磺化聚砜改性超滤膜的制备及性能

溶剂萃取过程的乳化现象是影响萃取率和产品质量主要问题,长期以来一直靠破乳剂解决,这会造成环境污染等问题[1,2]。膜分离技术能耗低、对具有生物活性的物质能保持其活性、分离产物易于回收,在抗生素提炼中的应用研究近年来十分活跃[3 5]。本文以磺化聚砜为膜材料、N,N 二甲基酰胺为溶剂,采用多元复合添加剂,用湿法相转移化法制备出孔径为400-500 、具有指孔状或海绵状结构的磺化聚砜改性超滤膜,作为抗生素提炼的分离膜。1　实验部分1 1　主要仪器及试剂扫描电镜(S 250,英国Cambridge公司);离子活度计(PXS 215,上海分析仪器厂)。聚…     

脂肪酸加氢改性Ni及Ni-Pd催化剂的制备

工业动植物油脚的主要成分为不饱和脂肪酸,通过催化加氢制得的硬脂酸[1,2],可作橡胶添加剂。但不饱和脂肪酸的酸值较高,易使镍催化剂皂化中毒而失活。本文在镍催化剂的基础上,加入微量的过渡或碱士等活泼金属作助剂,提高催化剂的抗皂化性能;加入微量钯,提高催化剂的活性,采用沉淀法,以硅藻土为载体,制备了负载型改性Ni及Ni Pd催化剂。并与国内化工企业常用的棕榈酸(酸值为188 6mgKOH/g)进口加氢催化剂USA 140和USA 110在相同条件下对进行对比。1　实验部分1 1　催化剂制备将18gNi(NO3)2:6H2O溶于130ml水,再依次加入一定配比的过…     

邻氨基苯酚改性壳聚糖树脂的制备及吸附性能的研究

本文制备了一种邻氨基酚改性壳聚糖树脂，用红外光谱和扫描电镜表征其结构，研究了该树脂对金属离子Cu^2 、Pb^2 、Ca^2 的吸附性能。结果表明，改性壳聚糖树脂为蜂窝状多孔微球树脂，平均戏约250μm，不溶于水、酸、碱，其对金属离子的吸附在pH=4时，2h基本达到平衡，对金属离子Cu^2 、Pb^2 、Ca^2 的静态饱和吸附量分别为2.95mmol/g、1.95mmol/g、1.32mmol/g。     

磷酸铁锂的制备及其电化学性能

以LiOH·H2O,FeSO4·7H2O和H3PO4为原料[n(Li)∶n(Fe)∶n(P)=3∶1∶1],采用水热法合成了LiFePO4(P),其结构经XRD,FE-SEM,HR-TEM和SEAD表征。考察了pH值、反应温度、反应时间和表面活性剂对P的结晶度、颗粒形貌、晶粒大小和择优取向的影响。结果表明:在pH为9.27,0.5%的聚乙烯醇为表面活性剂,于150℃反应8 h合成的P表现出规则的片状形貌,衍射峰强I(200)/I(211)为0.492 5;P在垂直b轴方向有一定的择优生长;P在ac面为最大面,b轴方向尺寸最短;采用乙炔黑为导电剂制备的P扣式电池表现出优良的电化学性能,于室温0.1 C倍率充放电,放电比容量为108.3 mAh·g-1;葡萄糖包覆改性后的扣式电池,0.1 C倍率放电比容量为148 mAh·g-1,1 C倍率放电时,放电比容量仍保持在133.9 mAh·g-1左右。     

稀土改性PVC膜的制备及性能研究

利用硝酸稀土作为改性剂，加入到聚氯乙烯（PVC）的四氢呋喃（THF）溶液中，用流延法制得表观透明均匀的PVC膜，经紫外辐射交联后，测试其力学和物理性能，发现经稀土改性后的PVC薄膜的力学和物理性能均有了较大的提高。     

氨基改性聚醚型聚硅氧烷的制备及其柔软性能研究

用含氢硅油、烯丙基缩水甘油醚、烯基聚醚的硅氢化加成产物-聚醚/环氧硅油与胺反应制得了氨基改性聚醚型聚硅氧烷（APEPS）,对其结构与性能进行了表征和研究。结果表明,含氢硅油分子量、有机胺结构、氨基改性聚醚型聚硅氧烷的硅含量对APEPS性能有影响。提高硅含量、增加氨值,可改善APEPS的柔软性与滑爽感,但对织物的吸湿性影响不大。     

壳聚糖衍生物的制备及其吸附性能

壳聚糖衍生物的制备及其吸附性能曲荣君，马千里，郑秀丽，孙言志（烟台师范学院化学系烟台２６４０２５）关键词壳聚精衍生物，制备，吸附壳聚糖（ＣＴＳ）是重金瞩离子的吸附剂￣［１，２］，由于壳聚精分子中的－ＮＨ＿２在ｐＨ较低的水溶液易形成而使ＣＴＳ溶于水，造...     

β-NiOOH的制备及充放电性能

电池正负极材料有充放电态之分 ,如 Mn O2 、Zn处于充电态 ,Ni(OH) 2 、MH、Li Co O2 、L i Ni O2等处于放电态 ,将起始荷电态不同的电极组装成电池 ,必然存在充放电态不匹配的问题 ,给电池化成带来困难 [1,2 ] .如 Zn/Ni电池正极改用充电态Ni OOH为原材料 ,则负极就可用充电态 Zn为原材料 ,很显然 Zn作为负极材料优于 Zn O,这就引发了将 Ni(OH) 2 氧化为 Ni OOH的研究 .本文采用改进的化学氧化法由β- Ni(OH ) 2 制备β-Ni OOH粉体 [3,4 ] ,对纯样及其与 Mn O2 混合的掺杂样的充放循环性能和反应机理进行了研究 .所用试剂…     

制备方法对MnOx鄄TiO2吸附剂脱汞及抗硫性能的影响

针对燃煤烟气中单质汞(Hg⁰)不溶于水很难去除和锰基吸附剂抗硫能力差的问题,以浸渍法、溶胶鄄凝胶法和沉积鄄沉淀法等三种方法制备MnO_x 鄄TiO₂ 为吸附剂,在固定床实验台架上考察了制备方法对MnO_x 鄄TiO₂ 吸附剂Hg⁰ 吸附量和抗硫性能的影响;利用N₂ 吸附/ 脱附、TG鄄DSC、XRD、TEM、H2鄄TPR 和XPS 等手段对吸附剂进行表征。结果表明,制备方法对MnO_x 鄄TiO₂ 吸附剂的脱汞活性影响颇大;沉积鄄沉淀法制备的MnO_x 鄄TiO₂ 吸附剂具有较高的Hg0 吸附量和抗硫能力。吸附剂的BET 比表面积高低与其脱汞活性无直接相关性;与浸渍法和溶胶鄄凝胶法相比,沉积鄄沉淀法制备的MnO_x 鄄TiO₂ 吸附剂不但可以增强其还原性和MnO_x分散度,而且还会显著提高吸附剂表面Mn⁴⁺/Mn 的比率和表面化学吸附态氧含量,进而增强吸附剂的脱汞活性和抗硫性能。     

3-羟基-L-酪氨酸改性聚乙烯醇的制备及其性能

以3-羟基-L-酪氨酸（L-dopa）为原料,经酯化反应将L-dopa接枝到聚乙烯醇分子链上,制得具有低温（10 ℃）水溶性的改性聚乙烯醇,其结构和性能经¹H NMR, FT-IR, DSC, TGA和DTG表征。     

改性硝酸铵自敏化结构特征

对经复合表面活性剂处理的改性硝酸铵及普通硝酸铵晶体进行电镜扫描,孔径孔容分布,粒径分布,比表面积测定,抗吸湿结块性,差示量热分析以及爆炸性能的实验研究,结果表明,与普通硝酸铵相比,改性硝酸铵的晶形歧化,比表面积大,富含气孔,大部分的有效孔径座落在介孔范围,有较好的粒度级配,晶变热降低,且晶变点后移,具备自敏化结构特征,并且有良好的抗吸湿结块性,用它代替普通硝酸铵所制得的粉状工业炸药具有良好的物理性能和爆炸性能。     

A Fluorescence-Based Sensor for Ammonium and Nitrate

Abstract

Measurement of nitrite and nitrate in rain samples was performed using a fluorescence based sensor. Nitrite and nitrate were reduced to ammonia using Devarda's alloy, and the gas was then passed through a membrane and reacted with o-phthalaldehyde. A linear relationship between the nitrate concentration and the luminescence intensity was observed over the concentration range of 1 – 5 mg/1, with a relative standard deviation (RSD) of 2.3% at a nitrate concentration of 1 mg/1 (n = 5). The system did not show any response toward sulfate or chloride. Results obtained from the measurement of river water samples using the sensor showed good agreement with those obtained using a conventional method.     

铈硝酸盐及其硝酸铵复盐的结晶制法及性质

通过对硝酸铈、硝酸铈铵复盐的制备,叙述了硝酸铈的溶解度[1]、复盐形成等性质, 分析了结晶方式不同对铈硝酸盐及其硝酸铵复盐产品质量的差别, 指出通过改变其传统的结晶法制备工艺, 提高产品质量具有重要的现实意义.     

Ionic Transport in Electrodialysis of Ammonium Nitrate

During the electrodialysis of ammonium nitrate solution, the fluxes of salt ions pass through the maximum, which is observed near the limiting current, with increasing current density. A decrease in the flux of ammonium ions at the overlimiting current densities is caused by the effect of competitive transport of solution ions and by the formation of weak NH₃ ? H₂O electrolyte due to the alkalization of solution layer adjacent to the cation-exchange membrane in the desalination channel. A decrease in the flux of nitrate ions in the overlimiting current modes is caused by a change in the composition and catalytic activity of the functional groups of anion-exchange membrane towards the dissociation of water molecules due to the effect of ammonium ions.     

Ceric Ammonium Nitrate Catalyzed Oxidation of Aldehydes and Alcohols

A variety of aromatic, aliphatic and conjugated aldehydes and alcohols were transformed to the corresponding carboxylic acids and ketones with a quantitative conversion in high yields with 70% t‐BuOOH solution in water in the presence of catalytic amounts of ceric ammonium nitrate [Ce(NH₄)₂(NO₃)₆] (CAN) under room temperature conditions. The scope of our catalytic system is applicable for a wide range of aromatic, conjugated and aliphatic substrates. These aldehydes were converted to the corresponding carboxylic acids in good isolated yields in reasonable times. This method possesses a wide range of capabilities since it can be used with other functional groups which may not tolerate oxidative conditions, involves fairly simple method for work‐up, exhibits chemoselectivity and proceeds under ambient conditions. The resulting products are obtained in good yields within reasonable time.     

季铵型硝化纤维素的合成及应用

高分子吸附剂;肌酸酐;季铵型硝化纤维素的合成及应用     

Kinetics and Mechanism of Thermal Decomposition of Guanidinium Nitrate and Its Mixtures with Ammonium Nitrate

The kinetics of heat release in thermal decomposition of guanidinium and ammonium nitrates and their mixtures in the liquid phase in a calorimeter was studied. The kinetic equations of these processes and temperature dependences of the kinetic constants in these equations were evaluated. The oxidation rate constants of guanidinium and ammonium cations with molecular nitric acid in aqueous nitric acid solutions were found; these constants were calculated by solution of the reverse problem for salt melts. The temperatures and H values of melting of the initial salts and their eutectic mixture were determined.     

单分子层自组装技术应用于硝酸铵防吸湿的探讨

表面活性剂;单分子层自组装技术应用于硝酸铵防吸湿的探讨     

Revisiting the Solution Structure of Ceric Ammonium Nitrate

Ceric ammonium nitrate (CAN) is a single‐electron‐transfer reagent with unparalleled utility in organic synthesis, and has emerged as a vital feedstock in diverse chemical industries. Most applications use CAN in solution where it is assigned a monomeric [Ce^IV(NO₃)₆]^2? structure; an assumption traced to half‐century old studies. Using synchrotron X‐rays and Raman spectroscopy we challenge this tradition, converging instead on an oxo‐bridged dinuclear complex, even in strong nitric acid. Thus, one equivalent of CAN is recast as a two‐electron‐transfer reagent and a redox‐activated superbase, raising questions regarding the origins of its reactivity with organic molecules and giving new fundamental insight into the stability of polynuclear complexes of tetravalent ions.