查找使用阿拉丁产品的科研文献

Efficient adsorption of methylene blue by xanthan gum derivative modified hydroxyapatite

Xi Chen,Panyu Li,Xiaotong Zeng,Yan Kang,Jie Wang,Hongyang Xie,Yali Liu,Yongkui Zhang

In this work, hydroxyapatite modified by xanthan gum (XG) derivative material (XMH) was prepared and applied to remove methylene blue (MB) from water. The physicochemical properties of XMH were characterized by Fourier transform infrared spectroscopy , scanning electron microscopy, X-Ray spectroscopy and thermogravimetric analysis . Results showed the operating variables (pH, ionic strength and adsorbent dosage) were related to the MB removal efficiency. Adsorption kinetic and adsorption isotherm were well fitted by the pseudo-second-order model and the Langmuir isotherm model, respectively. It indicated that the adsorption process was a monolayer layer adsorption and chemisorption process. Besides, the result of intra-particle diffusion model demonstrated that the intra-particle diffusion was not the only rate determining step. The maximum adsorption capability on MB was 769 mg/g. Thermodynamic parameters (Δ G 0 , Δ H 0 , and Δ S 0 ) showed that the adsorption was a spontaneous and endothermic process. Adsorption mechanisms of MB on XMH might be governed by electrostatic attraction and hydrogen-bonding. Furthermore, XMH could be regenerated well and retained MB removal efficiency of 81% after five cycles of adsorption and desorption. Therefore, XMH is a promising adsorbent for the efficient removal of MB from aqueous solution due to its low cost, good thermal stability and excellent adsorption performance.

Mesoporous structure TiO2/SiO2 composite for methylene blue adsorption and photodegradation

Jidong Wang,Zhijie Gu,Jialin Zhang,Xin Chen,Mengjuan Li,Yuan Yu,Mingqiao Ge,Xiaoqiang Li

In this work, a mesoporous structure TiO 2 /SiO 2 (M-TS) composite with excellent adsorption and photocatalytic properties was fabricated by a sol–gel process combined with calcination. The structure of the samples was characterised by scanning electron microscopy and Brunauer–Emmett–Teller analysis. The factors influencing the adsorption behaviours of methylene blue (MB) onto M-TS, including ingredient, dosage, initial concentration and temperature were investigated. The M-TS was produced by removing poly(vinylpyrrolidone) from the precursor gel was vital to the excellent adsorption capacity. Furthermore, the isotherm and kinetic data were fitted by using Langmuir and Freundlich isotherm models, pseudo-first-order and pseudo-second-order equations, and the intra-particle diffusion model. The Langmuir isotherm model and the pseudo-second-order kinetics were the most suitable models for describing the adsorption of MB onto M-TS. It was also found that the adsorption capacity of cationic dyes on M-TS is better than that of anionic dyes. The experimental results of adsorption and photodegradation proved that improvement of adsorption capacity enhances the decolourisation efficiency. This work shows that the M-TS could be used as an effective adsorbent and photocatalyst to remove cationic dyes from wastewater.

Calcium carbonate-methylene blue nanohybrids for photodynamic therapy and ultrasound imaging

Fan Weili,Qi Yu,Wang Ranran,Xu Chen,Zhao Nana,Xu Fu-Jian

Photodynamic therapy plays an important role in cancer treatment. In this work, methylene blue (MB)-embedded calcium carbonate nanorods (CaCO 3 -MB NRs) have been synthesized for pH-responsive photodynamic therapy and ultrasound imaging. The morphology of CaCO 3 -MB NRs can be controlled by modulating the concentration of Na 2 CO 3 aqueous solution. The generation of effective reactive oxygen species (ROS) were confirmed by 1,3-diphenylisobenzofuran (DPBF) probe. Both photodynamic therapy performance and echogenic performance of CaCO 3 -MB NRs were investigated to confirm the feasibility of CaCO 3 -MB nanohybrids for ultrasound image-guided photodynamic therapy.

Modification of chitin with high adsorption capacity for methylene blue removal

Yun-Li Cao,Zi-Hong Pan,Qing-Xiang Shi,Jun-Ying Yu

Porous chitin sorbents (PChs) with different content of chitin, ranging from 0.9% to 3.5%, were prepared by gel method with CaBr 2 ·xH 2 O/CH 3 OH solution and characterized by FT-IR, XRD and SEM. The adsorption isotherms and kinetic analysis of methylene blue (MB) onto PChs were studied. Experimental results illustrated lower crystallinity and more pores of PChs containing 3.5% chitin displayed higher adsorption capacity, the removal of MB was 79.8%. The adsorption equilibrium isotherm curve of MB onto PChs adsorbents conformed to the Freundlich equation . The PFO, PSO and Weber-Morris models were applied to fit with the adsorption kinetics . The results demonstrated the adsorption of MB might be the mass transfer of heterogeneous system and involve multiple diffusion steps. The adsorption capacity of PChs with 3.5% chitin can maintain 65% removal ratio of MB after being used six adsorption-desorption cycles. It was supposed that PChs may be a promising, cheap, environmentally friendly and efficient adsorbent for some dye wastewater treatment in the near future.

Synthesis and DNA Cleavage Activity of Cationic Methylene-Blue-Backboned Polymers

Xuetong Cai,Xiaoran Zhang,Yajie Zhang,Fude Feng

Methods of DNA cleavage have broad bioapplications in gene editing, disease treatment, and biosensor design. The traditional method for DNA cleavage is mainly through oxidation or hydrolysis mediated by small molecules or transition metal complexes. However, DNA cleavage by artificial nucleases using organic polymers has been rarely reported. Methylene blue has been extensively studied in the fields of biomedicine and biosensing due to its excellent singlet oxygen yield, redox properties, and good DNA affinity. Methylene blue mainly relies on light and oxygen for DNA cleavage, and the cutting rate is slow. Here, we synthesize cationic methylene-blue-backboned polymers (MBPs) that can bind DNA efficiently and induce DNA cleavage through free radical mechanisms in the absence of light and exogenous reagents, showing high-efficiency nuclease activity. In addition, MBPs with different structures showed selectivity for DNA cleavage, and the cleavage efficiency of the flexible structure was significantly higher than that of the rigid structure. Studies on the DNA cleavage mechanism have shown that the cleavage mechanism of MBPs is not through the common ROS-mediated oxidative cleavage pathway, but through the radical of MBP• inducing DNA cleavage. Meanwhile, MBPs can simulate topoisomerase I (Topo I)-mediated topological rearrangement of superhelical DNA. This work paved a way for the application of MBPs in the field of artificial nucleases.

Photocatalytic degradation of methylene blue over 2D CuTCPP/B–TiO2 composites

Yang Yang,Lu Jie,Ma Zhichun,Zhao Yi,Wang Shuang,Ge Kai,Yang Yongfang

Two dimensional (2D) CuTCPP/B–TiO 2 composites were successfully synthesized by addition of B–TiO 2 NPs into the system for preparation of 2D CuTCPP nanosheets under hydrothermal condition. 2D CuTCPP nanosheets with large specific surface area can not only act as supportor to decrease the aggregation of B–TiO 2 and improve the adsorption capacity of methylene blue (MB) but also provide more transfer pathway to effectively facilitate interfacial charge transfer and separation of photogenerated electrons and holes, thus leading to a superior efficiency for photodegradation of MB. The photocatalytic degradation rate constant of 2D CuTCPP/B–TiO 2 composites is 0.0486 min −1 , which is about 15.2, 5.92 and 4.23 times that of P25 (k = 0.0032 min −1 ), 2D CuTCPP nanosheets ((k = 0.0082 min −1 ) and B–TiO 2 NPs (k = 0.0115 min −1 ). This study demonstrates that the combination of B–TiO 2 NPs and 2D CuTCPP is a viable strategy to improve the photocatalytic efficiency for degradation of MB.

Study on the Degradation of Methylene Blue by Cu-Doped SnSe

Li Fan,Hongliang Zhu,Kaili Wang,Hao Liu,Weina Hu,Xin Xu,Shancheng Yan

Treatment of organic wastewater is still a difficult problem to solve. In this paper, Cu-doped SnSe powder was synthesized by a convenient and efficient hydrothermal method. Meanwhile, the degradation effect of different doping concentrations of SnSe on methylene blue was investigated. It was found that at low doping concentrations, the degradation effect on methylene blue was not obvious because Cu was dissolved in the lattice of the SnSe matrix at low concentrations. As the doping concentration increased, SnSe changed from a layered structure to a nanocluster structure with reduced particle size, and a mixed phase of SnSe and Cu2SnSe4appeared. In fact, the degradation effect on methylene blue was significantly enhanced, and we found that the catalytic degradation effect on methylene blue was best at a doping concentration of 10 wt.%.

Porous BCNO fibers for efficient methylene blue adsorption from aqueous solution

Dong Wang,Zirui Song,Shaobo Yang,Song Yan,Yaxin Gu,Yi Fang,Chaochao Cao,Chengchun Tang

With the development of dye production and the printing/dyeing industry, the discharge of dyestuff wastewater has sharply increased, posing a threat to the health of organisms. Therefore, it is necessary to develop efficient adsorbent materials to remove dyes. Porous BCNO (pBCNO) was prepared via pyrolysis of melamine borate modified by hydroxyethyl cellulose (HEC). Compared to traditionally pyrolytic melamine borate, the incorporation of HEC can not only alter the product's microstructure, but also significantly adjust its bonding and chemical composition. Specifically, the specific surface area and total pore volume of pBCNO are as high as 1102.4 m 2 /g and 0.55 cm 3 /g, respectively. The generation of B–N, C–B, C–O, N–C and B–O bonds enriches the bonding and chemical activity of pBCNO. Encouraged by these unique microstructures and chemical compositions, pBCNO exhibits excellent methylene blue (MB) adsorption and recycling capabilities, showing a maximum adsorption capacity and removal efficiency of 709.5 mg/g and 99.9 %, respectively. The adsorption behavior is dominated by chemical adsorption , following Langmuir adsorption theory and pseudo-second-order model. This study not only provides a new synthesis route to pBCNO, but also establishes an experimental and theoretical foundation for the practical adsorption of pBCNO toward organic pollutants in industrial effluent.

Facile Synthesis of Highly Ordered Macroporous CeO2 Film for Methylene Blue Degradation

Cheng Bao Liu,Jun Chao Qian,Feng Chen,Zheng Ying Wu,Zhi Gang Chen

Negative-charged PS microspheres were prepared through emulsifier-free emulsion polymerization method. High-quality PS colloidal crystals were obtained via the horizontal deposition method. Hierarchically ordered macroporous CeO2 sheets were fabricated on fluorine-doped tin oxide (FTO) substrates using PS colloidal crystals as template by a continuous infiltration process. The structure and morphology of the products were characterized by X-ray diffractometer (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM) and nitrogen adsorption-desorption. The characterized results showed that macroporous CeO2 sheets replicated well three-dimensionally (3D) ordered structure derived from PS colloidal crystals template and possessed a relatively large specific surface area. Moreover, the synthesized hierarchical CeO2 sheets showed the highest photocatalytic activity under solar irradiation and also exhibited remarkable ability to remove methylene blue, suggesting they are promising catalyst for wastewater treatment.

Nanosorbcats of methylene blue on novel Fe2O3 nanorods for photocatalytic water oxidation

Qiu-Yun Chen,Dong-liang Huang,Yin-Bing Wang,Jian Shao,Ling-Ling Qu

The development of dye-loaded nanosorbcats can make best use of their advantages in removing dyes from wastewater, also bypassing their disadvantages. Herein, functionalized Fe2O3 nano-rods (pfa@Fe2O3) were synthesized by using tween-80 induced assembly of pyrrol-2-methanoic acid (pfa) and iron(III) salts, and characterized by FT-IR, XRD, EPR, and SEM. The pfa@Fe2O3 nanorods’ adsorption capacity for methylene blue (MB) was 450 mg g−1 compared to only 39 mg g−1 for α-Fe2O3. Moreover, the kinetics to reach equilibrium were approximately 0.5 h and the pfa@Fe2O3 nanorods can be used as efficient recyclable adsorbents for MB. In particular, the MB loaded MB@pfa@Fe2O3–water system could also be used as dioxygen generator when irradiated with red LED light (10 W). The light induced intramolecular charge transfer between catalysts and photosensitizers was more efficient in the MB@pfa@Fe2O3/H2O system, and it exerted higher activity for water oxidation than the traditional catalyst/Ru(bpy)32+ system. Control experiment results suggested that the α-Fe2O3 can’t be used as LED light driven catalysts for water oxidation. In conclusion, the MB@pfa@Fe2O3 nanorods were efficient recyclable nanosorbcats for LED-light-driven dioxygen generation using water as oxygen source.

Carbon nanotubes-based polymer nanocomposites: Bio-mimic preparation and methylene blue adsorption

Defu Gan,Jibo Dou,Qiang Huang,Hongye Huang,Junyu Chen,Meiying Liu,Hongxu Qi,Zhenyu Yang,Xiaoyong Zhang,Yen Wei

The effective removal of environmental pollutants using nanomaterials and their composites has attracted great attention over the past few decades. Among them, carbon nanotubes (CNTs) have been extensively applied as adsorbents to remove various environmental pollutants for their small size, large surface areas and unique chemical structure. However, the adsorption performance of pristine CNTs is largely limited for their poor dispersibility and lack of functional groups. In this work, CNTs based composites ( [email protected] (S- co -MA-DA)) have been successfully synthesized through combination of ring-opening reaction and mussel inspired chemistry. The pristine CNTs and as-prepared [email protected] (S- co -MA-DA) were characterized by transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS). The influence of various experimental factors on the adsorption process, such as contact time, initial MB concentration, solution pH and temperature, was studied. Experimental results show that adsorption capacity of [email protected] (S- co -MA-DA) is about 4 times that of pristine CNTs in same experimental conditions. The kinetics and isotherms studies suggest that pseudo-second-order kinetic and Freundlich isotherm models could well fit with the adsorption data. The thermodynamic studies imply that the adsorption process of MB onto [email protected] (S- co -MA-DA) is endothermic and spontaneous. The adsorption mechanism might be the synergistic action of physical adsorption of [email protected] (S- co -MA-DA) particles and electrostatic interaction between the MB and functional groups on the surface of [email protected] (S- co -MA-DA) composites, including carboxyl, acylamino, hydroxyl and aromatic moieties. These obtained results and facts indicate that the as-prepared [email protected] (S- co -MA-DA) could be utilized as high-performance adsorbents with great potential applications in environmental treatment.

Porous polyurethane hydrogels incorporated with CMC for eliminating methylene blue from water

Li Wang,Qing Yang,Yong Yang,Kun Luo,Ruqing Bai