查找使用阿拉丁产品的科研文献

The effects of binders on the lithium storage of Fe3O4/NiO heterostructures

Zhang Canping,Zhou Qin,Wang Hairui,Liu Jianwen,Zhang Yanqing,Wang Shiquan

Fe 3 O 4 and Fe 3 O 4 /NiO heterostructures were successfully prepared by a simple one-step solvothermal method. The morphology of Fe 3 O 4 /NiO heterostructures is flower-like spheres composed of nanosheets with a thickness of 10–20 nm. As anode material for lithium-ion batteries (LIBs), the electrochemical performance of the Fe 3 O 4 and Fe 3 O 4 /NiO heterostructures are comparatively investigated. At current density of 100 mA g −1 , the Fe 3 O 4 /NiO heterostructures can maintain 1021 mAh g −1 after 100 cycles. The discharge capacity can still maintain at 500 mAh g −1 and the coulomb efficiency is always stable at 99.6% after 1000 cycles at 1 A g −1 . The Fe 3 O 4 /NiO heterostructures also have lower impedance and better rate capability, compared with the bare Fe 3 O 4 electrode. Moreover, the electrochemical properties of the Fe 3 O 4 /NiO heterostructures can be further improved when the new binder CMC-Li is used. At 100 mA g −1 , it can still maintain 1544 mAh g −1 after 100 cycles. These loose-layered nanosheets can effectively alleviate the volume expansion of materials in the process of charge and discharge. Meanwhile, the large surface area can provide more reaction sites. The ultra-thin nanosheet can also reduce the diffusion distance of lithium ions, so that the Fe 3 O 4 /NiO heterostructures have excellent performance in lithium-ion batteries.

Self-Healing Gels Based on Bimetallic ion Cross-Linking for Mining Fire Prevention and Extinguishing

Liang Zhou,Zhen Liu,Guanglong Dai,Ruxiang Qin

To address the environmentally friendly issue of fire prevention and extinguishing materials in coal mines, a new biomass gel material was prepared using sodium carboxymethyl cellulose (CMC) as the matrix, ferro aluminum citrate (Fe-AlCit) as the cross-linking agent, and gluconic acid-δ-lactone (GDL) as the pH modifier. Through performance tests of gel micromorphology, thermal stability, viscoelasticity and yield stress, it was found that the CMC-3 gel material with a ratio of 2.5% CMC + 4% Fe-AlCit +2% GDL had a dense surface structure, good thermal stability and moderate viscosity, which was the most suitable for pipeline transport. A metal coordination bond favorable to the stability of CMC-3 gel is formed by the carboxylate ion in CMC and the double high-valent metal ions Fe3+ and Al3+ dissociated by Fe-AlCit. CMC-3 gel exhibits excellent fire prevention and extinguishing properties. The results of the programmed warming experiments showed that the inhibition rate of the coal sample treated with CMC-3 gel against CO and C2H4 gases reached 44.84% and 46.57% at 220°C, respectively, and the growth rate of the activation energy in the first and second stage reached 17.63% and 22.68%, respectively, which plays a significant inhibitory role. The infrared spectroscopy test showed that after adding CMC-3 gel, the content of -OH and Ar-C-O in the coal samples was reduced by 49.58% and 40.82%, respectively, and the content of stable C=C in the aromatics was increased by 6.14%, which effectively blocked the coal-oxygen chain reaction and reduced the tendency of coal spontaneous combustion. The thermogravimetric test showed that the characteristic temperature points of the coal sample treated with CMC-3 gel were all increased to different degrees. The fire extinguishing test showed that CMC-3 gel could significantly reduce the temperature of coal sample and extinguish the coal fire quickly. Moreover, the CMC-3 gel material also has excellent self-healing properties, which can self-repair the damaged network through the abundant reversible hydrogen and ionic bonds inside the gel in only 90 s. The study has certain guiding significance for the development of efficient and environmentally friendly self-healing mining fire prevention and extinguishing materials.

A polymeric three-dimensional adhesive network for a high initial Coulombic efficiency silicon anode

Siying Li,Zhengwei Wan,Zhuoying Wu,Dan Qian,Kun Wang,Xingyu Sun,Chuhan Zhou,Min Ling,Chengdu Liang

The inevitable side reactions during the cycling of silicon electrodes lead to the low initial Coulombic efficiencies. Binders play a vital role as a crucial component of electrodes in enhancing the initial Coulombic efficiencies in the cycling process. The water-soluble grafted CMC/PAA binder can form a three-dimensional adhesion network to cover Si particles. A large proportion of hydroxyl and carboxyl groups in the binder can generate a strong interaction with Si–OH bond to attach to the surface of Si particles. The dynamic cross-linked network helps to maintain the structural integrity of the electrodes while simultaneously enhancing the kinetics of lithium ion transportation. The Si@CMC/PAA electrode achieves a high initial Coulombic efficiency of 90.61 %, stable cycling performance and high rate capacity of 880 mAh·g −1 at 2 C.

A Novel Drug-Carrier Based on CMC/MATPP-PTX(CTP) and In Vitro Release

ChengHong Huang,Hong Tang,Shu Jiang,Hongjie Chen,Xiaorong Huang,Kangrui Wang,Ying Fang,Rongrong Men,Jie Gao

Fabrication and characterization of tea polyphenols loaded pullulan-CMC electrospun nanofiber for fruit preservation

Ping Shao,Ben Niu,Hangjun Chen,Peilong Sun

Edible packaging films using polymer for food preservation have been developed for a long time. In this study, the effects of different concentrations (0.5%, 1%, 1.5%, w/v) of tea polyphenols incorporated into pullulan-Carboxymethylcellulose sodium (Pul-CMC) solutions on electrospun nanofiber films were evaluated. The fiber size distribution was characterized by scanning electron microscopy. The morphological features of nanofibers were modulated through adjusting process parameters (e.g. concentration of polymer solution, applied voltage and feeding rate). Increasing the applied voltage from 19 to 21   kV and the feed rate from 0.36 to 0.6   mL/h leads to a reduction in mean fiber diameter. Fruit packaging potential was evaluated using strawberry. The pullulan-CMC-TP nanofibers significantly decreased weight loss and maintained the firmness of the strawberries, and improved the quality of the fruit during storage. The findings demonstrate a facile packaging route to improve food sustainability and reduce waste.

The synergetic depression effect of KMnO4 and CMC on the depression of galena flotation

Yu Li,Liu Quanjun,Li Shimei,Song Chao,Gao Yang,Song Jianwen

The mechanism of carboxymethyl cellulose (CMC) on the galena surface and the enhancement of KMnO4 on the depression of CMC to galena were investigated by flotation test, surface adsorption experiments, scanning electron microscopy-energy dispersive spectrometry (SEM-EDS), and X-ray photoelectron spectroscopy (XPS). Flotation test results indicated that the addition of KMnO4 under alkaline condition significantly enhanced the depression effect of CMC on galena. Surface adsorption experiments of butyl xanthate (BX) and CMC demonstrated that the adsorption amount of BX decreased after CMC was added into the pulp. And the adsorption amount of CMC increased while BX decreased sharply when KMnO4 was added into the pulp. After galena was treated with KMnO4 and CMC, dim spots (oxidation sites) on the surface of galena were observed by SEM-EDS. Results showed the high contents of C and O on the oxidation sites. XPS results indicated that oxidation-reduction reaction occurred on the mineral surface, and PbS2O3 or Pb(OH)2 was probably the main component of the oxidization sites. The CMC could be adsorbed on the oxidation sites by the hydrogen bond to form a hydrophilic membrane on the mineral surface lead to galena depression. All results showed that KMnO4 could enhance the depression effect of CMC on galena.

Highly Selective and Sensitive Sensor Based IL and CMC-MWCNTs Nanocomposite for Rutin Determination

Xin Meng,Bao-Lin Xiao,Xin-Yan Song,Xin-Xin Ma,Yang-Yang Li,Lin-Lin Ma,Yu-Jie Chen,Yu-Ying Li,Ke-Xin Xu,Jian-She Wei,Tao Hong,Ali Akbar Moosavi-Movahedi,Jun Hong

Rutin is a natural antioxidant flavonoid compound with anti-inflammatory, antioxidant, and antiviral effects that is used to prepare drugs with wide application in clinical treatment. Therefore, the quantitative detection of rutin has important practical significance. In this work, a novel electrochemical sensor based on glassy carbon electrodes (GCEs) modified with sodium carboxymethylcellulose (CMC), multi-walled carbon nanotubes (MWCNTs), and 1-butyl-3-methylimid (ionic liquid, IL) was developed for the super-sensitive detection of the flavonoid rutin. The properties of these modified materials were analyzed by transmission electron microscope (TEM), cyclic voltammograms (CVs), and electrochemical-impedance spectroscopy (EIS). CMC was used to disperse MWCNTs to further enhance their hydrophilicity and biocompatibility. The modified MWCNTs improved the sensitivity of rutin detection. The square-wave voltammetry (SWV) technique showed that the linear range of rutin concentration determination was 0.01 μM to 1 µM and 1 µM to 10 µM. The minimum concentration detection of rutin was 0.83 nM and 6.6 nM, respectively. The proposed sensor presented good selectivity for rutin and successfully analyzed rutin content in the pharmaceutical rutin tablets. These results are consistent with those measured by ultra-high-performance liquid chromatography (UHPLC). Therefore, this sensor has latent application value in the analysis of rutin in food and drug tablets and nutraceutical samples.Keywords:sensor;multi-walled carbon nanotubes;ionic liquid;sodium carboxymethylcellulose;rutin

Chemical and Enzymatic Fiber Modification to Enhance the Mechanical Properties of CMC Composite Films

Xiaobao Li,Zhengjie Tang,Zhenbing Sun,John Simonsen,Zhinan Luo,Xiaoping Li,Jeffery J. Morrell

Carboxymethyl cellulose (CMC) is a cellulose derivative that can be obtained from wood, bamboo, rattan, straw, and other cellulosic materials. CMC can be used to produce biofilms for many purposes, but the properties of these resulting films make them unsuitable for some applications. The effects of three kinds of plant fiber addition on CMC film properties was investigated using CMC derived from eucalyptus bark cellulose. Tensile strength (TS) and elongation at break (EB) of CMC/sodium alginate/glycerol composite films were 26.2 MPa and 7.35%, respectively. Tensile strength of CMC composite films substantially increased, reaching an optimum at 0.50 g of fiber. The enhancement due to industrial hemp hurd fiber on CMC composite films was more obvious. Pretreatment with hydrogen peroxide (H2O2) and glacial acetic acid (CH3COOH) produced films with a TS of 35.9 MPa and an EB of 1.61%. TS values with pectinase pretreated fiber films was 41.3 MPa and EB was 1.76%. TS of films pretreated with pectinase and hemicellulase was 45.2 MPa and EB was 4.18%. Chemical and enzymatic treatment both improved fiber crystallinity, but film tensile strength was improved to a greater extent by enzymatic treatment. Surface roughness and pyrolysis residue of the film increased after fiber addition, but Fourier transform infrared spectroscopy (FTIR), opacity, and water vapor transmission coefficients were largely unchanged. Adding fiber improved tensile strength of CMC/sodium alginate/glycerol composite films and broadened the application range of CMC composite films without adversely affecting film performance.Keywords:eucalyptus bark;Yunnan pine wood;bamboo culms;industrial hemp hurd;FTIR;XRD;TG;mechanical properties

A series of sensitive and visible fluorescence-turn-on probes for CMC of ionic surfactants: Design, synthesis, structure influence on CMC and sensitivity, and fast detection via a plate reader and a UV light

Xiaotie Cai,Weijie Yang,Lan Huang,Qiuhua Zhu,Shuwen Liu

We recently developed a unique and sensitive fluorescence-turn-on probe (THP-1, a C-6 unsubstituted tetrahydropyrimide) for critical micelle concentration (CMC) of ionic surfactants based on its unusual properties: no emission in micelles but strong aggregation-induced emission (AIE) in solution. Herein other fifteen THPs (THP-2–16) were designed and synthesized to investigate into structure influence on the CMC values of ionic surfactants (anionic SDS , cationic CTAB and zwitterionic CHAPS) and their fluorescent sensitivities. All these THPs show the unusual properties in these surfactant solutions as THP-1 and can be used as fluorescence-turn-on probes. The determined CMC values are in the range reported. It was found that 4-CF 3 is a crucial functional group for increase of sensitivities of THP probes. Compared with THP-1, the concentration detecting CMC decreased by 10.8 times but fluorescence intensity increased 2.8 times. It worth mentioning that the changes in the fluorescent intensity of THPs about CMC of SDS and CTAB are so sensitive that the CMC values of SDS and CTAB can be detected using a simple UV light . In addition, we investigated into the practical applications of THPs in semi-micro and high throughput CMC determination. Since AIE fluorophores and surfactants have wide applications, it is expected these highly sensitive fluorescence-turn-on probes for CMC based on unusual no emission in surfactant micelles but strong AIE in surfactant solutions can be used in wide practical application areas.

Remediation of soil contaminated with PAHs and γ-HCH using Fenton oxidation activated by carboxymethyl cellulose-modified iron oxide-biochar

Yue Gao,Yanan Xue,Kai Zhen,Jiacheng Guo,Xuejiao Tang,Peng Zhang,Cuiping Wang,Hongwen Sun,Jizhou Wu

The remediation of soil contaminated with hydrophobic organic pollutants has attracted great public concern. In the present study, a novel catalyst using biochar supported ferro ferric oxide modified by carboxymethyl cellulose (CMC-Fe 3 O 4 /BC) was developed to activate the Fenton reaction for hazardous hydrophobic organic pollutants , and the degradation mechanisms were analyzed in terms of free radicals , electron transfer pathways and degradation intermediates. The results showed that the CMC-Fe 3 O 4 /BC-activated H 2 O 2 system degraded nearly 100% of pyrene in the aqueous system after a 1440-min reaction. The catalyst was also applied to remediate industrial field soil contaminated with PAHs and γ-HCH. The removal rate of the total pollutants reached 61.1% after a 10-day reaction, which was higher than that of Fe 3 O 4 /BC without modification. CMC enabled the Fe 3 O 4 particles to more equably distribute on the BC surface, further effectively activating H 2 O 2 to generate more ⋅OH and forming different degradation products compared to the Fe 3 O 4 /BC. Additionally, the CMC-Fe 3 O 4 /BC-activated H 2 O 2 system obviously enhanced electron transfer on the BC surface. Thus, the PAHs and γ-HCH could be degraded via electron transfer pathways.

Synergistic mechanism of green corrosion inhibitors COS and CMC-Na in Co electrochemical mechanical polishing

Chunlin Cai,Min Zhong,Meirong Yi,Xiaobing Li,Jianfeng Chen,Wenhu Xu

Electrochemical mechanical polishing (ECMP), through the introduction of electric field, promotes the chemical reaction during polishing. However, the addition of electric field will accelerate the oxidative corrosion, at this time the effective corrosion inhibitor must be added in the polishing solution. Nevertheless, most traditional corrosion inhibitors are toxic and inhibition efficiency is low. In order to meet this technical challenge, this paper investigates the effect of two green corrosion inhibitors, chitosan oligosaccharide (COS) and carboxymethylcellulose sodium (CMC-Na), on Co ECMP, and compares them with the traditional inhibitor TAZ. The results show that when COS and CMC-Na are added at the same time, the polished Co surface quality can be greatly improved, and the surface roughness decreases by 94.6 %. It indicates that adding COS and CMC-Na simultaneously can play the best corrosion inhibition effect and achieve the best surface quality. The synergistic behavior and action mechanism of COS/CMC-Na are analyzed by polishing experiments, static corrosion, electrochemical tests, XPS, and AFM. This study provides a reference for the development of green polishing solutions for Co ECMP.

Lysozyme-Functionalized PVA/CMC/β-Cyclodextrin/Pectin Hydrogel Films for Strawberry Preservation and Flexible Sensing

A multifunctional hydrogel film, denoted as PCDGPL, was developed for strawberry preservation, and its prospective flexible-sensing capability was evaluated. Distinct from previous systems centered on colorimetric freshness indication or chemically/photocrosslinked sensing networks, PCDGPL employs a physically crosslinked, freeze-thawed PVA/CMC/pectin/β-CD matrix to couple lysozyme-associated antibacterial preservation with NaCl-enabled tensile and compressive deformation responses; a full-formulation-minus-β-CD control further isolated the network-modulating contribution of β-CD. The hydrogel network was proposed to be stabilized by freeze–thaw-induced PVA physical junctions, together with multiple hydrogen-bonding interactions among CMC, pectin, and β-cyclodextrin. Glycerol improved flexibility and moisture retention, NaCl provided ionic conductivity, and lysozyme incorporation contributed to the antibacterial activity of the film. The optimized PCDGPL film showed balanced mechanical properties, stable cyclic tensile/compressive behavior, and reliable strain-dependent resistance responses under stretching and compression. It also exhibited effective antibacterial activity againstEscherichia coliandStaphylococcus aureuswith good cytocompatibility. In strawberry preservation tests, PCDGPL reduced weight loss to approximately 2.5% and decay rate to 15%, while maintaining approximately 97% of the initial firmness after 10 days. This work provides a promising hydrogel-based active packaging platform for strawberry preservation, together with a prospective capability for mechanical deformation sensing.