活性酚醛树脂中羟甲基含量的测定

本文提出一种酚醛树脂中羟甲基含量的化学分析法，分别以＾１３ＣＮＭＲ和化学分析法测定酚醛树脂的羟甲基含量。将两种测试结果与已知的投料量进行比较，证明所建立的化学分析法可行。     

取代苯系列衍生物电子结构与毒性关系的量子化学研究

取代苯系列衍生物电子结构与毒性关系的量子化学研究苏忠民，徐贤姬，李金昶（东北师范大学化学系，长春，１３００２４）赵宝忠，盛连喜（东北师范大学环科系，长春，１３００２４）关键词：取代苯衍生物，分子毒性，ＭＮＤＯ采用量子化学半经验ＡＭＩ、ＭＮＤＯ方法，从...     

（PdCl2—PVP）／Al2O3催化剂中Pd状态的探讨

氯化钯先锚定在聚乙烯吡咯烷酮上后进一步负载到Al_2O_3上所制的催化剂[简称(PdCl_2-PVP)/Al_2O_3]是一种活性、选择性高,稳定性好的烯烃、二烯烃和多烯烃加氢催化剂。本文结合加氢反应,使用XPS、FT-IR、电镜及用CO为探针的FT-IR,对这种催化剂进行了考察。实验说明,在这种催化剂中,钯的价态是在0—2之间。红外光谱在486cm~(-1)处有一微弱的小峰,说明存在Pd—N的配位键。催化剂中钯含量低时(0.2wt％)稳定性好,不吸附CO,活性中心是络合钯原子;当钯含量较高时(0.7wt％),催化剂的初活性虽不低,稳定性却较差,这种催化剂能吸附CO,IR谱图上仅在1919cm~(-1)处有CO桥式吸附态的伸缩振动。表明除络合钯原子外,还有聚集的钯金属存在。FT-IR尚表明,PVP在Al_2O_3上可能并非单纯的物理吸附。电镜结果表明,PVP在Al_2O_3上呈30—70(?)的微球状,(PdCl_2-PVP)/Al)_2O_3上的(PdCl_2-PVP)亦呈微球状,与前者无明显区别,这种催化剂中其活性中心是络合钯原子。     

Swelling kinetics and release characteristic of crosslinked chitosan: Polyether polymer network (semi-IPN) hydrogels

The aqueous swelling kinetics of a series of crosslinked chitosan (cr-CS) with glutaraldehyde (GA) interpenetrating polyether hydrogels have been studied as functions of pH, the N-deacetylation degree of chitosan, the amount of crosslinking agent, the electrolyte composition in solution, temperature, and gel composition. Based on these results, the swelling mechanism of the hydrogels was discussed. The release profiles of chlorhexidini acetas from the semi-IPN were also investigated. © 1994 John Wiley & Sons, Inc.     

RESEARCH ON CATALYSTS OF ANTI-CARBON DEPOSITION FOR CH_4 REFORMING WITH CO_2

IntroductionMethaneandcarbondioxidearetWomaincompositionsforthegreenhouseeffectandtheworldglobewanningll].ItisbeneficialtoourlivingenviroIUnenttocontrolthereleaseofthesetwogases.Theconversionofmethanetothecommonfeedstocksynthesisgas(carbonmonoxideandhydro…     

气液色谱法研究Ni[(C8H17)O)2PS2]2与脂肪胺加合反应的热力学性质

The equilibium constants of acid-base interaction between Mi(Octyl_dtp)_2 and alkylamine were determined by GLC method at several temperatures. Thermodynamic parameters △H and △S were evaluted as follows:ethylamine: △H=-11.5kJ mol~(-1) △S=-22.7J K~(-1) mol~(-1)diethylamine: △H=-18.1kJ mol~(-1) △S=-42.1J K~(-1) mol~(-1)The variations of logK versus temperature fit following equations:ethylamine: lgK=-1.19+598.9/Tdiethylamine: lgK=-2.20+945.6/T     

Novel alginate-poly(L-histidine) microcapsules as drug carriers: in vitro protein release and short term stability

Spherical, smooth-surfaced and mechanically stable alginate-poly(L-histidine) (PLHis) microcapsules with narrow particle size distributions were prepared by incubating calcium alginate beads in aqueous solutions of PLHis. The in vitro release characteristics, drug loading and encapsulation efficiency of the microcapsules were investigated using bovine erythrocytes hemoglobin (Hb) as a model drug. The results showed that the concentration of Ca(2+) ions had a considerable effect on the drug loading, encapsulation efficiency and in vitro release behavior of the microcapsules. When the concentration of CaCl(2) in the PLHis solution was increased from 0 to 3.0% (w/v), the drug loading and encapsulation efficiency decreased significantly from 38.0 to 4.3% and from 92.9 to 8.0%, respectively, while the total cumulative release of Hb from microcapsules in phosphate buffered saline solution (PBS, pH 6.8) decreased from 96.2 to 72.8% in 24 h. No significant protein release was observed during 70 h of incubation in hydrochloric acid solution (pH 1.2). However, under neutral conditions (PBS, pH 6.8), the Hb was completely and stably released within 24-70 h. An explosion test showed that the stability of alginate-PLHis microcapsules depended strongly on the concentration of PLHis and the calcium ions in solution. [Diagram: see text] Microscopy photo of Hb-loaded alginate-PLHis microcapsules.     

HMS和NaY固载酒石酸钛配合物的研究

利用化学键合和“瓶中造船”方法,成功地将酒石酸钛配合物接枝到HMS(heragonal mesoporous silicas)上或包络合于微孔NaY内.FT-IR表征表明酒石酸钛在HMS上是通过与载体表面羟基发生交换作用而被固载的;在NaY载体上则是通过包络合被封装在载体的超笼内.UV-Vis可见漫反射表征表明两类固载型催化剂有着相似的钛配位环境.在催化肉桂醇环氧化反应中,HMS键合型催化剂的反应转化率比NaY包络型催化剂的高;但后者在环氧化选择性上要高于前者.回收样品的重复使用实验结果表明,两类固载型催化剂在重复使用过程中均存在不同程度的失活.     

富勒烯化聚环氧丙基咔唑的合成与表征

通过Ｆｒｉｅｄｅｌ－Ｃｒｒａｆｔｓ反应制备了富勒烯化的聚环氧丙基咔唑，聚合物中Ｃ６０的含量最高可达７．６ｗｔ％。通过凝胶渗透色谱法测定了聚合物分子量，并采用＾上Ｈ和＾１３Ｃ－ＮＭＲ，ＩＲ，热分析及光谱等手段对其结构进行了分析与表征。     

水热合成CdS纳米晶体的形貌控制研究

研究了水热合成CdS纳米晶体形貌的化学控制，选择不同的络合试剂为模板,研究其对水热合成CdS纳米晶体形貌的影响.实验发现若以络合试剂乙二胺、甲胺为模板时，产品CdS晶体的形貌分别为（20～30） nm×（200～600） nm和（40～50） nm×（200～600） nm尺寸的纳米棒;而以络合试剂吡啶、 氨为模板时，产品CdS晶体的形貌分别为平均尺寸约30 nm和20 nm的纳米颗粒.用XRD、TEM、XPS、PL和Raman光谱等技术对所得CdS纳米棒进行了表征.同时对水热合成CdS纳米晶体形貌的模板控制机制进行了探讨，提出了一种水热合成CdS纳米棒的络合物结构诱导生长机理.