巯基乙酸修饰ZnS纳米颗粒的水相合成及表征

以巯基乙酸(HSCH2COOH, RSH)为表面修饰剂,采用水相合成法制备了表面修饰巯基乙酸的ZnS纳米颗粒. 采用透射电子显微镜、粒度分布、X射线衍射和红外光谱等对ZnS纳米颗粒进行了表征,并对ZnS纳米粒子的制备条件进行了详细的考察. 结果表明,水相合成法的最佳制备条件为：反应pH值8.0, Zn2+:S2-:RSH(摩尔浓度比)为1:1.34:2. 在最佳条件下可制备粒径小(11 nm)且粒度分布窄、分散性好的ZnS纳米粒子,其晶体属面心立方b-闪锌矿结构.     

Effect of Cationic Surfactant Head Groups on Synthesis, Growth and Agglomeration Behavior of ZnS Nanoparticles

Colloidal nanodispersions of ZnS have been prepared using aqueous micellar solution of two cationic surfactants of trimethylammonium/pyridinium series with different head groups i.e., cetyltrimethylammonium chloride (CTAC) and cetyltrimethylpyridinium chloride (CPyC). The role of these surfactants in controlling size, agglomeration behavior and photophysical properties of ZnS nanoparticles has been discussed. UV–visible spectroscopy has been carried out for determination of optical band gap and size of ZnS nanoparticles. Transmission electron microscopy and dynamic light scattering were used to measure sizes and size distribution of ZnS nanoparticles. Powder X-ray analysis (Powder XRD) reveals the cubic structure of nanocrystallite in powdered sample. The photoluminescence emission band exhibits red shift for ZnS nanoparticles in CTAC compared to those in CPyC. The aggregation behavior in two surfactants has been compared using turbidity measurements after redispersing the nanoparticles in water. In situ evolution and growth of ZnS nanoparticles in two different surfactants have been compared through time-dependent absorption behavior and UV irradiation studies. Electrical conductivity measurements reveal that CPyC micelles better stabilize the nanoparticles than that of CTAC.     

Effects of the Template Composition and Coating on the Photoluminescence Properties of ZnS:Mn Nanoparticles

Mn-doped ZnS nanocrystals based on low dopant concentrations (0–2%) and coated with a shell of Zn(OH)₂ have been prepared via soft template and precipitation reaction. The results indicate that the ZnS:Mn nanocrystal is cubic zinc blende structure and its diameter is 3.02 nm as demonstrated by XRD. Measured by TEM, the morphology of nanocrystals is a spherical shape, and their particle size (3–5 nm) is similar to that of XRD results. Photoluminescence spectra under ultraviolet region shows that the volume ratio of alcohol to water in the template has a great effect on the luminescence properties of ZnS:Mn particles. Compared with unpassivated ZnS:Mn nanocrystals, ZnS:Mn/Zn(OH)₂ core/shell nanocrystal exhibits much improved luminescence and higher absolute quantum efficiency. Meanwhile, we simply explore the formation mechanism of ZnS:Mn nanocrystals in alcohol and water system and analyze the reason why alcohol and water cluster structures can affect the luminescent properties of nanoparticle.     

Facile Deposition of Silver Nanoparticles on Photonic Cellulose Nanocrystals Films: A Study on Solvent Stability and Post Antibacterial Activity

Cellulose nanocrystals (CNCs) incorporated with silver nanoparticles (AgNPs) photonic films have drawn considerable attention due to their plasmonic chiroptical activity. However, the exploitation of some fundamental properties for practical use such as the affinity analysis of metal nanoparticles attached to the surface of photonic films according to the solvent compatibility and antibacterial activity under physical conditions has yet not been studied. Hence, a facile process of in situ deposition of AgNPs into the chiral structure of CNC films is proposed. CNC photonic films, cross-linked by glutaraldehyde are prepared. This interaction generated the solvents-stable photonic film with a considerable amount of unreacted aldehyde functional groups that facilitates the reduction of Ag salt to AgNPs. The formed AgNPs in the photonic films show excellent stability over immersion in various polar and non-polar solvents. The post-solvent treated photonic films display excellent contact-based antibacterial behavior against gram-negative Escherichia coli.     

两亲性海藻酸衍生物对纳米TiO2颗粒在水溶液中聚集行为的影响

利用十二烷基改性海藻酸钠(Na Alg-Dode)在Ti O2纳米颗粒表面上的吸附,得到了稳定的纳米Ti O2颗粒悬浮液。采用傅里叶变换红外光谱仪(FTIR)、动态光散射仪(DLS)及流变仪对颗粒粒径、表面电位及其悬浮体系的流变性进行了测定,研究了不同p H下Na Alg-Dode对纳米Ti O2颗粒在水溶液中聚集行为和流变性的影响。结果表明,加入Na Alg-Dode后,在p H=4~8内均有利于悬浮体系稳定,p H=6.3(等电点)处Ti O2颗粒的平均粒径由2.5μm降低至500 nm左右,颗粒表面Zeta电位由0降低至-40 m V左右。同时随着Na Alg-Dode的加入,Ti O2悬浮体系的剪切应力逐渐增大,表明颗粒间的相互作用增强。由此推知,Na Alg-Dode提高纳米Ti O2颗粒悬浮体系的稳定机制:Na Alg-Dode分子在不同p H下能够通过静电作用、氢键作用及疏水作用等吸附在Ti O2颗粒上,改变颗粒表面电性及空间位阻,从而降低颗粒的团聚。     

Polymerization of Aniline by Cupric Sulfate: A Facile Synthetic Route for Producing Polyaniline

Polyaniline is an interesting and intensively investigated polymer due to its potential application for alternative energy sources. This report provides a simple method for the preparation of polyaniline nanofoil by using cupric sulfate as an oxidizing agent and, due to the counter reduction reaction, cupric sulfate was reduced resulting in the formation of copper nanoparticles within the size range 2–5 nm as evidenced by TEM images. SEM images demonstrate the morphology of the polymer whereas, UV-vis, Raman and IR spectra provide the structural information of the polymer.     

MDEA-TBEE复合溶剂吸收酸性气体性能的研究

合成了一种空间位阻胺TBEE(叔丁氨基乙氧基乙醇),并添加在MDEA溶剂中组成MDEA-TBEE复合溶剂。设计了,一套新颖的气体吸收装置-恒温填料反应器,测定了该复合溶剂吸收酸性气体(H2S,CO2)的性能。通过大量的实验数据,分析了影响吸收性能的各种因素(如吸收剂浓度、MDEA／TBEE摩尔比、反应温度及溶液负载),并将复合溶剂的吸收性能同MDEA及其它有机胺(MEA、DEA、DIPA)作了比较。实验表明,与MDEA或其它有机胺比较,MDEA-TBEE复合溶剂具有更高的吸收负荷和对H2S具有高选择性。实验同时证明了空间位阻胺是一种优良的酸性气体吸收剂。     

高比表面积活性炭(HSAAC)对水中Ni2+吸附性能的研究

以石油焦基为原料,采用KOH活化法制取高比表面积活性炭。考察了高比表面积活性炭吸附水中Ni(Ⅱ)时,PH值、Ni(Ⅱ)浓度、吸附时间和活性炭用量等因素对Ni(Ⅱ)吸附量和水中Ni(Ⅱ)残余浓度的影响。实验结果表明高比表面积活性炭在适宜条件下对Ni(Ⅱ)具有较大的吸附量和良好的再生效果。为HSAAC在废水中的实际应用提供了理论依据。     

2-甲基-1,3-丙二醇水溶液的表面性质研究

采用最大泡压法测定了常压下纯液体2-甲基-1,3-丙二醇(MPO)及不同浓度MPO水溶液在298.15~367.7 K范围的界面张力。实验结果表明,纯MPO及其水溶液的界面张力σ随温度升高而呈线性减小;恒温下σ随浓度的增加呈幂函数递减。MPO水溶液的表面层发生正吸附,与理论上低脂肪醇类表面张力的性质符合。而且低浓度下MPO水溶液的吸附等温线呈直线,与G ibbs吸附等温式描述的规律相吻合。     

Valine-Coated Magnetic Nanoparticles: Synthesis,Characterization, and Application in Removal of Cd(II) Ions from Aqueous Solution

A novel Valine coated magnetic nano-particles (MNPs-Val) has been synthesized for the removal of Cd(II) ions from aqueous solution. The MNPs-Val were developed by electrostatic attraction of valine (C₅H₁₁NO₂) on the bare surface of Fe₃O₄ nanoparticles and characterized by using FT-IR, XRD, SEM, and TEM analysis. The morphology and average particles size 15-27 nm of MNPs-Val were analyzed by SEM and TEM. The coated MNPs were applied for adsorptive removal of Cd(II) ions from aqueous solutions. Factors affecting the adsorption of Cd(II) ions on the MNPs-Val surface such as the pH, temperature, adsorbent dosage, and contact time were investigated which have significant effect on the metal ion removal. The Cd(II) ions adsorption equilibrium on the MNPs-Val could be achieved in 35 min at the optimized pH 5 and follow the pseudo-second order kinetics model. The experimental data for the adsorption of Cd(II) was followed by the Langmuir isotherm and the maximum adsorption capacity was obtained at 0.2 g L^?1 adsorbent dose at 308 K.     

Antifungal Effect of Nanoparticles against COVID-19 Linked Black Fungus: A Perspective on Biomedical Applications

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly transmissible and pathogenic coronavirus that has caused a ‘coronavirus disease 2019’ (COVID-19) pandemic in multiple waves, which threatens human health and public safety. During this pandemic, some patients with COVID-19 acquired secondary infections, such as mucormycosis, also known as black fungus disease. Mucormycosis is a serious, acute, and deadly fungal infection caused by Mucorales-related fungal species, and it spreads rapidly. Hence, prompt diagnosis and treatment are necessary to avoid high mortality and morbidity rates. Major risk factors for this disease include uncontrolled diabetes mellitus and immunosuppression that can also facilitate increases in mucormycosis infections. The extensive use of steroids to prevent the worsening of COVID-19 can lead to black fungus infection. Generally, antifungal agents dedicated to medical applications must be biocompatible, non-toxic, easily soluble, efficient, and hypoallergenic. They should also provide long-term protection against fungal growth. COVID-19-related black fungus infection causes a severe increase in fatalities. Therefore, there is a strong need for the development of novel and efficient antimicrobial agents. Recently, nanoparticle-containing products available in the market have been used as antimicrobial agents to prevent bacterial growth, but little is known about their efficacy with respect to preventing fungal growth, especially black fungus. The present review focuses on the effect of various types of metal nanoparticles, specifically those containing silver, zinc oxide, gold, copper, titanium, magnetic, iron, and carbon, on the growth of various types of fungi. We particularly focused on how these nanoparticles can impact the growth of black fungus. We also discussed black fungus co-infection in the context of the global COVID-19 outbreak, and management and guidelines to help control COVID-19-associated black fungus infection. Finally, this review aimed to elucidate the relationship between COVID-19 and mucormycosis.     

Removal of Cesium Ions from Aqueous Solution by Polyaniline: A Radiotracer Study

The present work deals with the study of uptake behavior of cesium ions by polyaniline applying a radiotracer technique. The parametric study reveals that the increase of adsorbate concentration (10⁻⁸ to 10⁻³ mol dm⁻³) and temperature (303 to 333 K) enhances the removal of the ions and from thermal and kinetic data it is inferred that the adsorption of cesium ions follows first order rate law, obeys Freundlich isotherm and is endothermic in nature. The radiation stability of polyaniline was also investigated by exposing it to a 11.1 GBq (Ra-Be) source associated with gamma dose of 1.72 Gyh⁻¹.     

The Effect of the Structure of Clay and Clay Modifier on Polystyrene-Clay Nanocomposite Morphology: A Review

Nanocomposites formation brings about an enhancement of many properties for polymers. They have attracted interests since they attain significant properties with far less clay content. It is generally assumed that exfoliation nanocomposites are preferred for the greatest increases in properties, but that is not correct in flame retardency properties. In this paper the effects of different types of clays and clay modifiers on final morphology of PS/clay nanocomposites were reviewed. Clay charge density and length, bulk, polarity, functional groups and polymerizability of the clay modifier are very significant in their efficiency and final morphology of PS/Clay nanocomposite.     

喷墨印花用液态活性染料稳定性研究

通过对液态染料溶解性、稳定性、耐水解程度等的测试,综合考察了添加剂的种类及用量对高浓度液态活性艳蓝P-3R性能的影响,结果表明:在所考察的四种有机共溶剂中,N-甲基吡咯烷酮(NMP)的效果最好,且其最佳用量为10%;缓冲溶液中Na2HPO4/NaH2PO4的效果较好,最佳用量为3%.     

碳纳米管吸附染料茜素红的性能研究

研究了碳纳米管对水中茜素红的吸附去除性能,结果表明:纯化的碳纳米管对水中茜素红的去除效果明显高于未纯化的碳纳米管,当其用量为0.1g时,纯化的碳纳米管对水中茜素红的吸附去除率达到87.3%;纯化的碳纳米管对水中茜素红的吸附在60分钟达到平衡;溶液pH值对水中茜素红的去除有一定的影响,在酸性和中性条件下的去除率大于碱性;温度升高,水中茜素红的去除率略有升高。平衡吸附量qe与平衡质量浓度pe之间的关系符合Freundlich和Langmuir等温吸附方程所描述的规律。     

活性炭纤维对水溶液中醋酸丁酯的吸附性能研究

研究了以活性炭纤维为吸附剂从水溶液中吸附醋酸丁酯的吸附静力学、动力学规律及动态吸附特性。实验表明，活性炭纤维对醋酸丁酯的吸附量较大，吸附速度快，动态吸附、脱附性能好。该方法可行，具有一定的实用价值。     

Synthesis of Bipyridine‐Stabilized Rhodium Nanoparticles in Non‐Aqueous Ionic Liquids: A New Efficient Approach for Arene Hydrogenation with Nanocatalysts

A new approach to stabilize metal nanoparticles with polynitrogen ligands in ionic liquids (ILs) is described. Zerovalent metal nanospecies in the size range of 2.0 nm were easily prepared in various ionic liquids by chemical reduction of a rhodium salt with an excess amount of sodium borohydride (NaBH₄) and efficiently stabilized by 2,2′‐bipyridine. The influence of the bipyridine ratio in various ILs according to the nature of the cation‐anion association was investigated. These nanocatalysts were evaluated in the hydrogenation of aromatic compounds in ILs under various catalytic conditions (P=1–40 bar, T=20–80 °C).     

Microorganism Inactivation by Ozone Dissolved in Aqueous Solution: A Kinetic Study Based on Bacterial Culture Lipid Unsaturation

Physiological solutions ozonated are widely used in the medical field (dentistry and surgery) as an effective bactericide. In this investigation, the inactivation of Escherichia coli and Pseudomonas aeruginosa by ozone dissolved in physiological solution was studied. There is a poor knowledge of the inactivation efficiency of this solution for different bacteria. The efficiency of the microorganisms’ inactivation was evaluated by the total unsaturation of lipids measured by the so-called Double Bond Index (DB-index). This is a sensitive analysis to evaluate the quantity of carbon-carbon double bonds (>C=C<) available in organic and biological samples, with high efficiency and in a short time. DB-index results were compared with the quantity of colony forming units (CFU) available in the culture. Three experimental systems were evaluated to determine the relationship between the DB-index variable and the microorganism’s inactivation: 1) using BHI agar as a culture medium to evaluate the dynamic growing curve when the ozone dissolved was dosed over the strain’s surface; 2) using a glucose solution (5%) as culture media and keeping the ozone concentration constant, which was dissolved in different physiological solutions, to observe the effects of solvent type over the bacteria growth; and, 3) using a glucose solution (5%) as culture media, and physiological solution of NaCl (0.9%) as a dissolved media for ozone at different concentrations. From the experimental data, a model of the ozone inactivation of each pathogen was built to obtain the inactivation kinetics. The model obtained showed a correlation between the CFU behavior and DB-index to each bacteria, since Pseudomona aeruginosa was more resistant to being oxidized than Escherichia coli.     

Fe-Al柱撑膨润土吸附染料酸性大红的性能

制备了Fe-Al柱撑膨润土,研究了其对染料酸性大红的吸附去除性能,结果表明:Fe-Al柱撑膨润土对染料酸性大红有很好的去除效果,当其用量为0.1g时,染料酸性大红的吸附去除率达到92.6%;Fe-Al柱撑膨润土对染料酸性大红的吸附在60分钟达到平衡;pH值对染料酸性大红的去除有一定的影响,在酸性和碱性条件下的去除率大于中性。平衡吸附量qe与平衡质量浓度pe之间的关系符合Freundlich和Langmuir等温吸附方程所描述的规律。