室温固相反应制备Keggin结构杂多酸铵盐纳米粒子

纳米材料由于其量子尺寸效应及表面效应而在磁、光、电等方面显示出许多常规粒子所不具有的特性[1] .纳米材料成功应用的实例及潜在应用前景推动了各种纳米粉末的合成及合成方法的发展 [2～ 4 ] .利用低温固相反应制备纳米粒子尚不多见 ,但已有报道 [5,6] .多金属氧酸盐因其独特的结构而具有较高的催化活性、导电性、磁性、光电致变色性以及抗病毒活性 ,因而有着广阔的应用前景 ,这些方面的研究已越来越引起人们的兴趣 [7～ 10 ] .本文采用室温固相反应首次制备了多金属氧酸盐纳米粒子 (NH4 ) 3PMo12 O4 0 · 9H2 O(1 )和 (NH4 ) 3PW12…     

Graft Copolymerization of 2-Hydroxyethyl Methacrylate onto Bovine Serum Albumin: Preparation and Characterization

ABSTRACT

Bovine Serum Albumin (BSA) was separated from the whole blood of freshly slaughtered animals. This BSA was graft copo-lymerized with poly (2-hydroxyethyl methacrylate) and characterized. The infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, and percentage of grafting of the composites were studied. The graft copolymers have better physico-chemical properties and, therefore, could be more useful in their field of application.     

Radiolytic Approach for Efficient,Selective and Catalyst-free CO2 Conversion at Room Temperature

The present study proposes a new approach for direct CO₂ conversion using primary radicals from water irradiation. In order to ensure reduction of CO₂ into CO₂^−. by all the primary radiation-induced water radicals, we use formate ions to scavenge simultaneously the parent oxidizing radicals H^. and OH^. producing the same transient CO₂^−. radicals. Conditions are optimized to obtain the highest conversion yield of CO₂. The goal is achieved under mild conditions of room temperature, neutral pH and 1 atm of CO₂ pressure. All the available radicals are exploited for selectively converting CO₂ into oxalate that is accompanied by H₂ evolution. The mechanism presented accounts for the results and also sheds light on the data in the literature. The radiolytic approach is a mild and scalable route of direct CO₂ capture at the source in industry and the products, oxalate salt and H₂, can be easily separated.     

以EDTANa2为矿化剂近中性条件下室温合成介孔二氧化硅

利用EDTANa2作为矿化剂, 在近中性条件下于室温合成了厚壁(约3 nm)蠕虫介孔分子筛. 在反应物配比为n(CTAB):n(TEOS):n(EDTANa2):n(H2O)=(0.05~0.2):(0.1~2):(0.1~0.5):(100~500)范围内都能得到介孔二氧化硅. 以XRD、N2吸附、FTIR、SEM和TEM详细考察了体系配比和温度对介孔二氧化硅结构和形貌的影响, 发现CTAB用量越大, 介孔d值相应增大. 温度对介孔二氧化硅的结构和形貌有很大的影响, 温度在2~15 ℃范围内都能生成孔径分布较规则的介孔, 介孔材料的形貌随温度的升高由空心管变成小颗粒聚集体; 合成的介孔分子筛中的模板剂可以通过乙醇萃取的方式除去. 提出了介孔的生成遵从(S+-E-)0-I0中性模板机理.     

Graphdiyne:a Highly Sensitive Material for ppb-Level NO2 Gas Sensing at Room Temperature

Detection of a trace amount of NO2 at room temperature has very important applications in air quality monitoring,protection of human health and medical diagnose.However,the existing NO2 sensors often suffer from low sensitivity when the concentration at the ppb-level.Here,we report a new kind of materials based on graphdiyne(GDY)for highly sensitive detection of ppb-level(ppb:part per billion)NO2 at room temperature.After thermal treatment of the as-prepared GDY at 600℃under argon atmosphere for 2 h(the obtained sample denoted as GDY-600),the prepared sensor with GDY-600 displays excellent sensitivity with a response value of 6.2％towards 250 ppb NO2 at room temperature,which is better than most of reported sensing materials.In addition,the sensor exhibits significantly high selectivity to NO2 against typical interfering gases including CO,CO2,NH3,H2,H2S and toluene.Moreover,the sensor shows remarkable stability after repetitive measurements.The superior sensing performance of GDY-600 can be ascribed to the highly π-conjugated structure with special acetylenic bonds and abundant oxygen-containing functional groups,which are all beneficial for the gas adsorption and redox reaction on the surface.     

Cr–MCM–41 Molecular Sieves Crystallized at Room Temperature for Reaction of Ethane with CO2

室温晶化合成了掺杂不同Cr含量的Cr–MCM–41分子筛。应用XRD、FT-IR和DRS UV–Vis等技术对所制样品进行了表征。表征结果表明，用室温晶化法能合成较好结构的Cr–MCM–41分子筛，掺杂的Cr除了进入MCM–41分子筛骨架中，还弥散或高度分散在分子筛表面。在常压连续流动固定床反应器上考察了它们对乙烷和CO2氧化脱氢制乙烯反应的性能。实验结果表明，5%Cr-MCM-41在973K可使乙烷的转化率达到43.27%，乙烯的选择性达到86.70%、收率达到37.51%。Cr的掺杂量、反应温度等条件对该反应均有一定影响。Cr3+是催化活性中心。     

Synthesis of Well-Dispersed NiO Nanoparticles with a Room Temperature Ionic Liquid

NiO nanoparticles have been prepared in a room temperature ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate (bmimBF₄). The morphology and microstructures of the NiO nanoparticles were investigated by transmission electron microscopy (TEM) and x-ray diffraction (XRD). The TEM micrographs indicated that the nanoparticles are uniform hexagons and well-dispersed. From the XRD patterns, the nanoparticles could be identified as cubic phase. In the reaction, bmimBF₄ is likely to act as a stabilizer and as a template, controlling the dispersion and morphology of the product.     

纳米ZnO脱硫剂表面结构与室温脱除H2S性能的研究

采用均匀沉淀法制备纳米ZnO，经260 ℃，360 ℃，460 ℃和550 ℃焙烧制备的纳米ZnO均具有六方纤锌矿结构，平均粒径分别为14.3 nm，21.2 nm，24.1 nm和35.3 nm。通过TEM、TPR、XRD和XPS等技术对脱硫剂进行了表征。结果表明，纳米ZnO提高了对H₂S的室温去除率，室温脱除H₂S的活性时间是分析纯ZnO的近40倍；其脱硫性能随粒径增大，氧空位减少而下降，脱硫后高结合能的硫物种增多，硫取代晶格氧的趋势增大。说明粒径大小和氧空位是纳米ZnO室温脱硫的主要影响因素。纳米ZnO(14.3 nm)可直接将H₂S选择氧化为单质硫，尾气中未见SO₂产生。     

Solid‐State Synthesis of Silver Nanoparticles at Room Temperature: Poly(vinylpyrrolidone) as a Tool

Silver nanoparticles have been used for a long time and recently various methods have been additionally developed for their production. Here we report for the first time a solid‐state high‐speed vibration milling method for the synthesis of silver nanoparticles, in which poly(vinylpyrrolidone) is used for the reduction of the silver salt. The synthesis is performed at room temperature and no surfactant to direct the anisotropic growth of the nanoparticles is required. The formation of the nanoparticles was studied by UV–Visible spectroscopy, transmission electron microscopy, and powder X‐ray diffraction techniques. The nanoparticles synthesized were found to be uniform in size and shape with an average diameter of less than 5 nm. In addition, the antimicrobial activity of these silver nanoparticles was investigated against Escherichia coli and found to be positive.

     

舰艇用LZN-2型高性能阻尼材料释放物定性定量分析与评价

舰艇舱室多为密闭环境,舱室内使用的非金属材料释放物是舱室污染的主要来源,因此对所选用的非金属材料必须进行常温释放物的定性定量分析。由于舰艇的特殊性,不仅要求非金属材料在常温条件下释放物的浓度符合舰艇舱室容许浓度,还要求材料在高温条件(火灾或爆炸)下不产生高毒性的物质。本文根据有关军用标准和规程对舰船用LZN-2型高性能阻尼材料常温释放物和高温热解物进行定性、定量分析,从而对其使用的安全性进行评估。     

Orthogonal Trichromatic Upconversion with High Color Purity in Core-Shell Nanoparticles for a Full-Color Display

Materials with tunable emission colors has attracted increasing interest in both fundamental research and applications. As a key member of light-emitting materials family, lanthanide doped upconversion nanoparticles (UCNPs) have been intensively demonstrated to emit light in any color upon near-infrared excitation. However, realizing the trichromatic emission in UCNPs with a fixed composition remains a great challenge. Here, without excitation pulsed modulation and three different near-infrared pumping, we report an experimental design to fine-control emission in the full color gamut from core–shell-structured UCNPs by manipulating the energy migration through dual-channel pump scheme. We also demonstrate their potential application in full-color display. These findings may benefit the future development of convenient and versatile optical methos for multicolor tuning and open up the possibility of constructing full-color volumetric display systems with high spatiotemporal resolution.     

Direct Hydrogenation of Nitroaromatics at Room Temperature Catalyzed by Magnetically Recoverable Cu@Fe2O3 Nanoparticles

Metal embedded in metal oxide nanoparticles are active as catalyst in plethora of industrially important reactions. Herein, embedded Cu@Fe₂O₃ nanoparticles was synthesized via a one step hydrothermal strategy which selectively catalyzes the hydrogenation of diverse nitroaromatics in H₂O at room temperature. The remarkable catalytic performance is due to the successful hybridization of metallic Cu and Fe₂O₃ which in turn allows easy electroflipping between various oxidation states of Cu and Fe. Azo- and azoxy-compounds are not formed during the catalyzed process. This evidently establish that the hydrogenation of nitroaromatics proceeds via direct route with >99% selectivity to the corresponding anilines.     

Thermosensitive molecularly imprinted hydrogel cross‐linked with N‐malely chitosan for the recognition and separation of BSA

A novel temperature‐sensitive molecularly imprinted hydrogel composed of N‐isopropylacrylamide and acrylamide has been prepared by using free‐radical polymerization and was cross‐linked by modified water‐soluble N‐maley chitosan in aqueous solution. BSA (pI 4.9, MW 66.0 kDa) was used as the template protein. The produced hydrogels were characterized by environmental SEM to reveal the microcosmic morphology. A microporous structure was only found in the imprinted hydrogel, while no obvious microporous structure was found in nonimprinted hydrogels. The lower critical solution temperature of the hydrogels was 34°C, and the optimal binding conditions were tested, namely, the adsorption equilibrium time of 6 h and initial BSA concentration of 1.0 mg/mL. The adsorption capacity Q_max was determined by Langmuir isotherm plots and was 5.72 mg/g for imprinted hydrogel and 1.18 mg/g for nonimprinted hydrogels. A separation factor (β) of 4 was obtained when bovine hemoglobin (pI 6.9, MW 64.0 kDa) was selected as the particular reference protein. Molecular weights and pIs were chosen to investigate the selectivity of the hydrogels. It was shown that the shape memory and the size effect were the major factors for the recognition. This imprinted hydrogel was used to specifically adsorb the BSA from the protein mixture.     

室温下电化学活化CO2与环氧化合物反应合成环碳酸酯

室温下用铝为牺牲阳极, 以四丁基溴化铵/N,N-二甲基甲酰胺作电解质溶液, 在无隔膜电解池中电化学活化CO₂, 与环氧化合物反应, 合成了环状碳酸酯. 考察了不同电极材料、导电盐、CO₂的压力以及溶剂等因素对电合成结果的影响, 结果表明以Pt为阴极, 在0.05 mol•L^－1 Bu₄NBr/DMF电解质溶液中和4 MPa CO₂下, 环状碳酸酯产率可高达65%～98%.     

Periodic Mesoporous Organosilica Nanoparticles for CO2 Adsorption at Standard Temperature and Pressure

(1) Background: Due to human activities, greenhouse gas (GHG) concentrations in the atmosphere are constantly rising, causing the greenhouse effect. Among GHGs, carbon dioxide (CO₂) is responsible for about two-thirds of the total energy imbalance which is the origin of the increase in the Earth’s temperature. (2) Methods: In this field, we describe the development of periodic mesoporous organosilica nanoparticles (PMO NPs) used to capture and store CO₂ present in the atmosphere. Several types of PMO NP (bis(triethoxysilyl)ethane (BTEE) as matrix, co-condensed with trialkoxysilylated aminopyridine (py) and trialkoxysilylated bipyridine (Etbipy and iPrbipy)) were synthesized by means of the sol-gel procedure, then characterized with different techniques (DLS, TEM, FTIR, BET). A systematic evaluation of CO₂ adsorption was carried out at 298 K and 273 K, at low pressure. (3) Results: The best values of CO₂ adsorption were obtained with 6% bipyridine: 1.045 mmol·g⁻¹ at 298 K and 2.26 mmol·g⁻¹ at 273 K. (4) Conclusions: The synthetized BTEE/aminopyridine or bipyridine PMO NPs showed significant results and could be promising for carbon capture and storage (CCS) application.     

Safe and Selective Nitro Group Reductions Catalyzed by Sustainable and Recyclable Fe/ppm Pd Nanoparticles in Water at Room Temperature

As a result of a unique synergy between ligand‐free Fe/ppm Pd nanoparticles and PEG‐containing designer surfactants, a facile and selective reduction of nitro‐containing aromatics and heteroaromatics can be effected in water at room temperature in the presence of NaBH₄. This new nanotechnology involves low catalyst loadings, is highly chemoselective, and tolerates a wide variety of functional groups. The process, which includes recycling of the entire aqueous medium, offers a general, environmentally responsible, and notably safe approach to highly valued reductions of nitro‐containing compounds.     

Highly Sensitive and Selective Glucose Biosensing at Carbon Paste Electrodes Modified with Electrogenerated Magnetite Nanoparticles and Glucose Oxidase

This work reports the advantages of carbon paste electrodes modified with electrogenerated magnetite nanoparticles. The nanoparticles present catalytic activity towards hydrogen peroxide reduction. The incorporation of glucose oxidase (GOx) and magnetite in a carbon paste matrix have made possible the development of an efficient glucose biosensor. The effect of the amount of GOx and magnetite present in the composite on the response of the biosensor was critically evaluated. The biosensors demonstrated to be highly selective, with negligible interference of ascorbic acid and uric acid. The proposed biosensor was challenged with human blood serum demonstrating an excellent correlation with the spectrophotometric method.     

舰船用无溶剂环氧涂料常温释放物及高温热解物分析与评价

涂料作为舰船舱室及其部件的内部防护装饰材料已广泛地应用于舰船舱室,科技的发展使得涂料更新换代的步伐加快。舰船舱室经常处于全封闭状态,为减少舱室空气污染对船员的身心健康和战术技术发挥的不良影响,故对舰船舱室大气环境质量提出了更高更新的要求,因此舰船用涂料的筛选尤为重要。涂料作为常用的一种非金属材料其挥发物具有一定的毒性,尤其是对一些新的、毒性不明的涂料,必须先对其进行使用条件下的安全性评价,以便确定其可否应用于舰船舱室之中。本实验根据有关标准对舰船用低毒无溶剂环氧涂料常温释放物及高温热解物进行分析,并对其作卫生学评价,从而为舰船设计、建造部门在筛选艇用涂料方面提供可靠的科学依据。     

烷基壳聚糖纳米微球的制备及其紫杉醇负载研究

在碱性条件下通过卤代烃的N-烷基取代反应制备得到烷基壳聚糖衍生物。X射线光电子能谱计算结果表明烷基取代反应主要发生在壳聚糖的氨基上。动态光散射研究表明，该衍生物在水中可自动形成粒径在10—200nm范围的纳米微粒，负载紫杉醇后微球的粒径增大，在磷酸缓冲液（pH=7．4）中体外释放研究表明，随着烷基链长的增加，紫杉醇在磷酸缓冲液中达到平衡时的浓度降低。