纳米银插层膨润土抗菌剂的性能研究

以膨润土片层结构做模板,将银氨溶液与改性膨润土进行离子交换反应,通过光还原法制备得到了纳米银插层膨润土抗菌剂。通过高分辨透射电镜、能谱分析测试表征纳米银插层膨润土抗菌剂的结构与成分,并测试抗菌性能和白度变化。结果表明:纳米银插层膨润土抗菌剂的膨润土片层中夹插有球形纳米银,纳米银颗粒的主要粒径为2-8 nm,其中小部分粒径为8-17 nm,这种独特的模板结构确保纳米银抗菌剂结构稳定和性能稳定。纳米银插层膨润土抗菌剂中纳米银含银量为1.04wt%,有优异的抗菌性能,对金黄色葡萄球菌和大肠杆菌的最小抑菌浓度(MIC)分别为50μg/mL。纳米银插层膨润土抗菌剂具有颜色稳定性和持久抗菌性。     

载银硅藻土/PNAC复合凝胶制备及性能

以N,N-二甲基甲酰胺(DMF)为还原剂,聚乙烯吡咯烷酮(PVP)为分散剂制备纳米银,并将其负载于改性硅藻土;以N-异丙基丙烯酰胺、丙烯酸为单体,N,N-亚甲基双丙烯酰胺为交联剂,通过自由基聚合法与载银硅藻土合成载银硅藻土/PNAC复合凝胶。利用紫外可见分光光度计、傅里叶变换红外光谱(FTIR)和扫描电镜(SEM)分别对纳米银、复合凝胶和载银硅藻土进行表征,并对复合凝胶的pH值、温度响应性和抗菌性进行测定。扫描电镜结果表明合成的纳米银粒径为(75±10) nm,且纳米银负载于改性硅藻土表面孔洞中; FTIR表明复合凝胶制备成功;抑菌实验表明,复合凝胶能够持续缓释纳米银产生抑菌效果,对大肠杆菌的抑菌性优于金黄色葡萄球菌。     

纳米银/P(AAEM-St)复合材料的原位超声合成与表征

超声原位引发乙酰乙酸基甲基丙烯酸乙酯(AAEM)与苯乙烯(St)聚合,制备纳米银/P(AAEM-St)复合粒子。UV-Vis和XRD结果证明了纳米银粒子且其具有面心立方结构。TEM结果表明纳米银粒径在10～30 nm,且较均匀的分散在聚合物基体中。     

纳米银@石墨烯复合材料的绿色制备及其抑菌性能

以聚乙二醇为还原剂通过水热反应,还原氧化石墨烯同时在石墨烯表面原位生长银纳米粒子,制备纳米银@石墨烯复合材料。采用紫外-可见吸收光谱、X射线衍射、红外吸收光谱、透射电子显微镜对所制备的纳米银@石墨烯复合材料进行了表征。结果表明,银以单质形态成功负载在石墨烯表面,银纳米粒子的平均粒径为30nm。以大肠杆菌为模型对纳米复合材料的抑菌性能进行测试,纳米银@石墨烯复合材料在100 mg/L时可以完全抑制大肠杆菌的生长,是一种效果显著的新型抑菌材料。     

聚多巴胺功能化纳米银粒子制备及抗菌性能

采用一步法,以聚多巴胺(PDA)为还原剂和保护剂,制备PDA功能化的纳米银粒子(PDA-nanoAg)。提出PDA-nanoAg合成机理,并考察其在水相中的分散稳定性。通过紫外-可见吸收分光光度计(UV-Vis)、透射电子显微镜(TEM)、傅里叶变换红外光谱仪(FTIR)对产物形貌和结构进行表征。采用肉汤稀释法测试PDAnanoAg的抗菌性能。结果表明,所制备的PDA-nanoAg平均粒径为50 nm,具有良好的稳定分散性;对埃希氏大肠杆菌(E.coli)、金黄色葡萄球菌(S.aureus)的最小抑菌浓度(MIC)为7.56 mg/L,最小杀菌浓度(MBC)为30.24mg/L。     

聚多巴胺功能化纳米银粒子制备及抗菌性能研究

采用一步法,以聚多巴胺(PDA)为还原剂和保护剂,制备PDA功能化的纳米银粒子(PDA-nanoAg)。提出PDA-nanoAg合成机理,并考察其在水相中的分散稳定性。通过紫外-可见吸收分光光度计(UV-Vis)、透射电子显微镜(TEM)、傅里叶变换红外光谱仪(FTIR)对产物形貌和结构进行表征。采用肉汤稀释法测试PDAnanoAg的抗菌性能。结果表明,所制备的PDA-nanoAg平均粒径为50 nm,具有良好的稳定分散性;对埃希氏大肠杆菌(E.coli)、金黄色葡萄球菌(S.aureus)的最小抑菌浓度(MIC)为7.56 mg/L,最小杀菌浓度(MBC)为30.24mg/L。     

无患子提取液制备纳米银及其协同抗菌性研究

以无患子提取液为还原剂,制备了含有纳米银的无患子复合抗菌液,考察了无患子提取液用量、温度、硝酸银摩尔浓度等因素对纳米银形貌和粒径的影响,并借助UV-Vis可见分光光谱、X射线衍射(XRD)以及透射电子显微镜(TEM)对产物进行表征;通过抑菌环法探讨了复合抗菌液对大肠杆菌的抗菌活性。由UV-Vis图谱可知,复合抗菌液等离子体共振吸收峰(SPR)在418 nm左右,说明该复合抗菌液中有纳米银的存在;XRD图表明合成的纳米银为面心立方结构;TEM图表明合成纳米银粒径为10~40 nm。由此获得的含有纳米银的无患子复合抗菌液对大肠杆菌表现出显著协同抗菌活性,抑菌圈直径变大。     

油基-银纳米流体的制备及稳定性研究

采用化学还原法在由硝酸银水溶液、油酸、二乙胺构成的反应体系中制备油酸包裹的单分散纳米银颗粒,表面改性的纳米银颗粒在非极性有机溶剂中极易分散制成纳米流体。利用透射电镜(TEM)、粉末衍射(XRD)、红外光谱(IR)和紫外-可见光谱(UV-Vis)等对所得产物进行了表征。油酸分子的羧基端通过O与纳米银核发生一定的相互作用,牢牢地包裹在银核外层,使得其另一亲油端,即较长的碳链朝向外部,形成了一层保护膜,有效阻止纳米银间的团聚。50℃制备的表面改性的纳米银粒径均匀,平均粒径6.8 nm。采用紫外-可见光谱法测定纳米流体的热稳定性,结果表明,表面改性的纳米银分散在正庚烷中形成的纳米流体在120℃稳定时间超过14 h。     

油基-银纳米流体的制备及稳定性研究?

采用化学还原法在由硝酸银水溶液、油酸、二乙胺构成的反应体系中制备油酸包裹的单分散纳米银颗粒,表面改性的纳米银颗粒在非极性有机溶剂中极易分散制成纳米流体。利用透射电镜(TEM)、粉末衍射(XRD)、红外光谱(IR)和紫外-可见光谱(UV-Vis)等对所得产物进行了表征。油酸分子的羧基端通过O与纳米银核发生一定的相互作用,牢牢地包裹在银核外层,使得其另一亲油端,即较长的碳链朝向外部,形成了一层保护膜,有效阻止纳米银间的团聚。50℃制备的表面改性的纳米银粒径均匀,平均粒径6.8 nm。采用紫外-可见光谱法测定纳米流体的热稳定性,结果表明,表面改性的纳米银分散在正庚烷中形成的纳米流体在120℃稳定时间超过14 h。     

植物还原法制备纳米银溶胶对3种人参病原真菌的高效抗菌作用

[目的]探究植物还原法制备纳米银溶胶对人参病原真菌的高效抗菌作用,以减少内吸性杀菌剂对环境的污染。[方法]采用植物还原法,以黑心菊超声水提液为还原剂,制备纳米银溶胶,并对纳米银粒子进行全方位表征;通过菌丝生长速率法测定纳米银溶胶、内吸性杀菌剂和2者的混合物对3种人参病原真菌的抑菌活性。[结果]纳米银粒子平均直径为1.8 nm,且分散性均匀,产率为89.99%;14.29 mg/L纳米银溶胶(均低于3种内吸性杀菌剂质量浓度)对Botrytis cinerea、Cylindrocarpon destructans和Fusarium solani的抑制效果均为最好,EC_(50)值分别为1.6919、2.1046、4.3868 mg/L,EC_(90)值分别为39.5124、20.5182、78.6884 mg/L。[结论]植物还原法制备的纳米银溶胶与内吸性杀菌剂相比具有更高的抗菌活性,纳米银溶胶-内吸性杀菌剂复配物与内吸性杀菌剂相比,大量减少了内吸性杀菌剂的使用,为植物源农药的开发提供了一种新思路。     

An Antireflective Nanostructure Array Fabricated by Nanosilver Colloidal Lithography on a Silicon Substrate

An alternative method is presented for fabricating an antireflective nanostructure array using nanosilver colloidal lithography. Spin coating was used to produce the multilayered silver nanoparticles, which grew by self-assembly and were transformed into randomly distributed nanosilver islands through the thermodynamic action of dewetting and Oswald ripening. The average size and coverage rate of the islands increased with concentration in the range of 50–90 nm and 40–65%, respectively. The nanosilver islands were critically affected by concentration and spin speed. The effects of these two parameters were investigated, after etching and wet removal of nanosilver residues. The reflection nearly disappeared in the ultraviolet wavelength range and was 17% of the reflection of a bare silicon wafer in the visible range.     

Nanosilver Colloids-Filled Photonic Crystal Arrays for Photoluminescence Enhancement

For the improved surface plasmon-coupled photoluminescence emission, a more accessible fabrication method of a controlled nanosilver pattern array was developed by effectively filling the predefined hole array with nanosilver colloid in a UV-curable resin via direct nanoimprinting. When applied to a glass substrate for light emittance with an oxide spacer layer on top of the nanosilver pattern, hybrid emission enhancements were produced from both the localized surface plasmon resonance-coupled emission enhancement and the guided light extraction from the photonic crystal array. When CdSe/ZnS nanocrystal quantum dots were deposited as an active emitter, a total photoluminescence intensity improvement of 84% was observed. This was attributed to contributions from both the silver nanoparticle filling and the nanoimprinted photonic crystal array.     

Nanosilver induces minimal lung toxicity or inflammation in a subacute murine inhalation model

Background  

There is increasing interest in the environmental and health consequences of silver nanoparticles as the use of this material becomes widespread. Although human exposure to nanosilver is increasing, only a few studies address possible toxic effect of inhaled nanosilver. The objective of this study was to determine whether very small commercially available nanosilver induces pulmonary toxicity in mice following inhalation exposure.     

Nanosilver/hyperbranched polyester (HBPE): synthesis, characterization, and antibacterial activity

HBPE of different generations were synthesized using 4-hydroxybenzoic acid and 2,2′,2″-nitrilotriethanol via the A₂ + B₃ method. The reaction was carried out in a dry nitrogen atmosphere using p-toluene sulfonic acid (p-TSA) as an acid catalyst. The chosen molar ratios of 2,2′,2″-nitrilotriethanol to 4-hydroxybenzoic acid were 1:3, 1:6, and 1:21 for the G₁, G₂, and G₅ generations, respectively. The G₅ stage of HBPE was further coupled with acrylic acid to modify the terminal hydroxyl groups. The resulting products were analyzed using ¹H NMR, ¹³C NMR, FTIR spectroscopy, and GPC. Silver nanoparticles were prepared by a reductive technique using HBPEs of the G₅ generation as the matrix. XRD and TEM analysis indicated the formation of highly spherical and stable nanosilver in the HBPE. The antibacterial activity of the nanosilver/HBPE was evaluated against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) bacteria.     

纳米银胶体颗粒制备新方法及其荧光增强效应研究

在纳米银胶体颗粒的制备中引入固相分散基体——天然纤维素,利用其表面丰富的羟基、醚基等含氧基团,均匀吸附银离子后,浸入低浓度硼氢化钠,经历脱附、还原过程生成银纳米颗粒的胶体溶液.与经典制备方法相比,反应过程温和且无需添加任何稳定剂,所制得的银纳米颗粒细小、均一、稳定性高.荧光增强实验表明,由于消除了大分子稳定剂的阻碍,胶体溶液在较低浓度下即可获得很好的荧光增强作用.     

Sulfur Nanoparticles Synthesis and Characterization from H2S Gas, Using Novel Biodegradable Iron Chelates in W/O Microemulsion

Sulfur nanoparticles were synthesized from hazardous H₂S gas using novel biodegradable iron chelates in w/o microemulsion system. Fe³⁺–malic acid chelate (0.05 M aqueous solution) was studied in w/o microemulsion containing cyclohexane, Triton X-100 and n-hexanol as oil phase, surfactant, co-surfactant, respectively, for catalytic oxidation of H₂S gas at ambient conditions of temperature, pressure, and neutral pH. The structural features of sulfur nanoparticles have been characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), energy dispersive spectroscopy (EDS), diffused reflectance infra-red Fourier transform technique, and BET surface area measurements. XRD analysis indicates the presence of α-sulfur. TEM analysis shows that the morphology of sulfur nanoparticles synthesized in w/o microemulsion system is nearly uniform in size (average particle size 10 nm) and narrow particle size distribution (in range of 5–15 nm) as compared to that in aqueous surfactant systems. The EDS analysis indicated high purity of sulfur (>99%). Moreover, sulfur nanoparticles synthesized in w/o microemulsion system exhibit higher antimicrobial activity (against bacteria, yeast, and fungi) than that of colloidal sulfur.     

纳米银生物法绿色合成及其抗菌应用进展

纳米银是研究和应用最为广泛的纳米材料之一。近年来为避免纳米银合成过程中产生有毒副产物，人们在纳米银的绿色合成方向做了诸多研究。植物各组织和微生物细胞中富含的各类天然化合物均可完成纳米银的绿色合成，不同生物源合成纳米银的潜力有待进一步发掘。纳米银尺寸和形状的可控化，以及在使纳米银发挥抗菌作用的前提下减少迁移，减少副作用，是下一步的重点。综述了利用植物、细菌和真菌绿色合成纳米银的机制与方法，对各方法进行分析比较，介绍了纳米银的抗菌性能、抗菌机制和具体应用，对于未来发展提出建议。     

页岩储层保护用O/W纳米乳液的制备

针对钻井液滤液侵入页岩储层极易导致严重的水敏损害及液相圈闭损害问题,采用两步稀释法研备出粒径极小、分散性好且长期稳定的页岩储层保护用水包油(O/W)纳米乳液。选取Gemini季铵盐型表面活性剂GTN、Tween80与正丁醇三者复配作为表面活性剂组分(记为S+A),通过室内实验研究了水相中NaCl质量分数对NaCl溶液/(S+A)/正辛烷体系微乳液特性的影响,考察了微乳液相转变温度(PIT)、制备方法及其微观构型等因素对采用两步稀释法制备的纳米乳液粒径的影响,同时对纳米乳液体系的失稳机理进行研究。结果表明,NaCl溶液/(S+A)/正辛烷体系微乳液中NaCl的加入可以显著提高表面活性剂组分的乳化效率,改变微乳液微观构型,使PIT显著降低;当剂油体积比(R_os)为7:3时,通过调节双连续微乳液的PIT接近实验乳化温度,采用两步稀释法制备的O/W纳米乳液粒径最小且分布范围最窄;NaCl溶液/(S+A)/正辛烷体系纳米乳液主要失稳机理为奥氏熟化;纳米乳液具有良好的储层保护作用。     

草酸锌纳米粒子的合成动力学研究

以微乳液和均匀沉淀耦合法制备出纳米草酸锌粒子。为了研究纳米粒子生长的动力学特征,用稀释法求取了该过程所涉及的NP-9／正己醇／正庚烷／硝酸锌溶液微乳液体系的水核半径：检测了草酸二甲酯与硝酸锌的沉淀反应过程中浓度随时间的变化,建立了草酸二甲酯水解的动力学方程。根据微乳液法制备纳米粒子的扩散机理,推导出纳米粒子的粒径与反应时间的关系式,并将计算所得粒径与实验值进行对比。结果表明：NP-9／正己醇／正庚烷／硝酸锌溶液微乳液体系的水核半径在308K和318K分别为186nm和233nm,可以作为制备纳米粒子的微反应器。在有沉淀反应发生时,草酸二甲酯的水解为一级反应;草酸锌纳米粒子粒径的实验值比计算值大15～30倍,其生长的动力学过程可依照碰撞-融合-分裂机理解释。     

纳米硫酸钡制备过程中的蒸馏法破乳和微孔液的循环使用

以硫酸钠和氯化钡的W／O型微乳液反应制备纳米硫酸钡为实验体系,利用微乳液中各组分沸点的差异,提出了利用蒸馏法破坏微乳液,实现纳米颗粒与微乳液体系的分离以及微乳液循环利用的新工艺。研究了破乳时蒸馏温度、循环使用时体系中的盐浓度、含水量等因素对纳米颗粒品质的影响,比较了蒸馏法破乳和加高浓度盐、升高温度等方法破乳对纳米颗粒回收率的影响。实验结果表明,蒸馏温度升高不会导致纳米颗粒的团聚,随着循环次数的增加,粒径从第一次制备的14nm增加到第五次制备的25nm,但单分散性和分布仍然良好;体系中水含量过大,制备出的纳米颗粒粒径不均一;此外蒸馏法破乳回收纳米颗粒的收率可以达到82％,高于加盐破乳和升温破乳的回收率。