CHEMICAL ENGINEERING JOURNAL
·
2013
·
IF 3.473
Ning Pan,Debin Guan,Yuntao Yang,Zhenling Huang,Ruibing Wang,Yongdong Jin,Chuanqin Xia
We report a rapid, environmentally-friendly and cost-effective route for the preparation of a graphene-based nanomaterial, carboxyl graphene (aka. reduced graphene oxide , RGO) from graphene oxide (GO). Carboxyl graphene was prepared on the scale of several grams through the reduction of GO by thiourea dioxide (TUD) at a relatively low temperature (40 °C) in an alkaline medium (pH = 10). The reduction of GO was confirmed by FT-IR, UV–vis, X-ray photoelectron, and Raman spectroscopy. In addition, this reduction was also confirmed by thermal gravimetric analysis, X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and atomic force microscopy (AFM). Characterizations of these materials demonstrated that selective reduction of the epoxy and carbonyl groups occurred on the surface of GO, while carboxyl groups were left behind. In addition, the conjugation of the carbons in the structure was restored through this reduction and a single-layer of carboxyl graphene (with a thickness of 0.80 nm, as observed by AFM) was obtained under these conditions. Carboxyl graphene had a high surface area (of 454.52 m 2 g −1 ) and contained approximately 6.9 ± 1.6 mmol of carboxyl groups per gram of material, as determined via Boehm titration. The mechanism for selective reduction of the epoxy and carbonyl groups on GO to form carboxyl graphene by TUD is proposed and discussed in detail.
研究领域:
纳米材料化学
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材料科学
·
表面化学
·
碳基纳米材料
·
功能化纳米材料
✓ 已验证
DOI
高影响因子
Polymer Chemistry
·
2024
·Vol. 15
·期 23
·2370-2376
·
IF 4.1
Kai Chen,Haiming Xie,Jun Liu
Self-healing polymers (SHPs) improve sustainability by increasing the longevity of materials and equipment. However, a single self-healing mechanism cannot realize the balance between mechanical and self-healing properties. Herein, we report a poly(thiourea-disulfide) (PTUSX) elastomer prepared via an amine–isothiocyanate click reaction. Due to its similar structure to polyurethane, the optimized sample PTUS8 exhibits strong mechanical properties. The synergistic effects of three types of dynamic bonding (disulfide bonds, thiourea bonds, and hydrogen bonds) empower PTUS8 to exhibit desirable self-healing capabilities at ambient temperatures. Moreover, the soft–hard segments design endows PTUS8 with flexibility and toughness. In addition, a solid polymer electrolyte membrane has been fabricated by adding a lithium salt to PTUS8, and it displays high ionic conductivity and can recover the original conductivity after self-healing. Thus, these results not only indicate that the PTUS8 elastomer has considerable potential for application in solid-state lithium batteries, but they also provide new ideas for the development of novel SHPs by combining the synergistic effects of several different types of dynamic bonding.
研究领域:
高分子材料科学
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功能高分子
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电化学能源材料
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智能材料
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自修复材料
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DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2021
·
IF 4.759
Liying Guo,Jiajia Liu,Jinqiu Li,Lin Hao,Weihua Liu,Chun Wang,Qiuhua Wu,Zhi Wang
ABSTRACT In this work, a core-shell structured magnetic covalent organic framework named as M-TpDAB was constructed with 3,3′-diaminobenzidine (DAB) and 1,3,5-triformylphloroglucinol (Tp) as building units. M-TpDAB was characterized by infrared spectroscopy, nitrogen adsorption-desorption isotherms, powder X-ray diffraction, scanning electron microscopy and transmission electron microscopy. Using the M-TpDAB as adsorbent, a simple and highly effective method was proposed for preconcentrating phenylurea herbicides before high performance liquid-phase chromatography analysis. In the optimized conditions, a good linearity was achieved within the range of 0.15-100 ng mL −1 for water sample, 1.0-100.0 ng mL −1 for tea drink samples. The limits of detection for the analytes were 0.05-0.15 ng mL −1 for water sample and 0.30-0.50 ng mL −1 for drink samples. Satisfactory recoveries of spiked target compounds were in the range of 84.6%-105% for water sample and 80.3%-102% for tea drink samples. Finally, the M-TpDAB based method was successfully used to determine phenylurea herbicides in tea drinks and water samples, demonstrating a good alternative for analyzing trace level of phenylurea herbicides in water samples.
研究领域:
分析化学
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环境科学
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材料科学
✓ 已验证
DOI
PubMed
高影响因子
Nature Communications
·
2019
·Vol. 10
·期 1
·1-8
·
IF 11.878
Cui Bin-Bin,Han Ying,Huang Bolong,Zhao Yizhou,Wu Xianxin,Liu Lang,Cao Guangyue,Du Qin,Liu Na,Zou Wei,Sun Mingzi,Wang Lin,Liu Xinfeng,Wang Jianpu,Zhou Huanping,Chen Qi
As one of next-generation semiconductors, hybrid halide perovskites with tailorable optoelectronic properties are promising for photovoltaics, lighting, and displaying. This tunability lies on variable crystal structures, wherein the spatial arrangement of halide octahedra is essential to determine the assembly behavior and materials properties. Herein, we report to manipulate their assembling behavior and crystal dimensionality by locally collective hydrogen bonding effects. Specifically, a unique urea-amide cation is employed to form corrugated 1D crystals by interacting with bromide atoms in lead octahedra via multiple hydrogen bonds. Further tuning the stoichiometry, cations are bonded with water molecules to create a larger spacer that isolates individual lead bromide octahedra. It leads to zero-dimension (0D) single crystals, which exhibit broadband ‘warm’ white emission with photoluminescence quantum efficiency 5 times higher than 1D counterpart. This work suggests a feasible strategy to modulate the connectivity of octahedra and consequent crystal dimensionality for the enhancement of their optoelectronic properties.
研究领域:
材料科学
·
光电学
·
半导体
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DOI
高影响因子
Soft Matter
·
2024
·Vol. 20
·期 48
·9614-9621
·
IF 2.9
Fengkai Liu,Xi Chen,Zhigang Suo,Jingda Tang
A composite of a knitted fabric and a soft matrix enables applications that require low stiffness and high crack resistance. Examples include heart valves and stretchable strain sensors. Here we study processes of crack growth in such a composite under monotonic and cyclic stretch. We fabricate a composite using a knitted fabric of nylon yarn and an elastomer matrix of polycarbonate urethane. We precut a sample with a crack, monotonically stretch the sample, and observe the growth of the crack. The crack grows in the matrix as the yarn slips and breaks. The stretch is converted to energy release rate G. We identify two critical energy release rates, GA and GB. When G < GA, the yarn does not slip, and the crack does not grow in the matrix. When GA < G < GB, the yarn slips but does not break, and the crack grows in the matrix stably and arrests when the stretch stops increasing. When G = GB, the yarn slips and breaks, while the crack grows unstably. When the sample is subject to cyclic stretch, we observe analogous behavior of crack growth and arrest, as well as yarn slip and yarn break. However, the two critical values, Ga and Gb, are much smaller than the corresponding values under monotonic stretch.
研究领域:
生物医学工程
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材料科学
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柔性电子
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组织工程
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力学与材料
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DOI
高影响因子
FASEB JOURNAL
·
2024
·Vol. 38
·期 17
·e70019
·
IF 4.4
Yuxue Xu,Yue Peng,Xiaojun Wu,Feixue Ni,Daxi Sun,Pengfei Zhang,Yang Yang,Miao Yan,Jia Mi,Geng Tian
Non-proliferative diabetic retinopathy (NPDR) is the early stage of diabetic retinopathy (DR) and is a chronic oxidative stress-related ocular disease. Few treatments are approved for early DR. This study aimed to investigate the pathogenic mechanisms underlying the retinal micro-vasculopathy induced by diabetes and to explore an early potential for treating early DR in a mouse model. The mouse model of type 1 diabetes was established by intraperitoneal injection of streptozotocin (STZ, 180 mg/kg), which was used as the early DR model. The body weight and blood glucose mice were measured regularly; The retinal vascular leakage in the early DR mice was determined by whole-mount staining; Label-free quantitative proteomic analysis and bioinformatics were used to explore the target proteins and signaling pathways associated with the retinal tissues of early DR mice; To detect the effects of target protein on endothelial cell proliferation, migration, and tube formation, knockdown and overexpression of VEGF-B were performed in human retinal vascular endothelial cells (HRECs); Western blotting was used to detect the expression of target proteins in vitro and in vivo; Meanwhile, the therapeutic effect of VEGF-B on vascular leakage has also been evaluated in vitro and in vivo. The protein expressions of vascular endothelial growth factor (VEGF)-B and the Rho GTPases family member CDC42 were reduced in the retinal tissues of early DR. VEGF-B upregulated the expression of CDC42/ZO1/VE-cadherin and prevented hyperglycemia-induced vascular leakage in HRECs. Standard intravitreal VEGF-B injections improved the retinal vascular leakage and neurovascular response in early DR mice. Our findings demonstrated, for the first time, that in diabetes, the retinal vessels are damaged due to decreased VEGF-B expression through downregulation of CDC42/ZO1/VE-cadherin expression. Therefore, VEGF-B could be used as a novel therapy for early DR.
研究领域:
糖尿病
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眼科学
·
分子生物学
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细胞生物学
✓ 已验证
DOI
PubMed
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 80
·42252-42259
·
IF 3.708
Shengbo Zhu,Zhongwei An,Xinbing Chen,Pei Chen,Qianfeng Liu
The modification of π-linkers represents a viable strategy to improve the performance of organic dye in dye-sensitized solar cells (DSSCs). On the basis of the π-linker modification, four cyclic thiourea functionalized dyes (AZ260, AZ261, AZ262, and AZ263) were synthesized and their effects on the short-circuit current density (Jsc) and open-circuit voltage (Voc) were investigated. The results showed that AZ261 bearing an n-hexyl chain on the π-linker generated higher Jsc (16.02 mA cm−2) and Voc (739.4 mV) than AZ6 without a substituent on the bithiophene (Jsc = 15.89 mA cm−2, Voc = 729.2 mV, PCE = 7.20%), and a higher PCE of 7.42% was obtained from AZ261. Furthermore, insertion of a double-bond into the π-linker (AZ263) yielded the highest Jsc (17.83 mA cm−2) with a somewhat lower Voc (719.2 mV), and delivered the highest PCE up to 8.24%. In addition, the function of mesoporous spherical TiO2 on the photoanodes were also systematically examined and proven to be beneficial in increasing the Jsc.
研究领域:
材料科学
·
光伏技术
·
有机化学
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2021
·
IF 3.764
Yingchao Cai,Chunmei Li,Yumin Yang,Haonan Li,Yuhang Wang,Qiuyu Zhang
Owing to excessive energy consumption and environmental deterioration, thermosets with permanent covalent crosslinks have encountered unprecedented challenge in the sustainable development. An effective method to address this intractable problem is to construct covalent adaptive networks that contain dynamic covalent bonds. Herein, self-healable and reprocessable cross-linked poly(urea-urethane) elastomers with high mechanical performance were simply developed by introducing dynamic oxime–carbamate bonds (POUUs). The studies on nuclear magnetic resonance indicated that the sufficient exchange rather than the reversible dissociation of oxime–carbamate bonds was the key to network arrangement at elevated temperatures. Due to the incorporation of strong polar urea bonds, POUUs showed excellent mechanical performance with a tensile strength of 27.8 MPa and toughness of 52.5 MJ m–3. The good self-healing ability of POUUs was demonstrated by the disappearance of scratches at 80 °C after 15 h. All POUUs were easily remolded (130 °C, 5 MPa) into transparent films with a maximum recovery efficiency of 80%. Furthermore, complete dissolution in N,N-dimethylformamide was achieved at 100 °C after 4 h, exhibiting high recyclability of the cross-linked POUUs.
研究领域:
高分子科学
·
材料工程
·
化学合成
·
可持续发展
·
力学性能研究
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DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2019
·
IF 3.375
Can Wu,Xiaodong Wang,Junying Zhang,Jue Cheng,Ling Shi
A novel type of microencapsulated ammonium polyphosphate (MAPP) with a triallyl cyanurate (TAC)/SiO2 double-layered shell was synthesized through in-situ polymerization, followed by the thiol–ene photograted reaction. With a double bond in the TAC outer shell, MAPP could be utilized as a highly efficient flame retardant for intumescent flame-retarded natural rubber (NR). The chemical structure, morphology, and performance of MAPP were characterized by X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, water contact angle (WCA), scanning electron microscopy, and thermogravimetric analysis. MAPP exhibited a hydrophobic feature with a WCA of 101° because of its organic outer shell, which made MAPP well dispersed in the NR matrix as well as enhanced the compatibility between the MAPP and NR matrix. The resulting intumescent flame-retardant NR compounds not only achieved excellent flame-retardant performance but also obtain improved mechanical properties because of the presence of 3D-cross-linking networks between the MAPP and NR matrix. The NR/MAPP compounds also presented good water resistance because of the microencapsulation of APP with an SiO2 inner shell, which provided a waterproof barrier for APP. Based on the cone calorimetric results, the NR/MAPP compounds also presented a decline in total heat release and heat release rate but an improvement in ignition time due to the fact that both the SiO2 inner layer and TAC outer shell could enhance the formation of a high-strength thermally stable char layer during combustion, thus preventing heat transmission and diffusion. The significant enhancement in flame-retardant performance was principally ascribed to the synergistic char-forming effect derived from the APP core and TAC/SiO2 shell. This work provides a new idea for development of APP-based flame-retardant additives and also explores their potential applications in intumescent flame-retardant polymeric systems.
研究领域:
高分子材料科学
·
阻燃化学
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功能材料
·
纳米复合材料
·
表面工程
·
热稳定性分析
·
聚合物改性
✓ 已验证
DOI
高影响因子
Materials Chemistry Frontiers
·
2021
·Vol. 5
·期 14
·5371-5381
·
IF 6.482
Qianyun Zhong,Xingxing Chen,Yuxuan Yang,Chenhui Cui,Li Ma,Zhen Li,Qiang Zhang,Xiaoming Chen,Yilong Cheng,Yanfeng Zhang
Transparent and degradable polyurethane elastomers with high strength and toughness are in demand for various applications, such as tissue engineering and flexible electronics. However, designing specific chemical structures is challenging, and thus fabricating novel elastomers is sometimes unattainable. An effective approach to develop elastomers is through the introduction of sacrificial bonds, e.g. hydrogen bonds, to enhance their mechanical properties and toughness, which provide hidden lengths and hierarchical structures for energy dissipation. This study introduced a facile and efficient strategy by employing imidazolidinyl urea (IU) as a multiple hydrogen-bonding motif to fabricate transparent and degradable polyurethane elastomers (PHI) with superior breaking strength and excellent toughness. The resultant breaking strength and toughness reached up to 24.9 MPa and 168.2 MJ m−3, respectively. Additionally, the breaking strength increased to 49.9 MPa after the sample was pre-stretched to 600% strain due to strain-induced crystallization (SIC). Moreover, the PHI film with degradability and good biocompatibility showed potential application in post-operative anti-adhesion.
研究领域:
材料科学
·
生物医学工程
·
高分子化学
✓ 已验证
DOI
高影响因子
Letters in Drug Design & Discovery
·
2019
·Vol. 16
·期 9
·1020-1030
·
IF 0.953
Liang Zhaochang,Huang Yuping,Wang Shiben,Deng Xianqing
Background: Several series of pyrazole derivatives containing (thio) semicarbazide (4a-4h, 5a-5l, 6a-6f, 7a-7c) were designed and synthesized to screen dual inflammatory and antimicrobial activities. Methods: The products were characterized by1H NMR, 13C NMR and HRMS. In vitro
LPS-induced TNF-α model and in vivo xylene-induced ear-edema model were used to evaluate their antiinflammatory activity. Their in vitro antimicrobial activities were evaluated using a serial dilution method against several gram-positive strains, gram-negative strains and a fungi strain.
Results: Bioassays indicated that most of the compounds markedly inhibited the expression of TNF- α at the concentration of 20 μg/mL Compounds 5i, 6b, and 7b had comparable in vivo antiinflammatory activity to the reference drug dexamethasone at the dose of 50 mg/kg. In addition,
several compounds showed antimicrobial activity against different strains, and compounds 5g and 5h exhibited potent inhibitory activities with the MIC value of 8 μg/mL against the Streptococcus pneumoniae CMCC 31968 and Staphylococcus aureus CMCC 25923, respectively. Compound 7b, which
exhibited both anti-inflammatory and antimicrobial activities, should be studied as it is or after derivatization. Conclusion: It can be concluded that pyrazoles, with (thio)-semicarbazone moieties, have the potential to be developed into new anti-inflammatory agents.
研究领域:
药理学
·
药物化学
·
传染病学
·
炎症研究
✓ 已验证
DOI
高影响因子
Foods
·
2024
·Vol. 13
·期 17
·2729
·
IF 4.7
Xiaoqing Xu,Lingling Du,Meng Wang,Ran Zhang,Junjie Shan,Yu Qiao,Qing Peng,Bo Shi
Agrobacteriumsp. are notable for their ability to produce substantial amounts of exopolysaccharides. Our study identified an exopolysaccharide (Galacan, 4982.327 kDa) fromAgrobacteriumsp. FN01. Galacan is a heteropolysaccharide primarily composed of glucose and galactose at a molar ratio of 25:1. The FT-IR results suggested that Galacan had typical absorption peaks of polysaccharide. The results of periodate oxidation, Smith degradation, and NMR confirmed the presence of structural units, such as β-D-Galp(→, →3)β-D-Galp(1→, →2,3)β-D-Glcp(1→, β-D-Glcp(1→, and →2)β-D-Glcp(1→. Galacan demonstrated significant biological activities. In experiments conducted with zebrafish, it facilitated the proliferation ofLactobacillus brevisin the intestinal tract, suggesting potential prebiotic properties. Moreover, in vivo studies revealed its antihyperglycemic effects, as evidenced by significant reductions in blood glucose levels and enhanced fluorescence intensity of pancreatic β cells in a streptozotocin (STZ)-induced hyperglycemic zebrafish model. Additionally, antiaging assays demonstrated Galacan’s ability to inhibit β-galactosidase activity and enhance telomerase activity in a hydrogen peroxide (HP)-induced aging zebrafish model. These findings emphasized the potential of Galacan as a natural prebiotic with promising applications in diabetes prevention and antiaging interventions.
研究领域:
微生物学
·
生物化学
·
药理学
·
分子生物学
·
水生生物学
✓ 已验证
DOI
PubMed
高影响因子
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