用原位聚合法制备的PA6/GO纳米复合材料的结构和性能

以己内酰胺(CL)和6-氨基己酸(ACA)为聚合反应单体,用Hummers法制备氧化石墨烯(GO),再以GO为纳米填料用原位开环聚合法制备了GO改性PA6纳米复合材料(PA6/GO),并对PA6/GO纳米复合材料的结构及性能进行了研究。结果表明,PA6的黏均分子量达到104数量级,但加入过多的GO使PA6的分子量降低。形貌分析表明,GO均匀地分散在PA6基体中,并诱导了PA6基体的晶型由α晶型转变成γ晶型。同时,GO作为异相成核剂促进了PA6/GO复合材料中PA6基体的结晶,提高了PA6/GO复合材料的结晶度。拉伸测试结果表明,随着GO的加入PA6/GO纳米复合材料的拉伸强度先提高后降低,GO加入量为0.4份时拉伸强度达到最大值61.72 MPa,比纯PA6(48.52 MPa)提高了27.21%。导热性能分析表明含1.0份GO的PA6/GO纳米复合材料其50℃和100℃的热导率分别为0.317 W/(m·K)和0.280 W/(m·K),较纯PA6分别提高了33.19%和33.23%。     

原位聚合制备PANI/GO复合材料及其电化学性能研究

利用原位化学氧化聚合的方法制备了聚苯胺/氧化石墨烯(PANI/GO)复合材料。通过X射线衍射(XRD)、扫描电镜(SEM)及红外光谱(IR)等方法对其结构和形貌进行了表征。利用自制的PANI/GO复合材料作为电极材料分别组装了超级电容器及锂离子电池,并对其电化学性能进行了测试。结果表明,GO在不同的电化学器件中均能够明显改善PANI的电化学性能。以PANI/GO作为超级电容器电极材料,放电时其比电容达413.28F/g,高于纯PANI的322.56F/g,1 000次循环后,容量保持率为70%。以PANI/GO作为锂离子电池正极材料,0.1C下首次放电比容量达104.4mAh/g,50次循环后,容量未见衰减。     

原位聚合法制备PA6/SiO2纳米复合材料

以正硅酸乙酯(TEO S)为前驱体,环氧丙基三乙氧基硅烷(W D-60)为改性剂,经原位聚合制备PA 6/S iO2纳米复合材料。利用端基滴定、力学性能测试、DSC、SEM、AFM等手段对材料的结构和性能进行研究。结果表明,经原位改性的S iO2纳米粒子在PA 6基体中分散均匀;与纯PA 6相比,复合材料的平均分子量下降,结晶速度明显加快,结晶度略有降低,材料的力学性能随S iO2加入量的增加而有一定的提高。     

聚乳酸/蛭石纳米复合材料的原位聚合与性能研究

首次用原位聚合的方法制备了剥离型聚乳酸/蛭石纳米复合材料.以液态的单体丙交酯溶胀蛭石,然后引发单体进行聚合.XRD和TEM分析表明原位聚合法制备的纳米复合材料中蛭石片层完全剥离,分散与PLA基体中.用XRD和DSC分析和观察了聚乳酸/蛭石纳米复合材料基材的结晶性能,结果表明层状纳米蛭石聚乳酸的结晶度降低,球晶粒径大大降低.拉伸性能的考察表明制得的纳米复合材料的力学性能大大提高.     

尼龙11/蒙脱土纳米复合材料的流变性能

使用XLY-Ⅱ型流变仪研究了尼龙11和尼龙11／蒙脱土纳米复合材料的流变行为,并对其1gηa～1／T、1gηa～1gγw、1gτw～1gγ,曲线进行了分析。实验结果表明,尼龙11和尼龙11／蒙脱土纳米复合材料均为假塑性流体,在215℃～245℃的非牛顿指数范围为0．35～0．69．其表现粘度随着蒙脱土含量的增加而升高．在高剪切速率下,蒙脱土对粘度的影响减小。荥脱土的加入使尼龙11的粘流活化能降低,故熔体流变特性受温度影响变小。     

原位聚合尼龙11/石墨烯氧化物纳米复合材料的等温结晶和熔融行为

采用原位聚合法制备了尼龙11/石墨烯氧化物纳米复合材料,并利用差示扫描量热分析仪(DSC)研究了材料的等温结晶动力学和熔融行为。研究结果表明,Avrami方程能够较好地描述尼龙11及其纳米复合材料的等温结晶动力学;尼龙11结晶速率受晶体生长速率控制,而纳米复合材料的结晶速率在不同的结晶温度范围内分别受晶体生长速率或成核速率控制;与纯尼龙11相比较,复合材料具有较低的平衡熔点和表面折叠自由能。     

原位聚合制备不饱和聚酯树脂/高岭土纳米复合材料及性能表征

利用超声法制备了高岭土-DMSO插层复合物前驱体,采取二步取代,原位聚合制备了不饱和聚酯树脂/高岭土纳米复合材料,并用XRD、FT-IR等手段对材料结构进行了表征,研究了纳米复合材料的阻燃性能。结果表明:当DMSO分子插入到高岭土层间时,d(001)值由0.717 nm增大到1.12 nm,插层率为91%,而不饱和聚酯树脂取代DMSO进入高岭土层间后,表征层状结构的d(001)特征衍射峰完全消失,高岭土内表面羟基吸收特征峰(3651 cm-1)和DMSO两个甲基的对称和反对称伸缩振动的吸收特征峰消失。燃烧实验表明这种材料相比纯树脂具有更好的阻燃性能。     

原位聚合法制备PMMA/膨胀石墨纳米复合材料

通过原位聚合将甲基丙烯酸甲酯(MMA)单体插入膨胀石墨层间,制备出以石墨层片为纳米分散相的导电复合材料.用红外光谱和X-射线衍射分析证实复合材料的合成,并讨论了石墨含量对复合材料的力学性能和导电性能的影响.     

DSC法研究原位聚合聚乙烯/凹凸棒石纳米复合材料的结晶行为

用DSC热力学分析手段着重对原位配位聚合法制备的聚乙烯／凹凸棒石纳米复合材料(IPC)进行研究，并与同组分的熔体机械共混法制备的聚乙烯／凹凸棒石复合材料(MBC)进行对比。结果表明，无机相的引入对纳米复合材料中的基体聚乙烯的结晶有很大影响；从Avrami等温结晶理论出发，得出IPC比MBC具有较强的结晶能力，结晶机理也不相同的结论。     

原位聚合制备LDPE/凹凸棒土纳米复合材料

利用超声波分散处理凹凸棒土,分别采用硅烷偶联剂KH570对其进行表面修饰和溶液聚合法在修饰后的凹土表面原位接枝聚合MMA单体,将经上述处理的凹土与LDPE(低密度聚乙烯)复合制备LDPE／AT纳米复合材料。结果表明,通过超声波分散的方法可以得到凹凸棒土纳米棒晶,凹凸棒土对MMA无阻聚作用,表面包覆的聚甲基丙烯酸甲酯(PMMA)能有效地解决复合材料的界面粘接,提高复合材料的性能。     

氧化石墨烯/聚氨酯杂化膜的原位聚合构建及气体渗透性

采用Hummers法制备了3种不同氧化程度的氧化石墨烯(GO),通过聚氨酯(PU)单体(4,4’-二异氰酸苯酯(MDI)和1,4-丁二醇(BDO))与GO的原位聚合构建了GO/PU杂化膜。利用XRD、Raman、FTIR和TEM等表征了GO的结构;探讨了GO填充量对GO/PU杂化膜的形貌和CO2、N2渗透性的影响。结果表明:3种不同氧化程度的GO均呈完全剥离状态,为半透明片状结构;随着氧化程度的增加,拉曼D峰与G峰的相对强度比分别为0.947、1.103和1.245;GO的氧化程度对GO在溶剂和杂化膜中的分散性有较大影响,氧化程度越高,分散性越好。GO/PU杂化膜的CO2、N2渗透系数及CO2/N2渗透选择因子均随GO填充量的增加先增大后减小;当中等氧化程度的GO(M-GO)与(MDI+BDO)的质量比为1.0%时,M-GO/PU杂化膜的CO2渗透系数为63.6×10-13 cm3(STP)/(cm·Pa·s),其中STP表示标准温度及压力,CO2/N2渗透选择因子可达48.5;填充适量的GO能显著提高GO/PU杂化膜的CO2渗透性及CO2/N2渗透选择性。     

原位聚合法制备尼龙66/蒙脱土纳米复合材料及其性能

采用原位聚合法制备了尼龙66/有机蒙脱土纳米复合材料,利用TEM观察了复合材料的微观结构,测试了其力学性能、热稳定性和阻燃性能,探讨了复合材料结构与性能之间的关系。研究结果表明:蒙脱土以纳米尺度均匀分散在尼龙66基体中,蒙脱土的加入改善了材料的力学性能、热稳定性和阻燃性能。     

聚酰胺6/氧化石墨烯复合材料的制备及其性能

为研究氧化石墨烯对聚酰胺6的相容性和力学性能的影响,以天然鳞片石墨为原料,采用改良的Hummers方法制备氧化石墨烯,用氯化亚砜将其活化得到酰氯修饰氧化石墨烯,再与氨气反应制备氨基化氧化石墨烯,采用原位聚合法制备出聚酰胺6/氧化石墨烯复合材料,利用扫描电子显微镜对其进行表征分析,通过在甲酸中的分散实验研究该材料的相容性,并利用拉伸实验测试其力学性能.结果表明:聚酰胺6成功以化学键形式键接到氨基化氧化石墨烯表面;氧化石墨烯在聚酰胺6基体中呈现均匀稳定分散;氧化石墨烯均匀分散于甲酸中,其在甲酸中的相容性得到了明显改善;氨基化氧化石墨烯质量分数为0.1%时,聚酰胺6/氧化石墨烯的拉伸强度和杨氏模量分别达到133和736 MPa.     

Fe_3O_4-ODA/GO/PANI复合材料的制备及其电容性能

在当今能源紧缺的情况下,超级电容器由于具有功率密度高、充放电时间短、循环寿命长等优点而被广泛应用于工业自动化控制、电力、国防以及新能源汽车等众多领域。本文以十八胺修饰的四氧化三铁纳米粒子(Fe_3O_4-ODA),氧化石墨烯(GO)以及苯胺单体为原料,通过原位聚合成功制备了Fe_3O_4-ODA/GO/PANI三元复合电极材料,其比电容高达516F/g,远高于二元复合材料GO/PANI和Fe_3O_4-ODA/PANI的比电容(分别为224F/g和345F/g)。并且,在1000次循环充放电之后,其容量仍可维持86.5%。此外,利用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线粉末衍射(XRD)和傅立叶变换红外光谱仪(FT-IR)等手段对该复合材料的形貌和结构进行了表征。     

Investigation of irradiated graphene oxide/ultra-high-molecular-weight polyethylene nanocomposites by ESR and FTIR spectroscopy

Graphene oxide/ultra-high-molecular-weight polyethylene (GO/UHMWPE) nanocomposite has a potential application for artificial joints. However, free radicals and antioxidative properties of irradiated GO/UHMWPE were not clearly clarified. In this paper, GO/UHMWPE nanocomposites were prepared and irradiated by gamma-irradiation with a dose of 100 kGy. Afterward, test samples were aged in air. Free radicals and molecular structures of test samples were investigated by electron spin resonance (ESR) spectroscopy and Fourier transform infrared (FTIR) spectroscopy, respectively. These studies indicated that irradiation enhanced GO radical concentrations. And GO radicals were stable in air and even could not be quenched after accelerated aging. GO radicals were superimposed on free radicals of irradiated UHMWPE. Although GO showed free radical-scavenging capacity, the influence of GO on free radicals of irradiated UHMWPE was too weak to be observed in ESR spectroscopy. Free radicals concentrations of irradiated GO/UHMWPE nanocomposites were gradually decayed with aging time evolving in air. Observing the oxidation index values of test samples, it was proposed that irradiated GO/UHMWPE might show very weak antioxidative properties.     

Effect of reduced graphene oxide (rGO) on structural,optical, and dielectric properties of Mg(OH)2/rGO nanocomposites

In this paper, we report the synthesis of Mg(OH)₂ NPs and Mg(OH)₂–rGO nanocomposites (NCs) by microwave assisted co-precipitation method. The crystal phase, structural morphology and functional groups of the as-synthesized samples were analyzed by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR). Raman spectroscopy was used to study the defects in the samples. Raman spectroscopy and the SEM results validate the growth of Mg(OH)₂ NPs on the rGO nanosheets. The chemical composition of the prepared samples was analyzed by EDAX. Optical properties of the as-synthesized samples were studied by UV–visible spectroscopy and the energy band gap was calculated by Tauc relation which shows a decrease in band gap with an increase in the amount of Graphene Oxide (GO) in the NCs. The dielectric properties were studied as a function of frequency over a range of 50 Hz to 5 MHz at room temperature. The value of dielectric constant decreases with an increase in frequency, this could be due to the existence of a polarization process at the border of the rGO sheets and Mg(OH)₂ NPs. The value of dielectric loss shows a decreasing trend with an increase in frequency whereas the larger value of AC conductivity in Mg(OH)₂–rGO NCs as compared to Mg(OH)₂ NPs approves the restoration of sp² network in the graphene sheets.     

A facile preparation of graphene/reduced graphene oxide/Ni(OH)2 two dimension nanocomposites for high performance supercapacitors

A Ni(OH)₂ composite with good electrochemical performances was prepared by a facile method. Ni(OH)₂ was homogeneously grown on the hydrophilic graphene/graphene oxide (G/GO) nanosheets, which can be prepared in large scale in my lab. Then G/GO/Ni(OH)₂ was reduced by L-Ascorbic acid to obtain G/RGO/Ni(OH)₂. Caused by the synergy effects among the components, the G/RGO/Ni(OH)₂ electrode showed good electrochemical properties. The G/RGO/Ni(OH)₂ electrode possessed a specific capacitance as high as 1510 F g⁻¹ at 2 A g⁻¹ and even 890 F g⁻¹ at 40 A g⁻¹. An asymmetric supercapacitor device consisting of G/RGO/Ni(OH)₂ and reduced graphene oxide (RGO) was installed and displayed a high energy density of 44.9 W h kg⁻¹ at the power energy density of 400.1 W kg⁻¹. It was verified that the G/GO nanosheets are ideal supporting material in supercapacitor.     

Zn还原氧化石墨烯(RGO)和ZnO/RGO自组装复合材料的电磁响应行为

以天然鳞片石墨为原料制备氧化石墨烯（GO）,通过Zn将其还原为石墨烯（RGO）,且生成的ZnO附着在RGO表面。采用XRD、SEM、FTIR、Raman、TEM和矢量网络分析仪（VNA）研究了不同还原温度对ZnO/RGO复合材料形貌、结构、氧化程度、电磁损耗特性、德拜弛豫模型及电磁响应行为的影响。结果表明:还原温度为50℃时RGO还原后结构更加完整,层间距为0.89 nm时ZnO/RGO复合材料的介电常数和磁导率均较高,在17.15 GHz时反射率达到-41.2 dB,反射损耗小于-10 dB的带宽为3.67 GHz。