纳米二氧化钛包覆沙对水中有机染料的吸附

以Ti(SO_4)_2和库布齐沙漠沙为原料,制备了纳米二氧化钛包覆沙。以X射线衍射及氮气吸附-脱附分析对样品进行了表征,并测试了合成样品对刚果红的吸附性能。结果表明,制备的样品为二氧化钛与沙子的纳米复合物,其比表面积随二氧化钛含量的升高而增大,最高可达87.1 m²/g。且该纳米复合物对刚果红的吸附性能与溶液酸碱度有关,吸附符合准二级吸附动力学模型以及Langmuir吸附等温式,为单分子层吸附,最大吸附量为246.3 mg/g。     

多孔Fe2O3-Ag纳米复合材料的制备及其在表面增强Raman散射光谱中应用EI北大核心CSCD

以多孔α-Fe2O3作为固相载体,通过水热合成法在α-Fe2O3孔道内沉积银纳米粒子。测试4种不同硝酸银用量时Fe2O3-Ag复合物的表面增强Raman散射光谱性能(SERS)。利用扫描电子显微镜、透射电子显微镜、X射线衍射和N2吸附等表征手段对Fe2O3-Ag复合物结构及组成进行分析表征。结果表明,当银纳米粒子的负载量为6.5%时(质量分数),Fe2O3-Ag纳米复合物的比表面积为26.57 m2/g,增强因子可以达到102~103,SERS活性最好。所制备的Fe2O3-Ag纳米复合物具有良好的SERS活性和吸附性能,可以进一步应用于其他待测物的吸附检测。     

多孔Fe_2O_3-Ag纳米复合材料的制备及其在表面增强Raman散射光谱中应用

以多孔α-Fe_2O_3作为固相载体,通过水热合成法在α-Fe_2O_3孔道内沉积银纳米粒子。测试4种不同硝酸银用量时Fe_2O_3-Ag复合物的表面增强Raman散射光谱性能(SERS)。利用扫描电子显微镜、透射电子显微镜、X射线衍射和N_2吸附等表征手段对Fe_2O_3-Ag复合物结构及组成进行分析表征。结果表明,当银纳米粒子的负载量为6.5%时(质量分数),Fe_2O_3-Ag纳米复合物的比表面积为26.57 m~2/g,增强因子可以达到10~2～10~3,SERS活性最好。所制备的Fe_2O_3-Ag纳米复合物具有良好的SERS活性和吸附性能,可以进一步应用于其他待测物的吸附检测。     

活性白土/壳聚糖复合物对多成分污染物的吸附行为研究

用十六烷基三甲基溴化铵(CTAB)作为修饰剂对活性白土进行修饰,将改性后的活性白土与壳聚糖混合并加入定量硅烷偶联剂,通过溶液插层技术制备活性白土/壳聚糖复合材料。通过红外光谱(FTIR)、热重分析(TG)、X-射线衍射分析(XRD)和透射电子显微镜分析(TEM)对所制备的活性白土/壳聚糖复合物进行表征。结果表明,硅烷偶联剂与活性白土形成了稳定的结构,十六烷基三甲基溴化铵和壳聚糖显著提高了活性白土的片层间距,有利于提高复合物的吸附性能。将制得的复合物对Fe⁽³⁺⁾、Cu(3+)、Cu⁽²⁺⁾以及NO_2(2+)以及NO_2^-溶液进行吸附研究,探讨了吸附温度、吸附时间、吸附pH、吸附剂用量以及被吸附物质浓度对吸附性能的影响。研究结果显示,活性白土/壳聚糖复合物对3种物质均有较好的吸附效果,其中对NO_2-溶液进行吸附研究,探讨了吸附温度、吸附时间、吸附pH、吸附剂用量以及被吸附物质浓度对吸附性能的影响。研究结果显示,活性白土/壳聚糖复合物对3种物质均有较好的吸附效果,其中对NO_2^-的吸附率达79.20%,对Cu-的吸附率达79.20%,对Cu⁽²⁺⁾的吸附率达99.98%,对Fe(2+)的吸附率达99.98%,对Fe⁽³⁺⁾的吸附率达92.59%。     

三聚氰胺改性木质素的制备及银离子吸附性能

以酶解木质素、三聚氰胺和甲醛为原料,通过接枝反应制备三聚氰胺改性酶解木质素(MEHL),并研究MEHL对银离子的吸附性能。接枝反应的研究结果表明,三聚氰胺和甲醛的添加量对产率有很大影响。酶解木质素、三聚氰胺、甲醛质量比为10:6:6,于90℃下反应4 h,所制得的MEHL的产率可达83.7%。红外光谱、热重和元素分析的结果表明,三聚氰胺成功接枝到酶解木质素分子上。MEHL的含氮量由酶解木质素的0.81%提高到18.55%。银离子的吸附研究表明,MEHL对银离子表现出很好的吸附性能。在银离子初始浓度为0.16 mol·L^-1,在MEHL用量为50 mg,吸附温度为30℃时吸附36 h,MEHL对银离子的吸附容量为944.1 mg·g^-1。     

MoS2/ZnO纳米复合材料的光学和光催化性能

在溶剂热法制备ZnO纳米粒子的基础上,利用物理剥离和纳米粒子互剪切作用成功制备了MoS₂/ZnO异质结构纳米复合物。以扫描电子显微镜、透射电子显微镜、X射线能量色散光谱、粉末X射线衍射、拉曼光谱仪、紫外-可见漫反射光谱、光致发光谱等对样品进行了结构形貌和性能表征。结果表明,利用物理剥离和互剪切作用能有效地获得MoS₂/ZnO复合物,复合作用使得MoS₂位于378cm^-1(E¹_2g)和400cm^-1(A_1g)处的两个特征拉曼峰显著增强。复合物中MoS₂含量越少,两个特征拉曼峰强度反而越高,且两峰波数间隔相应减小。可归因于MoS₂含量较低时,ZnO纳米粒子对MoS₂的物理剥离效果越显著,同时,MoS₂体现出良好的分散性和较小的厚度。MoS₂含量对MoS₂/ZnO的发光具有明显的调制作用,显著增强了复合物在可见光区域的吸收。随着MoS₂含量增加,其可见光发光强度迅速减小,紫外峰出现明显的蓝移。纯ZnO对苯酚的降解率最高达90%,而MoS₂/ZnO复合物对苯酚的降解率达100%,复合物对苯酚的最终降解率明显高于纯氧化锌。     

原位聚合制备聚丁烯-1/蒙脱土纳米复合材料及其性能

通过使用一种新型Ziegler-Natta催化剂/蒙脱土(MMT)复合型催化剂与丁烯-1进行原位聚合制备了剥离型聚丁烯-1(PB-1)/MMT纳米复合材料。通过广角X射线衍射(WAXD)和透射电子显微镜(TEM)对纳米复合物验证结构,通过热重分析(TGA)和差示扫描量热(DSC)对复合材料进行性能表征。结果显示,蒙脱土片层在聚丁烯-1基体中以纳米尺寸均匀分散,呈现剥离状态。随着蒙脱土含量增加,复合材料热分解温度升高,结晶度也升高。随着外给电子体含量增大,全同聚合物的含量增大。     

以碳球为模板合成氧化铈纳米空心球

以直径约为300nm的碳球为模板,通过无机物前驱体颗粒的自组装制备出CeO2/碳球复合物,煅烧去除碳球模板后,得到CeO2纳米空心球.借助透射电子显微镜、选区电子衍射、场发射扫描电子显微镜、X射线衍射、X射线光电子能谱和热重分析仪等测试手段对复合物的形貌和结构进行了表征.结果表明:产物空心球由面心立方相CeO2颗粒构成...     

钛网上CdS纳米微球的制备及可见光下产氢性能研究

为了提高催化剂的光催化产氢能力,本文采用简单的水热法,在处理后的钛网表面生长了CdS纳米微球。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和X射线光电子能谱(XPS)等测试手段对样品的成分、结构、形貌进行了表征,并研究了其光电化学性能及可见光下光催化性能。结果表明,钛网上生长的CdS微球由纳米棒组装而成,通过缺陷调控,Cd/S物质的量之比为1∶1(CdS-1)的样品具有良好的光电响应,在零偏压下最大光电流约为140μA,可见光下的产氢率可达212.6μmol·h^-1·cm^-2,并且方便回收,是一种理想的光催化产氢材料。     

锡掺杂溴铅铯钙钛矿纳米晶的合成、结构及发光性能

为了降低CsPbBr₃钙钛矿纳米晶的Pb²⁺毒性，同时优化Sn²⁺掺杂CsPbBr₃纳米晶的发光性能，采用热注入法合成了Sn²⁺掺杂的Cs Pb_1-xSn_x Br₃纳米晶(x=0.1、0.2、0.3、0.4和0.5)，使用X射线衍射仪(XRD)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)和荧光光谱仪(PL)对所合成纳米晶的物相结构、微观形貌及发光性能进行表征。结果表明，纳米晶中掺杂的Sn元素以Sn²⁺和Sn⁴⁺形式存在，且含有Pb²⁺阳离子空位，当x=0.3时，Sn元素实际掺杂物质的量分数高达43.91%。x=0.1～0.4时，纳米晶为纯单斜相钙钛矿结构，尺寸约16～20 nm，立方块形貌较均匀。Sn²⁺掺杂调控了Cs Pb_1-xSn_x Br₃纳米晶的...     

Development of Gelatin Based Inorganic Nanocomposite Hydrogels for Inactivation of Bacteria

In this investigation, silver nanocomposite hydrogels were developed by using acrylamide and biodegradable gelatin. Silver nanoparticles were generated throughout the hydrogel networks using in situ method by incorporating Ag⁺ ions and the subsequent treatment with sodium borohydride. The effect of gelatin on the swelling studies was investigated. The hydrogel synthesized silver nanocomposites were characterized by using Fourier transform infrared, UV–Visible spectroscopy, X-ray diffraction, thermogravimetric analysis, scanning electron and transmission electron microscopy techniques. The biodegradable gelatin-based silver nanocomposite hydrogels were tested for antibacterial properties. The results indicate that these biodegradable silver nanocomposite hydrogels can be useful in medical applications, as antibacterial agents.     

Preparation and Characterization of Polypyrrole Silver Nanocomposites via Interfacial Polymerization

Conducting polypyrrole silver (Ppy-AgNC) nanocomposite was synthesized by an interfacial polymerization method. Ag⁺ ions from the AgNO₃ solution were taken in the formation of Ppy-AgNC. The incorporated silver was confirmed by X-ray diffraction (XRD). During the polymerization in a nitrate ion-containing solution, the impregnation leads to the formation of metallic silver. The size distribution of Ag into the polymer is confirmed by transmission electron microscopy (TEM), and proves the formation of a uniform species with spherical particles of Ag (mean diameter of 8-12 nm) branching at the border of Ppy. The thermal behavior of the material was studied by thermogravimetric measurements.     

Preparation and characterization of porous acrylate terpolymer nanocomposite for removal of diesel oil from artificial seawater

The present work deals with the preparation of magnetic acrylate terpolymer nanocomposite by emulsion polymerization. This nanocomposite was applied for the removal of diesel oil from artificial seawater by magnetic separation. Magnetic terpolymer nanocomposite was characterized by Fourier transform infrared (FTIR) spectra, X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Specific surface area and pore size distribution were measured by the Brunauer–Emmett–Teller (BET) method. Contact angle (CA) measurement showed superhydrophobic properties of magnetic acrylate nanocomposite. Kinetics and isothermal studies indicate that oil sorption fits the second-order kinetic model and the Langmuir isotherm. Magnetic acrylate terpolymer can be regenerated for six cycles.     

Synthesis,Characterisation and DFT Studies of Stigmasterol Mediated Silver Nanoparticles and Their Anticancer Activity

The present investigation reports the facile, reproducible and eco-friendly biological synthesis of nano silver using Ficus Hispida leaf extract (FHLE) as a reductant. The properties of the synthesized silver nanoparticles (Ag-NP’s) is characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy (TEM), UV–visible spectroscopy, Fourier transform infrared spectroscopy and X-ray diffraction studies. The synthesized Ag-NPs are found to have spherical shape with average particle size in the range of 50–100 nm. The XRD studies and selected area electron diffraction pattern of TEM images confirm the face cantered cubic structure of biosynthesised silver nanoparticles. The DFT studies reveal that the stigmasterol present in FHLE is responsible for leaf extract to behave as a reducing agent for reduction of Ag⁺ ions into Ag⁰. The antitumor studies against DLA cell lines of the biosynthesized Ag-NPs is found to have 100% inhibition with concentration of 200 µg/ml of Ag-NP’s.     

Preparation of Poly(lactic acid) Nanocomposite via Catalyst-Modified Montmorillonite

Biopolymer nanocomposite of polylactic acid was synthesized from lactic acid using tin ions exchanged Cloisite Ca⁺⁺. The tin molecules between the Cloisite Ca⁺⁺ layers catalyzed the lactic acid polymerization and also this clay played a role as a nanofiller. Presence of tin molecules increased the molecular weight of the polymer compared with the polymer that was synthesized with the presence of just Cloisite Ca⁺⁺. Both exfoliated and intercalated nanocomposite structures were observed as the results of X-ray diffraction analysis and transmission electron microscopy images. Also, changes of polymer's thermal degradation and other thermal properties such as glass transition temperature, melting temperatures were investigated via thermogravimetric analysis and differential scanning calorimetry.     

Synthesis and intercalation of silver nanoparticles in kaolinite/DMSO complexes

Ag nanoparticles were synthesized in the interlamellar space of a layered kaolinite. Disaggregation of the lamellae of the nonswelling kaolinite was achieved by the intercalation of dimethyl sulfoxide (DMSO). The kaolinite was suspended in aqueous AgNO₃ solution and the adsorbed Ag⁺ ions were reduced on the surface of kaolinite lamellae with NaBH₄ or UV light irradiation. The silver nanoparticles formed were characterized by X-ray diffraction (XRD), small angle X-ray scattering (SAXS), and transmission electron microscopy (TEM). We studied the effects of the two reduction methods on the size and the size distribution of Ag nanoparticles and how clay mineral structure is altered as a consequence of particle formation. It was established that the size of Ag nanoparticles depends on both silver content and the reduction method. Photoreduction of silver led to the formation of relatively large Ag nanoparticles (diameter 8–14 nm).     

Synthesis and characterization of novel silver/L‐phenylalanine‐based optically active polyacrylate nanocomposite

Novel bioactive and optically active poly(N‐acryloyl‐L ‐phenylalanine) (PAPA) was synthesized by atom transfer radical polymerization. PAPA‐silver (Ag) nanocomposites have been successfully prepared via in situ reducing Ag⁺ ions anchored in the polymer chain using hydrazine hydrate as reducing agent in an aqueous medium. By controlling of the amount of Ag⁺ ions introduced, we have produced an organic/inorganic nanocomposite containing Ag nanoparticles with well controlled size. Nanocomposites were characterized by X‐ray diffraction (XRD), UV–Vis spectrophotometry, transmission electron microscopy, and Fourier transform infrared. XRD pattern showed presence of Ag nanoparticles. The PAPA/Ag nanocomposites with 1 : 10 silver nitrate (AgNO₃) : PAPA ratio revealed the presence of well‐dispersed Ag nanoparticles in the polymer matrix. All of these Ag nanoparticles formed are spherical and more than 80% of them are in the range of 15–25 nm. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Controllable preparation and heavy‐metal‐ion adsorption of lignosulfonate‐polypyrrole composite nanosorbent

Lignosulfonate‐polypyrrole (LS‐PPY) composite nanospheres were prepared facilely via an in situ polymerization of pyrrole monomers in the presence of lignosulfonate as a dispersant and ammonium persulfate as an oxidant. The LS‐PPY composite was characterized with Fourier Transform infrared spectroscopy (FTIR), thermogravimetric analysis, wide‐angle X‐ray diffraction (XRD), scanning electron microscopy (SEM), field‐emission SEM, and transmission electron microscopy. Uniform LS‐PPY solid composite nanospheres with an average diameter of 154 nm were obtained. The LS‐PPY composite nanospheres were applied to adsorption of Ag(I) and Pb(II) ions from aqueous solutions. Maximum adsorption capacities of Ag(I) and Pb(II) were up to 759.3 mg g⁻¹ and 207.5 mg g⁻¹, respectively. Furthermore, the silver ions can be reduced to metallic silver nanowires through a redox reaction between the LS‐PPY composite nanospheres and the silver ions. A productive no‐template route to fabrication of LS‐PPY composite nanospheres with controllable size and heavy‐metal‐ion adsorption ability was achieved. POLYM. COMPOS., 36:1546–1556, 2015. © 2014 Society of Plastics Engineers     

Morphology, structure and properties of a poly(1-butene)/montmorillonite nanocomposite

A specifically formulated nanocomposite based on isotactic poly(1-butene) (PB) and montmorillonite was studied, by wide angle X-ray diffraction (WAXD), small angle X-ray scattering (SAXS), transmission electron microscopy (TEM) and polarized light optical microscopy, investigating the polymorphism of the polymer, and examining the interaction between PB and the silicate. Montmorillonite was found to disrupt the ordered morphology of the polymer, determining a dramatic increase in the rate of the II→I phase transition. Interaction between polymer and clay was studied by TEM and SAXS also under a quantitative point of view. A significant enhancement of physical-mechanical properties was observed, even though exfoliation did not occur, but just a slight intercalation and a reduction in the size of tactoids.     

A Novel Approach to Prepare Poly(Vinyl Acetate)/Ag Nanocomposite for Effective Antimicrobial Coating Applications

Polyvinyl acetate nanocomposites were successfully prepared based on silver nanoparticles. First, silver nanoparticles were directly prepared during the in situ emulsion polymerization of vinyl acetate monomer using AgNO₃ as a source of Ag⁺ ions and poly(vinyl alcohol) was used for dual functions as emulsifier for emulsion polymerization and as a stabilizing agent, trisodium citrate (C₆H₅O₇Na₃) was used as reducing agent for Ag⁺ ions during the polymerization process. The prepared polyvinyl acetate/Ag nanocomposites were assessed using X-ray diffraction, scanning electron microscopy, Fourier transform infrared, transmission electron microscopy, and ultraviolet spectra. The antibacterial properties of the prepared polyvinyl acetate/Ag nanocomposites were investigated as antimicrobial activity against pathogenic bacteria, i.e., Staphylococcus aureus (G^+ve bacteria) and Escherichia coli (G^?ve bacteria). These polyvinyl acetate nanocomposites could be used as a promising material for enhanced and continuous antibacterial applications as coating and packaging materials.