Preparation of silver nanoparticle via active template under ultrasonic

A novel method was described for the production of silver nanoparticle by using nano-carbon as active template.Special ultrasonic condition was used to assure the active effect of the template and achieve an even and stable micro-reactor system,therefore yield uniform silver nanoparticle without obvious agglomeration.By laser granularity instrument measurement,the silver nanoparticles show a mean diameter of 20.4 nm and narrow distribution between 18.7 nm and 23.0 nm according to the optimum technology.Regular spherical morphology can be observed by transmission electron microscopy(TEM).X-ray diffraction analysis indicates that Ag+ is deoxidized to form metal Ag during producing precursor,subsequent calcinations promote phase transformation from nonholonomic crystal to complete cubic crystal,which is consistent with the standard JCPDS card of silver.The results reveal that the nano-carbon in active template system not only exerts micro-reactor and steric stabilization effect,but also acts as reducing agent during the reaction.

Biosynthesis of Copper Nanoparticles using an Extract of the root of Asparagus racemosus:Basic Synthesis,Antimicrobial,and Anti-oxidant Potentials

Copper nanoparticles(CuNPs)have emerged as a promising alternative due to their unique antimicrobial properties.The synthesis of CuNPs using Asparagus racemosus,commonly known as Shatavari,offers a sustainable and environmentally friendly approach to producing nanomaterials.Moreover,the resulting CuNPs have been found to possess excellent antibacterial,and antioxidant properties,which further expands their potential applications in medicine and environmental remediation.In this article,we discussed the in vitro characterization of the CuNPs.In vitro studies revealed that CuNPs have the potential for biomedical applications and as a base nanomaterial for the construction of drug delivery and targeting vehicles.

Synthesis, Characterization, and Evaluation Non-Stoichiometric of Copper Ferrite Nanoparticles in Disinfestation and Adsorption Efficiency for Organic Dye: Isotherms, Thermodynamics, and Kinetic Studies

Ferrite nanoparticles (FNPs) have attracted considerable attention due to their diverse applications in wastewater treatment. This study focused on synthesizing non-stoichiometric copper ferrite magnetic nanoparticles (CuFNPs) through co-precipitation and microwave methods. The synthesized adsorbents were characterized using techniques such as X-ray diffraction (XRD), vibration sample magnetometry (VSM), and scanning electron microscopy (SEM). XRD analysis revealed crystallite sizes ranging from 24 to 31 nm for all samples. Furthermore, adsorption experiments were performed to investigate the impacts of several factors, including dye concentration, contact time, adsorbent dosage, and pH, on the removal efficiency of Alizarin Yellow R (AYR) dye. The CuFNPs (5) sample achieved a maximum removal efficiency of 98.90% at a dye concentration of 50 ppm, pH 2, and an equilibrium time of 90 minutes. The kinetic investigation demonstrated that the adsorption of AYR dye onto the nanoparticles adhered to a pseudo-second-order (PSO) model. The adsorption equilibrium data were most accurately described by the Langmuir isotherm model, although the Freundlich model was also evaluated. The CuFNPs (4) sample showed superparamagnetic behavior with a saturation magnetization value of 58.28 emu/g. The antibacterial activity of the synthesized CuFNPs was evaluated against four bacterial strains, including gram-positive, gram-negative, and pathogenic fungal yeast. Results showed that the CuFNPs (5) sample demonstrated significant effectiveness against both gram-negative bacteria (E. coli, P. aeruginosa) and gram-positive bacteria (S. aureus, B. cereus), as well as the pathogenic fungal yeast C. albicans.

Comparative Study of Antibacterial Activity of Bacterial Cellulose/AgNPs Composites Prepared by Different Methods

Bacterial cellulose(BC) is a type of nanoscale cellulose produced by microorganisms.In this work,BC films were utilized as a template to in situ synthesize silver nanoparticles(AgNPs) by a variety of simple chemical strategies,including chemical reduction with NaBH4 or vitamin C,hydrothermal treatment and UV radiation.A comparative study of the formation of AgNPs such as the silver particle size and silver content,as well as the antibacterial activity of the BC-AgNPs nanocomposites by different preparation methods and reaction conditions was investigated.A beneficial support was provided for future applications of AgNPs contained BC composites with antibacterial properties.

Modification of tamarind fruit shell powder with in situ generated copper nanoparticles by single step hydrothermal method

Tamarind fruit shell powder(TFSP)with particle size of<50μm(obtained from cleaned tamarind fruit shells)was modified with in situ generated copper nanoparticles(CuNPs)by simple one step hydrothermal method.The modified TFSP was characterized by scanning electron microscope(SEM),Fourier transform infrared(FT-IR)spectroscopy,X-ray diffraction(XRD),thermogravi-metric analysis(TGA)and antibacterial tests.The generated stable CuNPs on the surface of the modified TFSP were spherical in shape with an average size of 88 nm.The FT-IR spectroscopy analysis indicated the involvement of the functional groups of the TFSP in the generation and stabilization of the CuNPs.The XRD analysis indicated the presence of both CuNPs and Cu 2 O nanoparticles in the modified TFSP.The thermal analysis indicated the presence of 5.6 wt%of copper nanoparticles as calculated from the difference of residual char content between the un-modified and modified TFSP.The modified TFSP with in situ generated CuNPs exhibited obvious antibacterial activity against both the Gram negative and Gram positive bacteria and hence can be considered as low cost filler in the preparation of antibacterial polymer hybrid nanocomposites for packaging and medical applications.

Synthesis and characterization of lanthanum-doped curcumin-functionalized antimicrobial copper oxide nanoparticles

Flavonoid-based nanomaterials have extensive potential in antimicrobial research because of their non-toxicity,large-scale producibility,and chemical stability.An efficient combination of flavonoids and rare earth metals can have excellent antimicrobial properties owing to their robust medicinal and physicochemical properties.In this study,we synthesized copper oxide(CuO)nanoparticles(NPs)using a reflux reaction and repeated doping with the rare earth element lanthanum to prepare La-CuO NPs.Next,these La-CuO NPs were functionalized with the flavonoid curcumin,and the modified NPs were termed Cu-La-CuO NPs.These NPs were chemically characterized via microscopic and spectroscopic techniques,including transmission electron microscopy(TEM),scanning electron microscopy(SEM),ultraviolet-visible(UV-Vis)adsorption,Fourier transform infrared spectroscopy(FT-IR)spectroscopy,and powder X-ray diffraction(XRD)analysis.The SEM-EDX analysis reveals the elements doped into the native CuO NPs.The TEM and XRD characterization results show,in detail,the distinct morphology and phase composition of the prepared CuO,La-CuO,and Cu-La-CuO NPs.The antimicrobial activity of the Cu-La-CuO NPs was investigated on bacteria,such as Escherichia coli(E.coli)and Bacillus subtilis(B.subtilis),and fungi,including Aspergillus niger(A niger).The Cu-La-CuO NPs delivers excellent antimicrobial effects due to the incorporation of lanthanum and curcumin into the CuO NPs.The Cu-La-CuO NPs show excellent antimicrobial potentials with an adequate zone of inhibition values around 2.2 and 2.9 mm in E.coli and A.niger,respectively.Live and dead analysis studies suggest the antimicrobial effects of lanthanum and curcumin moieties over native CuO NPs.The obtained results are significant in developing of rare earth metal-based flavo no id-conjugated nanocomposites against typical microbes.

Deposition of copper nanoparticles on multiwalled carbon nanotubes modified with poly （acrylic acid） and their antimicrobial application in water treatment

A novel hybrid material, Cu-PAA/MWCNTs （copper nanoparticles deposited multiwalled carbon nano- tubes with poly （acrylic acid） as dispersant, was prepared and expected to obtain a more effective and well-dispersed disinfection material for water treatment. X-ray energy dispersive spectroscopy （EDS）, transmission electron microscopy （TEM）, the X-ray fluorescence （XRF）, X-ray photoelectron spectra （XPS）, Fourier transform infrared spectra （FT-IR）, Raman spectroscopy, and thermal gravi- metric analyzer （TGA） were used to characterize the Cu- PAA/MWCNTs. Escherichia coli （E. coil） was employed as the target bacteria. The cell viability determination and fluorescence imaging results demonstrated that Cu-PAA/ MWCNTs possessed strong antimicrobial ability on E. coil. The deposited Cu was suggested to play an important role in the antimicrobial action of Cu-PAA/MWCNTs.

导电涂料中纳米铜粉抗氧化性的研究

为了提高纳米铜粉的抗氧化能力及其在聚合物基体中的分散性,在钠米铜粉表面包覆一层导电性和抗氧化性均佳的银.以水合肼为还原剂、PVP(聚乙稀吡咯烷酮)和硅烷偶联剂(KH-550)为分散剂,采用二月桂酸二丁基锡对纳米铜颗粒表面进行活化处理,然后采用置换反应法制备得到了与原纳米铜粉粒径和形貌大致相同的核壳型铜-银双金属粉末.采用X射线衍射(XRD)、XRF、TGA等手段分析了核壳铜-银双金属粉的抗氧化性能,并用透射电子显微镜(TEM)对粉末形貌进行表征.结果表明,经表面活化处理后得到的核壳铜-银双金属粉,在镀银质量分数较低(37.68%)时也能形成完全包覆型结构.包覆后的铜纳米颗粒在700℃以下没有任何氧化现象.

涤纶织物上激光诱导沉积银粒子活化种用于化学镀铜的研究

用激光辐射预先经聚乙烯吡咯烷酮(PVP)–AgNO_3胶体溶液处理的涤纶织物,在涤纶织物表面制备出银纳米粒子,再以银纳米粒子为活化点成功地催化织物进行化学镀铜。采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)和原子力显微镜(AFM)对涤纶织物表面上银粒子的形态、结构和粒径分布进行了表征,探讨了PVP在激光诱导银粒子沉积过程中的保护作用。激光辐射能有效地将涤纶织物表面的Ag^+还原成金属Ag纳米粒子。在激光辐射过程中,PVP能保护银粒子并起到辅助还原作用。适宜的PVP与AgNO_3的质量比为2∶1。在银粒子的催化作用下,涤纶织物表面能够顺利进行化学镀铜而得到均匀分布的铜沉积层。

氧化铜纳米粒子的制备与表征

纳米材料具有诸多优良特性,使其具有物理性质与常规块体材料不同,被誉为本世纪最有前途的材料。纳米氧化铜具有低熔融温度、低分解温度和高热释放已经成为可用于亚稳态含能复合材料中的比较理想的氧化剂材料。以PEG为模板,用CuCl2·2H2O和NaOH为原料,通过溶液反应制备CuO纳米粒子。分别讨论了反应物配比、PEG的分子量、PEG用量对产物形貌的影响,以得到制备CuO纳米粒子的最佳实验条件。

活性模板法制备纳米铜粉体

采用活性模板法制备了高纯纳米铜（Cu）粉体。研究了超声波频率、焙烧温度对纳米粉体性能的影响，通过X射线衍射（XRD）、透射电子显微镜（TEM）和激光粒度分析仪等手段对样品的成分、形貌、粒度及其分布进行了分析。结果表明，模板介质炭黑具有微反应器作用、空间位阻效应和较强的还原性，模板法制得的纳米Cu粉呈规则的链状球形，无明显团聚体，平均粒径为32．3nm，粒径分布窄，粒径范围在19．4～49．5nm。

“Stöber”模板法制备Ag@C纳米粒子及其催化性能

采用“Stöber”模板法合成了核-壳-壳结构的Ag@SiO_(2)@RF复合纳米粒子,经过碳化、刻蚀得到了“Rattle型”结构的Ag@C纳米粒子。采用透射电镜(TEM)、扫描电镜(SEM)、拉曼光谱(RS)、N2吸附及X线粉末衍射(XRD)表征检测,对其形貌、结构进行表征。结果表明:制备的Ag@C纳米粒子具有完整的球形结构、较大的空腔和可移动的纳米银内核,壳层上有介孔,平均孔径为7.8 nm,比表面积为866 m2/g。以2 mg Ag@C为催化剂,室温下用过量的KBH4还原1 mmol/L对硝基苯酚,测试Ag@C纳米粒子的催化性能。结果表明:反应3 min,其转化率为98%,催化剂使用6次活性没有明显下降。

基于蛋白质-RuO_(2)纳米颗粒构建电化学免疫传感器超灵敏检测甲胎蛋白

本文采用蛋白质牛血清白蛋白(BSA)为模板,绿色合成稳定、生物相容性好的金属氧化物纳米材料(BSARuO_(2)),基于此构建了一种夹心型免疫传感器,实现甲胎蛋白(AFP)的超灵敏检测。

纳米铜导电墨水的制备及研究

以次磷酸钠为还原剂、硫酸铜为前驱体,并添加LomarD、PVP等表面活性剂及分散剂,在一缩二乙二醇(DEG)有机液相溶液中采用化学还原法成功地制备了在室温下能稳定60天的纳米铜导电墨水,通过电渗析除去墨水中的杂质离子,再采用减压蒸馏的方法可使纳米铜在墨水中的质量分数达到5%～30%,其中电渗析的除杂效率在99%以上。以XRD、TEM、EDX、ICP、HORIBALB550粒度分布仪对墨水进行表征,结果显示,墨水中纳米铜的粒径为15～40nm,分布较窄。设计正交试验分析了影响墨水中铜晶粒大小的一些因素发现,还原剂与前驱体的物质的量比、反应温度、pH值以及分散剂与表面活性剂的物质的量比等都对铜晶粒的生长有很大影响。

硅基底上铜纳米粒子催化生长碳纤维的研究

采用微波加热法,在单晶硅基底上生长了铜纳米粒子,并以铜纳米粒子为催化剂,乙炔为碳源,氢气为保护气,在管式炉中制备了碳纤维。利用高视频显微仪观察单晶硅片的预处理情况,采用扫描电子显微镜(SEM)观察硅基底上铜纳米粒子的生长情况和碳纤维的形貌特征,并利用能量色散谱仪(EDS)对铜纳米粒子进行成分及元素分布分析。研究表明,采用抛光-腐蚀的硅片预处理方法,可以更高效地得到具有取向性、长径比大的碳纤维。

纳米铜对小油菜(Brassica chinensis L.)种子发芽和幼苗生理生化特性的影响

通过纸床培养,探究了不同剂量(1、2、4、6、8、10 mg·L^-1)纳米铜(Copper nanoparticles,Cu NPs)对小油菜(Brassica chinensis L.)种子发芽、幼苗Cu含量、根细胞微观特征以及幼苗生理生化特性的影响。结果表明,不同浓度Cu NPs处理对种子发芽率无显著影响(P>0.05),小油菜根和茎伸长量均随Cu NPs浓度增加先升高后降低,当Cu NPs添加量为2~10 mg·L^-1时小油菜根伸长抑制率为10.7%~59.9%,而当Cu NPs≥4 mg·L^-1时小油菜茎长显著低于对照组(P<0.05),降低了4.8%~15.8%。幼苗体内Cu含量随着Cu NPs浓度的增加而升高。通过透射电子显微镜可以看出,添加10 mg·L^-1Cu NPs使根细胞出现比较普遍的质壁分离现象。与对照组比较,Cu NPs处理后小油菜幼苗体内超氧化物歧化酶活性降低了4.5%~64.0%(1 mg·L^-1除外),过氧化物酶降低幅度达到4.4%~59.3%,而不同浓度Cu NPs处理对小油菜幼苗体内过氧化氢酶活性影响不显著(P>0.05),因此,小油菜生理生化特性对不同剂量Cu NPs响应不同。

PCB化学镀铜前纳米钯活化液的制备及性能

以PdCl2为原料，聚乙烯吡咯烷酮（PVP）和葡萄糖分别作分散剂和还原剂，制备得到纳米钯粉。表征了纳米钯粒子的形貌、结构、稳定性、分散性及其对化学镀铜的影响。结果表明，所得纳米钯是粒径为40～60nm的球形粒子，纯度高，且不易氧化。纳米钯活化液的分散性和稳定性好，将其用于通孔化学镀铜前的活化处理后，镀铜通孔的背光级数在9级以上，铜镀层平整。因此，采用本工艺制备的纳米钯是一种性能优异的沉铜催化剂。

溶剂热法制备铜粒子

采用简单的溶剂热法,在硅片上制备了铜纳米粒子,研究了反应方法、铜源等条件对铜粒子形貌及成分的影响。通过SEM、XRD等对产物进行表征。结果表明,改变铜源,可控制铜粒子的形貌变化;通过此法得到的铜粉产物纯净,但有团聚现象发生;铜源不同,制备的铜粒子结晶度也不同。

免模板法合成高纯介孔氧化镁纳米抗菌剂

通过尿素和四水合乙酸镁的水热沉淀反应合成了多孔碳酸镁纳米带,再经高温煅烧制备了高纯度介孔氧化镁纳米颗粒.对所得材料进行了结构性质的表征,并利用最小抑菌浓度试验、抑菌圈试验、和摇瓶灭活试验考察了该材料对常见致病菌的抗菌活性.结果表明,该材料平均粒径为50 nm,含有许多直径约为3 nm的介孔,比表面积可达193.7 m2·g-1,并赋予材料大量的缺陷位点和较高的抗菌活性,500 mg·L-1的材料在24 h内对大肠杆菌和金黄色葡萄球菌可达到99.9%的杀菌百分率.此外,X射线晶体衍射、元素组成分析和X射线光电子能谱分析证实,以尿素和乙酸镁为前体,可以获得高纯度纳米氧化镁材料.

溶剂热法制备铜纳米粒子

采用简单的溶剂热法在硅片上制备铜纳米粒子，发现反应方法、铜源等条件均会影响铜粒子的形貌及成分。通过扫描电子显微镜（SEM）、X射线衍射仪卿）等对产物进行表征，结果表明：改变铜源可以控制铜粒子的形貌变化，而通过此法得到的铜粉产物纯净但有团聚现象发生，另外铜源不同制备的铜粒子结晶度也不同。