RSC Advances
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2018
·Vol. 8
·期 33
·18647-18655
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IF 2.936
Xi Zhou,Xiaolin Lv,Wen Zhao,Tiantian Zhou,Shupeng Zhang,Zhan Shi,Shefang Ye,Lei Ren,Zhiwei Chen
This study reports a multifunctional core/shell nanoparticle (NP) that can be used for amplified magnetic resonance image (MRI), enhanced photothermal therapy (PTT) and magnetic hyperthermia therapy (MHT) due to its surface coating with a porous shell. Importantly, by means of introducing the surface coating of a porous shell, it helps entrap large quantities of water around NPs and allow more efficient water exchange, leading to greatly improved MR contrast signals. Besides, the porous shell helps the near-infrared (NIR) absorbance of the core, and then the extremely enhanced thermal effect can be obtained under synergistic combination of PTT and MHT. By synthesizing multifunctional porous MnFe2O4/PB as an example, we found that the transversal relaxivity (r2) of MnFe2O4 NPs might improve from 112.11 to 123.46 mM−1 s−1, and the specific absorption rate (SAR) of MnFe2O4/PB nanoparticles reached unprecedented levels of up to 4800 W g−1 compared with the SAR 1182 W g−1 of PTT under an 808 nm laser and 180 W g−1 of MHT under an external AC magnetic field. Meanwhile, when MnFe2O4 was decorated on PB nanoparticles, the magnetic properties became lower slightly, but the synergistic photothermal/magnetic hyperthermia conversion was enhanced greatly. Subsequently, in vitro T1–T2 dual-modal MRI, PTT and MHT results verified that MnFe2O4/PB could serve as an excellent MRI/PTT/MHT theranostic agent. Furthermore, the MnFe2O4/PB NPs were applied as a T1–T2 dual-modal MRI, PTT and MHT theranostic agent for in vivo MRI-guided photothermal and magnetic hyperthermia ablation of tumors by intratumoral injection in 4T1 tumor-bearing mice. The T1–T2 dual-modal MR imaging result shows a significantly contrast in the tumor site. The MPB-mediated PTT and MHT result shows high therapeutic efficiency as a result of high photothermal and magnetic hyperthermia conversion efficiency. The multifunctional NPs have a great potential application for future clinical tumorous diagnosis and treatment.
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CARBOHYDRATE POLYMERS
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2018
·
IF 5.158
Jian Li,Keman Zuo,Weibing Wu,Zhaoyang Xu,Yonggang Yi,Yi Jing,Hongqi Dai,Guigan Fang
This study describes the preparation of an aerogel adsorbent based on nanofibrillated cellulose(NFC) and polyethyleneimine(PEI) via electrostatic combination without chemical crosslinking. Purely physical crosslinking between NFC and PEI was confirmed by attenuated total refraction-Fourier transform infrared spectroscopy (ATR-FTIR) and thermogravimetric analysis (TGA). The NFC/PEI hybrid aerogels exhibited good structural stability and shape recovery in water. Absorption experiment shows that the hybrid aerogels are excellent adsorbents for the removal of heavy metal ions owing to the highly porous structure and the existence of plenty of amine groups. Thermodynamic and kinetic study showed pseudo-second-order equation and Langmuir model ( R 2 > 0.999) as the best fit. The maximum adsorption capacity of Cu(II) and Pb(II) according to Langmuir model was 175.44 mg/g and 357.44 mg/g, respectively. Besides, the Cu(II) or Pb(II) loaded NFC/PEI aerogel could be easily regenerated by EDTA and retain the adsorption capacity after repeatedly using. This environmentally friendly hybrid aerogels with high-performance are promising candidates for sewage disposal and metal pollution treatment.
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JOURNAL OF HAZARDOUS MATERIALS
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2018
·
IF 6.434
Wenbin Xu,Yuan Song,Kang Dai,Shuai Sun,Guyue Liu,Junrui Yao
Novel ternary nanohybrids, consisting of tetraethylenepentamine (TEPA), graphene oxide (GO) and manganese ferrite magnetic nanoparticles (TEPA-GO/MnFe 2 O 4 ), were prepared by a facile hydrothermal method and utilized to remove Pb(II) from aqueous solution effectively. The adsorbents were characterized by SEM, TEM, XRD, FTIR, zeta potential analysis, magnetization hysteresis loop, BET and XPS. These nanoparticles exhibited superparamagnetic behavior as well as high removal efficiency for Pb(II). Moreover, numerous amino groups of the functionalized pendant TEPA on GO coupled with the porous structure of TEPA-GO/MnFe 2 O 4 contribute to high Pb(II) adsorption capacity. The maximum Pb(II) adsorption capacity of TEPA-GO/MnFe 2 O 4 was determined to be 263.2 mg/g at the optimized solution pH of 5.5, much higher than that of GO/MnFe 2 O 4 (133.3 mg/g) and GO (196.1 mg/g). The kinetics and isotherm data fitted well with the pseudo-second-order kinetics and the Langmuir isotherm model, respectively. Thermodynamic studies revealed that the Pb(II) adsorption of TEPA-GO/MnFe 2 O 4 was a endothermic and spontaneous process. The experimental results corroborated that TEPA-GO/MnFe 2 O 4 can be efficaciously reused after washed with HCl, indicative of its potential applications in environmental cleanup.
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CHEMICAL ENGINEERING JOURNAL
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2018
·
IF 6.735
Xiulan Weng,Jing Wu,Li Ma,Gary Owens,Zuliang Chen
Graphene has a great potential in environmental remediation due to its unique physical and chemical properties. However, the relationships between synthetic conditions and contaminant removal are still unclear. In this study, a biogenic method was used for the reduction of graphene oxide (GO) using green tea extract and the reduced graphene oxide (RGO) produced was subsequently used to remove Pb(II) from aqueous solution. Hence, the impact of bioreduction synthetic conditions of RGO on Pb(II) removal efficiency was examined. The new findings included (1) that reduction of GO by green tea (GT) extract at a ratio of 2:1 (GO:GT), 80 °C and pH 8, led to a RGO material capable of removing 97.2% of a 10 mg·L −1 Pb(II) solution under the adsorption conditions of pH 4.5 and a RGO dose of 0.4 g·L −1 at 30 °C; (2) characterization results showed good dispersion of RGO, and removal of oxygen functional groups from GO, increased Pb(II) adsorption. Pb(II) removal efficiency was largely dependent on reduction conditions during synthesis of RGO; where efficient removal of oxygen-containing groups during reduction favored Pb(II) removal. Furthermore, during biogenic synthesis RGO was also capped by biomolecules such as polyphenols which decreased aggregation leading to enhanced Pb(II) removal efficiency.
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JOURNAL OF ENVIRONMENTAL MANAGEMENT
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2018
·
IF 4.005
Zishun Li,Xuekun Tang,Kun Liu,Jing Huang,Qian Peng,Minlin Ao,Zhiqiang Huang
An adsorbent, which is easy to be separated and reused after adsorption, is very important for the removal of pollutants in aqueous solution. Hence, a novel nanofibrous sandwich structured adsorbent of silica nanofiber/magnetite nanoparticles/porous silica (SNF/MNP/PS) was designed and synthesized for the first time. The magnetite nanoparticles with diameter less than 10 nm were evenly distributed on the surface of silica nanofiber, which was subsequently fully covered by a layer of porous silica. The novel adsorbent was proved possessing good adsorption capacity for both methylene blue (MB) and Pb (II) ion (Pb 2+ ), and the adsorption equilibrium could be well described by the Langmuir-isotherm model with the maximum adsorption capacity of 103.1 mg/g for MB and 243.9 mg/g for Pb 2+ at 288 K. Moreover, in MB-Pb 2+ mixed system the measured adsorption capacity reached 74.5 mg/g for MB and 202.4 mg/g for Pb 2+ , respectively. The saturated adsorbent could be readily magnetically separated from the solution and then efficiently regenerated by heterogeneous Fenton-like reaction (for MB) or acidic desorption process (for Pb 2+ ), respectively. After 5 cycles of adsorption-regeneration, the adsorption capacity of the reused adsorbent still reached 81.0% (for MB) and 70.9% (for Pb 2+ ) of the initial value. The SNF/MNP/PS behaves good adsorption properties for different types of pollutants, high magnetic recoverability and regeneration efficiency, which make it applicable to different contaminants removal .
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2018
·
IF 3.909
Yongcun Song,Li-Ye Yang,Yang-guang Wang,Di Yu,Jiafeng Shen,Xiao-kun Ouyang
In this work, amino-functionalized Santa Barbara Amorphous-15/calcium alginate (ASBA-15@CA) microspheres were fabricated and characterized by FTIR, SEM, XRD, TGA , and XPS analyses. The Pb(II) adsorption properties of the ASBA-15@CA microspheres were studied in terms of the effects of the adsorption time, adsorbent dose, solution pH, temperature, and initial concentration of Pb(II) on the adsorption capacity. At pH 6 and 298 K, the adsorption reached equilibrium after 100 min and the sample exhibited a good adsorption effect, affording a maximum adsorption capacity of 1029.58 mg/g and a removal rate as high as 98.99%. The adsorption process conformed to the Langmuir model ( R 2 = 0.9937) and followed the pseudo-second-order kinetics model ( R 2 = 0.9995). Regeneration experiments showed that the removal rate of the sample reached 75% even after 6 cycles. Overall, this study provides new insights into the development of novel, highly efficient, and repeatable degradation materials for the removal of Pb(II).
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JOURNAL OF HAZARDOUS MATERIALS
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2016
·
IF 4.836
Sheng Deng,Peng Wang,Guangshan Zhang,Yuan Dou
A novel thiosemicarbazide modified adsorbent (PAN MW –TSC) based on polyacrylonitrile fiber was successfully synthesized under microwave irradiation, which was applied for the uptake of Cd(II) and Pb(II) from aqueous solution subsequently. Microwave irradiation method is a new approach to achieve the modification and it turns out that just a 30 min process is enough for the anchoring of functional groups in the fiber matrix. The surface characterization was performed by fourier transform infrared spectroscopy (FT–IR), scanning electron microscopy (SEM) elemental analysis (EA) and thermogravimetric analysis (TGA), indicating that the modification was successfully accomplished. Batch adsorption experiments including equilibrium isotherms, kinetics and the effects of pH and temperature on the adsorption of Cd(II) and Pb(II) were systematically studied. Among three kinetic models, the pseudo-second-order kinetic model provides the best correlation for the process. The nonlinear resolution of the Langmuir isotherm equation has been found to show the closest fit to the equilibrium date. Thermodynamic parameters, involving △ G , △ H and △ S were also calculated from graphical interpretation of the experimental data, which suggest that metal ions adsorption onto PAN MW –TSC fibers is spontaneous and exothermic. Regeneration of PAN MW –TSC fibers loaded with metal ions was efficiently done with 0.5 M HNO 3 , by which the investigated adsorbent could be used reproductively for five times with a small decrease in sorption capacity. The feasible preparation of PAN MW –TSC fibers with high adsorption capacities opens a new perspective in the potential application for wastewater treatment .
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COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2016
·
IF 2.76
Juntao Gu,Shaojun Yuan,Wanting Shu,Wei Jiang,Shengwei Tang,Bin Liang,Simo Olavi Pehkonen
A novel pH-sensitive polystyrene (PS)-type resin was developed by grafting of poly(3-sulfopropyl methacrylate) (PSPMA) brushes onto a cross-linked poly(vinylbenzyl chloride) (PVBC) microsphere via surface-initiated atom transfer radical polymerization (ATRP), and was further utilized as a highly efficient and recyclable sorbent to remove Pb(II) ions from aqueous solutions. The as-synthesized PSPMA-grafted PVBC microspheres were characterized by ATR-FTIR, XPS and SEM. Batch adsorption results revealed that the solution pH had an evident effect on the adsorption capacity of the PSPMA-grafted microspheres towards Pb(II) ions with an optimal sorption pH of above 5.0. The PSPMA-grafted microspheres had rapid adsorption kinetics of Pb(II) ions to reach adsorption equilibrium within 60 min. The Langmuir-fitted adsorption isotherms at pH 5.0 with an initial Pb(II) concentration range of 0.12–0.97 mmol L −1 (i.e. 50–200 mg L −1 ) revealed a maximum capacity of Pb(II) ions of 0.82 mmol g −1 . The calculated thermodynamic parameters demonstrated an endothermic and spontaneous adsorption process of Pb(II) ions on the PSPMA-grafted microspheres. With the inherent stability, high adsorption capacity and good regenerability, the PSPMA-grafted PVBC microsphere resin provides a novel promising PS-type adsorbent for effective removal of heavy metal ions from aqueous solution.
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SCIENCE OF THE TOTAL ENVIRONMENT
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2016
·
IF 3.976
Y.H. Zhao,X. Jia,W.K. Wang,T. Liu,S.P. Huang,M.Y. Yang
Plant secondary metabolites play a pivotal role in growth regulation, antioxidant activity, pigment development, and other processes. As the global climate changes, increasing atmospheric temperatures and contamination of soil by heavy metals co-occur in natural ecosystems, which alters the pH of rhizosphere soil and influences the bioavailability and mobility of metals. Elevated temperatures in combination with heavy metals are expected to affect plant secondary metabolites, but this issue has not been extensively examined. Here, we investigated secondary metabolites in Robinia pseudoacacia seedlings exposed to elevated temperatures using a passive warming device in combination with Cd- and Pb-contaminated soils. Heavy metals significantly stimulated the accumulation of saponins, phenolic compounds , and flavonoids in leaves and stems; alkaloid compounds increased in leaves and decreased in stems, and condensed tannins fluctuated. Elevated temperatures, alone and in combination with Cd and Pb, caused increases in secondary metabolites in the plant tissues. Phenolic compounds showed the greatest changes among the secondary metabolites and significant interactive effects of temperature and metals were observed. These results suggest that slightly elevated temperature could enhance protective and defense mechanisms of Robinia pseudoacacia seedlings exposed to heavy metals by stimulating the production of secondary metabolites.
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Journal of the Taiwan Institute of Chemical Engineers
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2017
·
IF 4.217
Long Lv,Nan Chen,Chuanping Feng,Yu Gao,Miao Li
In this study, Xanthate-modified magnetic chitosan/poly (vinyl alcohol) particles (XMMCP) were synthesized by momentary gelation method and characterized to evaluate its properties. The results of FTIR and XRD analysis indicated that most of basic characteristic peaks were weakened in the spectrum of XMMCP compared with the spectrum of pure chitosan, PVA, and Fe 3 O 4 and the diffraction intensity decreased owing to a decline in crystallinity, respectively. The BET surface area, total pore volume and magnetization saturation value of XMMCP were 15.52 m 2 /g, 0.048 cm 3 /g and 34.8 emu/g, respectively, which ensured enough contact of material surface with the metal ions present for adsorption. Based on SEM images, rough and uneven surface of adsorbent was benefited to adsorption performance of Pb(II). Furthermore, the resulting adsorbent showed stability below 150 °C and good magnetic properties. The resulting material was stable in deionized water, acidic, and basic media in 10 days. Continuous adsorption–desorption cyclic results demonstrated that XMMCP could effectively adsorb Pb 2+ and Pb 2+ -loaded XMMCP could be effectively regenerated by HCl solution. Meanwhile, regenerated composite particles could be employed for repeated use without significant capacity loss. Therefore, XMMCP can be a promising material to treat water with Pb 2+ .
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CHINESE CHEMICAL LETTERS
·
2016
·
IF 1.947
Ting-Ting Zhang,Jing-Yang Jiang,Yan-Hua Wang
Various supported Pt-Pb bimetallic catalysts were prepared and applied for the catalytic conversion of nitrobenzene to p -aminophenol in the environmentally benign pressurized CO 2 /H 2 O system. Among the bimetallic catalysts prepared, Pt-Pb/SiO 2 is the best and nitrobenzene could be converted to p -aminophenol with a selectivity as high as 82% when the reaction was carried out using this catalyst at 110 °C under 5 MPa CO 2 and 0.2 MPa H 2 .
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SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Youyu Cao,Mengshuo Du,Fei Han,Xueli Luo,Weixia Yang,Wanmei Lin,Yingying Wang,Wenzhi Tang,Zhonghong Li
Pb(II) removal from water is essential for human health due to their high toxicity and carcinogenicity. Metal-organic frameworks (MOFs) have potential to remove heavy metal ions because of their adjustable structure and tunable pore size. However, the microporous structure limits their removal performance because Pb(II) mainly exists in water as hydrated ion, which is larger than the pore size of MOFs. Defect engineering is promising to form suitable pore to capture Pb(II). Herein, we developed an etched Cu 0.3 Zr 0.7 -MOF-808 MOF by a mixed-metal strategy followed with an etching process. We replaced part of Zr 4+ in the MOF-808 skeleton with Cu 2+ through competition between Zr 4+ /Cu 2+ for coordinating with –COOH on 1,3,5-Benzenetricarboxylic acid (H 3 BTC) to increase its specific surface area. Then H 3 PO 4 and EDTANa 2 ·2H 2 O as etchants were used to break the coordinate bond between Zr 4+ /Cu 2+ and –COOH on H 3 BTC to achieve macroporous structure to inhabit Pb(II). The powder property of MOFs limits their practical applications due to their poor recyclability. We crosslinked the MOF on CMC by coordinating Zr 4+ on the MOF with –COOH on CMC to form aerogel to facilitate its recyclability. The maximum adsorption capacity for Pb(II) was 542.77 mg/g at 45 °C. The adsorption of Pb(II) conformed to the intra-particle diffusion model and the Langmuir model, illustrating that the adsorption process was monolayer adsorption and affected by intra-particle diffusion. The electrostatic attraction and chelation between Pb(II) and –COOH accounted for the effective Pb(II) removal performance. This work provides a novel idea for the removal of heavy metal ions from water.
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