用渗透系数推算单电解质二元无机水溶液的方法

本文提出了一种推算单电解质二元无机水溶液(火用)值的方法。其中,根据Pitzer普遍方程所得到的渗透系数公式和Gibbs—Duhem方程,推算出二元无机水溶液的化学值计算式,利用该计算式推导出NaCl、NH_4Cl和NaNo_3三种无机水溶液的化学与浓度的关系式,可方便地计算出不同浓度及溶液的化学,进而计算溶液     

Improving toughness of ultra-high molecular weight polyethylene with ionic liquid modified carbon nanofiber

Ionic liquids (ILs) with long alkyl substituted groups, including 1-docosanyl-3-methylimidazolium bromide (IL-1) and 1-docosanyl-3-methylimidazolium hexafluorophosphate (IL-2), were synthesized and used to modify the surface of carbon nanofibers (CNF). The nanocomposite film prepared by solution-blending of ionic liquid modified CNF (i-CNF) and ultrahigh molecular weight polyethylene (UHMWPE) displayed better toughness when compared with pure UHMWPE even at very low concentrations (e.g. 0.4 wt%). The effect of ionic liquids on the elongation-to-break ratio of this nanocomposite system was investigated. The ionic liquid with hexafluorophosphate as the anion was more efficient to increase the toughness of UHMWPE due to the improved compatibility of IL with UHMWPE in the polymer matrix than that of the bromide. The rheological behavior of molten nanocomposites revealed that the storage modulus and the complex viscosity decreased with increasing ionic liquid content in the high frequency region. However, a reverse trend was observed when the frequency was less than 0.05 s⁻¹. In-situ monitoring in the change of crystallinity of the nanocomposite during tensile deformation suggested a mechanism of sliding between UHMWPE crystal regions and the surface of carbon nanofibers.     

碱化度对聚合氯化铝混凝除硅的影响

通过对实验室现有工业级聚合氯化铝进行碱化度分析,向多个化学试剂厂调研得出,现场常用聚合氯化铝的碱化度在1.5～2.7之间。通过合成不同碱化度(2.0～2.4)的聚合氯化铝,对模拟成垢水进行系统的混凝实验,考察碱化度对聚合氯化铝混凝除硅的影响。研究表明,碱化度会决定铝形态的分布,进而影响混凝除硅的效果。随着碱化度的升高,Al_a含量逐渐降低,Al_b含量先增大后减小,Al_c含量逐渐增加。对模拟污水处理后,残余硅酸形态有很大差异,用聚合氯化铝(2.0)除硅后Si_a含量变为32.1mg/L,Si_c含量变为15.3mg/L;聚合氯化铝(2.2)除硅后Si_a含量变为28.71mg/L,Si_c含量变为30.5mg/L;聚合氯化铝(2.4)除硅后Si_a含量变为22.4mg/L,Si_c含量变为41.2mg/L。聚合氯化铝(2.0)除硅后Si_a降低的比例最大,聚合氯化铝(2.4)除硅后Si_c降低的比例最大。随着碱化度的升高,全硅剩余含量依次为47.4mg/L、59.5mg/L、63.6mg/L,表明碱化度越低,除硅效果越好。     

Analysis of long term catalytic performance for isobutane alkylation catalyzed by NMA–AlCl_3 based ionic liquid analog

Isobutane alkylation with 2-butene to produce high-quality gasoline was catalyzed by Nmethylacetamide(NMA)-AlCl_3 based ionic liquid(IL) analog with a NMA/AlCl3 molar ratio of 0.75 and CuCl modification,which was marked as CuCl-modified 0.75 NMA-1.0 AlCl_3.The long-term experiment was carried out in the autoclave operated in continuous mode to investigate the distribution of alkylate under different experimental nodes.The result indicated that the long-term alkylation was divided into three stages:rising,stable,and descending regions.C8 selectivity and molar ratio of trimethylpentanes(TMPs) to dimethylhexanes(DMHs) reached the highest level in the stable region,and research octane number(RON) of alkylate was as high as 97.Anionic Al species([AlbCl_7]~-,[A1 CuC15]-) and cationic Al species([AlCl_2 L]~+) from IL analog as two active Lewis acidic species played a catalytic role in the long-term alkylation,whereas the neutral Al species did not participate into the alkylation.Moreover,the structure of CuCl-modified 0.75 NMA-1.0 AlCl_3 was destroyed after the deactivation,and CuCl was enriched in the CD_2 Cl_2-insoluble substance,resulting in a decreasing TMP/DMH ratio.The catalytic lifetime of IL analog was similar with CuCl-modified 0.55 Et_3 NHCl-1.0 AlCl_3 IL,but IL analog had a lower cost.     

A facile one-pot ultrasound assisted synthesis of 1,8-dioxo-octahydroxanthene derivatives catalyzed by Brønsted acidic ionic liquid (BAIL) under green conditions

A simple and efficient one-pot procedure for the synthesis of 1,8-dioxo-octahydroxanthene derivatives in water under ultrasound irradiation is described. These heterocycles were prepared by condensation of dimedone with various aromatic aldehydes in the presence of Brønsted acidic ionic liquids as a convenient, cheap, readily synthesized and eco-friendly catalyst. This procedure has a lot of advantages such as: excellent yields, simplicity of the workup, low cost, short reaction times and green conditions. Ionic liquids could be recycled several times without significant loss of activity and high purity.     

Microbial Fuel Cell Application for Azoic Dye Decolorization with Simultaneous Bioenergy Production Using Stenotrophomonas sp.

A single‐chamber air‐cathode microbial fuel cell (MFC) was successfully applied for decolorization of the diazoic dye Reactive Black 5 (RB5) with simultaneous production of electricity. An innovative low‐cost medium, the marine water‐glucose‐yeast extract medium (MWGY), was developed which appears as a textile marine effluent in terms of salinity. The anode compartment containing a single bacterial strain of Stenotrophomonas sp. showed almost complete dye decolorization with different RB5 concentrations after seven days of treatment. For the four dye concentrations used, a correlation between dye removal and production of electrical energy was found. The comparison of the decolorization process in the MFC with that in a batch reactor as control experiment highlights the efficiency of the single‐chamber air‐cathode MFC technology which improved the dye removal by the same bacterial strain.     

Surface coating of α-Al2O3 nanoparticles with poly(vinyl alcohol) as biocompatible coupling agent for improving properties of bio-active poly(amide-imide) based nanocomposites having l-phenylalanine linkages

Nanocomposites (NCs) containing metal oxide nanoparticles (NPs) as fillers are used in a wide range of applications and in various fields. Poly(vinyl alcohol) (PVA) is an attractive polymer because of its many desirable applications and characteristics. In this investigation, at first, the surface of alumina (α-Al₂O₃) NPs was modified with PVA as a biocompatible modifier. Then, the optically active poly(amide-imide) (PAI) nanostructure was prepared by using molten tetrabutylammonium bromide as a molten ionic liquid and triphenyl phosphite as the condensing agent. Finally, the modified α-Al₂O₃ (α-Al₂O₃-PVA) NPs were incorporated into the PAI matrix for the preparation of PAI/Al₂O₃-PVA NCs (PAPNCs). To investigate effect and nature of coating on the surface of the α-Al₂O₃ NPs and preparation of PAPNCs, the samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy and thermogravimetric analysis. The surface morphology examination demonstrated the monodispersed characteristics of α-Al₂O₃ NPs after surface modification with the PVA and incorporation into the PAI matrix.     

Low temperature densification by lithium co-doping and its effect on ionic conductivity of samarium doped ceria electrolyte

Low temperature densification and improving the ionic conductivity of doped ceria electrolyte is important for the realization of efficient intermediate temperature solid oxide fuel cell system. Herein, we report the effect of lithium co-doping (1, 3, 5 and 7?mol%) in 20?mol% samarium doped ceria on the low temperature sinterability and conductivity. The synthesized nanoparticles by citrate-nitrate combustion method showed a decrease in lattice parameter and increase in oxygen vacancy with lithium content after calcination due to the substitution of Li⁺ into CeO₂ lattice. Upon sintering at 900?°C, the density improved and reached a maximum value of 98.6% for 5% Li which exhibited a dense microstructure than at 7% Li. 5%Li co-doping exhibited the best conductivity of 3.65?×?10^?04–1.81?×?10^?3 S?cm^?1 in the operative temperature range of IT-SOFC (550–700?°C).Our results demonstrate the significance of lithium as co-dopant for efficient low temperature sintering as well as improving the electrolyte conductivity.     

城市垃圾焚烧飞灰中重金属形态及生物有效性研究

随着集中焚烧法逐渐成为我国城市生活垃圾处理的主要方式,焚烧飞灰的安全处置与利用也成为学者普遍关注的问题。由于在填埋过程中受到各种环境要素的影响,垃圾焚烧飞灰中的重金属有可能会发生迁移和转化,重金属形态、毒性也会随之变化。本文对不同粒径城市垃圾焚烧飞灰中重金属的总量、形态及生物有效性进行了研究,为其在安全填埋及资源化利用过程中预测重金属的环境风险提供参考。     

添加TiO2的聚合物电解质膜PVDF-HFP的性能研究

通过添加不同质量分数的TiO2纳米粒子制备多孔聚合物电解质膜PVDF-HFP,制备的聚合物电解质膜通过红外,交流阻抗,线性伏安扫描、首次充放电测试等方法进行了性能测试。添加TiO2纳米填料后,降低了聚合物链的结晶度和极性,当填料的质量分数为8%时,表现出较好的电化学性能,吸液率为184%,孔隙率为93%,室温电导率达到2.05×10-3 S/cm,电化学稳定窗口为4.7V,能满足要求。