPGS exhibited the fine particle size of 34.6 nm and Zeta potential of -0.67 mV. Moreover, the good stability of LAQ-loaded micelles in physiology-mimicking medium was confirmed by detecting their particle size, zeta potential and leakage of the loading drug. Therapeutic effect of LAQ-loaded micelles on DSS-induced mice was proved by detecting DAI score, colon length and loss of body weight. Moreover, the morphology and colonic mucosal barrier of the injured colon of DSS-induced mice was largely recovered after treatment with LAQ-loaded micelles. Meanwhile, the inflammation of colitis colon was also obviously alleviated by LAQ-loaded micelles. Conclusively, polymeric micelles of TPGS may be a promising delivery vehicle of LAQ for the management of inflammatory bowel disease.
✓ 已验证
DOI
PubMed
高影响因子
Algal Research-Biomass Biofuels and Bioproducts
·
2019
·
IF 3.723
Jiao Yang,Chang Liu,Hengjiang Cai,Dongyu Gu,Zhenni Ji,Xinfeng Guo,Jing Tian,Jing Meng,Yi Yang
Sargassum fusiforme is an edible alga that possesses a number of bioactivities , such as antidiabetic effects. In the present study, the n -hexane extract of S. fusiforme showed inhibitory activity against α-amylase. To interpret the α-amylase inhibitory activity of this extract, a method based on GC–MS and molecular docking was established. A total of 25 compounds were identified using GC–MS and then individually docked with α-amylase to simulate interactions between the latter and the ligands. Among the compounds determined, phenol, 2,2′-methylenebis[6-(1,1-dimethylethyl)-4-methyl- (PMDM) was completely enfolded in the active site of α-amylase via hydrophilic and electrostatic interactions, van der Waals forces, hydrogen bonds and π-π stacking interactions and showed the lowest binding energy (−6.25 kcal/mol). The activity of PMDM against α-amylase was further tested and verified in vitro, and its IC 50 was found to be 79.96 ± 0.34 μM. Thus, this compound is responsible for the α-amylase inhibitory activity of the n-hexane extract of S. fusiforme .
✓ 已验证
产品关联
DOI
高影响因子
Food & Function
·
2018
·Vol. 9
·期 7
·3974-3985
·
IF 3.289
Lei Wang,Chun Chen,Bin Zhang,Qiang Huang,Xiong Fu,Chao Li
A novel acidic polysaccharide (RTFP-3) was isolated and purified from Rosa roxburghii Tratt fruits. Structural analyses revealed that RTFP-3 is a homogeneous polysaccharide with a molecular weight of 67.2 kDa and mainly consists of arabinose (37.20%), galactose (34.40%), glucose (10.02%) and fucose (18.30%). The structural chain of RTFP-3 was proven to be composed of →6)-α-D-Galp-(1→, →4)-α-D-GalpA-(1→, →5)-α-L-Araf-(1→, →4)-β-D-Glcp-(1→, β-D-Glcp-(1→ and →3,4)-β-L-Fucp-(1→ residues by periodate oxidation–Smith degradation, methylation, and 1D- and 2D-NMR analyses. Bioassay results showed that RTFP-3 exerted favorable mixed type inhibitory activities against α-glucosidase, and its half inhibitory concentration (IC50) value was determined as 4.15 mg mL−1. RTFP-3 showed static type quenching of the intrinsic fluorescence of α-glucosidase, during which the binding process induced the conformational change of α-glucosidase. These results suggest that RTFP-3 has the potential to be a novel α-glucosidase inhibitory agent for use in functional foods.
✓ 已验证
DOI
PubMed
高影响因子
MOLECULES
·
2018
·Vol. 23
·期 10
·2518
·
IF 3.098
Xuan Zheng,Hongwei Wang,Peng Zhang,Lin Gao,Ning Yan,Panpan Li,Xinmin Liu,Yongmei Du,Guoming Shen
Chaenomeles speciosa(Sweet) Nakai is a medicinal plant. Until date, there are no studies focusing on comparing the chemical profiles, antioxidant activity andα-glucosidase inhibitory activity of the dried fruits ofC. speciosafrom different production regions. In the study, we investigated the chemical components of dried fruits ofC. speciosafrom Yunnan, Chongqing, Zhejiang and Anhui provinces in China in relation to the antioxidant activity andα-glucosidase inhibitory activity.C. speciosafrom Yunnan had higher total flavonoid (47.92 ± 3.79 mg/g), total polyphenol (29.15 ± 0.29 mg/g) and polysaccharide (27.60 ± 1.56 mg/g) contents than plants from other production areas. Samples from Yunnan, Zhejiang and Anhui (all > 3200 mg/kg) had higher free amino acid contents than those from Chongqing (2286.66 mg/kg). Oleanolic acid and ursolic acid levels were highest in samples from Zhejiang (555.98 ± 20.88 μg/g) and Anhui (321.06 ± 14.64 μg/g), respectively.C. speciosafrom Chongqing had low total flavonoid, total polyphenol, polysaccharide, free amino acid, oleanolic acid and ursolic acid contents but high levels of palmitic acid (12.04 ± 0.02 mg/g) and stearic acid (2.23 ± 0.08 mg/g). Among four production areas, Yunnan represented the highest antioxidant activity andα-glucosidase inhibitory activity. In addition, correlation analysis revealed that total flavonoid, total polyphenol, polysaccharide and ursolic acid were the major components responsible for the antioxidant activity ofC. speciosa, while total flavonoid and polysaccharide were the main contributors forα-glucosidase inhibitory activity of the plant. These results would be helpful for evaluating the quality ofC. speciosain the different production areas.Keywords:Chaenomeles speciosa;chemical composition;antioxidant activity;α-glucosidase inhibitory activity
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Lubricants
·
2018
·Vol. 6
·期 3
·63
·
IF 0
Yingjing Dai,Hong Xu,Jinxiang Dong
Vegetable oil has significant potential as a base oil, and substitute for mineral oil in grease formulation due to its biodegradability, low toxicity and excellent lubrication. This paper studied the development of vegetable oil-based greases with α-Zr(HPO4)2·H2O (α-ZrP) as an additive, exploring base oil influence in tribological behavior. The results demonstrated that the addition of α-ZrP in vegetable-based greases is beneficial to anti-wear property. α-ZrP particles exhibit good performance in anti-wear, friction-reduction and load-carrying capacity, and its tribological performances are better than the normally used molybdenum disulfide and graphite additives. Owing to its superior tribological properties as a vegetable oil-based grease additive, α-ZrP holds great potential for use in environmentally friendly applications in the future.Keywords:anti-wear additive;α-Zr(HPO4)·H2O;vegetable oil;anhydrous calcium grease
✓ 已验证
产品关联
DOI
POLYMER INTERNATIONAL
·
2018
·Vol. 68
·期 1
·151-159
·
IF 2.352
Jingshi Cao,Huaming Wang,Changlin Cao,Hongzhou Li,Liren Xiao,Qingrong Qian,Baoquan Huang,Qinghua Chen
Polydopamine (PDA) was employed to modify micrometric Al 2 O 3 platelets to improve the interfacial compatibility between α -Al 2 O 3 powder and ultrahigh-molecular-weight polyethylene (UHMWPE). The structure of PDA-coated Al 2 O 3 and UHMWPE composites was investigated via Fourier transform infrared spectroscopy, scanning electron microscopy and X-ray photoelectron spectroscopy. The thermal stability and mechanical performance of the samples were also evaluated. It is clear that UHMWPE/PDA-Al 2 O 3 composites exhibit better mechanical properties, higher thermal stability and higher thermal conductivity than UHMWPE/Al 2 O 3 composites, owing to the good dispersion of Al 2 O 3 powder in the UHMWPE matrix and the strong interfacial force between the macromolecules and the inorganic filler caused by the presence of PDA. The tensile strength and the tensile elongation at break of UHMWPE/PDA-Al 2 O 3 composite with 1 wt% PDA-Al 2 O 3 are 62.508 MPa and 462%, which are 1.96 and 1.98 times higher than those of pure UHMWPE, respectively. The thermal conductivity of UHMWPE/PDA-Al 2 O 3 composite increases from 0.38 to 0.52 W m −1 K −1 with an increase in the dosage of PDA-Al 2 O 3 to 20 wt%. The results show that the prepared PDA-coated Al 2 O 3 powder can simultaneously enhance the mechanical properties and thermal conductivity of UHMWPE. © 2018 Society of Chemical Industry
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Peng Zhou,Libao Chen,Mingyu Zhang,Qizhong Huang,Chao Cui,Xiu Li,Liping Wang,Liewu Li,Cheng Yang,Yuhao Li
Long-cycle-life and high-capacity nitrogen-doped carbon-coated α-MnSe nanofibers (α-MnSe/N-CNFs) electrodes were prepared by using an electrospinning process. The one-dimensional structural of α-MnSe/N-CNFs possesses great stability and play a key role in obtaining a long-cycle life for lithium-ion batteries. With nitrogen doping, improved pseudocapacitive behavior and conductivity were observed and the reversible capacity of the was increased to 956.3 mA h g −1 at 0.2 A g −1 after 200 cycles. The discharge capacity of α-MnSe/N-CNFs after 500 cycles reached 613.0 mA h g −1 even at a high current density of 1 A g −1 . The excellent electrochemical performance of α-MnSe/N-CNFs holds great promise as a candidate anode material for high-performance lithium-ion batteries.
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Zunlan Hu,Yiyao Ge,Jian Liu,Zhipeng Xie
In this paper, α-Si 3 N 4 nanobelts assembled by Si 3 N 4 microcrystals on the nanowires were synthesized from amorphous Si 3 N 4 powders that were prepared by thermolysis of silicon diimide powders. By prolonging the heating time at 1550 °C, the amorphous Si 3 N 4 powders were converted to hexagonal phase α-Si 3 N 4 microcrystals which were adhered to the surface of nanowires to obtain α-Si 3 N 4 nanobelts. The obtained α-Si 3 N 4 nanobelts were hollow in the centre with a width of ∼850 nm and a thickness of ∼150 nm. Microcrystals were deposited on the surface of 2–3 parallel nanowires. The diameter of the Si 3 N 4 microcrystals was 30–230 nm, and the diameter of the nanowires was 50–100 nm. Evaporation of the amorphous Si 3 N 4 powders released Si vapour and N vapour, which led to the formation of the Si 3 N 4 microcrystals. The nanowires grew on the surface of the amorphous Si 3 N 4 powders due to the nucleation and diffusion of Si and N atoms of amorphous Si 3 N 4 powders. The growth mechanism of the products with unique morphology can be considered as a combination of vapour-solid mechanism and secondary nucleation process.
✓ 已验证
产品关联
DOI
高影响因子
Polymer Chemistry
·
2019
·Vol. 10
·期 21
·2706-2715
·
IF 4.76
Yongjie Yuan,Lifang He,Jindi Li,Hailiang Zhang
A series of luminescent side chain polymers containing a D–π-A structure and different flexible spacer lengths, namely, poly[(Z)-ω-(4-(1-cyano-2-(4-cyanophenyl)vinyl)phenoxy)alkyl methacrylate]s (PMmPVPCN, m = 2, 4, 6, 8), were successfully prepared. With the combination of aggregation-induced emission enhancement (AIEE) luminogens and mesogens, the resultant polymers are expected to possess both liquid crystal characteristics and AIEE characteristics. The phase structure of PMmPVPCN was explored by differential scanning calorimetry (DSC), polarized optical microscopy (POM), and one-dimensional wide-angle X-ray diffraction (1D WAXD). Photophysical properties of PMmPVPCN were studied by UV spectra and fluorescence spectra. Test results suggested that the phase structure of PMmPVPCN transformed from the amorphous phase (PMmPVPCN, m = 2, 4) to the nematic phase (PMmPVPCN, m = 6, 8) with the increase of polymer spacer length. All the synthetic monomers and polymers exhibited AIEE properties and the luminescence behavior of PMmPVPCN was associated with their chemical structure. The solid fluorescence quantum yields of PMmPVPCN increased from 22.4% to 42.7% with increasing spacer length. The polymer films also showed reversible fluorescence photo-responsive properties. The emission color and the emission intensity of polymer films changed when exposed to a 365 nm UV lamp. The change process was reversible and they could turn back to their original state when irradiated with a 254 nm UV lamp or heated at higher temperature.
✓ 已验证
产品关联
DOI
高影响因子
CHEMISTRY-A EUROPEAN JOURNAL
·
2018
·Vol. 25
·期 9
·2330-2336
·
IF 5.16
Jing Liu,Xiuxia Zhao,Peng Jing,Wei Shi,Peng Cheng
Graphical Green hybrid : A Z-Scheme system, g-C 3 N 4 /α-Fe 2 O 3 , was synthesized by a MOF-derived template method. The optimized system shows excellent photocatalytic hydrogen evolution performance with visible light response. As one of the most efficient systems for photocatalytic hydrogen evolution, the Z-Scheme system, consisting of different semiconductors with a reversible donor–acceptor pair, has attracted great attention. Considering the non-toxicity and low cost of photocatalysts, a series of g-C 3 N 4 /α-Fe 2 O 3 hybrids were rationally constructed based on the Z-Scheme mechanism for the first time, using a metal-organic framework template approach that can fine tune the compositions and properties of the hybrids. An optimized hybrid, g-C 3 N 4 /α-Fe 2 O 3 -2, exhibited prominent photocatalytic water splitting performance with a visible light response. Under irradiation of visible light ( λ >420 nm), the hybrid shows a high durability and superior hydrogen production rate of 2066.2 μmol g −1 h −1 from water splitting, which is approximately three times greater than that of bulk g-C 3 N 4 because of the effective separation of photo-excited charge carriers by two narrow band gap semiconductors, tightly coupled with the Z-Scheme structural feature.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）