碳纤维化学镀银工艺

采用以氨水和乙二胺为复合配位剂，葡萄糖和酒石酸钾钠为复合还原剂的镀液对碳纤维表面化学镀银。研究了镀液中AgNO₃、葡萄糖和KOH的质量浓度对碳纤维化学镀银后增重率的影响。采用扫描电镜(SEM)、能谱仪(EDS)和X射线衍射仪(XRD)分析了碳纤维在不同工序后的表面形貌和元素组成。结果表明，当AgNO₃质量浓度为14 g/L、葡萄糖质量浓度为8 g/L、KOH质量浓度为7 g/L时，碳纤维的增重率最高，达125.4%，镀层均匀、连续地覆盖于碳纤维表面，厚度约为0.305μm。     

多巴胺改性粉煤灰化学镀银工艺

先用多巴胺预处理粉煤灰(FA)在其表面获得聚多巴胺(PDA)膜，再化学镀Ag，获得具有核-壳结构的Ag包覆粉煤灰复合材料。研究了多巴胺改性和镀液中AgNO₃质量浓度对粉煤灰化学镀Ag的影响。结果表明基体表面的PDA膜具有还原性，能够将银离子还原为银单质，但银纳米粒子易团聚；较佳的AgNO₃质量浓度为10 g/L。在较佳工艺下，粉煤灰表面化学镀得到的Ag层均匀、致密，无杂质。     

HPLC法和改进型AgNO3滴定法测定肉毒毒素冻干制剂中氯化钠的方法学比较

目的：依据《中华人民共和国药典》中“通则3107氯化钠测定法”(AgNO₃滴定法),对自建高效液相色谱法(HPLC)和改进型AgNO₃滴定法在肉毒毒素制剂中氯化钠含量检测的准确性进行比较,为肉毒毒素制剂质量控制中氯化钠含量测定提供方法学依据。方法：采用AgNO₃滴定法、HPLC法和改进型AgNO₃滴定法分别对肉毒毒素制剂中氯化钠进行测定,运用SPSS 25.0软件对标准曲线进行线性回归分析,对三组方法精密度进行单因素方差分析,分别对HPLC法和改进型AgNO₃滴定法重复性测定值与标准方法测定值进行单组设计t检验。结果：HPLC法和改进型AgNO₃滴定法线性决定系数(R²)分别为0.999 9和0.999 3;AgNO₃滴定法、HPLC法和改进型AgNO₃滴定法回收率分别为95.05%～98.66%、91.74%～97.35%和93.56%～97.12%,精密度相对标准偏差分别为1.73%、0...     

均苯三甲酸银[{Ag(H2btc)}{Ag2(Hbtc)}]n配位聚合物的光催化性能和抗菌性能研究

采用1,3,5-苯三甲酸(H₃btc)与硝酸银(AgNO₃)在MeOH/H₂O混合溶液中通过自组装反应构建出[{Ag(H₂btc)}{Ag₂(Hbtc)}]n配合物。利用扫描电镜(SEM)、X-射线粉末衍射仪(XRD)、傅里叶变换红外光谱(FT-IR)对材料的形貌和组成进行表征。以亚甲基蓝(MB)和罗丹明B(RhB)为脱色降解模型,测定样品可见光下的光催化降解性能。通过抑菌环、生长曲线和最小抑菌浓度(MIC)检测其抗菌性能。结果表明所得的化合物材料纯度较高,具有良好的可见光下光催化性能和抗菌性能。     

医用钴铬合金化学镀银工艺及其抗菌性能

钴铬合金具有良好的力学性能和生物相容性，被广泛用作医用金属植入物，但钴铬合金的抗菌性能较差，容易引发细菌感染。为此，在钴铬合金表面化学镀银以提高其抗菌性能。研究了AgNO₃质量浓度、温度和pH对化学镀银层厚度的影响。结果表明，随AgNO₃质量浓度、温度或pH增大，Ag镀层厚度先增大后减小。较佳的配方和工艺条件为：AgNO₃ 5 g/L,NaOH 2.5 g/L,NH₃·H₂O 20 mL/L，葡萄糖0.45 g/L，酒石酸钾钠1.25 g/L，硫脲2 mg/L,pH 12.6，温度25℃，时间2 h。在该条件下制备的Ag镀层厚度为6μm，均匀、致密，无杂质，结合力达到12 N，具有良好的抗菌性能。     

基于pH测量的CO2吸收到钠基溶液动态实验及模型

采用基于pH测量的CO₂吸收速率研究方法。将pH与溶液中的成分相关联,采用分段拟合获得CO₂吸收速率,获得溶液成分对吸收速率的影响规律。对于低浓度的NaOH来说,吸收速率一直保持不变直到CO₂物理吸收到NaHCO₃溶液中。对于高浓度的NaOH,NaOH完全转化成Na₂CO₃时,吸收速率降低。但在两个吸收阶段中,吸收速率不变,CO₂物理吸收到NaHCO₃中时,吸收速率随CO₂饱和度的增加而降低。对CO₂吸收到NaOH中,CO₂和钠离子浓度都促进吸收,钠离子浓度影响更大;对于CO₂吸收到Na₂CO₃中,当Na₂CO₃浓度大于0.05mol/L,吸收速率不随浓度增加;对于CO₂吸收到NaHCO₃中,低浓度的钠可以促进CO₂吸收,而高浓度的钠抑制CO₂吸收,这主要由于析盐的作用。为避免CO₂大量吸收,优先选择0.5mol/L以上浓度的NaHCO₃。     

膜蒸馏-结晶耦合从高浓度KCl-MgCl2-H2O溶液中回收KCl

用直接接触膜蒸馏处理高浓度的KCl和MgCl₂溶液,考察了盐水浓度(1.0～4.0 mol·L^-1)、循环流速(0.1～0.5 m·s^-1)对膜蒸馏性能的影响;结果表明:随着盐水浓度的升高,膜通量下降,这是由于盐溶液的蒸汽压(即溶液中水的活度)下降的缘故;当浓度超过3.0 mol·L^-1时,MgCl₂溶液的膜通量出现负值,这主要归结为MgCl₂溶液低的水的活度和高黏度的协同影响;提高循环流速,膜通量增大,尤其对高黏度的盐水(即MgCl₂溶液),增大流速对减少温度和浓度极化的影响更加有效。利用膜蒸馏-结晶耦合技术和间歇式操作,从高浓度KCl-MgCl₂-H₂O溶液中回收纯水和KCl结晶产品,考察了不同冷却方式对溶液过饱和度、KCl晶体形貌、粒度和粒度分布的影响。结果表明,自然冷却有利于形成形貌规整、粒度分布相对集中的结晶产品;在KCl降温过程中,自然冷却过程中的最大过冷度比快速降温过程小,从而有效地控制晶核形成的数量和晶体的生长速率。     

液相还原法制备微米级银粉及其性能研究

为解决导电银浆用银粉烧结温度高和电阻率大的问题，以硝酸银(AgNO₃)为原料，硫酸亚铁(FeSO₄·7H₂O)为还原剂，柠檬酸(C₆H₈O₇·H₂O)为添加剂制备银粉。采用正交实验探究不同工艺参数对银粉尺寸和形貌的影响。通过X射线衍射仪(XRD)、扫描电子显微镜(SEM)、四探针测试仪等对制备产物的晶体结构、形貌、烧结温度、电阻率等进行了表征。结果表明：改变柠檬酸的浓度可以调整银粉的尺寸大小和形貌，无柠檬酸条件下可以得到尺寸大小约为3μm的球形银粉，且在最佳烧结温度550℃下电阻率为2.39×10^-7Ω·m；浓度为0.015 mol·L^-1条件下可以得到尺寸大小约为3.5μm的片状银粉，且在最佳烧结温度150℃下电阻率为4.77×10^-6Ω·m；浓度为0.060 mol·L^-1条件下可以得到尺寸大小约为0.5μm的球形银粉，且在最佳烧结温度250℃...     

模板浸渍法制备ZrO2纤维研究

将15 cm×15 cm×1 cm的粘胶纤维模板放入浓度为1、2及3 mol·L^-1的ZrOCl₂溶液，分别在20、40、60℃下浸渍20 h,经过洗涤、离心、干燥得到ZrO₂纤维前驱体，再对前驱体进行600、800、1 000、1 200℃保温2 h热处理制得ZrO₂纤维。研究浸渍温度、浸渍液浓度、热处理温度对ZrO₂纤维形貌和相组成的影响。结果表明，随着浸渍温度由20℃提高到60℃,浸渍液浓度由1 mol·L^-1提高到3 mol·L^-1,纤维横截面微观形貌由扁平状向圆柱状变化，同时纤维的平均直径逐渐增大，说明提高浸渍温度和浸渍液浓度有利于粘胶纤维模板对Zr⁴⁺的吸附。ZrO₂纤维经过热处理后，主要是以单斜相ZrO₂存在。随着热处理温度的增加，ZrO₂纤维晶粒变大，结晶程度增加，同时纤维表面经历由光滑到小晶粒出现再到裂纹出现的转变。     

AgNO3/NaY吸附纯化HFE-347的研究

通过等体积浸渍法成功制备了AgNO₃/NaY吸附剂,并对其进行XRD、N₂吸-脱附和ICP-AES等表征。将制备的AgNO₃/NaY应用于1,1,2,2-四氟乙基-2,2,2-三氟乙基醚(HFE-347)中的杂质1,1,1-三氟乙基-1,1,2-三氟乙烯基醚的吸附脱除研究。结果表明,4%-AgNO₃/NaY可将HFE-347中1,1,1-三氟乙基-1,1,2-三氟乙烯基醚的浓度由920 mg/kg降至82 mg/kg,去杂率高达91%,为HFE-347在高端领域的应用提供了技术支撑。     

Growth of silver nanowires on carbon fiber to produce hybrid/waterborne polyurethane composites with improved electrical properties

One dimensional silver nanowires (AgNWs) were grown on carbon fiber (CF) by a facile polyol method. Fourier transform infrared spectrometer (FTIR), laser Raman spectrometer (Raman), field‐emission scanning electron microscopy (FESEM), X ray diffraction instrument (XRD), energy dispersive spectrometer (EDS), and X‐ray photoelectron spectrometer (XPS) were carried out to reveal the structure, morphology, and formation mechanism of the CF‐AgNWs. It was found that AgNO₃ concentration of 1.5 mM, reaction temperature of 160°C, and reaction time of 120 min were appropriate conditions for growth of AgNWs on CF. Moreover, a mechanism was suggested that the cysteamine on CF acted as nucleation centers for growth of silver nanoparticles and then small sized silver nanoparticles reduced from silver nitrate were grown on CF via the silver bonding to sulfur. Through an Ostwald ripening process, small sized silver nanoparticles were grown into larger particles. With the assistance of polyvinylpyrolidone (PVP), these larger particles were directed to grow in a definite direction to form nanowires. It was found that the resistance of CF‐AgNWs was decreased to 19.5 Ω, compared with that of CF (102.6 Ω) with the same quality. Thus, the CF‐AgNWs was added into waterborne polyurethane (WPU) to improve the electrical and dielectric properties of WPU. Results showed the WPU/CF‐AgNWs composite presented a lower percolation threshold than WPU/CF composite. When the content was 2.5 wt %, the volume resistivity of the WPU/CF‐AgNWs (1.90 × 10⁴ Ω cm^?1) was lower by approximately three orders of magnitude than that of WPU/CF (4.19 × 10⁷ Ω cm^?1). When the content was 2.5 wt %, the dielectric constant and dielectric loss of the WPU/CF‐AgNWs were improved to 15.24 and 0.21, which were 34.5 and 40.8% higher than that of WPU/CF. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43056.     

Electroless silver deposition on Si(100) substrate based on the seed layer of silver itself

A new method for silver electroless deposition on Si(100) wafer, based on the silver itself as the seed layer, was developed. The seed layer was first deposited onto the etched wafer surface in an acidic solution of 0.005 mol l⁻¹ AgNO₃+0.06 mol l⁻¹ HF. Then the silver thin film was electrolessly deposited upon the seed layer in the electroless bath of AgNO₃+NH₃+acetic acid+NH₂NH₂ (pH 10.2). The NH₂NH₂ was taken as the reducing agent. The morphology of the seed layer and the silver film were characterized by atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and energy-dispersive X-ray analysis (EDX). The experimental results indicated that the seed layer showed excellent catalytic function for silver electroless deposition.     

Influence of tartaric acid on the electrodeposition of silver from aqueous AgNO3 solutions

Silver electrodeposition from aqueous AgNO₃ solutions never gives compact, smooth plates unless an organic additive such as tartaric acid (H₂A) is used as growth inhibitor. However, depending on the bulk pH, H₂A may exist either as a neutral molecule of H₂A or as dissociated entities such as HA⁻ or A²⁻. We have shown previously that the relevant parameter governing growth inhibition was the activity, α_HA-, of tartaric monoanions when silver was plated from a solution of constant AgNO₃ concentration. The aim of the present work is to show what happens when this concentration is no longer constant. In these conditions, the relevant parameter governing growth inhibition is proved here to be the bulk concentration of a neutral complex Ag(HA) formed in the solution between Ag⁺ and tartaric monoanions HA⁻. On this concentration depend most of the structural features of Ag deposits, e.g. their grain size, superficial roughness and even the amount of incorporated organic material.     

Facile growth of novel morphology correlated Ag/Co-doped ZnO nanowire/flake-like composites for superior photoelectrochemical water splitting activity

In this paper, novel morphology correlation between silver nanowires (AgNWs) and cobalt (Co)-doped ZnO (Co-ZnO) flake-like thin films (nanowire/flake-like) has been proposed for enhanced photoelectrochemical (PEC) water splitting activity. Here in, high-quality AgNWs/Co-ZnO heterostructures enabled superior visible light water splitting activity compared to the pure ZnO and AgNWs/ZnO. To address the strategic effect of AgNWs coupling and transition metal (Co-2?at%) doping into the ZnO host lattice, we have carried out the X-ray diffraction, field emission scanning microscopy, X-ray photoelectron spectroscopy, UV–Vis transmittance, water contact angle and PEC analyses. In this way, PEC water splitting activity was mainly examined by linear sweep voltammetry (I-V), amperometric I-t and photoconversion efficiency (η) studies. The experimental results provide clear evidence of morphology correlation between AgNWs and Co-ZnO flake-like structures for strong visible light absorption. Specifically, AgNWs/Co-ZnO composites exhibited significant enhancement in the photocurrent density (7.0?×?10^?4 A/cm²) than AgNWs/ZnO (3.2?×?10^?4 A/cm²) and pure ZnO (1.5?×?10^?6 A/cm²). As a result, detailed AgNWs/Co-ZnO geometry has great potential for photoconversion efficiency (0.73%). In a word, the merits of controllable AgNWs/Co-ZnO heterostructure are proposed to improve the visible light harvesting and charge carrier generation for energy conversion devices.     

Fabrication of porous silicon nanowires by MACE method in HF/H2O2/AgNO3 system at room temperature

In this paper, the moderately and lightly doped porous silicon nanowires (PSiNWs) were fabricated by the ‘one-pot procedure’ metal-assisted chemical etching (MACE) method in the HF/H₂O₂/AgNO₃ system at room temperature. The effects of H₂O₂ concentration on the nanostructure of silicon nanowires (SiNWs) were investigated. The experimental results indicate that porous structure can be introduced by the addition of H₂O₂ and the pore structure could be controlled by adjusting the concentration of H₂O₂. The H₂O₂ species replaces Ag⁺ as the oxidant and the Ag nanoparticles work as catalyst during the etching. And the concentration of H₂O₂ influences the nucleation and motility of Ag particles, which leads to formation of different porous structure within the nanowires. A mechanism based on the lateral etching which is catalyzed by Ag particles under the motivation by H₂O₂ reduction is proposed to explain the PSiNWs formation.     

Preparation and Characterization of Gelatin Nanofibers Containing Silver Nanoparticles

Ag nanoparticles (NPs) were synthesized in formic acid aqueous solutions through chemical reduction. Formic acid was used for a reducing agent of Ag precursor and solvent of gelatin. Silver acetate, silver tetrafluoroborate, silver nitrate, and silver phosphate were used as Ag precursors. Ag⁺ ions were reduced into Ag NPs by formic acid. The formation of Ag NPs was characterized by a UV-Vis spectrophotometer. Ag NPs were quickly generated within a few minutes in silver nitrate (AgNO₃)/formic acid solution. As the water content of formic acid aqueous solution increased, more Ag NPs were generated, at a higher rate and with greater size. When gelatin was added to the AgNO₃/formic acid solution, the Ag NPs were stabilized, resulting in smaller particles. Moreover, gelatin limits further aggregation of Ag NPs, which were effectively dispersed in solution. The amount of Ag NPs formed increased with increasing concentration of AgNO₃ and aging time. Gelatin nanofibers containing Ag NPs were fabricated by electrospinning. The average diameters of gelatin nanofibers were 166.52 ± 32.72 nm, but these decreased with the addition of AgNO₃. The average diameters of the Ag NPs in gelatin nanofibers ranged between 13 and 25 nm, which was confirmed by transmission electron microscopy (TEM).     

Silver Electrodeposition from AgNO3 Solutions Containing Organic Additives: Electrodeposition from Binary Water–Methanol Solvent Systems in the Presence of Tartaric Acid

The electrodeposition of silver at 25 °C from AgNO₃/tartaric acid solutions in binary water–methanol solvent systems was investigated. This study shows that it is possible to obtain compact and coherent silver deposits from AgNO₃ solutions only in the presence of tartaric acid (H₂A). The relevant chemical entity controlling growth inhibition is a neutral associate Ag(HA) formed in the solution between Ag⁺ and tartaric monoanions HA^–. Most of the structural features of Ag deposits such as grain size, surface roughness and degree of the preferred orientation 1 1 0, depend on the concentration of this associate. These properties of the deposits can easily be controlled by:(a) modifying the concentration of AgNO₃ or H₂A, (b) adjusting the pH of the bulk solution by addition of HNO₃ and (c) modifying the composition of the mixed solvent system.     

The dependence of morphology of solid polymer electrolyte membranes on transient salt type: effect of cation type

The structures of poly(N‐vinyl pyrrolidone) (PVP) and poly(ether sulfone) composite membranes were investigated with transient salt addition. The effects of type and concentration of AgNO₃ and Cu(NO₃)₂ on membrane morphology were evaluated through attenuated total reflection Fourier transform infrared (ATR‐FTIR) spectroscopy, differential scanning calorimetry (DSC) and atomic force microscopy. Complex formation between carbonyl groups (on PVP chains) and Cu²⁺ or Ag⁺ decreases the strength of the carbonyl bond as evidenced through ATR‐FTIR spectroscopy. The results indicate that the copper salts create more powerful interactions than the silver salts in the polymer matrix. DSC experiments reveal that the glass transition temperature of polymeric films containing silver or copper cations is lower than that of the PVP reference film. Comparison of the thermograms of PVP + AgNO₃ and PVP + Cu(NO₃)₂ shows that copper ions disrupt the polymer crystallinity more than silver ions. Therefore, DSC observations confirm the ATR‐FTIR results in the case of the strength of the complexes formed. A morphological analysis of membrane surfaces reveals the existence of electrostatic interactions in the polymeric membrane structure. This is a result of the addition of salt to the casting solution, wrinkling the polymer chains including the surface layer, and accordingly the surface of the facilitated transport membranes is rougher than the initial PVP membrane. Copyright © 2010 Society of Chemical Industry     

In vitro efficacy and toxicology evaluation of silver nanoparticle‐loaded gelatin hydrogel pads as antibacterial wound dressings

The silver nanoparticle (nAg)‐loaded gelatin hydrogel pads were prepared from 10 wt % gelatin aqueous solution containing silver nitrate (AgNO₃) at 0.75, 1.0, 1.5, 2.0, or 2.5 wt % by solvent‐casting technique. These AgNO₃‐containing gelatin solutions, that had been aged for 15, 12, 8, 8, and 8 h, respectively, showed noticeable amounts of the as‐formed nAgs, the size of which increased with an increase in the AgNO₃ concentration (i.e., from 7.7 to 10.8 nm, on average). The hydrogels were crosslinked with a glutaraldehyde aqueous solution (50 wt %, at 1 μL mL^?1). At 24 h of submersion in phosphate buffer saline (PBS) or simulated body fluid buffer (SBF) solution, about 40.5–56.4% or 44.4–79.6% of the as‐loaded amounts of silver was released. Based on the colony count method, these nAg‐loaded hydrogels were effective against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, with at least about 99.7% of bacterial growth inhibition. Unless they had been treated with a sodium metabisulfite aqueous solution, these hydrogels were proven, based on the indirect cytotoxicity evaluation, to be toxic to human's normal skin fibroblasts. Lastly, only the hydrogels that contained AgNO₃ at 0.75 and 1.0 wt % were not detrimental to the skin cells that had been cultured directly on them. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Calculation of chloride concentration at color change boundary of AgNO3 colorimetric measurement

AgNO₃ colorimetric measurement of chloride in cement-based materials can be implemented owing to chemical reactions between Ag⁺ and Cl⁻ or OH⁻ ions, which result in the precipitation of AgCl and Ag₂O. When the mass ratio of AgCl to precipitated AgCl + Ag₂O reaches a critical value (P_crit-AgCl), a color change boundary appears. In this paper, chloride concentrations required for the formation of the critical mass ratio of AgCl to precipitated AgCl + Ag₂O derived from the AgNO₃–NaCl–NaOH system were calculated based on the solubility products of silver hydroxide and silver chloride, and mass conservation of the chemical reactions. P_crit-AgCl was determined as 0.65 through a series of AgNO₃ colorimetric measurements on cement-based materials. Calculated results indicated that if Ag⁺ could react with all OH⁻ and Cl⁻, there existed a linear relationship between the critical chloride concentration for color change (C_crit-Cl^–) and OH⁻ concentration (C_OH^–), namely C_crit-Cl^– = 1.6C_OH^–. If Ag⁺ could react with only partial OH⁻ and Cl⁻, there existed an exponential relationship among C_crit-Cl^– and C_OH^–, Ag⁺ concentration (C_Ag⁺), volume of AgNO₃ solution (V_Ag⁺) as well as the volume of NaCl + NaOH solution (V_{OH^–+ Cl^–}), namely C_crit-Cl^– = 0.00695C_OH^– + 0.608C_Ag⁺V_Ag⁺/V_{OH^–+ Cl^–}. It can be concluded that the alkalinity of cement-based materials, concentration and volume of sprayed AgNO₃ solution and volume of pore solution have effects on chloride concentration at the color change boundary (C_d). Calculated C_d values ranged between 0.03 and 0.96 mol/L (in pore solution) or 0.011% to 2.27% (by the mass of binder), respectively. This explains why reported range of chloride concentration at the color change boundary in publications varied in a broad range.