氯化银比浊法快速测定湿法炼锌过程溶液中微量氯离子

实验采用丙三醇作为稳定剂,增强了氯化银比浊溶液的稳定性,讨论了氯化银比浊法测定湿法炼锌过程中氯离子的条件,该方法在测定过程中,其它共存离子的干扰较小,氯比浊线性范围0~350μg/25 m L,方法检出限为10μg/25 m L,加标回收率92.6%~104.3%,方法简便、快速,经实践用于测定湿法炼锌过程溶液中微量氯离子,效果良好。

蒸汽辅助溶液过程制备钙钛矿材料及钙钛矿太阳能电池

有机无机杂化钙钛矿材料被广泛应用于光电器件领域,特别是其作为太阳能电池的吸光材料,受到学术界和工业界越来越多的关注。钙钛矿太阳能电池的产业化进程正在进行中,而在进一步降低制备成本、提高电池转换效率的同时,研究出一种操作简单且可重复性高的制备钙钛矿薄膜的技术具有十分重要的意义。与其他传统的溶液处理方法不同,蒸汽辅助溶液过程(VASP)处理法避免了薄膜在生长过程中溶解以及溶剂化作用,抑制了晶核的形成,使薄膜快速重组,获得致密的高质量钙钛矿薄膜。目前报道,基于此薄膜制备的平面结构钙钛矿太阳能电池转换效率高达16.8%。本文综述了低温(<150℃)VASP法制备的钙钛矿薄膜及光伏器件的相关研究进展,并对该技术的产业化前景做了展望。VASP制备过程简单、薄膜性能优异且可重复性高,为进一步制备大面积、高质量薄膜提供了可能。

用聚合隔膜电解氯化钠溶液过程的研究

在当今用隔膜法生产氯碱中多半采用石棉隔膜和石棉聚合隔膜。这些隔膜的共同缺点是寿命短(逐次降低阳极和阴极的寿命)相当厚的膜会导致电阻增大,况且石棉又是致癌物。因此。

超临界流体过程与药物的超细化

用超临界流体过程制备微米和纳米级微粒,是近年来发展的一种粉体超细化处理的新技术,特别适用于具有热敏性和生物活性等特殊性能材料的超细化处理,在制药行业具有广阔的应用前景。介绍了超临界溶液快速膨胀过程和超临界反溶过程的原理、特点及其在药物微粒和微胶囊制备中的应用。

超临界溶液快速膨胀法制备盐酸氟桂利嗪微粒的研究

采用超临界溶液快速膨胀法制备盐酸氟桂利嗪药物微粒,研究了该方法使盐酸氟桂利嗪微粒化过程中萃取温度、萃取压力、膨胀室温度、喷嘴温度、喷嘴直径以及夹带剂用量对药物微粒的粒径大小以及形态的影响,并用正交实验法对该工艺条件进行优化.结果表明:采用超临界溶液快速膨胀法成功制备了粒径小且分布均匀的球型或类球型盐酸氟桂利嗪微粒,平均直径为1.285~6.893μm,经正交实验优化得到该工艺的最佳条件为:萃取温度35℃,萃取压力25 MPa,喷嘴温度140℃,夹带剂用量0.3 m L/min,此时得到微粒的平均粒径为1.386μm.采用扫描电镜、红外光谱、X射线衍射、热重分析对药物微粒进行了分析表征,超临界溶液快速膨胀前后盐酸氟桂利嗪药物微粒物理化学性质、晶体结构基本保持稳定.

在固态和熔融态下RESS过程制备萘的超细颗粒

针对传统 RESS过程中存在着颗粒质量和产量问题 ,本文分别以超临界 CO2 作为溶剂在萘的固态和熔融状态下利用 RESS过程制备了萘的超细颗粒 ,研究了萘在固态和熔融态下各种操作变量 ,如萃取温度和压力、膨胀前温度和喷嘴尺寸等对产品尺寸的影响。结果表明 ,膨胀前温度和萃取压力的作用规律相同。提高膨胀前温度则颗粒变大 ;提高萃取压力则颗粒变小。萃取温度在萘的不同状态下表现出不同的作用规律 ,即在固态下 ,提高萃取温度 ,颗粒尺寸变小 ;而在熔融状态下反之。在该研究范围内 。

衰减全反射-紫外/可见光谱技术应用

本文对衰减全反射法(ATR)的光学测定原理、衰减全反射-紫外/可见光谱方法(ATR-UV)的特点以及它们在一些典型的工业过程溶液,如高浓度和含有大量固体颗粒和微乳液聚合等体系检测的应用进行了综述。ATR-UV光谱技术适宜实时地反馈工业过程溶液的组分改变和浓度变化,从而帮助我们了解该过程的进展。这些优良的特性能帮助我们开发在线的传感器,因此可用于监测许多典型的工业过程溶液。其方法简单、迅速,一般无需对试样进行预处理或稀释。ATR-UV作为光谱学测定的重要波段,其技术开发将在化工过程检测方面具有重要的意义。

苯并噻二唑为中心的A-π-A-π-A型小分子光伏材料合成与性能研究

以苯并噻二唑为中心给体,利用Suzuki偶联和Knoevengel缩合等经典有机反应将吸电子基团氟原子和氰基引入到分子末端,完成了两个未见报道的以苯并噻二唑为中心的A-π-A-π-A型小分子化合物2F-TT-BT和2CN-TT-BT的合成,其化学结构通过核磁和高分辨质谱予以证实.通过紫外-可见吸收光谱、电化学循环伏安法及密度泛函理论计算对其光物理和电化学性质进行了实验及理论的研究.研究表明,合成的小分子材料对太阳光的吸收可覆盖整个紫外-可见吸收范围,具有与PC61BM相匹配的HOMO和LUMO能级,满足了溶液过程有机太阳能电池制备的基本要求.初步探索了材料的光伏性能,以小分子2F-TT-BT为给体,制作了结构为ITO/PEDOT:PSS/2F-TT-BT:PC61BM(质量比1∶2)/Al的体异质结(BHJ)太阳能电池,能量转换效率为0.53%,实验结果表明此类小分子是潜在的有机太阳能电池材料.

炸药超临界流体细化技术研究进展

本文介绍了超临界流体的概念及超临界细化原理,综述了国内外炸药超临界重结晶细化技术研究进展,并指出了存在的问题。

Rolling route for refining grains of super light Mg-Li alloys containing Sc and Be

Pioneering work on Sc or/and Be added Mg-Li alloys with refined grains was initiated. Various rolling-based thermo-mechanical treatments on these Mg-Li alloys were carried out. Four Mg-Li alloys were prepared by vacuum melting process. A unique route for producing fine grains was applied which concluded solution treatment at 350 ℃, cold rolling with 60% thickness reduction and 250 ℃ annealing, successively.

Thermodynamic analysis of Li-Ni-Co-Mn-H2O system and synthesis of LiNi0.5Co0.2Mn0.3O2 composite oxide via aqueous process

The constructed potential-pH diagrams of Li-Ni(Co,Mn)-H2O system indicate that the LiNiO2,LiCoO2 and LiMnO2 are thermodynamically stable in aqueous solution within the temperature range of 25-200°C and the activity range of 0.01-1.00.A predominant co-region of LiNiO2,LiCoO2 and LiMnO2 oxides(Li-Ni-Co-Mncomposite oxide)is found in the Li-Ni-Co-Mn-H2O potential-pH diagrams,in which the co-precipitation region expands towards lower pH with rising temperature,indicating the enhanced possibility of synthesizing Li-Ni-Co-Mn composite oxide in aqueous solution.The experimental results prove that it is feasible to prepare the LiNi0.5Co0.2Mn0.3O2 cathode materials(NCM523)by an aqueous routine.The as-prepared lithiated precursor and NCM523 both inherit the spherical morphology of the hydroxide precursor and the obtained NCM523 has a hexagonalα-NaFeO2 structure with good crystallinity.It is reasonable to conclude that the aqueous routine for preparing NCM cathode materials is a promising method with the guidance of the reliable potential-pH diagrams to some extent.

Influence of magnesium and aluminum salts on hydrolysis of titanyl sulfate solution

The influence of magnesium and aluminum salts as impurities on the hydrolysis of titanyl sulfate was investigated.The degree of TiOSO4 conversion to hydrated titanium dioxide（HTD） and the particle size of HTD were measured as functions of the concentrations of MgSO4 and Al2（SO4）3 in the TiOSO4 solution.The Boltzmann growth model,which focuses on two main parameters,namely the concentrations of Mg2＋ and Al3＋（ρ（Mg2＋） and ρ（Al3＋）,respectively）,fits the data from the hydrolysis process well with R20.988.The samples were characterized by ICP,SEM,XRD,and laser particle size analyzer.It is found that the addition of Mg SO4 simultaneously improves the hydrolysis ratio and the hydrolysis rate,especially when F（the mass ratio of H2SO4 to TiO2） is high,hydrolysis ratio increases from 42.8% to 83.0%,whereas the addition of Al2（SO4）3 has negligible effect on the chemical kinetics of HTD precipitation during the hydrolysis process,hydrolysis ratio increases from 42.8% to 51.9%.An investigation on the particle size of HTD reveals that the addition of Mg SO4 and Al2（SO4）3 clearly increases the size of the crystallites and decreases the size of the aggregates.

Rapid biosorption and reduction removal of Cr(Ⅵ) from aqueous solution by dried seaweeds

Four types of common seaweeds(Laminaria japonica,Undaria pinnatifida,Porphyra haitanensis,and Gracilaria lemaneiformis) were examined to remove Cr(Ⅵ) ions from aqueous solution.The experimental parameters that affected the biosorption process including pH,biomass dosage,contact time and temperature were investigated via batch experiments.The surface characteristics of seaweeds before and after Cr(Ⅵ) adsorption were studied with scanning electron microscopy and Fourier transform infrared spectroscopy.The results show that an initial solution with the pH of 1.0 is most favorable for Cr(Ⅵ) adsorption.Rapid adsorption is observed in the initial stage and adsorption equilibrium state is reached within 1 h.The adsorption efficiency by Porphyra haitanensis is the maximum among four types of seaweed powders,followed by Laminaria japonica and Undaria pinnatifida with biosorption efficiency up to 90%.The removal rate of Gracilaria lemaneiformis is less than 60%.The kinetic data obtained using the seaweeds are found to follow pseudo-second order kinetic model.Experimental sorption data adequately correlate with the Langmuir model.FTIR indicates that amino and carboxyl groups play an important role in the process of Cr(Ⅵ) adsorption and a large percentage of Cr(Ⅵ) ions are reduced by reductive groups on the surface of seaweeds.

Copper solvent extraction from alkaline cyanide solution with guanidine extractant LIX 7950

The use of the guanidine extractant LIX 7950 extracting copper and cyanide from alkaline cyanide solution was investigated.The extraction of copper and cyanide under different initial copper and extractant concentrations was examined and the stoichiometric extraction constant of Cu(CN)32- with LIX 7950 was calculated.Both the distribution coefficient and the stoichiometric extraction constant of Cu(CN)3 2-with LIX 7950 decrease when the temperature is varied from 25℃to 45℃, indicating the extraction process is exothermic.The calculated enthalpy change of the reaction(-HΘ)is about-190 kJ/mol.The copper extraction isotherms under different molar ratios of cyanide to copper are established.The preferential extraction of Cu(CN)32- over Cu(CN)4 3-and CN -has been confirmed and a high cyanide-to-copper molar ratio tends to suppress copper loading. The loaded copper and cyanide can be stripped efficiently by the moderately strong NaOH solutions(0.5-1.0 mol/L)and the presence of NaCN in the stripping solution facilitates copper stripping.

Experimental study on freezing of liquids under static magnetic field

Freezing processes of several liquids under static magnetic field(SMF) less than 50 mT were investigated. Central temperature of liquid samples held in glass test tubes immersed in a liquid bath was measured and collected. Nucleation temperature and phase transition time were obtained from freezing curves. Normality tests were performed for nucleation temperature of these liquids with/without magnetic field and normality distributions were justified. Analysis of variances was carried out for nucleation temperature of these liquids with magnetic field flux density as the influencing factor. Results showed that no significant difference was found for deionized water with or without SMF. However, differences exist in 0.9% NaCl solution and 5% ethylene glycol solution with and without SMF. Nucleation temperature of 0.9% NaCl with SMF is lower than that without SMF, while its phase transition time is shorter than that without SMF. Nucleation temperature of 5% ethylene glycol with SMF is higher than that without SMF, while its phase transition time is not modified with SMF.

The Electrodeposition of Rhenium in Alkaline and Acidic Elektrolytes

The investigation of electrodeposition of rhenium in alkaline and acidic electrolytes was carried out, polarization curves were obtained by electrochemically and cyclically potentiodynamic methods. By the investigation of rhenium concentration, sulphuric acid, alkali, ammonium sulphate, temperature and acidity of solution, it was found that reaming velocity was an optimal regime and electrolyte composition for an obtaining of high quality rhenium deposits from an alkaline electrolyte and acidic electrolyte. It was defined that the process of electrodeposition of rhenium in alkaline electrolyte is accompanied by chemical polarization and the electrodeposition of rhenium in acidic electrolyte goes gradually with the formation of intermediate films of sediments,

Stability of [BMIM]HSO_4 for using as additive during zinc electrowinning from acidic sulfate solution

The stability of ionic liquid additive 1-butyl-3-methylimidazolium hydrogen sulfate （[BMIM]HSO4） during zinc electrowinning from acidic sulfate solution was investigated by cyclic voltammetry, electrochemical impedance spectroscopy and scanning electron microscopy. Compared with the traditional industrial additives, gelatine and gum arabic, [BMIM]HSO4 has more excellent chemical and thermal stabilities. The inhibition effects of gelatine and gum arabic on the zinc electrocrystallization are observed to markedly weaken due to their part degradation after 12 h longtime successive electrolysis and high temperature （90 ℃） treatments. In contrast, the activity of [BMIM]HSO4 is practically unaffected after 24 h longtime successive electrolysis and high temperature treatments. These results are corroborated with the corresponding morphological analysis of the cathodic deposits.

A rapid one-step electrodeposition process for fabrication of superhydrobic surfaces on anode and cathode

This work presents a method to solve the weak solubility of zinc chloride(ZnCl_2) in the ethanol by adding some reasonable water into an ethanol electrolyte containing ZnCl_2 and myristic acid(CH_3(CH_2)_(12)COOH).A rapid one-step electrodeposition process was developed to fabricate anodic(2.5 min) and cathodic(40 s) superhydrophobic surfaces of copper substrate(contact angle more than 150°) in an aqueous ethanol electrolyte.Morphology,composition,chemical structure and superhydrophobicity of these superhydrophobic surfaces were investigated by SEM,FTIR,XRD,and contact angle measurement,respectively.The results indicate that water ratio of the electrolyte can reduce the required deposition time,superhydrophobic surface needs over 30 min with anhydrous electrolyte,while it needs only 2.5 min with electrolyte including 10 mL water,and the maximum contact angle of anodic surface is 166° and that of the cathodic surface is 168°.Two copper electrode surfaces have different reactions in the process of electrodeposition time,and the anodic copper surface covers copper myristate(Cu[CH_3(CH_2)_(12)COO]_2) and cupric chloride(CuCl);while,zinc myristate(Zn[CH_3(CH_2)_(12)COO]_2) and pure zinc(Zn) appear on the cathodic surface.

Role and maintenance of redox potential on chalcopyrite biohydrometallurgy:An overview

Chalcopyrite is one of the most important copper minerals;however,the extracted efficiency of chalcopyrite is still not satisfactory in hydrometallurgy owing to its high lattice energy which leads to its low dissolution kinetics.To overcome the difficulties,many advanced technologies have been developed,including the selection of high effectively bacteria,the inhibition of the passivation film adhered onto the minerals surface,and the maintenance of solution redox potential under an optimum range.Up to date,considerable researches on the first two terms have been summarized,while the overview of the last term has been rarely reported.Based on corresponding works in recent years,key trends and roles of solution redox potential in copper hydrometallurgy,including its definition,effect and maintenance,have been introduced in this review.

Experimental Research on SOx from Ship Emissions by Lye Absorption

To protect environment, and to comply with the IMO＇s （International Maritime Organization） newest regulations about ship＇s SOx emission. This thesis illustrates a closed recycling absorb system based on NaOH solution recycling particularly for SOx onboard. The goal is to use NaOH solution to absorb SOx, and reduce the damage the ships made towards environment. The thesis analyzes the main features that could influence the absorption of SOx on board, and the precipitations during the experiment. To reveal that NaOH solution is very highly effective and economic in absorption of SOx on ships by this experiment, and to set a theoretical basic fundamental for future application of alkali solution recycling absorption system for SOx.