Carbon nanomaterials and their composites for supercapacitors

As a type of energy storage device between traditional capacitors and batteries,the supercapacitor has the advantages of energy saving and environmental protection,high power density,fast charging and discharging speed,long cycle life,and so forth.One of the key factors affecting the performance of supercapacitor is the electrode material.Carbon materials,such as carbon nanotube,graphene,activated carbon,and carbon nanocage,are most widely concerned in the application of supercapacitors.The synergistic effect of composites can often obtain excellent results,which is one of the common strategies to increase the electrochemical performance of supercapacitors.To further improve the performance of binary composites,it is a relatively simple method to increase the components as the“bridge”between the two materials to form the ternary composites.The review mainly introduces the current research progress of supercapacitors with pure carbon nanomaterials and multistage carbon nanostructures(composites)as electrodes.The characteristics and application directions of different pure carbon nanomaterials are introduced in detail.Different ways of multilevel structure(material)composite have their own effects on the development of high-performance supercapacitors.We also highlight the recent advances related to these fields and provide our insight into high-energy supercapacitors.

A Review on the Advancement of Renewable Natural Fiber Hybrid Composites: Prospects, Challenges, and Industrial Applications

Naturalfibre(NFR)reinforced functional polymer composites are quickly becoming an indispensable sustainable material in the transportation industry because of their lightweight,lower cost in manufacture,and adaptability to a wide variety of goods.However,the major difficulties of using thesefibres are their existing poor dimensional stability and the extreme hydrophilicity.In assessing the mechanical properties(MP)of composites,the interfacial bonding(IB)happening between the NFR and the polymer matrix(PM)plays an incredibly significant role.When compared to NFR/syntheticfibre hybrid composites,hybrid composites(HC)made up of two separate NFR are less prevalent;yet,these hybrid composites also have the potential to be valuable materials in terms of environmental issues.A new dimension to theflexibility of composites reinforced with NFR is added by the cost-effective manufacture of hybrid composites utilising NFR.The purpose of this study is to offer an over-view of the keyfindings that were presented on hybrid composites.The emphasis was focused on the factors that influence the performance of the naturalfiber composites,diverse approaches to enhancing MP,physical,electri-cal,and thermal characteristics of the HC.HC study in polymer science gains interest for applications in con-struction and automotive industries.

Bulk Composite Nanomaterial with Multiwall Carbon Nanotubes

The properties of the composite nanomaterials (CNM) based on bovine serum albumin (BSA) and multi-walled carbon nanotubes (MWCNT), both functionalized and non-functionalized, were investigated. In order to obtain the solid-state bulk CNM from the ultradispersed aqueous solutions of 25 wt.% BSA and (0.0015 - 0.04) wt.% MWCNT, the methods of nanotechnology and laser technology were used. It is revealed that the CNM density is 10% - 20% higher than that of water and the hardness is higher than that of BSA by a factor of 3 - 6 times. An increase in hardness Hv (by Vickers) of CNM correlated with an increase in the concentration of MWCNT, and Hyreached ~300 MPa for the case of the non-functionalized MWCNT, while for the case of the functionalized MWCNT, i.e. MWCNTf, Hy was 25% lower.

Synthesis and characterization of Cu-Cr-O nanocomposites

Cu-Cr-O nanocomposites that can be used as additives for the catalytic combustion of AP(ammonium perchlorate)-based solid-state propellants were synthesized via a citric acid(CA) complexing approach. Techniques of TG-DTA, XRD as well as TEM were employed to characterize the thermal decomposition procedure, crystal phase, micro-structural morphologies and grain size of the as-synthesized materials respectively. The results show that well-crystallized Cu-Cr-O nanocomposites can be produced after the CA-Cu-Cr precursors are calcined at 500 ℃ for 3 h. Phase composition of the as-obtained Cu-Cr-O nanocomposites depends on the molar ratio of Cu to Cr in the starting reactants. Addition of the as-synthesized Cu-Cr-O nanocomposites as catalysts enhances the burning rate as well as lowers the pressure exponent of the AP-based solid-state propellants considerably. Noticeably, catalyst with a CuCr molar ratio of 0.7 exhibits promising catalytic activity with high burning rate and low pressure exponent at all pressures, due to the effective phase interaction between the spinel CuCr2O4 and delafossite CuCrO2 contained in the as-synthesized Cu-Cr-O nanocomposites.

Preparation of waterborne polyurethane/β-cyclodextrin composite nanosponge by ion condensation method and its application in removing of dyes from wastewater

Currently,polymer nanosponges have received extensive attention.However,developing new synthetic techniques for novel nanosponges remains a challenge.Furthermore,to date,composite nanosponge adsorbents based on waterborne polyurethane(WPU)andβ-cyclodextrin(β-CD)have not been reported.Herein,a novel green method,ion condensation method,was developed in this study for the preparation of polymer nanosponge adsorbents for efficient removal of dyes from wastewater.Based on the principle of charge repulsion between nanoparticles to maintain emulsion stability,waterborne polyurethane/β-cyclodextrin composite nanosponges(WPU-x,y)were prepared by coagulating the emulsions synthesized from 2,2-dimethylolpropionic acid,polypropylene glycol and hexamethylene diisocyanate as raw materials in a mixture of hydrochloric acid and anhydrous ethanol.The structure and appearance of WPU-x,y were characterized by attenuated total reflectance Fourier transform infrared spectroscopy,thermal gravimetric analyzer,scanning electron microscope and mercury intrusion porosimetry.The adsorption capacity of WPU-x,y was tested by parameters such as cross-linking degree,β-CD dosage,contact time,initial dye concentration and p H value.The study found that WPU-4,4.62 had the best adsorption effect on methylene blue(MB),the maximum removal rate was 93.42%,and the maximum adsorption capacity was 136.03 mg·g^(-1).Moreover,the Sips isotherm and pseudo-second-order-model were suitable for MB adsorption.Therefore,this study provides some perspectives for the fabrication of nanosponge adsorbents.

Polyamide-baghouse dust nanocomposite for removal of methylene blue and metals:Characterization,kinetic,thermodynamic and regeneration

In this research,polyamide modified baghouse dust nanocomposite(PMBHD)was synthesized from steel industry waste using the interfacial polymerization technique.Adsorption capacities of the PMBHD were examined for the uptake of cadmium Cd(Ⅱ),lead Pb(Ⅱ),and methylene blue MB from simulated solutions.The effects of different operational factors of the adsorption,including contact time,pH,adsorbent dosage,initial concentration,and temperature,were investigated.The obtained results revealed that the equilibrium data of MB,Pb(Ⅱ),and Cd(Ⅱ)were best fitted to Dubinin-Radushkevich,Langmuir,and Freundlich isotherm.Maximum removal uptake was found to be 6.08,119,and 234 mg·g^(-1),whereas maximum removal efficiencies of 90%,99.8%,and 98%were achieved for MB,Pb(Ⅱ),and Cd(Ⅱ).Adsorption kinetics of MB and metals well-fitted to the pseudo-second-order kinetic.The characterization results showed the presence of polymeric chain on the surface of the PMBHD.The thermodynamic study revealed that the values of the free energy DG for Pb(Ⅱ)and Cd(Ⅱ)were found to be negative,which indicates spontaneous,energetic,and favorable adsorption.While for MB removal,positive values of(DG)were noticed,which implies that the adsorption was unfavorable.The proposed mechanism for the adsorption of MB and metals on the PMBHD showed that the dominating mechanism is physisorption.The adsorption/desorption results verified the high reusability of the PMBHD for adsorption of MB and metals.

Research of Nanostructures Formation during Self-Propagating High-Temperature Synthesis of Boride-Containing Composite Materials

This paper considers the technique of obtaining boride-containing nanostructured composite materials by the method of self-propagating high-temperature synthesis (SHS). It is shown that the selection of regimes and conditions of reactions allows receiving materials on the basis of titanium and chromium borides as well as aluminum oxide with finely dispersed structure and high mechanical properties.

Advanced strategies for marine antifouling based on nanomaterial-enhanced functional PDMS coatings

Marine biofouling seriously affects human marine exploitation and transportation activities,to which marine antifouling(AF)coatings are considered to be the most cost-effective solution.Since the mid-20th century,human beings have dedicated their efforts on developing AF coatings with long cycle and high performance,leading to a large number of non-target organisms?distortion,death and marine environmental pollution.Polydimethylsiloxane(PDMS),is considered as one of the representative environment-friendly AF materials thanks to its non-toxic,hydrophobic,low surface energy and AF properties.However,PDMS AF coatings are prone to mechanical damage,weak adhesion strength to substrate,and poor static AF effect,which seriously restrict their use in the ocean.The rapid development of various nanomaterials provides an opportunity to enhance and improve the mechanical properties and antifouling properties of PDMS coating by embedding nanomaterials.Based on our research background and the problems faced in our laboratory,this article presents an overview of the current progress in the fields of PDMS composite coatings enhanced by different nanomaterials,with the discussion focused on the advantages and main bottlenecks currently encountered in this field.Finally,we propose an outlook,hoping to provide fundamental guidance for the development of marine AF field.

Research Analysis on the Microscopic Properties and Damping Performance of Carbon Nanomaterial-Modified Cement Mortar

The application of carbon nanomaterials, particularly graphene and carbon nanotubes, in cement-based composites is highly significant. These materials demonstrate the multifunctionality of carbon and offer extensive possibilities for technological advancements. This research analyzes how the integration of graphene into cement-based composites enhances damping and mechanical properties, thereby contributing to the safety and durability of structures. Research on carbon nanomaterials is ongoing and is expected to continue driving innovation across various industrial sectors, promoting the sustainable development of building materials.

Review of recent developments in cement composites reinforced with fibers and nanomaterials

The quest for high-performance construction materials is led by the development and application of new reinforcement materials for cement composites.Concrete reinforcement with fibers has a long history.Nowadays,many new fibers associated with high performance and possessing eco-environmental characteristics,such as basalt fibers and plant fibers,have received much attention from researchers.In addition,nanomaterials are considered as a core material in the modification of cement composites,specifically in the enhancement of the strength and durability of composites.This paper provides an overview of the recent research progress on cement composites reinforced with fibers and nanomaterials.The influences of fibers and nanomaterials on the fresh and hardened properties of cement composites are summarized.Moreover,future trends in the application of these fibers or of nanomaterial-reinforced cement composites are proposed.

Recent Progress in Two-dimensional Nanomaterials Following Graphene for Improving Fire Safety of Polymer(Nano)composites

The high fire safety of polymer nanocomposites is being pursued by research institutions around the world.In addition to intrinsic flame retardancy strategy,the additive-type flame retardants have attracted increasing attention due to low commercial cost and easy fabrication craft.However,traditional additive-type flame retardants usually need high addition amount to achieve a desirable effect which causes many side-effects on the overall performance of polymer materials,such as deteriorated mechanical property and processability.At present two-dimensional(2D)nanomaterials have also been applied to reduce the fire hazards of polymer(nano)composites with the coupling of barrier function and catalysis as well as carbonization effect.Even though most research work mainly focus on graphene-based flame retardants,more emerging two-dimensional nanomaterials are taking away research attention,due to their complementary and unique properties,mainly including hexagonal boron nitride(h-BN),molybdenum disulfide(MoS2),metal organic frameworks(MOF),carbon nitride(CN),titanium carbide(MXene)and black phosphorene(BP).In this review,except for graphene,the flame retardant mechanism involving different layered nanomaterials are also reviewed.Meanwhile,the functionalization method and flame retardancy effect of different layered nanomaterials are emphatically discussed for offering an effective reference to solve the fire hazards of polymer materials.Moreover,this work objectively evaluates the practical significance of polymer/layered nanomaterials composites for industrial application.

Research progress of nanoparticles reinforced composite filler metal

Composite filler metal refers to the traditional filler metal by adding a certain proportion of various forms of superalloy,carbon fiber and ceramic particles as reinforcement phase.Due to the addition of the reinforcement phase,the filler metal can have a suitable thermal expansion coefficient,which can effectively reduce the residual stress at the brazing joint caused by the different thermal expansion coefficients of the base metal and improve the comprehensive performance of the brazing joint.In recent years,with the progress of science and technology,the research on nanomaterials has been deepening,and nanomaterials are widely used in the modification of composite filler metals because of their special surface effect,small size effect,quantum size effect and macroscopic quantum tunneling effect.The modification performance of different composite solders by nanoparticles in recent years is reviewed,the advantages and disadvantages of nano-reinforced composite solders are analyzed,and the future research direction of composite solders is prospected.

Percolation of carbon nanomaterials for high-k polymer nanocomposites

High-k polymer composite materials are next-generation dielectrics that show amazing applications in diverse electrical and electronic devices. Establishing near-percolated network of conducting filler in an insulating polymer matrix is a promising approach to develop flexible high-k dielectrics. However, challenges still exist today on fine controlling the network morphology to achieve extremely high k values and low losses simultaneously. The relationship between the network morphology and the dielectric properties of polymer composites is raising a number of fundamental questions. Herein, recent progress towards high-k polymer composites based on carbon nanomaterials is reviewed. Particular attention is paid on the influence of the network morphology on the dielectric properties. Some perspectives that warrant further investigation in the future are also addressed.

纳米材料增强植物纤维复合材料研究进展

对近4年来纳米材料增强植物纤维复合材料制备方法进行了综述。纳米材料增强植物纤维复合材料的制备方法主要包括硅烷偶联剂处理、溶胶-凝胶法、化学接枝法、横穿结晶技术和机械混杂法,总结了各种方法的优缺点,讨论了纳米纤维增强植物纤维复合材料制备过程中存在的问题,最后展望了纳米材料增强植物纤维复合材料未来的发展方向。

拟除虫菊酯农药类特异性传感体系构建及其在柑橘农残检测中的应用

拟除虫菊酯类农药在我国柑橘等果品中的施用量占全球第一,对其残留的快速筛查和监管对于保障我国果品食用安全具有重要意义。该文研究多功能纳米材料(NaYF_(4)∶Yb,Er-Fe_(3)O_(4)@MIP)的制备条件,采用傅里叶变换红外光谱、透射电子显微镜对该材料进行表征,通过对NaYF_(4)∶Yb,Er-Fe_(3)O_(4)@MIP的吸附和选择性实验,验证了其对4种拟除虫菊酯类农药具有较好的选择性和吸附性能,并构建基于该材料的拟除虫菊酯农药类特异性传感体系对柑橘果品菊酯类农残进行快速检测。结果表明,该传感体系在0.02~2.5 mg/L内对拟除虫菊酯类农药(溴氰菊酯、氯氰菊酯、氟氯氰菊酯、氰戊菊酯)具有良好的线性关系,检出限分别为6.17×10^(-4)、6.65×10^(-4)、7.21×10^(-4)、9.61×10^(-4)、6.43×10^(-4)mg/L。结合柑橘鲜果专属前处理技术进行实际柑橘样品检测,加标回收率为87.9%~105.8%,相对标准偏差为0.53%~6.41%,方法准确、灵敏、稳定,可以用于实际柑橘样品中拟除虫菊酯类农药的检测。

阻燃聚氨酯纳米复合材料的研究进展

聚氨酯(PU)具有优异的力学性能,在皮革、功能材料和医疗等领域被广泛应用。但PU易燃烧,因此在PU中引入具有阻燃功能的纳米材料,对提高PU材料防火安全性具有重要意义。文章首先概括性地总结了纳米材料相比传统阻燃剂的优势,再根据引入纳米材料的类型(如碳纳米管、金属有机框架、MXene等),综述了阻燃PU纳米复合材料的制备及阻燃机理的研究进展,概述了阻燃PU纳米复合材料在皮革和功能材料方面的应用,并对其未来发展方向做出展望。

二维纳米材料/多糖复合薄膜及其在果蔬采后保鲜上的研究进展

该文从多糖、二维纳米材料性质的角度出发,综述了近年来国内外对于二维纳米材料/多糖复合薄膜的研究以及其在果蔬采后保鲜上的研究进展。首先阐述了不同种类多糖薄膜及它们在果蔬保鲜上的应用,其次阐述了当下研究较多的不同二维纳米材料及多糖复合薄膜制备的方法,最后对二维纳米材料/多糖复合薄膜在果蔬保鲜中的应用进行总结,以期为多糖复合薄膜的研究提供参考。

磁性碳基复合纳米材料对四环素类抗生素的吸附和降解研究进展

近年来,磁性碳基复合纳米材料(magnetic carbon-based composite nanomaterials,MCCN)因其具有比表面积大,方便磁分离及回收循环利用等优点而引起众多科研工作者关注.鉴于四环素类抗生素(tetracycline antibiotics,TCs)在环境中耐性强、不易分解,长期累积对人体健康造成潜在的威胁.由此,本文综述了近3年来发展的各类新型MCCN作为优良吸附剂和催化剂应用于TCs的去除,并在吸附和降解两方面对去除TCs的机理和影响因子作出总结.重点阐述了磁性碳基复合纳米材料作吸附剂时,其碳前驱体被炭化、活化、磁化以及杂原子改性后获得的磁性碳基材料,通过氢键、π-π作用、静电作用等机制吸附去除TCs;作为催化剂时,磁性碳基材料主要作为基底,负载功能化催化剂,通过激活一些过硫酸盐,促使催化过程中产生活性物种如·O_(2)^(-)、·OH、^(1)O_(2)等,将TCs降解为CO_(2)、H_(2)O或其他小分子物质.最后,对磁性碳基纳米复合材料未来的研究方向提出一些建议.

纳米氢氧化镁制备及其阻燃应用进展

纳米氢氧化镁因其绿色、高效等优势在塑料、橡胶等高分子材料的阻燃方面有广泛的应用前景。随着研究的深入,沉淀法、水热/溶剂热法和微波辅助法等制备方法已在纳米氢氧化镁的制备中占据主导。本文首先从纳米氢氧化镁形貌与粒径的控制方面介绍了这3种主流制备方法,对部分制备过程中的作用机理进行了探究,对每种制备方法的优劣进行了阐述,进而对制备方法进行对比总结。其次讨论了纳米氢氧化镁在应用领域存在的问题及解决办法,概述了其在多种高分子材料阻燃领域的应用,并以理论结合实例从多个角度探究了纳米氢氧化镁的阻燃机理。最后对目前纳米氢氧化镁制备方法和应用方面遇到的机遇和挑战进行了展望,希望能为纳米氢氧化镁的进一步深入研究提供有益的启发和参考。

延期药燃速控制技术综述

基于延期药燃速控制技术研究现状,从延期药配方、燃速调节剂和制备工艺等方面对影响延期药燃速及延期精度的因素进行了归纳总结,讨论了延期药组分、配比及粒度对燃速的影响机理,介绍了碳纳米材料、钙钛矿材料、增材制造技术及微流控技术在延期药制备中的应用现状,分析了其对加快延期药燃速、改善燃烧性能以及提高燃烧过程稳定性的优化效果,以期为延期药配方设计、延期火工品的燃速及精度控制提供参考。