Effects of ionic liquid additive [bmim]BF4 on fabrication of Ni-decorated Al2O3 powders by electroless deposition

Continuous and uniform Ni coating layer on the surface of Al₂O₃ powders are implemented by electroless deposition from sulfate solution with 25 g/L [bmim]BF₄ ionic liquid as additive. The effects of [bmim]BF₄ concentration on the surface morphologies, coating thickness, and element distribution of Ni-decorated Al₂O₃ powders have been investigated. It is demonstrated that with the increase of [bmim]BF₄ concentration in the range of 0–35 g/L, the formation of separated Ni powders and clusters away from Al₂O₃ surfaces are decreased. This can be explained by preferential adsorption of [bmim]BF₄ additive on the protrusions and sharp points of Al₂O₃ surface to inhibit the fast nucleation and crystal growth of Ni so that uniform Ni-decorated Al₂O₃ powders is obtained. When [bmim]BF₄ concentration is 25 g/L, the Ni grains on Al₂O₃ surface are uniform and spheroidal with a mean size of 0.5–1.5 μm and the coating thickness is about 2.0–3.0 μm. Besides, the deposition sequences of Ni coating layer is analyzed according to the changes in morphology of coated products obtained from different reaction stages. Furthermore, an empirical model of the deposition process of Ni-decorated Al₂O₃ powders with [bmim]BF₄ as additive is proposed to further elaborate the formation mechanism of the coating layer structure.     

[Bmim]BF叔水相中苋菜红与牛血清白蛋白作用研究

在离子液体四氟硼酸1-丁基-3-甲基咪唑（[Bmim]BF4）和NaH2PO4形成的双水相体系中,研究了离子液相中食用色素苋菜红（AT）与牛血清白蛋白（BSA）复合物的光谱行为。实验了离子液体用量、盐的浓度、溶液酸度、反应时间及共存物质对体系测定的影响。结果表明,在pH6．0的条件下,苋菜红牛血清白蛋白（BSA）复合物的最大吸收波长在540nm处,比单纯AT红移15nm,复合物表观摩尔吸光系数为2．81x10^4L·mol^-1·cm^-1,用摩尔比法求得最大结合数为150。应用加入无机离子及不同类型表面活性剂方法,初步探讨了食用色素苋菜红与牛血清白蛋白之间的作用机理。     

[Bmim]BF_4双水相中苋菜红与牛血清白蛋白作用研究

在离子液体四氟硼酸1-丁基-3-甲基咪唑([Bmim]BF4)和NaH2PO4形成的双水相体系中,研究了离子液相中食用色素苋菜红(AT)与牛血清白蛋白(BSA)复合物的光谱行为。实验了离子液体用量、盐的浓度、溶液酸度、反应时间及共存物质对体系测定的影响。结果表明,在pH6.0的条件下,苋菜红牛血清白蛋白(BSA)复合物的最大吸收波长在540nm处,比单纯AT红移15nm,复合物表观摩尔吸光系数为2.81x104L.mol-1.cm-1,用摩尔比法求得最大结合数为150。应用加入无机离子及不同类型表面活性剂方法,初步探讨了食用色素苋菜红与牛血清白蛋白之间的作用机理。     

Experimental investigation on the wettability of respirable coal dust based on infrared spectroscopy and contact angle analysis

Respirable dust does great harm to human health. In this paper, we focused on the wetting characteristics of respirable coal dust, and the effect of functional groups of respirable coal dust on its wettability was investigated. We selected five different types of coal samples (Lignite, Gas fat coal, Coking coal, 1/3 Coking coal, and Anthracite) from some typical mining areas in China. We used a Fourier Transform Infrared Spectrometer (FT-IR) to obtain the IR spectrum of the respirable coal dust, and the percentage of functional groups for each respirable coal dust was obtained by the peak area normalization method and then analyzed. And the wettability of respirable coal dust was evaluated by contact angle measurement. It is found that the benzene rings, aromatic hydrocarbons with benzene rings, aliphatic hydrocarbons with methyl, methylene, and so on, which have carbon-containing macromolecular structures, are hydrophobic. While the oxygen-containing functional groups represented by hydroxyl and carboxyl groups, and silicates and carbonate minerals are hydrophilic. Besides, the results show that respirable coal dust of different metamorphic grade coals has different wettability. This study has important theoretical significance for understanding the wettability of respirable coal dust.     

Kinetic investigation of zinc electrodeposition from sulfate electrolytes in the presence of impurities and ionic liquid additive [BMIM]HSO4

The effects of some common impurities such as copper, iron, nickel, cobalt, lead and their interaction with an ionic liquid additive 1-butyl-3-methylimidazolium hydrogen sulfate-[BMIM]HSO₄ on zinc electrodeposition from acidic sulfate electrolyte were characterized in terms of the polarization behavior and the kinetics of zinc deposition using cyclic voltammetry and potentiodynamic polarization measurements. The results showed that these metallic impurities studied exerted some different changes in cyclic and cathodic polarization voltammograms. The addition of [BMIM]HSO₄ was observed to counteract the detrimental effects of these impurities and induced a blocking effect on the zinc electrodeposition process through its cathodic adsorption on the electrode surface. The adsorption of this additive shifted the electroreduction potential of zinc ions towards more negative values, restricted impurities ions from being electroreduced, and inhibited hydrogen evolution. Moreover, the kinetics analysis of cathodic polarization suggested that the presence of these impurities alone and in combination with [BMIM]HSO₄ had no effect on the Tafel slope and transfer coefficient but affected the exchange current density for the zinc deposition.     

Experimental investigation of the wetting ability of surfactants to coals dust based on physical chemistry characteristics of the different coal samples

To select suitable surfactant as water-spray additive to improve dust suppression efficiency, six types of coal sample (lignite, long flame coal, non-caking coal, gas coal, coking coal, and anthracite) were selected from some typical mining areas in China, the influence of the physical chemistry characteristics of coal samples on the wetting ability of surfactants to the coals dust was investigated. Their proximate composition, ultimate content, chemical structure, surface morphology, pore structure parameters, and contact angle were determined. Three kinds of anionic surfactants – Sodium Alcohol Ether Sulphate (AES), Sodium Alpha-Olefin Sulfonate (AOS), Fatty Acid Methyl Esters Ethoxylate Sulfonate (FMES) – and one kind of nonionic surfactant – Coco Diethanolamide (CDEA) – were selected to carry out sedimentation experiments on the coal samples dust, to explore the main factors influencing the wettability of the coal samples dust. Among these factors, pore size is the main factor determining the wettability of coal dust, the contact angle decreases linearly (R² = 0.96) with pore size increase. The experimental results demonstrate that the following factors produce correspondingly increased wettability: higher moisture content, lower carbon content, higher oxygen content, more oxygen-containing functional groups, and increased pore size. In addition, the wettability of the six types of the coal samples dust shows a high-low-high trend with metamorphic degree increase, lignite has the strongest wettability, and the coking coal with the highest degree of metamorphism in the selected bituminous coal sample has the weakest wettability. Moreover, compared with nonionic surfactants, anionic surfactants have stronger wetting ability, but the same anionic surfactants have different wetting abilities to coal dust with different metamorphic degrees. AOS has stronger wetting ability to the dust of long flame coal, non-caking coal, and anthracite; AES has stronger wetting ability to the dust of lignite and coking coal; and FMES has stronger wetting ability to the dust of gas coal. The research results provide a theoretical basis for different coal mines to select suitable surfactants as water-spray additives to improve dust suppression efficiency.     

Effect of microwave irradiation on crystal growth of zeolitized coal fly ash with different solid/liquid ratios

In the present work, coal fly ash (CFA) was converted to zeolite (CFAZP) experimentally at atmospheric pressure via a conventional hydrothermal heating for 6 h at low temperature (90 ± 3 °C) followed by microwave irradiation for 30 min. The synthesized products were characterized using XRD, TGA/DTA, SEM, PSD, BET, and cation-exchange capacity (CEC) techniques. The effect of microwave on the crystal growth of nucleated CFAZP at different solid/liquid ratios (suspended CFA mass to NaOH solution volume, g/mL) was studied. A three-variable, three level central composite statistical experimental design was applied to investigate the effect of the independent variables on the response function defined as the ratio of the characteristic peak intensity at 2θ: 28° of a sample to that of the same peak of a sample run for 24 h with conventional heating. The relative peak intensity of CFAZP as high as 97% was achieved under optimum experimental conditions with 1 M of NaOH concentration, 6 h of conventional heating followed by 30 min microwave irradiation with a solid/liquid ratio of 0.40 g/mL. Under constant microwave energy, higher solid/liquid ratios led to higher relative peak intensity of the product.     

离子液体[bmim]PF6中制备纳米金属Ni及其催化苯乙烯加氢的研究

以化学还原手段分别在水溶液和离子液体1-丁基-3-甲基咪唑六氟磷酸盐([bmim]PF6)中制备了纳米金属Ni粉末,采用X射线衍射(XRD)、透射电镜(TEM)、傅立叶红外光谱(FT-IR)、紫外可见光谱(UV-vis)及热重(TG-DTA)对所制备样品的形貌和结构进行了表征.XRD表征结果显示:与水溶液制备纳米Ni相比,在[bmim]PF6中制备的纳米Ni具有立方相结构,无氧化峰出现;TEM结果显示:在[bmim]PF6中制备的纳米Ni具有更小的粒径和更好的颗粒分布,团聚现象不明显;FT-IR显示:离子液体不仅仅作为反应的介质,而且和纳米颗粒表面间存在着一定的化学结合,吸附在纳米颗粒的表面,有效的阻止了Ni纳米颗粒的团聚和氧化;TG-DTA及UV-vis结果进一步验证了Ni表明离子液体层的存在.苯乙烯加氢产物的分析结果表明,在[bmim]PF6中制备的纳米Ni催化苯乙烯加氢的活性显著高于常规制备的Ni催化剂.     

[C_4mim][BF_4]粘度的模拟与实验

为了研究离子液体的粘度特性,以1-丁基-3-甲基咪唑四氟硼酸盐([C4mim][BF4])离子液体为研究对象进行模拟计算与实验测试.基于分子动力学原理,编译了离子液体粘度的模拟计算程序,对[C4mim][BF4]离子液体完成了粘度模拟计算.搭建了粘度测试系统,进行离子液体的粘度测试.通过实验数据与模拟数据的对比,验证了模拟结果的准确性.另外,根据模拟粘度值的拟合曲线,分析了离子液体粘度的变化规律.同时,通过与水粘度的比对研究,阐述了[C4mim][BF4]离子液体的粘度特点.     

Preparation of Sb2S3 nanostructures by the [BMIM][BF4] ionic liquid assisted low power sonochemical method

Sb₂S₃ nanorods were successfully synthesized by the ionic liquid assisted sonochemical method (ILASM). The starting reagents were Sb₂Cl₃, Thioacetamide, absolute ethanol (ETA) and the selected ionic liquid (IL) was 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF₄]). The synthesized materials were subjected to 200 °C annealing treatment under controlled vacuum conditions. X-ray powder diffraction analysis showed that ultrasound irradiation played a key role on the crystallization degree of Sb₂S₃, whilst Scanning Electron Microscopy analysis showed that the addition of IL was fundamental for the formation of 1-D Sb₂S₃ nanostructures. XPS confirmed the formation of Sb₂S₃.The optical properties (band gap) were similar to previously reported for bulk Sb₂S₃.     

离子基团对PBO纤维的表面性能及其界结性能的影响

PBO作为增强纤维存在与环氧树脂基体界面粘结性能差的问题.通过在聚合过程中添加少量5-磺酸钠-间苯二甲酸部分替代对苯二甲酸与4,6-二氨基间苯二酚盐酸盐进行共聚,合成了大分子链上含有离子基团的SPBO共聚物,并制得SPBO初生纤维.通过接触角测试和XPS研究了纤维的表面性能,通过微脱粘实验和SEM评价了纤维与环氧树脂基体的界面粘结性能.结果表明: 与PBO纤维相比,SPBO纤维表面浸润性能提高,表面含氮、氧量均增加,与环氧树脂的界面剪切强度从8.2MPa提高到10.1Mpa,提高了23%.     

离子基团对PBO 纤维的表面性能及其界面粘结性能的影响

PBO 作为增强纤维存在与环氧树脂基体界面粘结性能差的问题。通过在聚合过程中添加少量5-磺酸钠2间苯二甲酸部分替代对苯二甲酸与4 , 6-二氨基间苯二酚盐酸盐进行共聚, 合成了大分子链上含有离子基团的SPBO 共聚物, 并制得SPBO 初生纤维。通过接触角测试和XPS 研究了纤维的表面性能, 通过微脱粘实验和SEM评价了纤维与环氧树脂基体的界面粘结性能。结果表明: 与PBO 纤维相比, SPBO 纤维表面浸润性能提高, 表面含氮、氧量均增加, 与环氧树脂的界面剪切强度从8. 2 MPa 提高到10. 1 MPa , 提高了23 %。      

液膜常用表面活性剂对青霉素提取率及液膜溶胀的研究

采用以磷酸三丁酯(TBP)为流动载体,液体石蜡为膜相添加剂,煤油为膜溶剂与表面活性剂组成的W/O型乳状液膜体系提取模拟发酵液中的青霉素,考察了单一表面活性剂、混合表面活性剂对青霉素传质和液膜溶胀的影响.实验结果表明:聚胺类表面活性剂(兰113B、N205、ECA4360)对青霉素的提取率优于酯类表面活性剂(span80),且用量少、液膜溶胀率低;酯类表面活性剂与聚胺类表面活性剂不能配伍使用,聚胺类表面活性剂混合性能优于单一表面活性剂,有利于提高青霉素的传质,降低液膜溶胀.表面活性剂在液膜分离中起着极为重要的作用,直接影响着液膜的稳定性、溶胀性能及液膜的破乳.选择性能优良的表面活性剂,适宜的液膜配方和操作条件,有利于控制液膜溶胀,提高青霉素的提取率.     

板料弯曲回弹影响因素的有限元模拟研究

通过静态力学、动态力学实验方法,研究了热致性液晶聚合物(LCP)的种类对环氧树脂共混物在不同温度下的拉伸强度和应力-应变曲线的影响,通过TEM观察了共混物的相形态结构.结果表明,反应型液晶聚合物(LCPU)比其它种类的液晶聚合物对环氧树脂的改性效果更好;在不同温度下,其拉伸强度和应力～应变行为均比其它材料优越;固化物的动态力学结果表明:反应型的液晶聚合物键入了固化网络,出现新的松弛,TEM结果表明,反应型的液晶聚合物在基体材料中形成大小在nm数量级的液晶聚集微区,没有反应基团的液晶聚合物PHBHT在10%的加入量下,与环氧的共混物结构也有液晶聚集微区产生,但是聚集区大小在微米量级.     

Effects of rigid structures containing (meth)acrylate monomers and crosslinking agents with different chain length on the morphology and electro-optical properties of polymer-dispersed liquid crystal films

ABSTRACT

This contribution investigates the preparation of polymer-dispersed liquid crystal (PDLC) films based on meth(acrylate) monomers containing rigid structures. The current study specifically focuses on comparison of the monomers on the basis of meth(acrylate) side group, flexible/rigid structures and rigidity. We find that methacrylate monomers exhibit more preferable electro-optic properties than that of the acrylate monomers. Furthermore, through the systematic variation of rigidity, composition of the monomers and chain length of crosslinking agents, both the morphologies and electro-optic properties of these films are found to be adjustable. A composite film is demonstrated by employing moderately rigid monomer (tetrahydrofurfuryl methacrylate) with low driving voltage (21.0?V) and high contrast ratio (87.5). Therefore, the studies here provide a new approach to optimize the electro-optical properties of the PDLC films by introducing monomers with rigid structures.     

Effects of acid solution of different components on the pore structure and mechanical properties of coal

To explore the influence of acid solution with different components on the pore structure and mechanical properties of coal, nuclear magnetic resonance (NMR), scanning electron microscope (SEM), energy dispersion spectrum (EDS) and uniaxial compression experiments were used to analyze the acid-treated coal samples. The results show that acid treatment can obviously improve the connectivity of coal, increase the porosity of coal, and is conducive to the circulation and diffusion of gas, but the promotion effect of acid solutions of different components on pores with different pore sizes is different. After acid treatment, the number of mineral particles on the surface of the coal samples are obviously reduced, and the space filled with mineral particles is gradually exposed, thus increasing the density of pores and fractures of the coal samples. The energy spectrum analysis shows that acid solution added HF has a good removal effect on kaolinite minerals, iron minerals and calcite minerals. For the mechanical properties of the coal samples, acid treatment can reduce the strength and elastic modulus of coal samples, but increase its toughness. In addition, the fracture evolution of the acid-treated coal samples mainly goes through four stages: initial stage, transition stage, expansion stage and destruction stage. Because most of the energy accumulated in the acid-treated coal samples is used to damage the coal body, the acid-treated coal samples are easy to form fracture network, and is mostly broken in blocks when unstable.     

Effects of polymer viscosity on the polymerization switching and electro-optical properties of unaligned liquid crystal/UV curable polymer composites

Polymer dispersed ferroelectric liquid crystal composite films consisting of varying polymer viscosities were prepared by polymerization induced phase separation (PIPS) technique. It was found that polymer viscosity influences the polarization switching and optical responses. A polymer dispersed ferroelectric liquid crystal film of low polymer viscosity shows faster switching, however a higher optical transmission at ~ 70% was observed in a higher polymer viscosity film.