Synthesis and characterization of carboxymethyl cellulose/organic montmorillonite nanocomposites and its adsorption behavior for Congo Red dye

A series of carboxymethyl cellulose/organic montmorillonite （CMC/OMMT） nanocomposites with different weight ratios of carboxymethyl cellulose （CMC） to organic montmorillonite （OMMT） were synthesized under different conditions. The nanocomposites were characterized by the Fourier transform infrared （FT-IR） spectrophotometer, X-ray diffraction （XRD） method, transmission electron microscope （TEM）, scanning electron microscope （SEM）, and thermal gravimetric （TG） analysis. The results showed that the introduction of CMC may have different influences on the physico-chemical properties of OMMT and intercalated-exfoliated nanostructures were formed in the nanocomposites. The effects of different reaction conditions on the adsorption capacity of samples for Congo Red （CR） dye were investigated by controlling the amount ofhexadecyl trimethyl ammonium bromide （CTAB）, the weight ratio of CMC to OMMT, the reaction time, and the reaction temperature. Results from the adsorption experiment showed that the adsorption capacity of the nanocomposites can reach 171.37 rag/g, with the amount of CTAB being 1.0 cation exchange capacity （CEC） of MMT, the weight ratio of CMC to OMMT being l：l, the reaction time being 6 h, and the reaction temperature being 60~C. The CMC/OMMT nanocomposite can be used as a potential adsorbent to remove CR dye from an aqueous solution.

Organic/inorganic nanocomposite polymer electrolyte

The organic/inorganic nanocomposites polymer electrolytes were designed and synthesized. The organic/inorganic nanocomposites membrane materials and their lithium salt complexes have been found thermally stable below 200 °C. The conductivity of the organic/inorganic nanocomposites polymer electrolytes prepared at room temperature was at magnitude range of 10(?6) S/cm.

Synthesis and characterization of luminescent organic-inorganic hybrid nanocomposite from polyhedral oligomeric silsesquioxane

A novel polyhedral oligomeric silsesquioxane(POSS)-based organic-inorganic hybrid nanocomposite(EF-POSS) was prepared by Pt-catalyzed hydrosilylation reaction of octahydridosilsesquioxane(T_8H_8,POSS) with a luminescent substituted acetylene(2- ethynyl-7-(4-(4-methylstyryl)styryl)-9,9-dioctyl-9H-fluorene(EF)) in high yield.The hybrid nanocomposite was soluble in common solvents such as CH_2Cl_2,CHCl_3,THF and 1,4-dioxane.Its structure and property were characterized by FTIR, NMR,TGA,UV and PL,respectively.The results show that the hybrid nanocomposite with high thermal stability emits stable blue light as a result of photo excitation and possesses high photoluminescence quantum efficiency(φ_(FL)).

Structures and magnetic properties of nanocomposite CoFe_2O_4-BaTiO_3 fibers by organic gel-thermal decomposition process

The nanocomposite xCoFe2O4-(1-x)BaTiO3(x=0.2,0.3,0.4,0.5,molar fraction) fibers with fine diameters and high aspect ratios(length to diameter ratios) were prepared by the organic gel-thermal decomposition process from citric acid and metal salts.The structures and morphologies of gel precursors and fibers derived from thermal decomposition of the gel precursors were characterized by Fourier transform infrared spectroscopy,X-ray diffractometry and scanning electron microscopy.The magnetic properties of the nanocomposite fibers were measured by vibrating sample magnetometer.The nanocomposite fibers consisting of ferrite(CoFe2O4) and perovskite(BaTiO3) are formed at the calcination temperature of 900 ℃ for 2 h.The average grain sizes of CoFe2O4 and BaTiO3 in the nanocomposite fibers increase from 25 to 65 nm with the calcination temperature from 900 to 1 180 ℃.The single fiber constructed from these nanograins of CoFe2O4 and BaTiO3 has a necklace-like morphology.The saturation magnetization of the nanocomposite 0.4CoFe2O4-0.6BaTiO3 fibers increases with the increase of CoFe2O4 grain size,while the coercivity reaches a maximum value when the average grain size of CoFe2O4 is around the critical single-domain size of 45 nm obtained at 1 000 ℃.The saturation magnetization and remanence of the nanocomposite xCoFe2O4-(1-x)BaTiO3(x=0.2,0.3,0.4,0.5) fibers almost exhibit a linear relationship with the molar fraction of CoFe2O4 in the nanocomposites.

Sandwich-Like Fe&TiO2@C Nanocomposites Derived from MXene/Fe-MOFs Hybrids for Electromagnetic Absorption

Electromagnetic pollution has been causing a series of problems in people’s life,and electromagnetic absorbers with lightweight and broad absorbing bandwidth properties are widely desired.In this work,novel sandwich-like 2D laminated Fe&TiO2 nanoparticles@C nanocomposites were rationally designed and successfully developed from the MXene–MOFs hybrids.The formation of Fe and rutile-TiO2 nanoparticles sandwiched by the two-dimensional carbon nanosheets provided strong electromagnetic energy attenuation and good impedance matching for electromagnetic wave(EMW)absorption.As expected,the nanocomposites achieved a broad effective absorption bandwidth of 6.5 GHz at a thickness of only 1.6 mm and the minimum reflection loss(RL)value of−51.8 dB at 6.6 GHz with a thickness of 3 mm.This work not only provides a good design and fabricating concept for the laminated metal and functional nanoparticles@C nanocomposites with good EMW absorption,but also offers an important guideline to fabricate various two-dimensional nanocomposites derived from the MXene precursors.

An Explosive Organic/Inorganic Hybrid: Synthesis and Thermal Property of Octa(2,4-dinitrophenyl)silsesquioxane

Octaphenylsilsesquioxane(OPhS) was prepared by a modifying method and a new core-shell nanocomposite, octa(2,4-dinitrophenyl)silsesquioxane, [(R_2PhSiO_ 1.5)_8, R=—NO_2, ODNPhS], was synthesized by nitration of OPhS in a mixed acid solution of nitric and sulfuric acids at about 60 ℃. Their molecular structures were determined by DRIFTS, 1H NMR, 13C NMR spectra analysis. The thermal analysis shows that ODNPhS is an explosive that detonates at about 420 ℃.

Synthesis and Characterization of Poly(St-co-BA) Latex with an Organic-Inorganic Hybrid Compound as Emulsifier

A poly (St-co-BA) latex was successfully synthesized by using an organic-inorganic hybrid compound (OIHC), an aliphatic carboxylate sodium/nano-silica composite, as the emulsifier, and investigated by particle size analyzer, transmission electron microscope (TEM), optical contact angle measurement (OCA) and dynamic mechanical analyzer (DMA). It was found that the protective agent, sodium polyacrylate (PA),could obviously improve the polymerization stability and the functional monomer, glycidyl methacrylate (GMA), could enhance the store stability of the latex. The particle size of poly(St-co-BA) latex decreased and then leveled off as OIHC content increased. TEM shows that the prepared polymers were a~:tually organic-inorganic nanocomposites, and these films have better waterproof property than those prepared by traditional poly(St-co-BA) latex or organic silicone modified poly(St-co-BA) latex. The nanocomposite polymer has much higher glass transition temperature than organic silicone modified poly(St-co-BA) polymer containing the same organic silicone content.

High-performance self-organized Si nanocomposite anode for lithium-ion batteries

Silicon is being investigated extensively as an anodic material for next-generation lithium ion batteries for portable energy storage and electric vehicles.However,the large changes in volume during cycling lead to the breakdown of the conductive network in Si anodes and the formation of an unstable solid-electrolyte interface,resulting in capacity fading.Here,we demonstrate nanoparticles with a Si@Mn22.6Si5.4C4@C double-shell structure and the formation of self-organized Si-Mn-C nanocomposite anodes during the lithiation/delithiation process.The anode consists of amorphous Si particles less than 10 nm in diameter and separated by an interconnected conductive/buffer network,which exhibits excellent charge transfer kinetics and charge/discharge performances.A stable specific capacity of 1100 mAh·g-1 at 100 mA·g-1 and a coulombic efficiency of 99.2%after 30 cycles are achieved.Additionally,a rate capacity of 343 mAh·g-1 and a coulombic efficiency of 99.4%at 12000 mA·g-1 are also attainable.Owing to its simplicity and applicability,this strategy for improving electrode performance paves a way for the development of high-performance Si-based anodic materials for lithium ion batteries.

Structure and Evolution of Clay-Organic Nanocomposites in Three Leading Shales in China

Organic matter(OM)in shales occurs as nanometer-sized intercalations with clay minerals that are termed as clay-organic nanocomposites;however,the OM occurrence in nanocomposites at different stages of maturation is still unclear,and the co-evolution process of OM and clay under burial is not well understood.To reveal the variation of OM occurrence and clarify the relationship between petroleum generation of OM&transformation of clay minerals in nanocomposites as a function of maturity,this study investigates the structure and clay-OM association in 44 samples from three leading shales at different maturity stages from two basins in China.A total of 15 samples of lacustrine shale from upper Triassic Yanchang Formation,15 samples of marine shale from Lower Silurian Longmaxi Formation,and 14 samples of marine shale from Lower Cambrian Niutitang Formation were analyzed based on organic geochemistry,X-ray diffraction(XRD),and field emission-scan electron microscopy(FE-SEM),focused ion beam(FIB)sample preparation and consequent high resolution-transmission electron microscopy(HR-TEM)observations combined with energy dispersive spectroscopy(EDS).The results from this study show that most shale samples are organic-rich,and these three shales represent thermal evolutionary process from oil-window mature to overmature in a sequence of Triassic Yanchang,Silurian Longmaxi,and Cambrian Niutitang formations.Thorough observations indicate that sub-parallel bands of clays and intermingling of detrital minerals(such as quartz)dominate the nanocomposites in the Yanchang samples.While for Longmaxi and Niutitang shales,abundant nanopores and pyrite nanoparticles are observed in nanocomposites with features of layered distributions of OM and clay minerals.The structural investigation of nanocomposites shows that organic carbon between multi-layers dominates the OM occurrence in nanocomposites,which significantly extends the traditional opinion of OM-clay association.At an oil-window mature stage,the fluctuational interlayer spacing and a certain intensity of the carbon peak observed in the EDS spectra for corresponding clays provide a visual evidence of the organic molecules accessing the monolayer spaces of smectite.With the evolutional process of nanocomposites in shale and petroleum generation of OM&mineral transformation(illitization of smectite)running in parallel,it is inferred that the organic molecules migrate from monolayer spaces as gaseous hydrocarbons are generated,and eventually form stable clay-organic nanocomposites at an overmature stage.The results presented here will contribute to an improved understanding of diagenesis and organic-inorganic interactions in OM-rich shales.

One-step synthesis of three-dimensional mesoporous Co_(3)O_(4)@Al_(2)O_(3)nanocomposites with deep eutectic solvent:An efficient and stable peroxymonosulfate activator for organic pollutant degradations

The effective,stable,and secure catalysts are essential for sulfate radical(SO_(4)·−)-based advanced oxidation processes(SR-AOPs)to the degradation of organic contaminants in water.Heterogeneous supported cobalt-based catalysts are commonly used to activate peroxymonosulfate(PMS)to achieve the degradation.In this work,we synthesized Co_(3)O_(4)@Al_(2)O_(3)three-dimensional(3D)mesoporous nanocomposite(denoted as Co_(3)O_(4)@Al_(2)O_(33)DPNC)in just one step by calcining cheap and green deep eutectic solvent(DES)solution containing Co salt.Co_(3)O_(4)@Al_(2)O_(33)DPNC with the high specific surface area(93.246 m^(2)/g),uniform pore distribution(3.829 nm)and rich porosity(0.255 cm^(3)/g)were attained in a beautiful hierarchical structure which exhibited the open 3D propeller-like microstructure,two-dimensional lamellar substructure with rich folds,as well as the decoration of highly dispersed Co_(3)O_(4)nanoparticles on mesoporous amorphous Al_(2)O_(3).The excellent chemical and thermal stability of Al_(2)O_(3)ensures the high stability of the catalyst,and the formation of the complex hierarchical structure makes the active Co_(3)O_(4)be homogenously dispersed for effective catalysis.The catalyst demonstrated outstanding performance for catalytic degradations of organic pollutants(acetaminophen,oxytetracycline,5-sulfosalicylic acid,orange G and Rhodamine B)by generated SO_(4)·−,·OH and^(1)O_(2).With a very low cobalt content(equal to 28.2 mg/L of Co),the catalyst exhibited very high stability and excellent reusability in the recycling usages,while the leaching of the cobalt element(<0.145 mg/L)was also at a low level.Our catalyst achieved effective degradations of acetaminophen in cycles without losing its stable hierarchical nanostructure.

天然橡胶有机纳米复合材料的研究现状

综述了有机生物纳米填料、混合纳米填料与天然橡胶(NR)的复合材料的制备方法,以及各类有机纳米材料及其改性对NR拉伸性能、热稳定性和导电性等补强的研究现状。所述有机纳米填料与聚合物基体之间良好的相容性及界面作用能够使NR的性能得到明显改善。经功能化改性后的有机纳米填料可更好与NR基体产生相互作用,给NR的性能带来更优异的补强效果,而混合纳米填料可赋予复合材料更为多样的功能性。同时探讨了NR纳米复合材料在未来的应用发展前景,开发出多种功能化的有机纳米填料及使用混合纳米填料制备性能多样的NR纳米复合材料是该领域未来的研究重点。

有机化蒙脱土对XLPE/OMMT纳米复合电介质微观形态及水树枝老化特性的影响

文中采用熔融共混法分别制备了交联聚乙烯/有机化蒙脱土(XLPE/OMMT)纳米复合电介质,研究有机化蒙脱土种类对纳米复合电介质微观形态和水树枝老化特性的影响。对试样进行力学性能测试发现,OMMT质量分数为0.5%时,综合力学性能达到最佳;利用差示扫描量热法和扫描电子显微镜研究了试样的微观形态,经双十八烷基苄基季铵盐有机化改性并细化的有机化蒙脱土(OMMT3)起到明显的异相成核作用,使晶体更加完善,结晶度高达25.3%,晶体平均尺寸仅为16.67μm;采用水针电极法对各试样进行加速水树枝老化试验,剥离分散的OMMT3片层形成了更加曲折的迷宫路径,其对水分子的阻隔效应与XLPE交联网状结构对分子链运动束缚的共同作用,有效抑制了XLPE/OMMT3试样中水树枝的生长,引发概率下降至23.4%;傅里叶变换红外光谱对水树枝老化前后的化学结构进行了表征,纳米复合电介质水树区的羰基指数增加、羟基振动峰增强,表明水树枝老化是电化学降解的作用;在水树枝生长过程中,XLPE/OMMT3试样老化断链较少,表现出较优的耐热氧老化性能。

Synthesis of poly(ethylene glycol)-functionalized hydroxyapatite organic colloid intended for nanocomposites

Traditional modifications to hydroxyapatite （HA） nanoparticles usually occurred after HA synthesis and thus are insufficient to avoid particle agglomeration. In this study, a new heterofunctional poly（ethylene glycol） （PEG） with phosphoric acid and carboxyl end groups, Le., a-（N-2-phosphoethyl phosphoric acid）- amide, w-carboxyl-bismethyoxy poly（ethylene glycol） （ADP-PEG-COOH）, was synthesized as an in situ surface modifier to HA nanoparticles. The resulting modified HA （ADP-PEG-HA） can disperse in methanol, forming a colloid stabilized by peripheral carboxyl-endcapped PEG chains. The colloidal particles resembled nanospheres which agglomerated to some extent under examination by transmission electron microscope. This highly dispersible HA nanoparticles in organic solvent might find application in preparing new HA nanocomposites.

Synthesis,Characterization and Applications of MoO3-Fe3O4 Nanocomposite Material

In the present investigation,a series of nanocomposite material such as MoO3,Fe3O4 synthesized by co-precipitation method and Beta cyclodextrin(β-CD)doped MoO3-Fe3O4 and Graphite doped MoO3-Fe3O4 have been synthesized successfully by Sol-Gel method.Synthesized nanomaterials were characterized in detail by XRD,FT-IR,TEM-HRTEM,UV-Vis DRS techniques.The crystalline size was in the range of 10±2 nm.The activity of the prepared material as a heterogeneous catalyst was successfully tested on the organic reaction of synthesis of substituted m-Chloro-Nitrobenzene and it was found to give excellent yield.

Layer-by-layer assembly of nanocomposite films with thickness up to hundreds of nanometers

Polyelectrolyte/polyelectrolyte, organic molecule/colloidal CdS and polyelectrolyte/MWCNT films were fabricated via the layer-by-layer assembling technique. The assembled films were characterized by UV-vis spectrophotometer, X-ray diffractometry, nano profilometer and scanning electron microscopy. The results demonstrate that the layer-by-layer assembling technique can be used to make the nanoscaled films from polyelectrolytes and thicker composite films from suitable precursor materials. Both organic molecule/colloidal CdS films and PEI/MWCNT films with thickness of hundreds of nanometers were obtained. For the organic molecule/colloidal CdS films, a reasonable explanation for the result is that both the organic molecules and the CdS particles aggregate in the films. For the PEI/MWCNT films, obviously, it is the MWCNT that makes the great contribution to the film thickness.

环境污染物四溴双酚A的检测进展

四溴双酚A(Tetrabromobisphenol A,TBBPA)是全球产量最高的溴化阻燃剂之一,广泛分布在空气、土壤和水中。人体接触过量TBBPA会引起内分泌系统和生殖系统紊乱,因此,高效灵敏地检测环境中TBBPA十分重要。该文综述了2012—2021年环境样品中TBBPA的检测方法,重点关注新型材料如纳米复合材料、金属有机框架材料和分子印迹聚合物等在TBBPA检测中的应用。探讨了色谱法、光谱法及电化学方法检测环境样品中TBBPA的优势、研究进展及未来发展趋势。

用于高性能超级电容器的金属有机骨架衍生Co(OH)_(2)/C-N@GP纳米复合材料

本文报道一种制备β-Co(OH)_(2)/氮掺杂碳石墨烯纳米复合材料(Co(OH)_(2)/C-N@GP)的方法。首先,我们通过在含羧基的聚苯乙烯(PS)乙醇分散体中使Co(NO_(3))2·6H_(2)O与2-甲基咪唑反应,合成了ZIF-67/聚苯乙烯的复合材料。然后将ZIF-67/聚苯乙烯复合材料高温碳化,同时与硫代乙酰胺和石墨烯反应生成Co(SO_(4))_(2)/C-N@GP。最后,Co(SO_(4))_(2)/C-N@GP在KOH水溶液中浸泡以获得Co(OH)_(2)/C-N@GP纳米复合材料。所制备的Co(OH)_(2)/C-N@GP的扫描电镜图显示尺寸为10~20 nm的Co(OH)_(2)很好地分散在石墨烯上。电化学分析表明Co(OH)_(2)/C-N作为超级电容器的电极材料表现出典型的法拉第电荷转移行为,并且当石墨烯存在时,其比电容可显著增强。在2 mol·L^(-1)KOH中,Co(OH)_(2)/C-N@GP在2 A·g^(-1)下表现出985.4 F·g^(-1)的高比电容,1000次循环后的比电容保持率为76.6%。

交联度对交联聚乙烯/有机化蒙脱土纳米复合材料拉伸性能和介电性能的影响

为了研究交联度对纳米复合材料拉伸性能和介电性能的影响,通过调控交联时间,制备了不同交联度的交联聚乙烯/有机化蒙脱土(XLPE/OMMT)纳米复合材料。采用X射线衍射(XRD)测试判断蒙脱土的插层分散状态和试样聚集态结构的变化,利用扫描电子显微镜(SEM)观察试样的结晶形态,并对其拉伸性能、电导-温度特性、介电常数、介质损耗及击穿场强进行了测试。结果表明:交联形成的三维网状结构抑制了晶体生长,且晶体尺寸和结晶度随交联度的增加而不断减小;剥离分散的OMMT在XLPE/OMMT中充当了物理交联点,与交联键共同作用,提高了纳米复合材料的拉伸强度,且不断完善的交联网络,使复合材料的弹性模量增大,韧性增强。纳米复合材料的电导率随温度升高而增大,其活化能的大小与交联度和OMMT的界面区域有关。完善的交联网络和均匀分布的界面区,增加了势垒,提高了复合材料的活化能。交联度的增加,形成较强的分子间作用力,阻碍了偶极子和侧基的转向极化,使介电常数和介质损耗角正切值减小;OMMT的加入和交联结构的完善,共同提高了复合材料的击穿场强;但过度交联会影响OMMT在基体中的分散程度,使OMMT片层发生微重排,进而导致OMMT与基体的界面结合力下降,劣化的OMMT排列和分散,使自由电子易脱离束缚,对晶格结构造成破坏,增加了复合材料的微观缺陷,使击穿场强降低。