三明治式双极膜的制备及其光催化性能

以Cr3+交联羧甲基纤维素钠(CMC)作为阳膜层,戊二醛改性壳聚糖(CS)作为阴膜层,纳米TiO2光催化剂作为双极膜的中间层,在TiO2上涂布光敏剂八羟基喹啉（Oxine）以增强其光催化解离水的性能,制备了三明治式的双极膜（mCMC/TiO2-Oxine/mCS BPM)。 该双极膜在紫外光照射下,具有高的水解离效率,优良的亲水性能,双极膜阻抗小,工作电压低,当工作电流密度达0.12 A/cm2时,电槽工作电压小于5.0 V。     

A cleaner and simple spectrophotometric micro-fluidic procedure for copper determination using nitroso-R salt as chromogenic agent

A cleaner and simple spectrophotometric method using microflow analysis (muFA) was performed. It consisted of a T-junction with microcoil on a polymethyl methacrylate (PMMA) chip which was fabricated by laser ablation and a molded polydimethylsiloxane (PDMS) as top plate. The fabricated PMMA chip was integrated with light emitting diode (LED) as light source and spectrometer as detector. The proposed device was applied to determining copper in water samples using nitroso-R salt as chromogenic reagent at 495nm. It was found that the proposed muFA system was with less reagents and samples consumption with tiny waste generation. The relative standard deviation (R.S.D.) was less than 2% (n=11) with the percentage recovery of 98.0+/-1.7% (n=7). The linear range for determination of copper in water samples was over the range of 0.05-3.0mugmL(-1) with a correlation coefficient (r(2)) of 0.999. The limit of detection (3sigma) was 47ngmL(-1) with a sample throughput of 30h(-1).     

松香树脂酸异构化反应研究

以松香为原料、盐酸为催化剂、95%乙醇为重结晶溶剂进行超声波强化松香树脂酸异构化反应研究.通过正交优化实验考察了反应温度、反应时间、超声波频率、搅拌转速、盐酸用量对枞酸单离收率和纯度的影响,确定最佳异构化反应条件为: 超声频率47.2 kHz,反应温度55℃,盐酸用量0.06 mL盐酸·(g松香)-1 ,反应时间40 min,搅拌转速300 r·min-1,枞酸单离收率为31.76%,纯度为97.32%.采用气相色谱仪和圆盘旋光仪对枞酸产品进行了分析鉴定,实验值与文献值吻合.     

固定化过氧化氢酶的制备及其抗氧化作用

以烟用醋酸纤维的生物化学改性为目标,研究了以壳聚糖为载体时,吸附交联固定化过氧化氢酶的条件,并考察了固定化酶的性质。结果表明,固定化的最佳条件为:加酶量(酶活2×104C IU/m l)6m l,3%壳聚糖20m l,乙二醛浓度6%(w/v),交联剂用量100m l,吸附时间0.5 h,交联时间2.5h,酶活收率可达42.9%。过氧化氢酶固定化后,动学参数Km值为61.7mmol/L;对活性氧具有较好清除作用。     

Adsorption of metal ions on crosslinked poly(4-vinylpyridine) resins prepared with a metal ion as template

Poly(4-vinylpyridine) (PVP) was crosslinked with 1,4-dibromobutane with a metal ion as template. The adsorption behavior of copper, cobalt, zinc, and cadmium ions on the obtained resin (DBQP) was studied. The DBQP resin prepared with a metal ion as template preferentially adsorbed the metal ion used as template. The stability constant of the copper complex of DBQP was largest for the DBQP resin prepared with a copper ion as template, which was due to its large entropy change for the complexation.     

大孔及涂敷硅球作基质的组氨酸拟亲和色谱纯化人免疫球蛋白G

研究用分子组氨酸和配体、大孔硅球为基质的拟亲和色谱分离纯化人免疫蛋白Ｇ（ＩｇＧ），认为键合组氨酸具有半抗原体质而与ＩｇＧ发生免疫亲和作用，以色谱组份重新进样验证了色谱柱对ＩｇＧ亲和专一性，并用包敷Ｄｅｘｔｒａｎ大孔硅球作基质的拟亲和色谱纯化人血清中的ＩｇＧ，减少了色谱峰拖尾，缩短了分离时间。     

分子印迹基质固相分散-超高效液相色谱法测定儿童玩具中双酚A

以双酚A为模板分子,4-乙烯基吡啶为功能单体合成了双酚A分子印迹聚合物(BPAMIP),作为基质固相分散吸附剂,用于提取儿童玩具中双酚A。样品溶液均匀地分散在BPA-MIP中,风干后用二氯甲烷淋洗,然后用甲醇(35+65)溶液作洗脱剂将双酚A洗下,收集洗出液供高效液相色谱测定。结果表明:聚合物对印迹分子具有很好的亲和性和特异选择性。方法的线性范围为1.5～100.0mg·L~(-1),检出限(3S/N)为0.12mg·L~(-1)。在5个浓度水平下做加标回收试验,回收率在94.9%～99.1%之间,相对标准偏差(n=6)在1.2%～3.4%之间。     

11-钨过渡金属杂多阴离子为配体的配合物的热稳定性研究

通式为MW_(11)O_(39)的“不饱和”11-系列杂多阴离子仍然保持了基本的Keggin结构,但失去了其中的一个W-O基团。MW_(11)O_(39)具有很高的反应活性,当其他金属离子(或3A主族元素离子)进入这一空位时,便形成了三元杂多配合物ZMW_(11)和Ln(MW_(11))_2。ZMW_(11)(Z为3A主族金属离子和过渡金属离子)中,11-杂多阴离子起着五齿配体的作用,第六个配位位置被结构水占据,ZMW_(11)基本保持原来的Keggin结构。Ln(MW_(11))_2(Ln为镧系或锕系离子)     

N-甲基二苯胺-4-重氮盐制备及性质

二苯胺重氮盐(C₆H₅NHC₆H₄N₂⁺ X^-)与甲醛的缩合物重氮树脂,在光照下易与带侧链羟基的线型高分子形成亲墨性好的交联产物,被广泛用于阴图PS版的制备^{[1 5]}。用于PS版感光剂,最重要的一项性能是热稳定性要好,即制备重氮树脂用的重氮盐热分解温度要高,热分解速度要慢。     

Synthetic Hydromagnesite as Flame Retardant. A Study of the Stearic Coating Process

A synthetic hydromagnesite obtained from an industrial by-product rich in magnesium oxide was employed and evaluated as a non-halogenated flame retardant for poly(ethylene-co-vinyl acetate). The filler was characterized with different techniques (such as specific surface area, TGA, particle morphology and size measurements, WAXS). Significant differences were found between the synthetic hydromagnesite and the natural one. Synthetic hydromagnesite was coated with stearic acid and the effectiveness of the coating process was studied by the dye adsorption method and sedimentation volume measurements. The amount of coating agent ranged from 1 to 4.5%. This factor was found to have a significant effect on the thermal decomposition behaviour of the filler. A poly(ethylene-co-vinyl acetate) (27% of VA) was filled with the coated synthetic grades of hydromagnesite as well as with two commercial flame retardants and different physicochemical properties were evaluated, including their flame retardant effect.     

Preparation of temperature sensitive molecularly imprinted polymer for solid-phase microextraction coatings on stainless steel fiber to measure ofloxacin

A kind of new temperature sensitive molecularly imprinted polymer (MIP) with ofloxacin (OFL) as template was prepared for the coating of solid phase microextraction (SPME). Dopamine was self-polymerized on stainless steel fiber (SSF) as the SPME support followed by silanization. Then MIP was synthesized as SPME coating on the modified SSF in a capillary, with N-isopropyl acrylamide as temperature sensitive monomer and methacrylic acid as functional monomer. The synthesis could be well repeated with multiple capillaries putting in the same reaction solution. The obtained MIP fiber was evaluated in detail with different techniques and various adsorption experiments. At last the MIP fiber was used to extract the OFL in milk. Satisfied recoveries between 89.7 and 103.4% were obtained with the limit of quantification (LOQ_LC) of 0.04 μg mL⁻¹ by the method of SPME coupled with high performance of liquid chromatography (HPLC).     

STUDY ON POLYMER-RARE EARTH METAL ION COMPLEXES Ⅰ. FLUORESCENT PROPERTIES OF POLY(ACRYLIC ACID-CO-4-VINYLPYRIDINE)-RARE EARTH METAL COMPLEXES

A kind of copolymer of acrylic acid and vinylpyridine was synthesized and the fluorescent properties of the complexes of the copolymer with Eu~(3+) or Tb~(3+) were studied. It was found that the fluorescence intensity of the complexes of the eopolymer with Eu~(3+) was 20 times as high as that of the complexes of polyaerylic acid with Eu~(3+) and twice as high as that of the complexes of polyvinylpyridine with Eu~(3+). The effects of the composition of the copolymer and the content of Eu~(3+) or Tb~(3+) in the complexes were studied. The fluorescence lifetime of the complexes was measured and it was found that two or more kinds of energy transfer mechanism existed.     

甲基丙烯酸甲酯的反向原子转移自由基聚合反应 研究

在较低的温度(60℃)和较低的AIBN/CuCl~2/配位剂摩尔比(1:2:4)条件下,用乙腈为溶剂,实现了甲基丙烯酸甲酯(MMA)的反向原子转移自由基聚合(RATRP)。联二吡啶(bpy)为配位剂时,所合成的聚甲基丙烯酸甲酯(PMMA)的分子量分布可低至1.08。用1,10-菲咯啉(phen)代替bpy,MMA的聚合反应速率加快,但其分子量分布稍宽(1.40左右),并进一步研究了bpy和phen作为混合配位剂时对MMA反向ATRP聚合的影响。用RATRP反应所得的带有卤素端基的PMMA作为苯乙烯ATRP的大分子引发剂,成功地合成了具有预期结构的苯乙烯与甲基丙烯酸甲酯嵌段共聚物,大分子引发剂的引发效率接近于1,说明在RATRP过程中由自由基引发剂引发MMA进行一般自由基聚合反应的可能性甚微。     

通过原子转移自由基聚合合成可光交联的聚苯乙烯接枝共聚物

聚苯乙烯(PS)在氯化锌(ZnCl_2)做催化剂下,通过氯甲基甲基醚氯甲基化反应,合成了氯甲基化聚苯乙烯(CMPS).在氯化亚铜/联二吡啶(CuCl/bpy)催化下,以CMPS为大分子引发剂引发甲基丙烯酸甲酯(MMA)、甲基丙烯酸酯化查尔酮(MSPK)进行原子转移自由基聚合,成功合成了侧链含有查尔酮结构的光敏聚苯乙烯接枝共聚物(PSMM),所得聚合物结构经过红外光谱(FT-IR)、核磁共振氢谱(~1H NMR)得到确认,通过热重分析(TG)、示差扫描量热法(DSC)测试了该聚合物的热学性能.结果表明,该接枝共聚物具有较好的热学性能及良好的光敏性.     

羟丙哌嗪分子印迹的固相萃取

以L-羟丙哌嗪为模板分子, α-甲基丙烯酸为功能单体, 三羟甲基丙烷三甲基丙烯酸酯为交联剂, 合成了羟丙哌嗪分子印迹聚合物, 利用该聚合物进行羟丙哌嗪固相萃取应用研究. 实验证明, 所合成的分子印迹聚合物具有良好的识别萃取模板分子羟丙哌嗪的能力, 能够用于羟丙哌嗪的富集浓缩, 而空白聚合物却不具备这样的特性. 考察了模板分子与其结构类似物苄基哌嗪、N-异丙基哌嗪和乙氧基羰基哌嗪的固相萃取分离情况, 研究表明, 虽然其中的苄基哌嗪在印迹材料上具有最强的保留, 但是通过先后使用不同的洗脱溶液实现了模板分子与苄基哌嗪的选择性分离.探讨了印迹识别机理,并用PM3 半经验计算机模拟方法进行了辅助分析验证.     

Determination of 3-methyl-2,4-nonanedione in red wines using methanol chemical ionization ion trap mass spectrometry

A compound associated with oxidized flavor in red wines was recently-identified as 3-methyl-2,4-nonanedione (MND). In order to quantify it, positive chemical ionization (PCI) in an ion trap was studied using conventional liquid reagents such as methanol, acetonitrile, and acetone, as well as non-conventional liquid reagents such as ethyl acetate, diethyl ether, pentane, isohexane, and heptane. Under laboratory conditions, very different response factors were obtained with MND depending on the gas. We also compared the detection limit of conventional CI with hybrid chemical ionization (HCI). Finally, this compound was quantified in red wines by liquid/liquid extraction without any derivatization steps, followed by GC/MS-CI analysis, using methanol as the reagent gas. Coelutions of compounds with the same m/z were checked using methanol-d(4). The method we developed was linear in the 10-300 ng/L range of MND concentrations, with satisfactory repeatability. The detection limit was 4.3 ng/L, over 3 times lower than the olfactory perception threshold of this compound (16 ng/L). The suitability of this method for assaying this diketone in red wine was demonstrated by the analyzing many wines from different vintages.     

Direct enantiomeric TLC resolution of dl-penicillamine using (R)-mandelic acid and l-tartaric acid as chiral impregnating reagents and as chiral mobile phase additive

DL-Penicillamine has been resolved into its enantiomers by normal-phase TLC using L-tartaric acid as chiral impregnating reagent as well as chiral mobile phase additive, while (R)-mandelic acid has been found to be successful as a chiral impregnating reagent. The solvent system acetonitrile-methanol-water (5:1:1, v/v) was found to be successful when L-tartaric acid was used as impregnating agent while the solvent combination acetonitrile-methanol-(0.5% l-tartaric acid in water, pH 5)-glacial acetic acid (7:1:1.1:0.7, v/v) was successful as mobile phase as it contained L-tartaric acid as the chiral additive. (R)-mandelic acid was successful as chiral impregnating reagent with ethyl acetate-methanol-water (3:1:1, v/v), as the mobile phase. The effects of concentration of chiral selectors, temperature and pH were examined on enantiomeric resolution. The spots were detected with iodine vapors and the detection limits were found to be 0.12 microg for each enantiomer of penicillamine with L-tartaric acid, under both the conditions, and 0.11 microg with (R)-mandelic acid.     

高效液相色谱手性流动相添加法拆分奥昔布宁对映体

采用C18固定相,以羟丙基-β-环糊精为手性流动相添加剂,建立了奥昔布宁对映体的高效液相色谱拆分方法。考察了手性添加剂、有机极性调节剂、缓冲盐的种类和浓度以及流动相的pH值和流速及柱温等因素对对映体分离的影响。在最佳分离条件下,奥昔布宁对映体的分离度为1.54,检测限为1.0 ng。该方法简便,重复性好,比手性固定相法更加经济。     

分子印迹电化学传感器的制备及其对啶虫脒的响应特性

应用恒电位沉积法制备了以壳聚糖为功能基体,啶虫脒为模板分子、戊二醛为交联剂的印迹膜电极,并构建印迹传感器。借助阳离子指示探针Ru(NH3)6Cl3,研究该印迹传感器的电化学响应特性及其对模板分子啶虫脒的分子识别性能。结果表明,印迹传感器具有良好的印迹效果,相较于结构类似物如吡虫啉等,对啶虫脒有较高的结合速率和特异性识别能力,且在啶虫脒浓度为1.0 × 10-7 ~ 2.0 × 10-5 mol/L范围内呈线性响应,为农药残留物中啶虫脒的选择性分析提供新的思路。     

AGET ATRP of acrylonitrile using 1,1,4,7,10,10‐hexamethyltriethylenetetramine as both ligand and reducing agent

Atom transfer radical polymerization using activators generated by electron transfer (AGET ATRP) of acrylonitrile (AN) initiated by ethyl 2‐bromoisobutyrate was approached for the first time using 1,1,4,7,10,10‐hexamethyltriethylenetetramine (HMTETA) and 1,1,4,7,7‐pentamethyldiethylenetriamine (PMDETA) as both ligand and reducing agent. AGET ATRP of AN with HMTETA as both ligand and reducing agent was better controlled than with PMDETA as both ligand and reducing agent under the same experimental conditions. With an increase content of HMTETA, the polymerization provided an accelerated reaction rate and a broader polymer molecular weight distribution. The rate of polymerization with DMF as solvent was faster than with acetonitrile, cyclohexanone, toluene, and xylene as solvents. The polymerization apparent activation energy was calculated to be 45.7 kJ mol^?1. The end functionality of polyacrylonitrile (PAN) was confirmed by ¹H NMR spectroscopy. The living feature of PAN was verified by chain extensions of PAN with methyl methacrylate and AN. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 128–133, 2010