A Facile Approach to the Hydrothermal Synthesis of Silica Nanoparticle/Carbon Nanostructure Luminescent Composites

Luminescent carbon nanostructures (CNSs) have been intensively researched, but there is still no consensus on a fundamental understanding of their structure and properties that limits their potential applications. In this study, we developed a facile approach to the synthesis of luminescent composite SiO₂ nanoparticles/CNSs by the targeted formation of a molecular fluorophore, as the significant luminescent component of CNSs, on the surface of a silica matrix during a one-stage hydrothermal synthesis. Silica nanoparticles were synthesized by reverse microemulsion and used as a matrix for luminescent composites. The as-prepared silica nanoparticles had a functional surface, a spherical shape, and a narrow size distribution of about 29 nm. One-stage hydrothermal treatment of citric acid and modified silica nanoparticles made it possible to directly form the luminescent composite. The optical properties of composites could be easily controlled by changing the hydrothermal reaction time and temperature. Thus, we successfully synthesized luminescent composites with an emission maximum of 450 nm, a quantum yield (QY) of 65 ± 4%, and an average size of ~26 nm. The synthesis of fluorophore doped composite, in contrast to CNSs, makes it possible to control the shape, size, and surface functionality of particles and allows for avoiding difficult and time-consuming fractionation steps.     

Vanadium (V) Adsorption from Aqueous Solutions Using Xerogel on the Basis of Silica and Iron Oxide Matrix

Vanadium is considered a strategic metal with wide applications in various industries due to its unique chemical and physical properties. On the basis of these considerations, the recovery of vanadium (V) is mandatory because of the lack of raw materials. Various methods are used to recover vanadium (V) from used aqueous solutions. This study develops a clean and effective process for the recovery of vanadium (V) by using the adsorption method. At the same time, this study synthesizes a material starting from silica matrices and iron oxides, which is used as an adsorbent material. To show the phase composition, the obtained material is characterized by X-ray diffraction showing that the material is present in the amorphous phase, with a crystal size of 20 nm. However, the morphological texture of the material is determined by the N₂ adsorption–desorption method, proving that the adsorbent material has a high surface area of 305 m²/g with a total pore volume of 1.55 cm³/g. To determine the efficiency of the SiO₂Fe_xO_y material for the recovery of vanadium through the adsorption process, the role of specific parameters, such as the L-to-V ratio, pH, contact time, temperature, and initial vanadium concentration, must be evaluated. The adsorption process mechanism was established through kinetic, thermodynamic, and equilibrium studies. In our case, the process is physical, endothermic, spontaneous, and takes place at the interface of SiO₂Fe_xO_y with V₂O₅. Following equilibrium studies, the maximum adsorption capacity of the SiO₂Fe_xO_y material was 58.8 mg (V)/g of material.     

染矽小鼠体内KL-6含量与肺纤维化关系

目的 探讨染矽小鼠血液及支气管肺泡灌洗液(BALF)中涎液化糖链抗原-6(KL-6)含量与肺纤维化关系。方法 雌雄各半的60只C57BL/6小鼠,随机分为染矽组和对照组,染矽组经气管滴入二氧化硅,对照组滴入生理盐水;各组小鼠于染硒后30、45、60、75、90 d分批处死,收集血液和BALF检测KL-6含量;肺组织切片行Masson胶原染色,显微镜评估肺纤维化程度。结果 染矽组小鼠染硒45~90 d肺组织出现胶原沉积;与染矽 45 d小鼠比较,染矽60、75、90 d小鼠肺纤维化评分值均显著增加(P<0.01);染矽60、75、90 d小鼠血液KL-6含量明显高于对照组和染矽45 d小鼠(P<0.01);染矽75、90 d小鼠BALF中KL-6含量明显高于对照组和染矽60 d小鼠(P<0.01);小鼠血液及BALF中KL-6含量与纤维化评分值呈正相关(r=0.866、0.737,P<0.01)。结论 小鼠染矽45~90 d出现肺纤维化,血液及BALF中KL-6含量与肺纤维化程度呈正相关。     

Photoreduction of Copper Ions Using Silica–Surfactant Hybrid and Titanium (IV) Oxide under Sulfuric Acid Conditions

Photoreduction of Cu²⁺ ions to Cu metal by titanium(IV) oxide (TiO₂) was conducted in the presence of a silica–surfactant hybrid under sulfuric acid conditions. After irradiation, a dark-red color, reflections due to Cu metal in the X-ray diffraction pattern, and peaks due to Cu 2p_1/2 and 2p_3/2 in the X-ray photoelectron spectrum indicated the precipitation of Cu metal in the product. In addition, an increase in the Brunauer–Emmett–Teller specific surface area from 36 and 45 m²/g for the silica–surfactant and TiO₂, respectively, to 591 m²/g for the product, and a decrease in the intensity of the C-H stretching band in the Fourier–transform infra-red spectra implied the removal of surfactant during the reaction. These characteristics were never observed when TiO₂ was used solely. Therefore, this study indicated that the photoreduction of Cu²⁺ ions to Cu metal by TiO₂ was facilitated under the sulfuric acid medium, where the surfactants extracted from silica–surfactant hybrids by protons in the acidic condition were successfully photo-oxidized by TiO₂. Thus, this study presents a new application of the conversion of a silica–surfactant hybrid into mesoporous silicas.     

Valorization of Rice Husk and Straw Agriculture Wastes of Eastern Saudi Arabia: Production of Bio-Based Silica,Lignocellulose, and Activated Carbon

Bio-based silica, lignocellulose, and activated carbon were simply produced via the recycling of Hassawi rice biomass waste of Al-Ahsa governorate in the eastern Saudi Arabia region using a fast chemical treatment procedure. Rice husk and rice straw wastes were collected, ground, and chemically treated with sodium hydroxide to extract silica/silicate from the dried plant tissues. The liquid extract is then treated with acid solutions in order to precipitate silica/silicate at neutral medium. Lowering the pH of the supernatant to 2 resulted in the precipitation of lignocellulose. Thermal treatment of the biomass residue under N₂ gas stream resulted in activated carbon production. Separated products were dried/treated and characterized using several physical examination techniques, such as FT-IR, SEM/EDX, XRD, and Raman spectroscopy in order to study their structure and morphology. Silica and lignocelluloses products were then preliminarily used in the treatment of wastewaters and water-desalination processes.     

50例煤矿工人肺组织化学成份分析

本文报告了50例尸解煤矿工人肺组织生化成份及SiO_2含量(mg/g干肺)的分析结果。测定结果表明,矽肺和煤矽肺组总类脂与胆固醇含量均明显高于对照组(P<0.05),矽肺组磷脂亦有显著增高(p<0.01)。Ⅰ期煤工尘肺的总类脂、磷脂显著高于对照组(P<0.05),而Ⅱ期煤工尘肺的SiO_2含量显著增高(P<0.01),胶原亦有增高的趋势。当煤工并发肺癌或结核时,胆固醇明显增高(P<0.05)。 由此可见,肺组织化学成份的含量随煤工尘肺的不同类型和不同期别,以及有无合并症而有不同。     

Potential of Waste Marble Sludge for Repressing Alkali-Silica Reaction in Concrete with Reactive Aggregates

The continuous development of the marble industry has led to an increase in the accumulation of waste marble sludge causing landfilling and health-associated issues. The intention of the current study is to explore the potential of waste marble sludge powder (MS) utilization as a means of controlling alkali-silica reaction (ASR) in concrete. Specimen (cubes, prisms, and mortar bars) were prepared to incorporate reactive aggregates and various proportions of MS ranging from 5% to 40% as a replacement for aggregates. Expansion and mechanical strength characteristics were determined to investigate the effectiveness of MS to control ASRfor up to 150 days. Results revealed that on replacing aggregates in the control specimen with 25% MS, the ASR expansion at 14 days reduced from 0.23% to 0.17%, and the expansion at 28 days reduced from 0.28% to 0.17% which is within limits as per American Standard for Testing of Materials (ASTM) C1260. Furthermore, specimens incorporating MS exhibited improved compressive and flexural strength as compared to the identical specimen without MS. Microstructural analysis using Scanning electron microscopy (SEM) revealed micro-cracks in the control specimen while the specimen incorporating MS was found intact. Thus, it can be foreseen that the use of MS as a partial replacement of aggregates can control ASR in concrete as well as reduce the dumping and harmful emissions issue.     

红外分光光度法与焦磷酸重量法测定粉尘中游离二氧化硅的比较

本文对矿山粉尘和铸造粉尘的游离二氧化硅含量进行了红外分光光度法和焦磷酸重量法的对比测定。结果表明,红外法与重量法的结果之间有很好的相关性,其测定值在统计学上无显著性差异。两法测定值的相关回归方程:(?)=1.0001×-2.0610,r=0.947997。红外法的测定不受灰化的影响,对滤膜采集的粉尘中游离二氧化硅的含量测定是一简便、快速的方法,可较好地排除粉尘中难溶或不溶物质和无定形二氧化硅等因素的干扰,克服了重量法的不足。     

基于金磁微粒标记技术的可目视化蛋白质芯片检测方法的建立

目的：应用金磁微粒标记蛋白质技术,建立可目视化蛋白质芯片检测体系,比较金磁微粒和胶体金标记蛋白质技术应用于蛋白质芯片检测效果的优劣。方法：将人IgG点制于环氧基修饰的玻片上,分别与金磁微粒和胶体金标记的羊抗人IgG温育,银染显色,肉眼观察并用普通扫描仪记录结果。结果：基于金磁微粒的蛋白质芯片人IgG最佳点样浓度为0．2mg／ml,37℃温育2h,银染10～15min,检测结果信噪比高;基于胶体金的蛋白质芯片人IgG最佳点样浓度为0．1mg／ml,37℃温育1h,银染15～20min．检测结果信噪比高。结论：金磁微粒标记蛋白质技术应用于蛋白质芯片的检测,具有和胶体金一致的可目视化检测效果。且其标记技术简单,标记的蛋白质可定量。     

Recycled Untreated Rubber Waste for Controlling the Alkali–Silica Reaction in Concrete

Recycled rubber waste (RW) is produced at an alarming rate due to the deposition of 1.5 billion scrap tires annually around the globe, which causes serious threats to the environment due to its open land filling issues. This study investigates the potential application of RW in concrete structures for mitigating the alkali–silica reaction (ASR). Various proportions of RW (5%, 10%, 15%, 20%, and 25%) partially replaced the used aggregates. RW was procured from a local rubber recycling unit. Cubes, prisms, and mortar bar specimens were prepared using a mixture design recommended by ASTM C1260 and tested for evaluating the compressive and flexural strengths and expansion in an ASR conducive environment for specimens incorporating RW. It was observed that the compressive and flexural strength decreased for specimens incorporating RW compared to that of the control specimens without RW. For example, an 18% and an 8% decrease in compressive and flexural strengths, respectively, were observed for specimens with 5% of RW by aggregates volume at 28 days. Mortar bar specimens without RW showed an expansion of 0.23% and 0.28% at 14 and 28 days, respectively, indicating the potential ASR reactivity in accordance with ASTM C1260. A decrease in expansion was observed for mixtures incorporating RW. Specimens incorporating 20% of RW by aggregate volume showed expansions of 0.17% at 28 days, within the limit specified by ASTM C1260. Moreover, specimens incorporating RW showed a lower reduction in compressive and flexural strengths under an ASR conducive environment compared to that of the control specimen without RW. Micro-structural analysis also showed significant micro-cracking for specimens without RW due to ASR. However, no surface cracks were observed for specimens incorporating RW. It can be argued that the use of RW in the construction industry assists in reducing the landfill depositing issues with the additional benefit of limiting the ASR expansion.