POLYMER
·
2018
·
IF 3.483
Guodong Zhou,Weitao Wang,Mao Peng
Molecular composites using rigid-rod macromolecules as the reinforcement have attracted tremendous research interest. However, dispersion of rigid-rod macromolecules at molecular level in the matrix remains a great challenge. Herein, we report new epoxy (EP)-based molecular composites with sulfonated aromatic polyamides , poly( p -sulfophenylene terephthalamide) (sPPTA) and poly(benzidine-2,2′-disulfonic acid terephthamide) (PBDT), as the reinforcement, which disperse uniformly in epoxy. Covalent bonds formed by the reaction between the sulfonic acid groups of the polyamides and epoxy prevent reaction-induced phase separation during high temperature curing. The novel molecular composites exhibit extraordinarily high strength and toughness, with maximum tensile strength of sPPTA/EP and PBDT/EP (100.2 ± 4.8 MPa and 121.9 ± 12.5 MPa, respectively) increased by ∼81% and ∼120%, respectively. To the best of our knowledge, the improvement of mechanical properties surpasses those of molecular composites, nanofiller reinforced thermosets and liquid crystalline thermosets ever reported.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
Environmental Pollutants and Bioavailability
·
2019
·
IF 0
Yuehui Tan,Xianqiang Yin,Caiyun Wang,Huimin Sun,Aisheng Ma,Guilong Zhang,Nong Wang
The Cd(II) adsorption of kiwi biochar functionalized with Mg-Fe (3:1) layered double hydroxides (LDH) was studied. And the biochar was got via liquid-phase deposition, by incorporating Mg-Fe layered double hydroxide (Mg-Fe LDH) particles into kiwi biochar (KB/LDH). The batch of sorption experiments were studied, including adsorption kinetics and isotherm and the effects of pH, ion strength (IS) and co-existing ions. The KB/LDH composite showed a strong sorption ability to Cd(II) in aqueous solutions with the adsorption capacity of 25.6 mg g−1, compared with pristine biochar of 1.78 mg g−1. The adsorption of Cd(II) on KB/LDH composite increased with the decreasing of IS, decreased first and then grew larger with the increase of pH and was observed irrespective of the co-existence of K+, Cl− and NO3−. To sum up, the KB/LDH can be potentially used as an alternative adsorbent to amend the water and soil contaminated by Cd(II).
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
TRIBOLOGY LETTERS
·
2019
·Vol. 67
·期 1
·1-17
·
IF 2.235
Zhao Yuanliang,Qi Xiaowen,Zhang Wenli,Fan Bingli,Yang Qingxiang
The effects of copper nanoparticles (Cu) located in different regions of polytetrafluoroethylene/polyimide (PTFE/PI) blends on the morphology, thermal, mechanical, and tribological properties of PTFE composites were studied. Region one is PI phases (the corresponding composites is denoted as PPC), region two is PTFE phases and the interface between PTFE and PI (the corresponding composites is denoted as PPC-m). Results indicate that the incorporation of Cu nanoparticles into PI phases improves the dispersibility and homogeneity of PI phases. As a consequence, the crystallinity of PTFE composites is reduced, but compressive strength and modulus of PTFE composites are enhanced by 50.3% and 14.4% respectively. In addition, self-lubricity and wear resistance of PTFE composites are improved by 10.4% and 50.5%. Scanning electron microscopy (SEM) demonstrates that PI phases with Cu nanoparticles hinder the direct contact between PTFE matrix and counterparts. However, Cu nanoparticles located in PTFE matrix and the interface between PTFE and PI deteriorates the dispersibility and homogeneity of PI phases, which lead to the poor mechanical and tribological performance of PTFE composites.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2022
·Vol. 139
·期 24
·52368
·
IF 3.057
Xiongfei Zhang,Tianhui Zhao,Ting Cao,Peiyu Liu,Chuang Ma,Pengyun Li,Dang Huang
In this paper, bisphenol A (BPA), epichlorohydrin (ECH), and isocyanate trimer (TDI-T) are used as raw materials to synthesize a high toughness/trimer epoxy resin by graft copolymerization. It was cured at room temperature with low molecular weight polyamide 650 (PA650)/isophorone diamine (IPDA) and low molecular weight polyamide 650/triethylene tetramine (TETA) composite curing system respectively. The cured products of the two compound systems were studied by Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), thermogravimetry (TG), and mechanical property testing. The results show that with the increase of TETA and IPDA curing agents, the heat released during the curing process of the two systems also greatly increases, and the temperature rises from the initial 33.9–69.7°C and 52.8°C. The curing time is shortened from a few days to a few hours, and the controllability of the curing time is effectively realized. When the ratio of triethylene tetramine to low molecular weight polyamide 650 is 2.86:100, the compressive strength is the best, reaching 112.7 MPa, 12% higher than pure polyamide as curing agent, and the specimen can be completely restored to its original shape in a few minutes. When the ratio of TETA to PA650 is 2.86:100, the elongation at break reaches 21.4%.
研究领域:
高分子化学
·
材料科学
·
复合材料
·
热固性树脂
·
功能材料
✓ 已验证
DOI
高影响因子
FLUID PHASE EQUILIBRIA
·
2013
·
IF 2.379
Yumei Kai,Yonghong Hu,Zheng Cao,Xiang Liu,Yan Liu,Wenge Yang
The solubilities of l -malic acid in pure and mixture organic solvents were measured from 278.15 to 323.15 K using the laser monitoring observation system. The modified Apelblat equation, the semi-empirical Buchowski–Ksiazczak λh equation and the Combined Nearly Ideal Binary Solvent/Redlich (CNIBS/R-K) equation were proposed to correlate the experimental data. In pure and mixed solvents, the 100RD (relative deviation) <3.61 and 7.58, respectively, the 10 4 RMSD (root-mean-square deviations) <3.07 and 2.28, respectively, so the equations selected in this work fit the data very well. Van’t Hoff equation was used to predict the dissolution enthalpy and entropy of l -malic acid in the corresponding solvents.
研究领域:
药物化学
·
物理化学
·
溶液热力学
·
药物结晶
·
分子药剂学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Enze Xu,Yan Zhang,Hui Wang,Zhifeng Zhu,Junjie Quan,Yajing Chang,Pengcheng Li,Dabin Yu,Yang Jiang
Establishing advanced sodium-ion batteries (SIBs) with high energy density and eco-friendly electrode materials are still far from satisfactory due to the large-size of sodium-ions and sluggish redox kinetics during electrochemical processes. Herein, a novel ultrafast kinetics net electrode assembled via MoSe 2 /MXene heterojunction is synthesized by a simple hydrothermal method followed by thermal annealing. Featuring the Van der Waals force interaction between MoSe 2 and MXene , the volumetric change during the sodium ions insertion/extraction courses is effectively restrained, and the reaction kinetics is greatly enhanced further. Meanwhile, both the high electrical and ion conductivity (lower diffusion barrier between Na + /MXene ~0.066 eV) provided by the unique MXene based net heterostructure of our hybrid materials, as evidenced by DFT calculations, are beneficial to the transportation of sodium ions, thus enabling an outstanding rate and long-cycling capability. As a result, the fabricated cells exhibit high reversible capacities of 490 mAh g −1 at 1 A g −1 , as well as 250 mAh g −1 at a high current of 10 A g −1 with a coulombic efficiency of 99.8%, indicating the excellent electrochemical performance of our hybrid materials, especially at high current. This novel net MoSe 2 /MXene heterostructure, combined with our simple synthesis strategy together, are expected to have great potential in sodium-ions storage application.
研究领域:
材料科学
·
电化学
·
能源存储
·
纳米材料
·
固态物理
✓ 已验证
DOI
高影响因子
THERMOCHIMICA ACTA
·
2018
·
IF 2.189
Feng Bao,Lishuai Zong,Nan Li,Yuanyuan Song,Yunxing Pan,Jinyan Wang,Xigao Jian
In this study, a series of poly(phthalazinone fluorenyl ether ketone ketone) (PPFEKK) copolymers were designed and synthesized via nucleophilic aromatic substitution polymerization of 1,4-bis(4-fluorobenzoyl)benzene (BFBB), 4-(4-hydroxyphenyl)(2 H)-phthalazin-1-one (DHPZ) and 9,9-bis(4-hydroxyphenyl)fluorene (BHPF) to investigate the effects of bulky fluorene units on the processability and thermal degradation behavior of the polymers. The structures of the PPFEKKs were investigated and confirmed by FTIR, 1 H NMR, wide-angle X-ray diffraction (WAXD) and gel permeation chromatography (GPC) techniques. Traditional thermal measurements showed that the T d 5% and T d 10% values of the copolymers increased as the content of BHPF units increased from 0 to 100 mol%, while their glass transition temperatures gradually decreased. The rheological measurements showed that the processability of the copolymers significantly improved upon incorporation of BHPF units; the poly(aryl ether)s were less viscous and thus more processable. The thermal degradation kinetics were clarified using TGA with Kissinger’s method. The copolymer undergoes two thermal degradation processes: as the content of BHPF units in the copolymers increased from 0 to 100 mol%, the activation energy of the first degradation reaction increased from 228 to 254 kJ mol −1 , and the activation energy of the second degradation reaction increased from 271 to 298 kJ mol −1 . The resulting films displayed excellent tensile strength (higher than 76 MPa), and their Young’s modulus values were inversely proportional to their BHPF contents. Dynamic mechanical analysis showed storage modulus values at 30 °C of approximately 2662, 2826, 2698, 2791 and 2830 MPa for the prepared polymers. Furthermore, the PPFEKKs were soluble in a variety of organic solvents, making them suitable for film casting.
研究领域:
高分子化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
DRUG DEVELOPMENT AND INDUSTRIAL PHARMACY
·
2019
·
IF 2.367
Jingwen Luo,Jiang Sun,Xiaoting Luo,Yinghui Wei,Hangsheng Zheng,Chaofeng Mu,Wenjie Yao
Objective: This article aims to design low molecular weight chitosan (LMWC)-based conjugates of Rhein (RH) by means of an amino acid linker (Alanine) for improved solubility and enhanced bioavailability.Significance: Rhein is a potential candidate for the therapy of kidney disease. However, the poor solubility, inadequate bioavailability, and lack of proper formulation restrict its clinical applicability. LMWC-drug conjugates offer the potential to improve the water-solubility of RH, increase its oral absorption, and thereby enhance its bioavailability.Methods: The conjugates were synthesized via a carbodiimide reaction and confirmed using UV-vis, FTIR, and 1H-NMR spectroscopy. The water-solubility and in vitro release properties were evaluated. Free RH and RH-LMWC conjugates were administered at an equivalent oral gavage dose of RH at 35 mg/kg for pharmacokinetic studies in Sprague Dawley rats.Results: The conjugates with RH content of 9.65% were successfully synthesized and featured a satisfactory water-solubility of 9.73 mg/mL, which exhibited a sustained release pattern over 72 h, and the enzymes present may promote the degradation of the conjugate to increase the release of Rhein. Oral administration of RH-LMWC conjugates to rats led to seven-folds and 3.1-folds increase in the T1/2 and AUC0–∞, respectively, as compared to RH suspension.Conclusion: The present work demonstrated that the RH-LMWC conjugates exhibited sustained release properties with outstanding oral bioavailability enhancements compared to administration of RH itself. Potentially, RH-LMWC conjugates may serve as a promising lead for developing a new platform for RH oral delivery.
研究领域:
药剂学
·
药物化学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2019
·
IF 2.781
Faqiang Shi,Limeng Liu,Zhaoping Hou,Guihong Geng,Yujin Wang
Tantalum carbide ceramics with an overall composition of TaC 0.6 were prepared by hot pressing at 1700 °C for 1 h under 30 MPa pressure with fcc TaC and bcc Ta powder as starting materials. Effects of adding 0–30 mol% Cu on densification, phase formation, microstructural evolution , mechanical properties and electrical conductivity of the obtained composite ceramics were investigated. Full density could be reached at 20 mol% Cu addition and above. Reactions between TaC and Ta resulted in the final phases of hexagonal Ta 2 C and rhombohedral ζ-Ta 4 C 3-x . Plate-shaped ζ laminate grew in both TaC and Ta 2 C and consequently had their sizes confined by the parental grains. Addition of 20–30 mol% Cu could significantly grow the intermediate Ta 2 C grains, hence controlling length of the ζ laminates precipitated in them to form bimodal microstructures consisting of large grains. The 20 mol% Cu composition had a better flexural strength (706 ± 46 MPa) and fracture toughness (9.2 ± 1.7 MPa m 1/2 ). Electrical resistivity at room temperature of the composites decreased with Cu content from 1.03 μΩ m at 0 mol% addition to 0.12 μΩ m at 30 mol% Cu.
研究领域:
材料科学
·
陶瓷学
·
复合材料
·
粉末冶金
·
结构陶瓷
·
物理化学
·
固态化学
✓ 已验证
DOI
高影响因子
Desalination and Water Treatment
·
2024
·
IF 1
Yulong Yang,Jiao Feng,Shicui Zhu,Jinshu Zhou,Kejia Zhang,Xiaoyan Ma,Danial Gallagher,Andrea M. Dietrich
Nitrogenous disinfection by-products (N-DBPs) are more genotoxic and cytotoxic than the currently regulated carbonaceous DBPs (i.e., C-DBPs), and it has become a frontier issue of drinking water safety research. In this paper, the effect of granular activated carbon (GAC) on adsorption and its influencing factors was investigated for a typical N-DBP phenylacetonitrile, which is produced during chlorination of phenylalanine precursor during water treatment. The results showed that GAC had a high adsorption capacity (q max = 22.92 mg/g) for phenylacetonitrile, and the adsorption isotherm was fitted to the Langmuir isotherm model. Pseudo-second-order equation can well describe the behavior of phenylacetonitrile adsorption on activated carbon (R 2 > 0.990), and the adsorption rate constant k 2 = 0.7780–14.12 g/(mg h). Analysis of the influencing factors showed that higher phenylacetonitrile concentration improved the adsorption equilibrium capacity and the adsorption rate. Water temperature and pH had little effect on the capacity or rate of adsorption.
研究领域:
环境科学
·
水处理工程
·
毒理学
·
环境健康
✓ 已验证
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2024
·
IF 7.4
Kai Luo,Wensheng Zhang,Jiayuan Ye,Jun Li,Zhongyuan Lu,Xuehong Ren
The physical and microscopic properties of γ-C 2 S and β-C 2 S under hydration, carbonation , and hydration–carbonation cycle reactions were investigated. The hydration–carbonation cycle reaction facilitated the carbon sequestration of C 2 S, and the generation of CaCO 3 filled the pores of the matrix and enhanced the matrix density in the carbon fixation reaction process. In the subsequent hydration and reaction process, the formation of hydration products increased the number of pores in the matrix and reduced the matrix density. Post-hydration, γ-C 2 S slurry became powder and had no mechanical strength . However, after carbonation reaction and two carbonation–hydration cycles, γ-C 2 S exhibited better mechanical properties than β-C 2 S.
研究领域:
材料科学
·
硅酸盐化学
·
建筑材料
·
碳捕集与封存
·
无机非金属材料
✓ 已验证
DOI
高影响因子
JOURNAL OF WUHAN UNIVERSITY OF TECHNOLOGY-MATERIALS SCIENCE EDITION
·
2016
·Vol. 31
·期 1
·157-163
·
IF 0.4
Liu Rongpeng,Wan Liqiang,Huang Farong,Du Lei
The reaction kinetics between diazide(4,4’-biphenyl dibenzyl azide) and different diynes (dipropargyl bisphenol A and 1,3-diethynylbenzene) were studied by means of differential scanning calorimetry (DSC) and nuclear magnetic resonance spectroscopy ( 1 H-NMR). DSC was adopted to analyze the reactions under bulk polymerization condition, while 1 H-NMR for solution reaction polymerization was conducted. The apparent activation energies ( E
α ) calculated by Kissinger’s method were 77.96, 81.24 kJ/mol, which were confirmed by Friedman’s method, and 65.45, 69.36 kJ/mol by 1 H-NMR for dispropargyl bisphenol A/4,4’-biphenyl dibenzyl azide and 1,3-diethynylbenzene/4,4’-biphenyl dibenzyl azide, respectively. The polymerizations between the diazide and diynes were first-order reactions based on calculation from both DSC and 1 H-NMR. The results showed that the reaction between dipropargyl bisphenol A and 4,4’-biphenyl dibenzyl azide was easier than that between 1,3-diethynylbenzene and 4,4’-biphenyl dibenzyl azide, verifying that the reactivity of aliphatic alkyne was higher than that of aromatic alkyne.
研究领域:
高分子化学
·
物理化学
·
材料科学
·
有机化学
·
反应动力学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）