JOURNAL OF MATERIALS SCIENCE
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2018
·Vol. 54
·期 7
·5865-5876
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IF 2.993
Zhou Zhao-Xi,Li Yue-Wei,Zheng Yang-Qing,Luo Zhen,Gong Cui-Ran,Xu Ying,Wu Li-Xin
The adipic acid glycidyl methacrylate (AA-GMA) containing double bond of carbon and hydroxyl as an ultraviolet-polyurethane dual-curing oligomer was prepared as a precursor to resin for three-dimensional (3D) printing. A dual-curing resin for 3D printing was formulated from the AA-GMA, PHDI (hexamethylene diisocyanate-based polyisocyanates, mainly trimer) and other reagents. The dual-curing oligomer AA-GMA was synthesized by the epoxide ring-opening reaction with dicarboxylic acid and the molecular structure of which was characterized by FTIR and 1 H NMR analyses. AA-GMA has the double bond which could be cured via ultraviolet irradiation in the 3D printing process, and the hydroxyl could be cured by PU curing agent PHDI at the thermal post-curing process. The PHDI was not only employed as a diluent in the 3D printing process, but also acted as a reactant for post-curing. Compared to the traditional single-curing resin, this dual-curing resin could provide products with increased crosslinking density, flexibility and reduced volumetric shrinkage rate. The tensile strength of dual-curing sample was improved to 64 MPa after adding 20 wt% PHDI, which showed 18% boost compared to the sample without the PHDI. For the sample with a content of 30 wt% PHDI, the glass transition temperature ( T g ) was about 121 °C, presenting 35 °C higher than that of the blank sample.
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ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
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2018
·Vol. 25
·期 22
·22244-22258
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IF 2.8
Yan Xuechao,Zhang Xiaoping,Li Qian
In this paper, an effective chitosan/beta-cyclodextrin/nanometer zinc oxide (CS/β-CD/Nano-ZnO) composite porous membrane was synthesized by sol-gel and polymer-assisted inverting method. Preparation conditions of CS/β-CD/Nano-ZnO were investigated by single-factor and Box-Behnken response surface methodology optimizing triethoxyvinylsilane (JH-V151), beta-cyclodextrin (β-CD), and nanometer zinc oxide (Nano-ZnO), and applied to study the adsorption characteristics of Cong red (CR) from aqueous solution using batch experiments. The optimum preparation conditions were determined that the volume fraction of JH-V151 alcohol solution was 11%, the ratio of β-CD to CS was 5.35, and the ratio of Nano-ZnO’s mass to solution’s volume was 0.36%. Different characterization methods including field-emission scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, UV-visible spectroscopy, and Universal Materials Tester were used to prove the appearance, crystallinity, functional groups, swelling degree, transmittance, and tensile property of CS/β-CD/Nano-ZnO. The optimized batch experimental parameters were 50 mg L −1 , 4 h, 7.0, 0.5 g L −1 , and 55.0 °C as initial concentration, contact time, pH, adsorbent dose, and temperature, respectively. The maximum adsorption capacity on CR reached 96.33 mg g −1 , which is 4.34 times with respect to CS. The batch experimental data were best described by a pseudo-second-order kinetics model and Langmuir isotherm model ( R 2 = 0.9965, theoretical saturated adsorption capacity 147.28 mg g −1 ). The values ∆G were − 2.09, − 4.73, and − 7.37 kJ mol −1 at 298, 308, and 318 K temperatures, respectively. The ∆H value was 76.68 kJ mol −1 , indicating the endothermic and spontaneous adsorption in nature. The ∆S value was 0.26 kJ mol −1 K −1 , a signal of entropy increase during adsorption. The adsorption capacity decreased only by 5.8% after six recycling runs, which indicated the reusability of CS/β-CD/Nano-ZnO. Therefore, the CS/β-CD/Nano-ZnO composite porous membrane is a promising membrane material for the efficient removal of CR from any water at large and economic scales at moderate concentration.
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CHINESE JOURNAL OF POLYMER SCIENCE
·
2018
·Vol. 36
·期 11
·1207-1216
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IF 2.016
Zhang Wei,Jiang Bin-Bo,Ye Jian,Liao Zu-Wei,Huang Zheng-Liang,Wang Jing-Dai,Yang Yong-Rong
In this study, a series of aryloxy-aluminoxanes originated directly from the hydrolysis of reaction products of AlMe 3 and phenols were synthesized, which could serve as effective polymer-retarding activators for the iron-catalyzed ethylene oligomerization. The molar ratios of [PhOH]/[AlMe 3 ] and [H 2 O]/[Al] during the preparation were explored and their impacts on the oligomerization activity and product distribution were discussed. To obtain the effective activators with good polymer-retarding effect and relatively high activity, the optimized conditions were proposed to be [PhOH]/[AlMe 3 ] = 0.5 and [H 2 O]/[Al] = 0.7. Various aluminoxanes with different [―OH] sources confirmed the importance of using phenols in preparing the effective polymer-retarding activators. By utilizing these aryloxy-aluminoxanes, the mass fraction of polymers in the total products could be reduced to lower than 1.0 wt%, which is much lower than that of the MAO-activated systems (> 30 wt%). This is a potential benefit for the industrial application of the iron-catalyzed oligomerization process.
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Nano Research
·
2018
·Vol. 11
·期 6
·3385-3395
·
IF 7.994
Wang Wei,Zhao Yang,Yan Bei-Bei,Dong Liang,Lu Yang,Yu Shu-Hong
Calcium carbonate-doxorubicin@silica-indocyanine green nanospheres with high uniformity and monodispersity were designed and synthesized, in order to provide a photo-triggered strategy for drug-resistant cancer therapy. Under near-infrared laser irradiation, the nanospheres transformed laser power into local heat and reactive oxygen species via the connected indocyanine green molecule, thus exhibiting photothermal and photodynamic effects. Moreover, the photo-triggered drug release based on calcium-assisted silica degradation was observed, endowing the nanospheres with chemotherapeutic properties. Finally, combined therapeutic effects against drug-resistant human breast cancer cells were successfully obtained. These photo-triggered materials based on calcium carbonate could provide a promising platform for enhanced multimodal cancer therapies.
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Science China-Chemistry
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2018
·Vol. 61
·期 11
·1470-1474
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IF 4.448
Wang Lu-Liang,Yang Cheng-Xiong,Yan Xiu-Ping
Covalent organic frameworks (COFs) have been widely applied in gas capture and separation, but the fluorescent property of COFs with large π-conjugated system tends to be underexplored. Here we report the fluorescent properties of several COFs including TaTa, DhaTab, TRITER-1 and TzDa and the effect of metal ions of Na + , Mg 2+ , K + , Ca 2+ , Cu 2+ , Zn 2+ , Pb 2+ , Ag + , Cd 2+ and Fe 3+ on the fluorescence of these COFs. The results show that only Fe 3+ significantly quenched the fluorescence of the studied COFs. The possibility of the four COFs for selective sensing of Fe 3+ was demonstrated. The possible mechanism of the effect of Fe 3+ on the fluorescence of the COFs was based on the absorption competition quenching.
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JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 53
·期 16
·11355-11366
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IF 2.993
Tang Shilin,He Chuansheng,Li Dong,Cai Wenhao,Fan Louzhen,Li Yunchao
To obtain dual active near-infrared (NIR) nanomaterial with strong absorption and emission properties, we report herein a novel precursor reactivity differentiation strategy, i.e., utilizing 1-octadecene (ODE)–Se having the ability to react with Ag salts much stronger and faster than ODE–thiourea, for single-step preparation of Ag 2 Se@Ag 2 S nanocrystals (NCs). With this strategy, we were able to synthesize high-quality Ag 2 Se@Ag 2 S NCs with both excellent NIR absorption and emission properties. Particularly, these nanocrystals possess a rather strong and sharp excitonic absorption peak with a full width at half maximum less than 70 nm and a maximum fluorescence quantum yield as high as 24.3%. Their appealing optical properties and structural features were founded to be highly dependent on the Se to S precursor ratio in the reaction solutions, owing to such a ratio exerting a direct influence on the core sizes and shell thicknesses of the as-formed NCs. Taking advantage of their remarkable NIR absorption properties, self-powered photoelectrochemical-type photodetectors based on the as-prepared Ag 2 Se@Ag 2 S NCs were successfully fabricated, which demonstrate a much better response performance and photostability in comparison with those based on Ag 2 Se NCs.
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Frontiers of Materials Science
·
2018
·Vol. 12
·期 2
·129-138
·
IF 1.478
Ouyang Shenshen,Wang Tao,Zhong Longgang,Wang Shunli,Wang Sheng
Bulk poly( m -phenylene isophthalamide) (PMIA) can achieve flexibility upon dissolution by a LiCl/dimethylacetamide co-solvent, but remains hydrophobic despite the occasional emergence of cis amide groups providing a weak negative charge. In this study, based on the significant surface differences between PMIA membranes processed by nanofiber electrospinning and casting, a series of chemical analyses, in-situ Au nanoparticle depositions, and dye-adsorption experiments revealed that more cis-configuration amide groups appeared on the surface of the electrospun PMIA membrane than on that of the cast membrane. Based on this surface difference, a strategy was proposed to improve the dyeing properties of PMIA by reversibly changing the cis/trans configurations of electrospun and cast membranes. The reversible chain-segment switch mechanism is a novel method for tuning the macroscale properties of polymer materials based on inherent molecular characteristics.
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Nano Research
·
2018
·Vol. 11
·期 5
·2872-2884
·
IF 7.994
Iqbal Shoaib,Du Xiaojiao,Wang Jilong,Li Hongjun,Yuan Youyong,Wang Jun
Nanoparticle (NP) drug delivery systems have been successfully designed and implemented to orally deliver siRNAs for inflammatory disorders. However, the influence of surface charge on orally administered siRNA nanocarriers has not been investigated. In this study, we prepared structurally related poly(ethylene glycol)-block-poly(lactic-co-glycolic acid) (PEG 5K - b -PLGA 10K ) NPs with the assistance of a synthesized lipid featuring surface amine groups for subsequent charge tuning. NPs were prepared by a double emulsion method, and their surface charge could be tuned and controlled by a succinylation reaction to yield NPs with different surface charges, while maintaining their size and composition. The prepared NPs were termed as aminated NPs (ANPs), plain NPs (PNPs), or carboxylated NPs (CNPs) based on their surface charge. All NPs exhibited the desired structural stability and siRNA integrity after enzymatic degradation. In vivo studies showed that ANPs significantly accumulated in inflamed colons, and they were successful in decreasing TNF-α secretion and mRNA expression levels while maintaining colonic histology in a murine model of acute ulcerative colitis (UC). This study described a methodology to modify the surface charge of siRNA-encapsulating polymeric NPs and highlighted the influence of surface charge on oral delivery of siRNA for localized inflammatory disorders.
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MICROCHIMICA ACTA
·
2018
·Vol. 185
·期 6
·1-8
·
IF 5.705
Luo Dan,Liu Shi Gang,Li Nian Bing,Luo Hong Qun
Water-soluble fluorescent polymer dots (PDs) were prepared from polyethylenimine and glutathione and are shown to be viable fluorescent probes for selective and sensitive determination of Hg(II). The PDs possess bright blue fluorescence (with excitation/emission peaks at 340/462 nm) which is quenched on addition of Hg(II). Based on these findings, a fluorometric assay was worked out. Fluorescence linearly drops in the 0.1 to 100 μM Hg(II) concentration range, and the limit of detection is 32 nM.
The fluorescence of polymer dots prepared from glutathione and polyethyleimine (G-PEI PDs) is selectively quenched by Hg 2+ , and this finding was applied to the determination of Hg 2+ in environmental water samples.
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JOURNAL OF POLYMER RESEARCH
·
2018
·Vol. 25
·期 6
·1-6
·
IF 1.434
Chen Rongzhi,Ye Chunlin,Xin Zhong,Zhao Shicheng,Xia Jincheng,Meng Xin
Multi-wall carbon nanotubes (MWCNTs) are usually used as conductive fillers to improve the conductive and mechanical properties of ultra-high molecular weight polyethylene (UHMWPE) simultaneously. But the poor dispersion of MWCNTs in UHMWPE and the weak compatibility between MWCNTs and UHMWPE lead to lots of defect sites and limit the efficiency of load transfer between UHMWPE and MWCNTs. To solve these problems, octadecylamine (ODA) functionalized MWCNTs (MWCNT-ODA) were prepared and its effects on the conductive and mechanical properties of UHMWPE were investigated. The X-ray photoelectron spectrometer (XPS) measurements indicated that ODA was successfully grafted on the surface of MWCNTs. The electrical conductivity tests showed that 0.5 wt% addition of MWCNT-ODA can obviously reduce the volume resistivity of UHMWPE composites by 12 orders of magnitude compared to pure UHMWPE. Meanwhile, its impact strength achieved an increase of about 42.1% and the tensile strength was slightly improved from 33.5 MPa to 40.7 MPa compared with that of UHMWPE. The microstructure features of the impact fracture surfaces were analyzed by field emission scanning electron microscope (SEM). This result revealed the existence of a stronger interfacial force between the UHMWPE and MWCNT-ODA, which is responsible for the improvement of mechanical properties of UHMWPE.
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ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2018
·Vol. 25
·期 26
·26394-26404
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IF 2.8
Liu Yong,Lang Jie,Wang Ting,Jawad Ali,Wang Haibin,Khan Aimal,Chen Zhulei,Chen Zhuqi
Phenylurea herbicide residuals in soil may continuously contaminate surface water and groundwater due to unregulated and improper use. Herein, we reported a stable and active oxidation system including heterogeneous Fe-based layered double hydroxide materials as persulfate (PS) activators. Under mild conditions, 1% LDH in weight and 70 mM PS can completely degrade 500 mg/kg isoproturon in soil within 10 h, during which less than 0.1 ppm heavy metal leaching was detected. This remarkable performance was consistent in a broad pH range (3~11) and was resistant to various inorganic anions (Cl − , Br − , NO 3 − , HCO 3 − ) and humic acid. Mechanism studies from scavenging tests, EPR, and fluorescence spectra collectively proved that besides •OH and •SO 4 − , singlet oxygen ( 1 O 2 ) and superoxide (•O 2 − ) were also generated and were accounted for the oxidative degradation. This unique mechanism of generating diverse radicals was clearly distinguished from classic Fe(II)/PS system, significantly reduced the influence of varying parameters in water and soil matrix, and was suggestive to chemical oxidation system in soil remediation to avoid scavenging effects by background electrolytes or other components in water/soil matrix.
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MICROCHIMICA ACTA
·
2018
·Vol. 185
·期 8
·1-5
·
IF 5.705
Ni Pengjuan,Chen Chuanxia,Jiang Yuanyuan,Zhao Zhenlu,Lu Yizhong
A fluorometric assay is described for sulfide ions determination. It is based on the finding that the oxidation of the non-fluorescent substrate thiamine (TH) by Cu(II) in basic solution to form fluorescent thiochrome is inhibited by sulfide ions. This results in a decrease in fluorescence intensity which is proportional to the concentration of sulfide ions. Under the optimized conditions, the decrease in fluorescence, best measured at excitation/emission wavelengths of 370/440 nm, decreases linearly in the 0.03 to 2.5 μM sulfide ions concentration range. The detection limit is 20 nM. The method shows excellent selectivity over many potentially interfering ions and has been successfully applied to the determination of sulfide ions in spiked tap water, lake water and the synthetic wastewater samples. The method is time-saving and environmentally friendly, and in our perception shows a great potential in water quality inspection and environmental monitoring.
A fluorescent assay for sulfide ions detection is proposed based on its inhibitory effect on the oxidation of thiamine by Cu(II) ions.
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