查找使用阿拉丁产品的科研文献

Three-dimensional g-C3N4/MWNTs/GO hybrid electrode as electrochemical sensor for simultaneous determination of ascorbic acid, dopamine and uric acid

Haoye Wang,Aijuan Xie,Shuji Li,Jiajun Wang,Kaixuan Chen,Zilong Su,Ningning Song,Shiping Luo

A three-dimensional g-C 3 N 4 /MWNTs/GO hybrid modified electrode was constructed as an electrochemical sensor for the simultaneous determination of ascorbic acid (AA), dopamine (DA) and uric acid (UA). Due to the high conductivity of MWCNTs and the strong synergy between g-C 3 N 4 and GO , the combination of the three effectively improved the electrocatalytic activity of the modified electrode for the oxidation of AA, DA, and UA, and solved the problems such as overlapping anodic peaks. The electrochemical performance of the as-constructed sensor was investigated and optimized by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The linear response range of AA, DA, and UA in the optimal condition was 0.2–7.5 mM, 2–100 μM, and 4–200 μM, respectively. The detection limits (S/N = 3) of AA, DA, and UA were 96, 0.22, and 1.36 μM, respectively. The recoveries of AA, DA and UA in serum samples from three groups were 92.82–106.50%, and the relative standard deviations were less than 2%. The results show that the as-constructed g-C 3 N 4 /MWNTs/GO modified electrode has the advantages of simplicity, high sensitivity and good selectivity , and can simultaneously determine AA, DA, and UA.

Space-confined growth of 2D MOF sheets between GO layers at room temperature for superior PDMS membrane-based ester/water separation

Li-Hao Xu,Yan Li,Shen-Hui Li,Ming-Yu Lv,Zhi-Ping Zhao

Expanding the metal–organic frameworks (MOFs) category using room-temperature colloidal chemistry route with regular crystal structure is challenging, but important for reducing energy consumption and realizing an economically viable application in industry. Herein, we developed a novel advanced copper terephthalate MOF (CuBDC) between graphene oxide (GO) layers using a simple space-confined growth strategy at room temperature. The inclusion of CuBDC@GO can realize high filler loadings while maintaining uniform dispersion throughout PDMS matrix. The paralled arranged CuBDC sheets created 1D inner vertical channels, along with the enlarged GO interlayer space for rapid molecule permeselective transport. The resultant mixed matrix membranes (MMMs) with 30 wt% CuBDC@GO loading improved the separation factor from 190.6 to 576.3, and simultaneously increased the total flux from 575.2 to 1357.4 g m -2  h -1 for separating 0.5 wt% butyl acetate at 40 °C. The transport mechanism was explained by adjusting the CuBDC content in composites to examine the significant increase in membrane permeability (from 12.5 to 58.3) and selectivity (from 0.7 to 2.0). Compared to alcohol or ketone, the larger size strip-like butyl acetate molecules are ideal for rapid transport through the CuBDC-supported 1D continuous inner channels, and effectively inhibit the movement of water molecules, ultimately resulting in the largest pervaporation performance improvement in butyl acetate/water separation. This CuBDC@GO prepared by a simple, green and room-temperature synthesis route can be widely applied to prepare defect-free membranes with excellent performance for sustainable applications. We also anticipate that this advanced space-confined growth strategy can be extended to various other MOFs and applications.

Carbon Cloth Loaded NiCo2O4 Nano-Arrays to Construct Co-MOF@GO Nanocubes: A High-Performance Electrochemical Sensor for Non-Enzymatic Glucose

Bairui Tao,Jiao Li,Fengjuan Miao,Yu Zang

Construction of double cross-linking PEG/h-BN@GO polymeric energy-storage composites with high structural stability and excellent thermal performances

Rui Jing,Huanzhi Zhang,Chaowei Huang,Fucai Su,Bojing Wu,Zongxu Sun,Fen Xu,Lixian Sun,Yongpeng Xia,Hongliang Peng,Xiangcheng Lin,Bin Li,Yongjin Zou,Hailiang Chu,Pengru Huang,Erhu Yan

To improve phase-change behavior and thermal conductivity of the PEG-based polymeric SSPCMs, a series of SSPCMs with double cross-linking networks were constructed by introducing GO and hydroxylated h-BN into the polymer molecular chains of PEG-based SSPCMs through grafted polymerization and self-assembly. GO was the main hard supporting skeleton for the PEG segment, and h-BN as 2D thermal enhanced cells continuously was linked on the GO nano-sheets, forming into double cross-linking networks with PEG segments, which has good structural stability and regularity. Thus, the SSPCMs possessed good phase-change properties, excellent thermal reliability, and high thermal conductivity. Microscopies confirmed the successfully constructed chemical structure of the SSPCMs. Energy-storage capacities of the SSPCMs could reach 149.62 J/g, which displayed no obvious change after 100 thermal cycles, suggesting a good thermal cycling stability. Moreover, thermal conductivity of the prepared SSPCMs was enhanced by 71% compared with pure PEG, showing a good heat transfer efficiency. Therefore, this study represents a creative strategy towards the development of SSPCMs for thermal energy storage and thermal management applications.

Co-assembly of stearoylated cellulose nanocrystals and GO (or CNTs) for the construction of superhydrophobic hierarchical structure with enhanced photothermal conversion

Wei Huang,Xiangyu Tang,Wuming Fan,Qianqian Sun,Yonggui Wang,Zefang Xiao,Yanjun Xie

The development of photothermal materials with high photothermal-conversion efficiencies is important in a range of applications, such as power generation, sterilization, desalination , and energy-production. To date, a few reports have been published related to improving the photothermal conversion performances of photothermal materials based on self-assembled nanolamellae. Herein, hybrid films of co -assembled stearoylated cellulose nanocrystals (SCNCs) and polymer-grafted graphene oxide (pGO)/polymer-grafted carbon nanotubes (pCNTs) were prepared. The chemical compositions , microstructures, and morphologies of these products were characterized, and it was found that the self-assembled SCNC structures exhibited numerous surface nanolamellae due to crystallization of the long alkyl chains. The hybrid films (i.e., SCNC/pGO and SCNC/pCNTs films) consisted of ordered nanoflake structures, confirming the co-assembly behavior of the SCNCs with pGO or pCNTs. The melting temperature (~65 °C) and latent heat of melting (87.87 J/g) of SCNC 1.07 indicate its potential to induce the formation of nanolamellar pGO or pCNTs. Under light irradiation (50–200 mW/cm 2 ), the pCNTs exhibited a higher light absorption capacity than pGO, and as a result, the SCNC/pCNTs film exhibited the best photothermal performance and electrical conversion, ultimately demonstrating its potential for use as a solar thermal device in practical applications.

Highly sensitive detection of kaempferol using electrochemical sensors based on 3D-ordered mesh interconnect C60-GO, Ni-MOF, and β-cyclodextrin

Qian Tan,Chao Chen,Cuixia Lin,Jiahui Zhang,Saiwen Liu,Jin Zhang

Kaempferol (KA), which is a biologically active natural polyphenol compound with considerable medicinal value, can be used to fight various diseases. Herein, a β-cyclodextrin/fullerene-graphene oxide/Nickel-metal–organic framework (β-CD/C 60 -GO/Ni-MOF) composite-based electrochemical sensor was developed to detect KA; the composite was characterized using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and X-ray photoelectron (XPS) spectroscopy. The biocompatibility and host–guest recognition performance of β-cyclodextrin (β-CD); the porosity and the catalytic performance of the nickel-metal–organic framework (Ni-MOF); and the excellent electrical conductivity of fullerene-graphene oxide (C 60 -GO) work together to considerably improve the detection performance of the sensor for KA. The sensor has an extensive linear range (0.5–50 μM) and a low detection limit (58 nM) with an electrochemically active specific surface area of 0.0971 cm 2 ; furthermore, the redox mechanism of KA in the sensor is explained. For the detection of actual natural samples of broccoli containing KA, satisfactory recovery rates and accuracy were observed; the recovery rate was 96.4 %–101.1 %.

Construction of a Mesoporous Polydopamine@GO/Cellulose Nanofibril Composite Hydrogel with an Encapsulation Structure for Controllable Drug Release and Toxicity Shielding

Yingying Liu,Qing Fan,Ying Huo,Chao Liu,Bin Li,Youming Li

The development of intelligent and multifunctional hydrogels having photothermal properties, good mechanical properties, sustained drug release abilities with low burst release, antibacterial properties, and biocompatibility is highly desirable in the biomaterial field. Herein, mesoporous polydopamine (MPDA) nanoparticles wrapped with graphene oxide (GO) were physically cross-linked in cellulose nanofibril (CNF) hydrogel to obtain a novel MPDA@GO/CNF composite hydrogel for controllable drug release. MPDA nanoparticles exhibited a high drug loading ratio (up to 35 wt %) for tetracycline hydrochloride (TH). GO was used to encapsulate MPDA nanoparticles for extending the drug release time and reinforcing the physical strength of the obtained hydrogel. The mechanical strength of the as-fabricated MPDA@GO/CNF composite hydrogel was five times greater compared to that of the pure CNF hydrogel. Drug release experiments demonstrated that burst release behavior was significantly reduced by adding MPDA@GO. The drug release time of the MPDA@GO/CNF composite hydrogel was 3 times and 7.2 times longer than that of the polydopamine/CNF hydrogel and pure CNF hydrogel, respectively. The sustained and controlled drug release behaviors of the composite hydrogel were highly dependent on the proportion of MPDA and GO. Moreover, the rate of drug release could be accelerated by near-infrared (NIR) light irradiation and pH value change. The drug release kinetics of the as-prepared composite hydrogel was well described by the Korsmeyer–Peppas model, and the drug release mechanism of TH from the composite hydrogel was anomalous transport. Importantly, this carefully designed MPDA@GO/CNF composite hydrogel showed good biocompatibility through an in vitro cytotoxicity test. In particular, the toxicity of GO was well shielded by the CNF hydrogel. Therefore, this novel MPDA@GO/CNF composite hydrogel with an encapsulation structure for controllable drug release and toxicity shielding of GO could be used as a very promising controlled drug delivery carrier, which may have potential applications for chemical and physical therapies.

Removal of Ca2+ and Mg2+ from oilfield wastewater using reusable PEG/Fe3O4/GO-NH2 nanoadsorbents and its efficiency for oil recovery

Lei He,Lutao Yang,Luxia Zhang,Zhe Wang,Hongjie Cheng,Xiaoguang Wang,Jianrong Lv,Jun Zhang,Hong Mo,Jian Shen

The high salinity of oilfield-produced water caused by the presence of metal ions, such as Ca 2+ and Mg 2+ , has a significantly adverse effect on oil recovery. It is crucial to remove these metal ions efficiently before the oilfield wastewater is reinjected down into the oil wells. To address this issue, we prepared a PEG/Fe 3 O 4 /GO-NH 2 nanoadsorbent by aminating GO, incorporating magnetic Fe 3 O 4 nanoparticles and coating with PEG (PEG = poly(ethylene glycol); GO-NH 2 = aminated graphene oxide). We investigated the removal ratios of the nanoadsorbent for Ca 2+ and Mg 2+ . The respective removal ratios for Ca 2+ and Mg 2+ reached 69.8 % and 61.1 % at 10 min, indicating that the nanoadsorbent was capable of efficiently removing Ca 2+ and Mg 2+ . We also evaluated the reusability of the nanoadsorbent by recycling and reusing it 5 times. At the fifth recycling run, the nanoadsorbent retained relatively high reuse rates (79.1 % for Ca 2+ , 69.5 % for Mg 2+ ) and removal ratios (69.5 % for Ca 2+ , 64.3 % for Mg 2+ ), suggesting that the nanoadsorbent possessed relatively high reusability. Oilfield wastewater treated with the nanoadsorbent was employed for oil recovery in core displacement experiments. The oil recovery efficiency significantly increased by 11.8 % compared with untreated oilfield wastewater. Therefore, the PEG/Fe 3 O 4 /GO-NH 2 nanoadsorbent exhibits considerable potential for the treatment of oilfield wastewater to enhance oil recovery.

Ultrastretchable, self-adhesive, strain-sensitive and self-healing GO@DA/Alginate/P(AAc-co-AAm) multifunctional hydrogels via mussel-inspired chemistry

Xiaoqiang Jin,Huihong Jiang,Zhiming Zhang,Yuejun Yao,Xiaojiong Bao,Qiaoling Hu

For conductive hydrogels applied in biosensors, wearable devices and so forth, multifunctionality is an inevitable trend of development to meet various practical requirements and enhance human experience. Herein, inspired by nanocomposite, double-network (DN) and mussel chemistry, a new Graphene oxide@Dopamine/Alginate/Poly(acrylic acid- co -acrylamide) [GO@DA/Alginate/P(AAc- co -AAm)] hydrogel was fabricated through one-pot in-situ radical copolymerization. GO@DA nanofillers, prepared via GO confined DA polymerization, imparted the hydrogel with remarkable adhesiveness. Alginate/P(AAc- co -AAm) DN matrix, physically and chemically crosslinked by Fe 3+ and N,N'-Methylenebisacrylamide, made hydrogels ultrastretchable, self-healing and biocompatible. With contents of DA and alginate accurately regulated, the tensile strength, elongation, adhesion strength and conductivity of the optimal hydrogel could reach 320.2 kPa, 1198 %, 36.9 kPa and 3.24 ± 0.12 S/m, respectively. What’s more notable was that the synergistic integration of repeatable adhesiveness, strain sensitivity, use stability, self-healing ability and biocompatibility provided such hydrogels with tremendous possibility of practical application for strain sensors.

Fabrication of tight GO/PVDF hollow fiber membranes with improved permeability for efficient fractionation of dyes and salts in textile wastewater

Wang Chuanfeng,Chen Yingbo,Yang Kang,Hu Xiaoyu,Zhang Yufeng

In this study, a graphene oxide/polyvinylidene fluoride (GO/PVDF) tight hollow fiber membrane (HFM) with improved permeability was fabricated via one-step direct spinning process to fractionate the dyes and salts (NaCl and Na 2 SO 4 ) in textile wastewater. Scanning electron microscopy (SEM) indicated that the GO/PVDF HFM possessed a smooth and tight outer selective layer and a relatively porous and loose inner surface. The optimized HFM not only possesses a small mean pore radius of 1.14 nm, but also has a high pure water flux of 24.8 L/m 2 ·h·bar. The stronger negative charge (− 40 mV at pH = 7) was obtained by the GO/PVDF HFM. Due to the synergistic effects of size exclusion and charge repulsion, the resultant HFM exhibited excellent rejection for dyes (i.e., close to 100% for Congo red and Methyl blue, 98.9% for Eriochrome black T) and low salts rejection (i.e., 1% for NaCl, 11% for Na 2 SO 4 ). Besides, with appropriate addition of hydrophilic GO to the doped solution, the resultant membrane exhibited good hydrophilicity, antifouling property and excellent stability. The newly developed tight HFM would be of great significance for effective fractionation and treatment of textile wastewater.

High thermal-conductivity rGO/ZrB2-SiC ceramics consolidated from ZrB2-SiC particles decorated GO hybrid foam with enhanced thermal shock resistance

Yehong Cheng,Yaxiong Liu,Yumin An,Ning Hu

Graphene derivative materials exhibit excellent mechanical and thermal properties, which have been extensively used to toughen ceramics and improve thermal shock resistance . To overcome the thermal agglomeration of graphene oxide (GO) during heating and drying process, ZrB 2 -SiC particles decorated GO hybrid foam with uniformly anchored ceramic particles was synthesized by electrostatic self-assembly and liquid nitrogen-assisted freeze-drying process. Densified rGO/ZrB 2 -SiC ceramics with varying microstructure, thermal physical and mechanical properties were obtained by adjusting the content of decorated ceramic particles. Although the flexural strength of rGO/ZrB 2 -SiC ceramics have an attenuation compared with that of ZrB 2 -SiC ceramic, the thermal conductivity , work of fracture and thermal shock resistance are greatly improved. rGO/ZrB 2 -SiC ceramics exhibit delayed fracture and increasing R-curve behavior during the crack propagation . The novel preparation technology allows for the well dispersion of rGO in ZrB 2 -SiC ceramics and can be easily extended to other ceramic or metal materials systems.

Applications of GO/OA-POSS Layer-by-Layer self-assembly nanocoating on flame retardancy and smoke suppression of flexible polyurethane foam

Pengfei Jia,Wenhua Cheng,Jingyi Lu,Zhenting Yin,Zhoumei Xu,Liang Cheng,Yong Qiu,Lijun Qian,Yuan Hu,Weizhao Hu,Bibo Wang

Flexible polyurethane foam (FPUF) is extremely flammable and will release a large number of toxic fumes during the combustion process, which brings great safety hazards. Therefore, a binary hybrid nanocoating composed of graphene oxide (GO) and octaamino polyhedral oligomeric silsesquioxane (OA-POSS) is deposited on the surface of FPUF through layer-by-layer self-assembly technology, with the aim of enhance the flame retardancy and smoke suppression properties of the hybrid FPUF. Compared with pure FPUF, the peak heat release rate, the total heat release, the peak smoke production rate and the total smoke release of FPUF@GO/OA-POSS-6 is decreased by 67.3%, 28.3%, 65.03% and 42.9%, indicating the hybrid FPUF excellent flame retardancy and smoke suppression properties. Compared with pure FPUF, the tensile strength of FPUF@GO/OA-POSS-6 is increased by 42%, and after three times of compression, the compressive strength increases by 83.17% on average. Facts have proved that the hybrid effect between GO and OA-POSS enhances the flame retardancy, smoke suppressive effects, tensile strength and compressive strength of FPUF.