几种可溶性聚酰亚胺的合成与性能表征

以3,5-二硝基溴苯与对甲基苯酚为原料,合成出中间产物3,5-二硝基-4'-甲基-二苯基醚,再用钯/碳还原得到芳香二胺单体3,5-二氨基-4'-甲基-二苯基醚,以此芳香二胺和四种不同芳香二酐为单体,通过低温聚合反应合成了高分子量的聚酰胺酸,热亚胺化的产物在极性强的溶剂中具有较好的溶解性.差示扫描量热(DSC)和热重法(...     

Development of a New Selective Optical Sensor for Cd(II) Ions Based on 4-Hydroxy Salophen

A new sensor membrane based on immobilization of 4-hydroxy salophen on triacetyl cellulose has been developed for the determination of Cd(II) ions that displays excellent performance. The sensing membrane is capable of spectrophotometric determining of Cd(II) with an outstanding high selectivity over a dynamic range between 1.0$,times 10^{-6}$ and 5.0$,times 10^{-2}$ mol L$^{-1}$ with a limit of detection of 5.3 $,times 10^{-7}~$mol L $^{-1}$ (0.06 $mu$g mL $^{-1}$ The sensor shows a fast response time ($≪ {5}~$ min) and the membrane can be used for more than two months without observing any major deviation. The optode revealed very good selectivity with respect to many cations including alkali, alkaline earth, transition and heavy metal ions. The proposed sensor could be used to determine cadmium ions in water and waste water samples. Different experimental parameters such as variable affecting on sensor preparation and pH of the sample solution plus response time were studied. The optodes developed in the present work were found to be stable, cost effective, easy to prepare, and efficient for direct determination of Cd(II) in a variety of aqueous samples using spectrophotometry, with satisfactory results.      

Determination of Lead Ions by an Optical Sensor Based on 2-Amino-Cyclopentene-1-Dithiocarboxylic Acid

A new spectrophotometric sensor for the determination of lead at trace level was developed using chemically immobilized 2-amino-cyclopentene-l-dithiocarboxylic acid (ACDA) on a triacetylcellulose. The sensor provided a wide concentration range of 1.0 x 10^-6 to 5.0 x 10^-1 M Pb(II) with a limit of detection of 6.9 X 10^-7 M Pb(II). The method also showed a reproducible result with relative standard deviation of less than 3.5% and response time of the optode was 10 min. Interference studies showed that Co(II) and Ni(II) ions interfered during the determination. The interference of potential interfering ions could be eliminated using a simple extraction procedure. The method was successfully used to determination of Pb(II) ions in reference alloy, water, and waste water samples with satisfactory results.     

Synthesis, characterization and structure effects on preconcentration and extraction of N,N'-bis-(salicylaldehydene)-1,4-bis-(p-aminophenoxy) butane towards some divalent cations

Separation with solvent extraction of Cu(II), Co(II) and Ni(II) from aqueous solution using N,N'-bis-(salicylaldehydene)-1,4-bis-(p-aminophenoxy)butane (H(2)L) as the new extractant has been studied. The new Schiff base, was synthesized by reaction of 1,4-bis-(p-aminophenoxy)butane and salicylaldehyde. Microanalytical data, elemental analysis, UV-vis (1)H NMR and (13)C NMR spectra and IR-spectra were used to confirm the structures. The extractability and selectivity of divalent cations was evaluated as a function of relationship between distribution ratios of the metal and pH or ligand concentration. Cu(+2) showed the highest extractability and selectivity at pH 7.8, whereas Ni(+2) and Co(+2) showed at pH 9.2. From the loaded organic phase, Cu(II), Co(II), Ni(II) stripping were carried out in one stage with aqueous acid solution including various concentrations of HCl. The stripping efficiency was found to be quantitative in case of 1.5M HCl. From quantitative evaluation of the extraction equilibrium data, it has been deduced that the complexes extracted are the simple 1:1 chelates, CuL, CoL, NiL.     

浸没式新型PVC膜生物反应器在市政污水处理应用研究

利用一套浸没式新型PVC(Polyvinyl chloride)超滤膜材料的膜生物反应器(membrane bioreactor,MBR)处理市政污水,研究了该新型PVC-MBR的长期运行效果、运行状况及膜污染控制效果.结果表明:新型PVC-MBR对主要污染物COD、NH4+-N、TP和浊度等有很好的去除效果;对COD、NH4+-N去除率分别可以稳定在90%和95%以上;外加化学混凝辅助除磷条件下运行可保证出水TP小于0.5mg/L;膜出水浊度小于0.1NTU,出水水质可达到城市杂用水水质标准(GB/T 18920—2002)的要求.在20L/(m2·h)通量条件下,膜系统运行稳定,跨膜压差(TMP)基本保持在-35kPa以内,在第195天进行离线化学清洗,通过1×10-3NaClO和质量分数0.2%NaOH混合离线清洗后可以使膜运行的TMP恢复至接近新膜通量的水平.     

Comparative investigation of N,N'-bis-(dithiocarboxy)piperazine and diethyldithiocarbamate as precipitants for Ni(II) in simulated wastewater

The performances of a coordination polymerization precipitant, N,N'-bis-(dithiocarboxy)piperazine (BDP) were compared with the widely used heavy metal precipitant, diethyldithiocarbamate (DDTC), through the treatment of three kinds of nickel-containing wastewaters, NiSO(4), nickel citrate (NiCA) and Ni(2+)-dye. Results indicated that both BDP and DDTC at their stiochiometric doses could reduce 50.00 mg l(-1) free nickel(II) to lower than 1.0 mg l(-1) (discharge limit of nickel ions in China) and 10% precipitants doses increase could treat NiCA containing 50.00 mg l(-1) Ni(2+) to meet the discharge limit. But [NiBDP](n) coordination polymerization precipitates had more rapid settling speed than Ni(DDTC)(2) precipitates. It was also observed that BDP could still partly remove Reactive Brilliant Red X-3B from Ni(II)-dye integrated wastewater through the adsorption of the precipitates [NiBDP](n), in addition to precipitating Ni(II). A 1:1 stiochiometric dose of BDP/Ni(II) could decrease Ni(II) from 50.00 to 0.87 mg l(-1), and simultaneously reduce the dye from 30.00 to 19.52 mg l(-1).     

Highly Selective Potentiometric Membrane Sensor for Hg(II) Based on Bis(Benzoyl Acetone) Diethylene Triamine

A new ion selective PVC membrane sensor is described based on bis(benzoyl acetone) diethylene triamine as a potentiometric sensor for Hg²⁺ ions. The membrane having bis(benzoyl acetone) diethylene triamine as an electroactive material, sodium tetraphenyl phthalate (NaTPB), and dibutyl phthalate (DBP) as an anion excluder in PVC matrix in the percentage ratio 4.21:2.11:60.25:33.43 (Ionophore:NaTPB:DBP:PVC) (w/w) of exhibits a linear response to Hg²⁺ of 1.0 times 10^-6 to 1.0 times 10^-1 M with a limit of detection of 3.7 times 10^-7 M and with a slope of 29.8 plusmn 1.0 mV/decade over the pH range of 2.0-11.5. Selectivity coefficients for Hg(II) relative to a numbers of potential interfering ions were investigated. The sensor is highly selective for Hg²⁺ ions over a large number of mono-, bi-, and trivalent cations. Normal interferents like Ag⁺ and Cd²⁺ do not interfere in the working of the sensor. The sensor has been found to be chemically inert to other ions and showing a fast response time of 1 s and was used over a period of three months with a good reproducibility. The sensor was successfully applied to determine mercury(II) in water samples with satisfactory results.     

Triiodide PVC Membrane Electrode Based on a Charge-Transfer Complex of Iodine with 2,4,6,8- Tetraphenyl-2,4,6,8-tetraazabicyclo[3.3.0]octane

A novel triiodide ion-selective electrode based on a charge-transfer complex of iodine with 2,4,6,8-tetraphenyl-2,4,6,8-tetraazabicyclo[3.3.0]octane as membrane carrier was prepared. The electrode has a linear dynamic range between 5.0 × 10(-)(2) and 3.5 × 10(-)(6) M, with a near-Nernstian slope of 54.7 ± 0.8 mV decade(-)(1) and a detection limit of 2.0 × 10(-)(6) M. The potentiometric response is independent of the pH of the solution in the pH range 4.0-10.5. The electrode possesses the advantages of low resistance, short conditioning time, fast response, and, especially, very good selectivities over a wide variety of other anions. The electrode can be used for at least 10 months without any considerable divergence in potentials. It was used as an indicator electrode in potentiometric titration of triiodide ions.     

Extraction of Antimony(III) Ions from Solutions by Sorbents Based on Titanium(IV) Compounds

Inorganic Materials - Sorbents based on titanium(IV) compounds have been shown to be potentially attractive for quantitative removal of antimony(III) anions from liquid radioactive waste with...     

Cadmium Selective PVC-Membranes Sensor Based on 1, 2-Bis (Quinoline-2-Carboxamido) -4-Chlorobenzene as a Neutral Carrier

The 1, 2-bis(quinoline-2-Carboxamido)-4-chlorobenzene (H₂Clbqb) was used as an excellent ionophore in the construction of a cadmium(II)-selective PVC-based membrane sensor. The influences of membrane compositions on the potentiometric response of the electrodes have been found to substantially improve the performance characteristics. The best performance was obtained with a membrane composition of (H₂Clbqb) (5%): PVC (31%): DBP (61%): NaTPB (3%). The sensor shows a Nernestian response for cadmium ions over a wide concentration range (1.0times10⁶ to 1.0 times 10^-1 mol.L^-1) with slope of 30.3 plusmn0.4 mV decade¹. The limit of detection was 8.0 times10^-7 mol.L^-1. It illustrates a relatively fast response time in the whole concentration range (< 10 s) and it can be used for at least 8 weeks without any divergence in potential. The electrode can be used in the pH range from 2.4 to 9.0. The selectivity coefficient of some alkali, alkaline earth, transition and heavy metal ions towards Cd²⁺ion have been determined. The results show proposed Cd sensor is selective over a number of mono, bi- and trivalent cations such as Pb²⁺, Fe³⁺, Ni²⁺, K⁺, and Mg²⁺. The analytical usefulness of the proposed electrode has been evaluated by its application in the determination of cadmium in real samples. It was successfully applied for the direct determination of Cd²⁺ in standard and real sample solutions.     

聚甲基丙烯酸-N,N-二甲氨基乙酯中空纤维复合纳滤膜的制备与性能表征

以聚甲基丙烯酸-N,N-二甲氨基乙酯(PDM)作为交联预聚物,利用双苄基试剂在聚砜中空纤维超滤膜表面进行季铵化反应(界面聚合),制得荷正电复合中空纤维复合纳滤膜.研究了PDM浓度、外加碱、溶剂、交联剂和交联温度等制备条件的影响.所制备的中空纤维纳滤膜对2g/L MgSO4的截留率≥98%,通量19.5L/(m2·h),界面聚合时间为3.5h.     

An Antiferromagnetic Semiconductor Based on Ethylenedioxytetrathiafulvalenothioquinone-1,3-dithiolemethide, (EDO-TTFVS)·FeBr4

The 1:1 FeBr₄ ⁻ salt of a newly synthesized donor, ethylenedioxytetrathiafulvalenothioquinone-1,3-dithiolemethide (EDO-TTFVS) was prepared by an electrochemical oxidation. A crystal structure analysis and investigations on conducting/magnetic properties cleared that this (EDO-TTFVS)·FeBr₄ salt is a new antiferromagnetic semiconductor with a high Néel temperature of 15 K.     

Highly Efficient Adsorption of Copper Ions by a PVP-Reduced Graphene Oxide Based On a New Adsorptions Mechanism

Nano-Micro Letters - Polyvinylpyrrolidone-reduced graphene oxide was prepared by modified hummers method and was used as adsorbent for removing Cu ions from wastewater. The effects of contact time...     

聚甲基丙烯酸N,N-二甲氨基乙酯复合纳滤膜的制备

以AIBN为引发剂,采用本体聚合的方法制备了聚甲基丙烯酸N,N-二甲氨基乙酯(PDMAEMA),并采用中空纤维超滤膜技术滤除PDMAEMA水溶液中的低聚物和未反应的单体.以聚砜(PSf)超滤膜为基膜,以所精制的PDMAEMA为水相涂层液,以对二氯苄的正庚烷溶液为有机交联剂,利用界面聚合的方法制备了PDMAEMA/PSf荷正电复合纳滤膜.实验重点研究了PSf基膜和单体浓度、水相pH值及浸涂时间、水相沥干时间、交联反应时间等条件对所制备纳滤膜分离性能的影响,确定了较优的制膜条件.所制备的荷正电纳滤膜对1g/LMgSO4水溶液(0.8MPa,30℃)的截留率为86.7%,水通量为8.4L/(m2.h).     

Adsorption behavior of Cr(VI) on modified natural zeolite by a new bolaform N,N,N,N',N',N'-hexamethyl-1,9-nonanediammonium dibromide reagent

The demand for effective adsorbents is to increase in response to the widespread recognition of the deleterious health effects of Cr(VI)-oxyanions exposure through drinking water. In this study, Cr(VI)-oxyanions uptake from aqueous solutions by a new bolaform N,N,N,N',N',N'-hexamethyl-1,9-nonanediammonium dibromide reagent-modified natural zeolitic materials from Zahedan, Iran, was investigated using batch technique. Spectrophotometry method was used for Cr determination. The Cr(VI)-solution concentration varied between 2 and 104 mg L(-1). It was shown that the Cr(VI) uptake strongly depended on pH. The maximum removal of Cr(VI) occurred in acidic media at pH<1.5. The amounts of Cr(VI) adsorbed increased with increase in dose of both adsorbents and their contact time. Based on results an adsorption mechanism has been suggested. The adsorption data for modified zeolite using the amine was consistent with Langmuir isotherm equation and the equilibrium data was analyzed using the Langmuir isotherm.     

Magnetic Behavior of Light Rare Earth Ions in (Nd,Eu,Gd)-123 Superconductors

The paramagnetic light-rare-earth (LRE) ions significantly participate on the total measured magnetic signal of LRE-123 superconductors. At low temperatures, most of the paramagnetic LRE ions become magnetically ordered. The ordering depends on the ions distance in the given compound. We investigated magnetic behavior of LRE ions in the (Nd_0.33Eu_0.38Gd_0.28)Ba₂Cu₃O _y superconductor in a broad temperature and magnetic field range with the aim to find thermodynamic characteristics of the compound. The thermodynamic reversible magnetization and the associated thermodynamic characteristics were obtained.     

Crystal growth of bulk and cored fibre of 4-(N,N-dimethylamino)-3-acetamidonitrobenzene (DAN)

Large crystals of 4-(N,N-dimethylamino)-3-acetamidonitrobenzene (DAN) were grown from solutions by lowering the temperature; and bulk and cored fibre DAN crystals were grown by the Bridgman-Stockbarger (BS) method. The growth conditions and factors which affect the crystal quality were investigated.     

N,N'-双(2-硫酮基苯骈噻唑基-3-甲基)-正十二胺的缓蚀性能研究

以2-巯基苯骈噻唑、甲醛和正十二胺为原料在微波辐照下合成了N,N'-双(2-硫酮基苯骈噻唑基-3-甲基)-正十二胺(DTBMDA).采用失重法和动电位极化曲线法对合成的缓蚀剂进行了缓蚀性能测试,利用扫描电镜观察了腐蚀试样表面形貌,并对其缓蚀机理进行了初步探讨.结果表明,DTBMDA能够有效抑制饱和CO2环境下N80钢的腐蚀,属于混合型缓蚀剂.DTBMDA能与金属发生多中心吸附,同时能形成致密的疏水性保护膜,从而起到缓蚀作用.     

1,1-二(对-二乙氨基苯基)-4-(α-萘基)-4-苯基-1,3-丁二烯的合成及其光电性能研究

以α-溴代萘和苯乙酮为主要原料合成了1-(α-萘基)-1-苯基-3-氯丙烯,该化合物与4,4'-双(二乙氨基)二苯甲酮经Grignard反应,脱水后得到目标产物1,1-二(对-二乙氨基苯基)-4-(α-萘基)-4-苯基-1,3-丁二烯(CT),产品纯度98.86%,收率36.4%.通过质谱与核磁共振对产物的结构进行了表征,并对其进行X-射线单晶衍射分析,确定了分子构型.以Y-TiOPc为电荷产生材料,CT为空穴传输材料制备的功能分离型光导体光导性能参数为:V0=-850V,VR=-20V,Rd=17.5V,E1/2=0.60lx·s,表明CT具有优良的空穴传输特性.